Browse Subject Areas

Click through the PLOS taxonomy to find articles in your field.

For more information about PLOS Subject Areas, click here.

  • Loading metrics

Predominant Bacteria Detected from the Middle Ear Fluid of Children Experiencing Otitis Media: A Systematic Review

  • Chinh C. Ngo,

    Affiliations School of Medical Science, Griffith University, Gold Coast, Queensland, Australia, Molecular Basis of Disease, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia

  • Helen M. Massa ,

    Affiliations School of Medical Science, Griffith University, Gold Coast, Queensland, Australia, Molecular Basis of Disease, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia

  • Ruth B. Thornton,

    Affiliations School of Paediatrics and Child Health, University of Western Australia, Perth, Western Australia, Australia, Telethon Kids Institute, University of Western Australia, Perth, Western Australia, Australia

  • Allan W. Cripps

    Affiliations School of Medical Science, Griffith University, Gold Coast, Queensland, Australia, Molecular Basis of Disease, Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia

Predominant Bacteria Detected from the Middle Ear Fluid of Children Experiencing Otitis Media: A Systematic Review

  • Chinh C. Ngo, 
  • Helen M. Massa, 
  • Ruth B. Thornton, 
  • Allan W. Cripps



Otitis media (OM) is amongst the most common childhood diseases and is associated with multiple microbial pathogens within the middle ear. Global and temporal monitoring of predominant bacterial pathogens is important to inform new treatment strategies, vaccine development and to monitor the impact of vaccine implementation to improve progress toward global OM prevention.


A systematic review of published reports of microbiology of acute otitis media (AOM) and otitis media with effusion (OME) from January, 1970 to August 2014, was performed using PubMed databases.


This review confirmed that Streptococcus pneumoniae and Haemophilus influenzae, remain the predominant bacterial pathogens, with S. pneumoniae the predominant bacterium in the majority reports from AOM patients. In contrast, H. influenzae was the predominant bacterium for patients experiencing chronic OME, recurrent AOM and AOM with treatment failure. This result was consistent, even where improved detection sensitivity from the use of polymerase chain reaction (PCR) rather than bacterial culture was conducted. On average, PCR analyses increased the frequency of detection of S. pneumoniae and H. influenzae 3.2 fold compared to culture, whilst Moraxella catarrhalis was 4.5 times more frequently identified by PCR. Molecular methods can also improve monitoring of regional changes in the serotypes and identification frequency of S. pneumoniae and H. influenzae over time or after vaccine implementation, such as after introduction of the 7-valent pneumococcal conjugate vaccine.


Globally, S. pneumoniae and H. influenzae remain the predominant otopathogens associated with OM as identified through bacterial culture; however, molecular methods continue to improve the frequency and accuracy of detection of individual serotypes. Ongoing monitoring with appropriate detection methods for OM pathogens can support development of improved vaccines to provide protection from the complex combination of otopathogens within the middle ear, ultimately aiming to reduce the risk of chronic and recurrent OM in vulnerable populations.


Otitis media, may be simply defined as inflammation of the middle ear, and is the most common reason a child under the age of 5 will visit their general practitioner and be prescribed antibiotics in socioeconomically developed countries [1]. OM has a range of clinical presentations including AOM, which is characterised by the rapid onset of local and systemic symptoms, including otalgia, fever, vomiting and accumulation of fluid in the middle ear cavity and OME, where the child experiences MEF accumulation without the systemic symptoms. Both of these presentations may occur recurrently or chronically [2]. Globally, more than 700 million cases of AOM are diagnosed each year, with 50% of affected children being under five years of age [3]. Recurrent AOM (RAOM) occurs where a patient has 3 diagnosed AOM episodes within six months or more than 4 episodes in 12 months [4] and is commonly observed in up to 65% of children by 5 years of age[4] OME typically resolves spontaneously within 3 months [5] however, 30–40% of children experience persistent or chronic fluid in the middle ear for more than 3 months (chronic OME, COME) and may require surgical intervention to aid resolution [5].

Irrespective of clinical presentation, OM is a multi-factorial disease, with many associated risk factors, including environmental, immunological deficiency, gender, age and microbial exposure [4, 6]. Despite this complexity, bacterial and viral pathogens, individually and together, are strongly associated with OM development, for example, only 4% children diagnosed with AOM had no bacterial or viral pathogen detected using culture and PCR [7].

The three bacteria most frequently identified in association with OM are: S. pneumoniae, H. influenzae and M. catarrhalis [6], whilst the viruses most commonly associated with OM are respiratory syncytial virus, adenovirus, rhinovirus and coronavirus [6].

Monitoring both the identification and frequency of detection of common otopathogens in OM is central to evaluation of the effects of treatment and impact of vaccination programs. For example, pneumococcal carriage was reduced in association with the introduction of the heptavalent pneumococcal conjugate vaccine (PCV7) in the US and has also increased prevention of early AOM infections [8].

Implementation of PCV7 into national immunisation programs (NIPs) has also resulted in shifts to non-vaccine pneumococcal serotypes isolated from invasive pneumococcal disease and OM [912]. Importantly, PCV7 implementation has resulted in non-typeable (non-encapsulated) H. influenzae (NTHi) detection frequency surpassing S. pneumoniae detection in AOM patients within a number of countries including the US [12], Spain [13] and France [14]. The emergence of non-vaccine serotypes and their potential role as pathogens in OM is an area of ongoing research interest.

This systematic review examines the frequency of detection of bacteria within MEF from children experiencing OM, globally. Ongoing surveillance of bacteria predominant in OM patients, improved detection methods such as PCR and monitoring the impact of immunisations will continue to inform treatment decisions and ultimately vaccine development aimed to prevent OM development in young children.


Data sources and searches

The design and construction of this systematic review was informed and in compliance with PRISMA (2009) [15] (see S1 PRISMA Checklist). Published literature, including conference abstracts, was searched via PubMed database and only original articles with an English abstract were retrieved and reviewed. Publication dates were restricted from January 1st, 1970 to August 30th, 2014, with five different search strategies used, as detailed below.

PubMed search strategy

The following terms were used in five literature searches:

  • Search 1—Asian region: (otitis media (Asia (aetiology, otopathogens, pathogens, microbiology, bacteriology, bacteria))) or (otitis media (Bangladesh, Brunei, Cambodia, China, India, Indonesia, Iran, Israel, Japan, Korea, Laos, Lebanon, Malaysia, Pakistan, Philippines, Saudi Arabia, Singapore, Taiwan, Thailand, Turkey, Vietnam)) (S1 Fig)
  • Search 2—American region: (otitis media (America (aetiology, otopathogens, pathogens, microbiology, bacteriology, bacteria))) or (otitis media (Argentina, Brazil, Chile, Colombia, Costa Rica, Cuba, Dominica Republic, Ecuador, Honduras, Mexico, Panama, Paraguay, Uruguay, Venezuela, Canada, The US)) (S2 Fig)
  • Search 3—African region: (otitis media (Africa (aetiology, otopathogens, pathogens, microbiology, bacteriology, bacteria))) or (otitis media (Algeria, Cameroon, Cote D’lvoire, Egypt, Mozambique, Namibia, Nigeria, South Africa, Zambia, Zimbabwe)) (S3 Fig)
  • Search 4—European region: (otitis media (Europe (aetiology, otopathogens, pathogens, microbiology, bacteriology, bacteria))) or (otitis media (Britain, Denmark, England, France, Finland, Germany, Greece, Ireland, Italy, Netherlands, Norway, Poland, Portugal, Romania, Russia, Scotland, Spain, Sweden, Ukraine, Wales, The UK)) (S4 Fig)
  • Search 5—Oceanian region: (otitis media (Oceania (aetiology, otopathogens, pathogens, microbiology, bacteriology, bacteria))) or (otitis media (Australia, Cook Islands, New Zealand, Papua New Guinea, Solomon Islands)) (S5 Fig)

Selection criteria

All articles in English were assessed for relevance by review of abstracts when available, prior to full review of each article. Pre-determined inclusion selection criteria were used: (i) only human studies (ii) age range one month– 18 years (majority of reported study populations below 8 years old) (iii) otopathogenic bacteria were identified from MEF samples of children experiencing a range of presentations of OM, including AOM/RAOM/AOMTF or OME/COME but not chronic suppurative OM (CSOM) (iv) MEF samples were collected through clinical perforation of the tympanic membrane (myringotomy or tympanocentesis) only, rather than spontaneous perforation.

Study selection and data extraction

All articles meeting the keyword criteria, identified in the primary database search, were screened independently for relevancy by two of the authors (C.C.N. and H.M.M) who read all article titles and abstracts in a standardised manner. Abstracts and articles were reviewed and compared to the inclusion criteria above and key data evaluating the reported details of the study population (age), types of OM, sample size, sample collection methods, microbiological method and years of study were recorded for included studies. Furthermore, where the detail of the sample collection method or clinical criteria for diagnosis of type of OM was inconclusive, the full paper was retrieved and reviewed to determine inclusion. Discussion between reviewers resolved any disagreement regarding inclusion. Additional information was sought from the authors of included reviews, via emailed request seeking additional unpublished information regarding vaccination status and/or serotyping data, if available for the study populations, or to clarify information, such as sampling methods used in their published study. All bibliographies of the included studies were manually searched for additional relevant references.

Data items, synthesis and analysis

Data illustrating the frequency of detection of predominant bacteria from each report were collated and recorded. The antibiotic sensitivity of these bacteria and the vaccination status of the participants were recorded, where available. Data tables within this narrative report were compiled from the primary results from each included report. Meta-analysis was not performed due to variation of the designs of the included studies and study population characteristics within the published reports.

Evaluation of study quality

In this study, included studies were previously published in peer reviewed journals. The variety of individual study designs prevented use of a validated instrument to assess the quality of included studies. The assessment of risk of bias of individual studies was performed at the study level by the use of inclusion criteria. For example, clinical criteria describing the varied presentations of OM may have varied over the thirty years of published literature reviewed. Reviewing authors ensured that all published studies clearly differentiated acute AOM by the presence of otalgia and inflamed and/or bulging tympanic membrane which remain consistent characteristics within current definitions. Where vaccination status of the study population is unknown, comparison of the study dates versus the implementation of the NIPs was used to inform potential vaccination status. Only studies that sampled the MEF after clinical perforation of the tympanic membrane were included in this report. This criterion is likely to have generated selection bias on the basis of MEF collection being performed primarily for research purposes, rather than clinical or treatment reasons. The likely outcome would result in skewing representation to include more severe cases undergoing surgical treatment. In addition, there is a relative paucity of reports from some world regions.


The search “otitis media and children” identified 9,617 articles via PubMed database search over the period January 1st, 1970 to August 30th, 2014. After performing the key word screening for each of the 5 regions, as illustrated in Fig 1, 10,483 articles were identified, screened for eligibility and 857 abstracts and 110 full publications were reviewed. Sixty-six articles met all the previously described criteria. The number of articles varied for each of the 5 regions, studies reporting from the Americas (n = 20), Europe (n = 17), Asia (n = 21), Africa (n = 3) and Oceania (n = 5) (Fig 1). Within the Americas, European and Asian regions, the reports analysed described 8 different countries within each region. In contrast, within the African and Oceania regions, reports were restricted to only two countries each; South Africa and Egypt and Australia and New Zealand, respectively.

Clinical variants of OM presentation included in this review are AOM (n = 38 studies; 58%), OME/COME (n = 24; 36%), RAOM/AOMTF (n = 9; 14%) and RAOM/OME (n = 1, 2%) within the included studies (n = 66). This percentage is greater than 100% due to 4 studies, in which, more than one type of OM was investigated [1619]. All studies included in this review, reported microbiological findings from MEF collected via clinical perforation of the tympanic membrane.

Microbiology of AOM, RAOM/AOMTF and COME

Bacterial isolation overview.

This systematic review includes 66 reports of bacterial isolation, using culture techniques, from MEF samples of patients experiencing AOM (n = 38, mean percentage of samples positive for bacteria 62%; range 25%–95%), RAOM/AOMTF (n = 12; mean percentage of samples positive for bacteria 45%, range 27%- 68%) and OME/COME (n = 24, mean percentage of samples positive for bacteria 36%; range 14%-73%) from across the world. Eight studies reported bacterial identification for more than one clinical presentation of OM. Bacterial isolation and identification were performed using PCR and bacterial culture in 17 reports, with only 2 reports from AOM patients [18, 20] rather than RAOM, OME or COME patients.

The wide variety of bacteria isolated in each of the reviewed studies, from patients with AOM, RAOM/AOMTF and OME/COME are shown in S1S3 Tables, respectively. The frequency of detection of S. pneumoniae, H. influenzae and M. catarrhalis in these reports, identify them as the three predominant bacterial pathogens. Other bacteria isolated from the MEF included: Streptococcus pyogenes or Group A Streptococcus, Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis, Chlamydia trachomatis, Alloiococcus otitidis, Klebsiella pneumoniae, Escherichia coli. The variety of microbiota isolated and identified in these reports clearly varied with the experimental design, aims and methodology of each study and thus precludes direct comparisons of the frequency of individual pathogen detection. Thus, this review is focussed on the relative frequency of the predominant bacterial pathogens.

Previous reports for the different clinical presentations were collated and examined regionally. Identification of the three predominant bacteria within the MEF for children experiencing AOM, RAOM/AOMTF and OME/COME are presented in S1S3 Tables, respectively. These tables summarise the published reports of bacteria isolated and identified from MEF using bacterial culture (S1S3 Tables).


The bacterium most frequently identified from the MEF from children diagnosed with AOM, from previous reports across the world, was S. pneumoniae closely followed by H. influenzae (see Table 1). On average, S. pneumoniae detection was significantly higher than H. influenzae when all previous studies were pooled (P<0.036 2-way ANOVA without replication) and these reports included samples collected between 1979 and 2010.

Table 1. S. pneumoniae, H. influenzae and M. catarrhalis detected from MEF of patients with AOM.

Regionally, in MEF from AOM patients, the average frequency of S. pneumoniae was higher than NTHi detection for all regions, although there was no significant difference between average detection frequencies for these bacteria in the US (27.8% NTHi versus 28.6% S. pneumoniae). In contrast, NTHi was the predominant bacteria, comparing average frequencies of bacterial detection for all 3 regions that reported RAOM/AOMTF; South America, Europe and Oceania. Two studies conducted in Costa Rica showed that S. pneumoniae was predominant in RAOM.

Within each world region, the trend toward more frequent detection of S. pneumoniae, that is, the average frequency of S. pneumoniae was higher than NTHi detection for all regions. Indeed, where multiple reports were available for the same country within a region, reports from a number of countries including Finland, Colombia, USA and Japan showed changes in the predominant bacteria identified. Multiple studies from the USA provide evidence of temporal trends in the detection frequency changing from S. pneumoniae in studies recruiting between 1989–1998 [2123] to H. influenzae for similar studies recruiting between 2005–2009 [24, 25], then back to S. pneumoniae 2006–2010 [26] (Table 1).

For children experiencing AOM (Table 1), 29/38 of studies reported S. pneumoniae as the predominant bacteria compared to H. influenzae (primarily non-typeable) being clearly predominant bacteria in 6/38 studies (equivalent detection in 3 reports). The overall average frequency of detection for all studies was 27.8% (range 9.9%-49.9%) for S. pneumoniae compared to 23.1% (range 5.0%-54.6%) for H. influenzae, M. catarrhalis was detected in 34/38 studies at an average frequency of detection of 7.0% (range 0.5%–27.8%). Although detected less frequently overall, M. catarrhalis frequency, does not demonstrate a consistent temporal trend toward increasing detection in reports of AOM. Individual countries such as Finland, Costa Rica and Chile exhibit a temporal trend toward increasing rates of identification. In contrast, reports from the USA, Japan and Turkey show no consistent trend in identifications whilst reports from Israel do not support any temporal change in M. catarrhalis detection over time. Previous reports investigated chronic or longer term OM presentations such as RAOM/AOMTF (Table 2) or OME/COME (Table 3).

Table 2. S. pneumoniae, H. influenzae and M. catarrhalis detected from MEF of patients with RAOM/AOMTF.

Table 3. S. pneumoniae, H. influenzae and M. catarrhalis detected from MEF of patients with OME/COME.

Examination of the RAOM/AOMTF reports (n = 7 and n = 3, respectively) did not demonstrate a predominant bacteria overall (Table 2) although the average bacterial detection frequency for H. influenzae was demonstrated as 22.8% (range 12.2%-41.6%) in comparison to 18.6%; (range 5.6%-32.7%) for S. pneumoniae. M. catarrhalis detection was very low (not detected in 3 of 10 reports) and average detection frequency from bacterial culture was 4.1% (range 1.3%-8%). There were no significant regional or temporal trends observed, due to the paucity of studies and the challenge arising from recruitment of overlapping clinical presentations (RAOM/AOMTF) within different study designs.


Overall, MEF samples from patients diagnosed with OME/COME were less likely to be culture positive for the 3 predominant bacteria in comparison to MEF samples from patients diagnosed with AOM. This is evidenced by the average frequency of detection for H. influenzae and S. pneumoniae from OME/COME patients being approximately half that reported from AOM patients (11.6% vs 23% and 6.5% vs 27%) for these bacteria respectively.

Globally, H. influenzae was the predominant bacteria identified within the MEF of patients experiencing OME/COME (P<0.001 2-way ANOVA without replication) with the average detection frequency was 11.6% (range 3.2%-21.6%) compared to S. pneumoniae detection 6.5% (range 1.3%-16.2%).

Regionally, H. influenzae was identified most frequently from patients with OME/COME in South and North America, Europe, Asia, Africa and Oceania however in the Asian and European regions, four of the nine (44%) and two of nine (22%) of studies reported that S. pneumoniae was predominant, respectively.

Within this review, the bacterial pathogens associated with OM in the MEF were examined regionally and evidence of development of antibiotic resistance recorded. Where resistance was reported, it was included in the summary for each region provided below.

Regional variation of H. influenzae strains and Antibiotic sensitivity

Overall, there is a general paucity of reports in which H. influenzae strains and antibiotic sensitivity have been reported from the MEF of OM patients. In general, the available reports highlight the high proportion of NTHi isolates compared to other H. influenzae strains identified from AOM patients across almost all world regions; the Americas, Europe, Asia and Oceania, with no evidence available from Africa. The proportion of H. influenzae isolates from AOM patients that were β-lactamase positive ranged less than 20% for most regions to over 83% in a report from Mexico [35] with no consistent patterns recognisable in regions where multiple reports were available. H. influenzae isolates from COME patients generally reported a proportion of β-lactamase positive strains. The majority of reports from across the world identified very high proportions of M. catarrhalis strains as β-lactamase positive.

In South America, AOM-associated H. influenzae strains isolated within South America are predominantly NTHi, ranging from 63% [36] to 100% [17, 35] and H. influenzae types a, b, c, d and f which were identified in AOM patients in Chile [30] and Venezuela [36]. Less than 20% of all AOM-associated H. influenzae strains were β-lactamase positive [17, 2830, 34, 36]. In contrast, a recent study from Mexico reported that 83% of AOM-associated H. influenzae strains were β-lactamase positive [35], whilst other reports demonstrated that 100% of AOM-associated M. catarrhalis strains were β-lactamase positive [17, 29].

In North America, all AOM-related H. influenzae strains reported were non-typeable [81], with 20%-50% of these strains being β-lactamase positive [24, 81]. Furthermore, 100% of M. catarrhalis strains isolated from AOM patients were β-lactamase positive [81, 82]. Recently, two studies have reported that H. influenzae was the bacteria detected most often in MEF from children with AOM since the introduction of pneumococcal vaccine into the NIP [24, 25].

In Europe, a recent study from Germany, reported 86% of AOM-related H. influenzae strains were non-typeable, with H. influenzae type b and f also being identified in low frequencies (<10%) [41]. In France, more than 15% of AOM-associated H. influenzae strains isolated were β-lactamase positive [14, 55] and 95% of AOM-related M. catarrhalis strains were β-lactamase positive [14].

β-lactamase positive strains of H. influenzae were reported for 12% and 40% of strains isolated from OME/COME patients in England [63] and Spain [67], respectively.

In Asia, more than 80% of H. influenzae strains associated with AOM in this region were non-typeable and H. influenzae type a and b were identified in low frequencies (<20%) [52, 53, 83, 84], except two studies in Thailand [50] and Taiwan [49] where type b was reported in 63% and 100% of H. influenzae strains. Less than 20% of isolated H. influenzae strains were β-lactamase positive [43, 52, 53, 83, 85]. In contrast, all OM-associated M. catarrhalis strains isolated in Israel [43, 83, 85] and over 50% of strains isolated in Turkey [52, 53] were β-lactamase positive. Furthermore, more than 50% of H. influenzae isolates from children with COME in Lebanon were β-lactamase-negative ampicillin-resistant strains [76], however these strains were not typed.

In Africa, there are no reports of H. influenzae type from AOM patients in the African region, however a single report from Egypt confirmed that more than 80% and 60% of COME-associated H. influenzae and M. catarrhalis strains isolated were β-lactamase positive, respectively [77].

In Oceania, In Oceania, H. influenzae isolates from RAOM patients in Australia were all non-typeable strains with 17% of these strains were β-lactamase positive [56]. Similarly, in New Zealand, 95% of OM-related H. influenzae strains were non-typeable [58] and a single report of COME-associated H. influenzae strains in New Zealand reported that 6% (1/17) were type b and 94% (16/17) were not type b [80].

Changing microbial pattern pre- and post-PCV7 introduction

PCV7 has been introduced into NIPs since the year 2000. For a number of regions, including South America, Asia and Africa, this vaccine has either not yet been introduced to the NIP or only been recently introduced. For example, PCV7 was introduced into Israel’s NIP and South Africa’s NIP in 2009 [86, 87] or was recommended for high risk groups in Mexico in 2006 and subsequently introduced in to Mexico’s NIP in 2008 [35]. Furthermore, the introduction of PCV7 into NIP or high risk groups within individual countries in a region may also impact the aetiology of OM within that region.

The demonstrated impacts of PCV7 immunisation on the aetiology of OM, since its introduction in 2000 includes: reduction of PCV7 serotype detection in OM, replacement of PCV7 serotypes in AOM by non-vaccine serotypes, particularly serotypes 19A and 3 and changes in dominant otopathogens between H. influenzae and S. pneumoniae.

In South America, PCV7 was introduced partially in Costa Rica and Venezuela in 2004 [17, 36, 88] and Mexico in 2006 [35]. The vaccine was implemented in NIP of Costa Rica in 2009 [89] and Mexico in 2008 [35, 89].

The overall rates of pneumococcal OM were reduced in the South American region after PCV7 introduction, as did the ratio of S. pneumoniae and H. influenzae isolated from patients with OM. For example, in Costa Rica, the frequency of S. pneumoniae isolated from patients with OM decreased from 42% (1999–2001) to 28% (2002–2007) after PCV7 introduction in 2004, while the percentage of isolated H. influenzae increased from 14% (1999–2001) to 23% (2002–2007) [16, 17]. Similarly, in Mexico, the proportion of S. pneumoniae isolated from patients with OM dropped from 52% (2002–2003) to 31% (2008–2009) [35, 90].

Persistence of PCV7 serotypes was demonstrated in early follow up studies in Costa Rica and Mexico, within 3–4 years of PCV7 introduction, in which PCV7 serotypes were identified in 60% and 40% of pneumococcal isolates from patients with OM respectively in these countries [35, 91].

Emergence of non-vaccine serotypes was observed in both countries, with serotype 3 accounting for 10% of identified pneumococcal isolates in Costa Rica [88, 92] and serotypes 19A, 15B and 28A identified in 23%, 10% and 7% of serotypes from OM patients in Mexico, after PCV introduction [35]. In the longer term, 4 years after PCV7 introduction in Venezuela, the predominant pneumococcal serotype isolated from children with OM was serotype 19A (41% of identified serotypes), followed by other non-PCV7 serotypes such as 6A (9%), 11 (9%) and 15 (9%) [36]. Overall, the emergence of non-PCV7 serotypes was concurrent with an overall reduction in the frequency of pneumococcal isolation from children with OM.

In North America, PCV7 was first introduced in the United States to prevent invasive pneumococcal disease in 2000 and 93.6% of children aged from 19 to 35 months had received at least 3 doses of PCV7 [93].

After PCV7 introduction, the predominant pathogen identified in OM in the US changed from S. pneumoniae to H. influenzae. Prior to PCV7 introduction, S. pneumoniae was the most common bacteria isolated from patients with AOM [22, 23, 82] but 1–3 years following PCV implementation, H. influenzae emerged as the most common isolates from patients with OM [12, 24].

Changes in the S. pneumoniae serotypes causing AOM had been observed after PCV7 introduction in the United States. Before PCV introduction, vaccine serotypes accounted for more than 70% of pneumococcal strains isolated from middle ear samples of children with AOM [94]. One to two years post-vaccine introduction, these serotypes accounted for about 50% of OM-associated pneumococcal strains isolated from middle ear samples [94] and six to eight years later they were not observed/reported amongst pneumococcal strains isolated from MEF samples of children with OM [12]. Serotype 19A was the predominant serotype and accounted for 35% of OM-related S. pneumoniae strains isolated MEF samples [12]. Other non-PCV7 serotypes of S. pneumoniae, such as 3, 6A, 6C, 15, 23B and 11, were identified with lower frequencies in MEF samples of OM children [12, 94]. In recent years, although the pneumococcal serotypes are non-PCV7, frequencies of S. pneumoniae and H. influenzae isolates are equivalent [12].

In Europe, a 2008–2009 survey of 32 countries reported that only 17 countries recommended universal PCV7 immunization in children. The remaining countries had only used the vaccine for groups at high risk of infection or not used the vaccine universally [95]. Impacts of the vaccine on OM aetiology and pneumococcal serotypes identified from OM patients were observed in countries where the vaccine was introduced.

Following PCV7 introduction, the dominant otopathogen changed from S. pneumoniae to H. influenzae in France and Greece. In France, prior to the introduction of PCV7, S. pneumoniae was the otopathogen most commonly identified accounting for 54% of isolates and followed by H. influenzae (34%), however 1–2 years following PCV7 introduction, H. influenzae became the dominant bacteria, identified within approximately 46% of isolates and followed by S. pneumoniae (45%) [14]. This change in pattern was evident until 3–4 years post PCV7 implementation, where S. pneumoniae was again the most commonly isolated specie with mostly non-PCV7 serotypes [14]. Similarly, in Greece, S. pneumoniae isolation from the middle ear samples of children with AOM decreased from 42% to 31% post PCV introduction, while H. influenzae increased slightly from 34% to 37% [96].

Introduction of the PCV7 vaccine resulted in changes in the pneumococcal serotypes isolated from patients with OM. In France, pre-PCV7 vaccine introduction (this period, prior to 2004, is identified by the criterion that the rate of complete vaccination in infants under 2 years of age was below 50%), PCV7 serotypes accounted for more than 50% of S. pneumoniae associated with OM but 1–4 years post-PCV7 introduction, this decreased to less than 30% [14]. Similarly, in Spain, the percentage of PCV7 serotypes dropped from more than 60% to below 10% of pneumococcal strains isolated from patients with OM [9799]. Following PCV7 introduction, the frequency of the non-PCV7 serotype 19A, increased from 20% to 50% in patients with OM in France [14] and from 8% to 35% in Spain [98, 99].

In Asia, Singapore and Israel introduced PCV7 into their NIPs in 2009 [86, 100102]. Studies from Israel reported that PCV7 serotypes accounted for approximately 50% of S. pneumoniae strains associated with OM prior to the vaccine introduction [102, 103]. No studies have been identified in this review, which report rates following PCV7 introduction on microbial aetiology of OM or from other countries in this region.

In Africa, PCV7 was introduced into the NIP of South Africa in 2009 [87] and Gambia and Rwanda in 2010 [104]. A single study from South Africa examined S. pneumoniae serotypes pre- PCV7 and showed that PCV7 serotypes accounted for more than 90% of OM-associated S. pneumoniae [54].

In Nigeria, a shift in the predominant bacteria amongst the three main otopathogens detected from MEF samples of patients with AOM was observed, although information on PCV7 introduction has not been reported. In the early 2000s, S. pneumoniae was reported as the predominant otopathogen, followed by H. influenzae and M. catarrhalis [105], however more recently, H. influenzae was reported as the predominant otopathogen, followed by M catarrhalis and S. pneumoniae [106].

In Oceania, PCV7 was licenced and recommended for Australian Aboriginal children under 2 years of age and other children at high risk of pneumococcal infection in 2001. This recommendation was extended to all children in Australia in 2005 [107]. Pneumococcal serotypes recovered from middle ear samples showed progressive change after PCV7 immunisation. In 2000–2003, pre-PCV7 introduction, vaccine serotypes accounted for approximately 70% of the pneumococci isolated from ear discharges (ear swabs) of Australian children below 15 years of age [108]. In 2007–2009, 2–4 years post-PCV7 inclusion in NIP, non-PCV7 serotypes replaced the vaccine serotypes being isolated from middle ear samples from non-Aboriginal children with OM, accounting for more than 80% of identified serotype, of these serotype 19A made up 40% [56].

In contrast to other regions, H. influenzae has always been reported as the most common otopathogen isolated from both Aboriginal and non-Aboriginal children with OM in Australia [56, 79, 109111]. Thus, there has not been a shift between H. influenzae and S. pneumoniae as the predominant otopathogen observed pre- and post- PCV7 introduction in the country. Similar observations are reported for New Zealand, with H. influenzae identified as the most common bacteria isolated from children with OM (RAOM or OME/COME) before and after pneumococcal vaccine introduction (2008)[58, 80, 112].

Improvement of detection of existing and new otopathogens by PCR

The frequency of bacterial detection within MEF samples from children with OM have been compared using both culture and PCR. Across the world, 17 studies have reported bacterial identification, the majority (n = 15) examined MEF from patients with COME or RAOM, with 2 reports from AOM patients.

Overall, PCR detection methods improved the detection frequency of bacteria although the magnitude of the improvement varied between individual reports and ranged from no difference to 9-fold increase in bacterial detection. On average, the improvement in the frequency of detection for bacteria identified within the MEF of children with OM is 3.2 times higher using PCR compared to bacterial culture, for both S. pneumoniae and H. influenzae. The sensitivity of PCR techniques also improved M. catarrhalis detection by 4.5- fold, on average across all studies (Table 4).

Table 4. Comparison of otopathogen detection in MEF using culture and PCR.

The enhanced sensitivity of detection observed using PCR has resulted in detection of M. catarrhalis and S. pneumoniae in culture negative samples [18, 19, 71, 113].

PCR confirmation of the same predominant bacterium being identified within the same sample was observed in 10/17 reports however, in the 6 reports showing a different predominant bacteria, 4/6 changed to M. catarrhalis and 2/6 changed to H. influenzae. A predominant bacterium was not identified in one study. Where PCR identified a different predominant bacterium, there was no recognisable pattern compared to the culture result, with 3 changes from H. influenzae and 3 from S. pneumoniae as the predominant bacterium from the culture.

Globally, and consistent with the results from bacterial culture, PCR results confirmed overall that H. influenzae was the most frequently detected bacterium in the MEF of children experiencing COME/RAOM (11/15 studies). M. catarrhalis was predominant in 3/4 studies and all three bacteria were equally frequent in one study from Iran. The two studies that examined AOM patients MEF, identified M. catarrhalis most frequently, although Alloiococcus otitidis (A. otitidis) was equally or more frequently identified in these reports.

Regionally, from PCR results, H. influenzae was detected most frequently in the Americas, Asia and Oceania. In Europe, H. influenzae and M. catarrhalis were equally frequent (2/4 studies each).

PCR detection for A. otitidis from the MEF of OM patients, has been reported from a range of countries, including Turkey [114], Japan [18], Iran [74], Finland [20, 65, 66], Sweden [115], the United Kingdom [116] and the United States [25, 117]. Collectively, A. otitidis was detected in 20% to 60% of MEF samples from OM patients by PCR, but was largely undetected using culture (Table 4). Furthermore, A. otitidis was more frequently identified in patients with OME compared to patients with AOM [18, 117] and, was the most commonly detected bacteria in the middle ear of patients with OME/COME, detected using PCR [18, 74, 117, 118]. The use of PCR methodologies has improved detection rates for organisms that are difficult to culture, for example, detection of A. otitidis within MEF samples from patients with OM requires more than 3 days in culture, thus PCR analysis of MEF samples has improved detection of this organism and has resulted in consideration of A. otitidis having a role in OM pathogenesis [58, 67, 74, 119].


The frequency of bacterial pathogens of OM, identified within the middle ear fluid using primarily microbial culture, but also PCR, were reviewed over a range of clinical presentations, using reports published since 1970. This review focussed on pathogens actually identified within the MEF rather than extrapolation of upper respiratory tract pathogens coincident in the nasopharynx. Improved understanding of the polymicrobial nature of OM and its varied clinical presentations is informed by the identification of specific bacteria (and viruses) within the middle ear.

Overall, the frequency of bacterial isolation from MEF samples of patients with AOM was generally higher than that from other presentations including RAOM/AOMTF or OME/COME. This finding is consistent with recognition of AOM as an acute, frequently bacterial caused infection, whilst OME and COME are considered as a consequence of a previous AOM episode, or inflammation resulting from the presence of bacterial biofilm or intracellular infection within the middle ear epithelial cell [57]. COME and OME may also result from inflammatory and allergic conditions such as rhino-sinusitis [120].

This review confirms OM as a polymicrobial disease, with the same predominant microbes identified in MEF samples from patients with AOM, RAOM, AOMTF, OME and COME globally. Consistent with previous reports, the three bacteria most frequently identified in the MEF from culture and considered causal for OM were S. pneumoniae, H. influenzae and M. catarrhalis. In Latin American countries, Streptococcus pyogenes (S. pyogenes) was also frequently identified as a predominant bacterium, pathogenic for OM. Increasingly, A. otitidis has been identified within the MEF using PCR techniques, although this bacterium’s role in OM pathogenesis is still under investigation [121, 122]. Culture based detection of A. otitidis within MEF samples from patients with OM requires more than 3 days in culture and thus this organism may not have been successfully identified and reported in previous studies [58, 67, 74, 119].

S. pneumoniae remains the most frequently detected bacteria from patients with AOM in Asia, Africa, America and Europe. No significant differences between the clinical manifestations of AOM, resulting from the different pneumococcal serotypes, were identified but in general, PCV7 serotypes are reported to cause more otalgia or ear ache than non-PCV7-serotypes [123]. Additionally, children with AOM caused by S. pneumoniae are reported to experience higher fever and more redness of tympanic membrane than those with AOM caused by H. influenzae or M. catarrhalis [124], thus increasing the likelihood of presentation for medical treatment. AOM associated with S. pneumoniae is less likely to resolve without treatment when compared to that caused by M. catarrhalis [125].

Overall, use of PCV7 has initially reduced the incidence of AOM caused by S. pneumoniae and altered the serotypes causal for AOM. Replacement of PCV7 serotypes by non-vaccine serotypes has been observed in MEF samples of children with OM in all countries where the vaccine has been used, with serotype 19A, a predominant serotype recovered from vaccinated children with OM. A new genotype of this serotype, isolated from children with AOM was resistant to all USA Food and Drug Administration approved antimicrobial drugs for AOM treatment in children [126]. Therefore, 13-valent pneumococcal conjugate vaccine (PCV13), which includes serotype 19A, may help to reduce the incidence of OM. Since 2010, PCV13 has been licensed and recommended for children in a number of developed countries such as the United States, the United Kingdom, Singapore and Australia [101, 127129].

In contrast to AOM, H. influenzae is most frequently detected bacteria in the MEF of patients with RAOM or OME/COME globally and, with the exception of Australia, is the second most common pathogen in patients with AOM across the world. In Australia, H. influenzae is the predominant bacterium for AOM and OME for indigenous and non-indigenous children [110, 111, 130]. Bilateral AOM, eye symptoms, previous treatment with antibiotics, protracted and recurrent disease, are more likely for AOM caused by H. influenzae when compared with caused by other pathogens [131, 132].

In most studies included in this review, less than 50% of H. influenzae strains recovered from patients with OM were β-lactamase producers. β-lactamase is responsible for bacterial resistance to the β-lactam antibiotics, commonly used as the first line of treatment for OM, such as aminopenicillins, cephalosporins, cephamycins and carbapenems [133, 134]. Widespread use of these antibiotics for the treatment of OM has contributed to the development of antimicrobial resistance. β-lactamase-negative ampicillin-resistant (BLNAR) H. influenzae strains, have been isolated from the MEF of patients with OM in Mexico [35], Lebanon [76] and Japan [135]. The BLNAR strains identified from MEF in the latter two reports [76, 135] have been isolated elsewhere in the upper respiratory tract and reflect the most frequently detected mechanism of ampicillin resistance for H. influenzae across the world [136]. Although not based on MEF samples, a recent report has described the changing frequency of identification of BLNAR H. influenzae isolates, both globally and regionally, and confirmed reductions in detection in Europe and Africa between 2004–2008 and 2009–2012 whilst the proportion of detections rose in other regions including Latin America and the Middle East [137].

In this review, NTHi strains were most frequently reported and these strains are unaffected by H. influenzae b conjugate vaccination alone (Hib) [138]. Increasingly, inclusion of H. influenzae antigens to improve the opportunity for vaccine development is under development [139].

PCV7 introduction has been associated increased identification of H. influenzae in patients with OM when compared with S. pneumoniae. H. influenzae has gradually replaced S. pneumoniae as the predominant otopathogen in children with AOM for 1–5 years following PCV7 introduction and, in the absence of an approved vaccine for NTHi prevention, this shift could create another challenge for treatment and prevention of OM.

Until recently, most NTHi vaccine research interest was focussed on the 10-valent pneumococcal NTHi protein D conjugate vaccine (PHiD-CV10), which contains 10 pneumococcal serotypes and protein D of H. influenzae. This vaccine is immunogenic against protein D and well tolerated in studies conducted in America, Europe, Asia, Africa [140145] and Australia [129]. Originally considered a potential candidate to replace PCV7, a recent study from Australia demonstrated that 19% of NTHi strains isolated from the nasal cavity, nasopharynx and bronchoalveolar lavage fluid from asymptomatic carriage or children with bronchiectasis were missing the hpd genes encoding protein D of NTHi [146]. Further research is needed to trial a number of already identified NTHi vaccine candidates, with respect to the safety, immunogenicity and efficacy against OM [1]. M. catarrhalis has been recognised as an otopathogen since 1920s with significant increased detection occurring since the 1980’s [147]. Clinically, M. catarrhalis alone appears to be the least virulent pathogen [148] and is often associated with the first episode of disease, a younger age of onset, lower rates of spontaneous tympanic membrane perforation [149] and increased likelihood of spontaneous resolution [125]. M. catarrhalis however, most frequently occurs as a polymicrobial infection [149]. In this review, where culture findings of predominant bacteria were identified as different to that identified by PCR methods, M. catarrhalis was the new predominant bacterium.Most studies report that more than 90% of M. catarrhalis strains isolated from patients with OM were β-lactamase producers, although lower rates of 40%-50% have been reported from Turkey and Nigeria [52, 53, 106]. Whilst several vaccine candidates have been identified for M. catarrhalis, development of a vaccine strategy for M. catarrhalis is at an early stage [150152].

Otitis media is associated with other bacteria including S. pyogenes (Group A Streptococcus), the fourth ranked otopathogen [82] identified in this review. This bacterium is otopathogenic and more often identified in older children who experience low rates of fever and respiratory symptoms but, increased rates of spontaneous perforation and mastoiditis, compared with AOM due to other otopathogens [153]. It is speculated that the role of S. pyogenes in OM aetiology maybe under-recognised in some regions.

Increasingly, new organisms such as A. otitidis, Turicella otitidis, Pseudomonas otitidis and Corynebacterium mucifaciens have been detected in patients with OM, but their significance in OM pathogenesis remains unclear [154]. Of these organisms, A. otitidis is the most commonly identified in the MEF from patients with OME/COME [18, 117]. A. otitidis may be associated with a protracted clinical course, development of the mucoid MEF characteristic of OME [65] and was recently reported to induce inflammation within the middle ear cavity [122, 155] thus potentially contributing as a secondary pathogen in AOM with perforation [156].

In this review, we have reported on the global detection of bacterial otopathogens in the MEF of children experiencing OM. Although three bacteria, S. pneumoniae, H. influenzae and M. catarrhalis dominate, geographical differences are emerging. These differences relate to PCV use, antimicrobial treatment and potentially other local regional factors. This highlights the need for ongoing surveillance and reporting of the microbiology of OM globally, in order to better understand the pathogenesis of this disease and to guide development of appropriate intervention strategies.


Despite a paucity of comprehensive prospective studies examining the microbial aetiology of AOM/RAOM and OME/COME locally within the middle ear of children throughout the world, we conclude that S. pneumoniae, H. influenzae and M. catarrhalis, have remained remarkably consistent over the past 40 years, as the predominant bacteria causal for OM. Depending on the region, and the detection method, S. pneumoniae and H. influenzae vie for predominance as the bacteria most frequently isolated from the middle ear fluid from children with OM. A significant environmental change, the introduction of PCV7 and ongoing monitoring of serotype replacement throughout many regions of the world, continues to provide evidence of the predominance of these two bacteria in children with OM. Importantly, to identify and address the evolving development of bacterial resistance, such as β-lactamase production and potential pathogenicity of prevalent microbes such as S. pyogenes and A. otitidis ongoing monitoring is essential.

Future research is essential, whether development of vaccines that include multiple otopathogens [157], bacterial and viral, or trialling the use of probiotic supplementation to the upper respiratory tract [158] for children at high risk of OM. Investigators should continue to aim to minimise the incidence or indeed prevent OM pathogenesis and its long term sequelae for vulnerable children across the world.

Supporting Information

S1 Fig. Strategies for searching studies on pathogens of OM in Asia.



S2 Fig. Strategies for searching studies on pathogens of OM in the Americas.



S3 Fig. Strategies for searching studies on pathogens of OM in Africa.



S4 Fig. Strategies for searching studies on pathogens of OM in Europe.



S5 Fig. Strategies for searching studies on pathogens of OM in Oceania.



S1 PRISMA Checklist. PRISMA Checklist.



S1 Table. Proportion of bacteria detected from MEF samples of patients with AOM.



S2 Table. Proportion of bacteria detected from MEF samples of patients with RAOM/AOMTF.



S3 Table. Proportion of bacteria detected from MEF samples of patients with OME/COME.




Authors, who, upon email contact, assisted this review by providing clarification or additional information about their research.

Author Contributions

Conceived and designed the experiments: AWC HMM. Performed the experiments: CCN HMM. Analyzed the data: CCN HMM RBT AWC. Contributed reagents/materials/analysis tools: CCN HMM. Wrote the paper: CCN HMM RBT AWC.


  1. 1. Cripps AW, Kyd J. Bacterial otitis media: current vaccine development strategies. Immunol Cell Biol. 2003;81(1):46–51. pmid:12534945
  2. 2. Kong K, Coates HLC. Natural history, definitions, risk factors and burden of otitis media. Med J Aust. 2009;191(9):s39–s43. pmid:19883355
  3. 3. Monasta L, Ronfani L, Marchetti F, Montico M, Brumatti LV, Bavcar A, et al. Burden of Disease Caused by Otitis Media: Systematic Review and Global Estimates. PLos One. 2012;7(4):1–12.
  4. 4. Rovers MM. The burden of otitis media. Vaccine. 2008;26(suppl 7):G2–G4. doi: 10.1016/j.vaccine.2008.11.005. pmid:19094933
  5. 5. Physicians AAoF. Otitis media with effusion. Pediatrics. 2004;113:1412–29. pmid:15121966
  6. 6. Massa HM, Cripps AW, Lehmann D. Otitis media: viruses, bacteria, biofilms and vaccines. Medical journal of Australia. 2009;191(9):s44–s9. pmid:19883356
  7. 7. Chonmaitree T, Ruohola A, Hendley JO. Presence of Viral Nucleic Acids in the Middle Ear Acute Otitis Media Pathogen or Bystander? Pediatr Infect Dis J. 2012;31(4):325–30. doi: 10.1097/INF.0b013e318241afe4. pmid:22173136
  8. 8. Weil-Olivier C, van der Linden M, de Schutter I, Dagan R, Mantovani L. Prevention of pneumococcal diseases in the post-seven valent vaccine era: a European perspective. BMC Infect Dis. 2012;12(207):1–12.
  9. 9. Mokaddas E, Albert MJ. Impact of pneumococcal conjugate vaccines on burden of invasive pneumococcal disease and serotype distribution of Streptococcus pneumoniae isolates: an overview from Kuwait. Vaccine. 2012;30:G27–G40.
  10. 10. Isaacman DJ, McIntosh ED, Reinert RR. Burden of invasive pneumococcal disease and serotype distribution among Streptococcus pneumoniae isolates in young children in Europe: impact of the 7-valent pneumococcal conjugate vaccine and considerations for future conjugate vaccines. Int J Infect Dis. 2010;14(3):197–209.
  11. 11. Hsu KK, Shea KM, Stevenson AE, Pelton SI. Changing serotypes causing childhood invasive pneumococcal disease: Massachusetts, 2001–2007. Pediatr Infect Dis J. 2010;29(4):289–93. doi: 10.1097/INF.0b013e3181c15471. pmid:19935447
  12. 12. Casey JR, Adlowitz DG, Pichichero ME. New patterns in the otopathogens causing acute otitis media six to eight years after introduction of pneumococcal conjugate vaccine. The Pediatric Infectious Disease Journal. 2010;29(4):304–9. doi: 10.1097/INF.0b013e3181c1bc48. pmid:19935445
  13. 13. Pumarola F, Marès J, Losada I, Minguella I, Moraga F, Tarragó D, et al. Microbiology of bacteria causing recurrent acute otitis media (AOM) and AOM treatment failure in young children in Spain: shifting pathogens in the post-pneumococcal conjugate vaccination era. Int J Pediatr Otorhinolaryngol 2013;77(8):1231–6. doi: 10.1016/j.ijporl.2013.04.002. pmid:23746414
  14. 14. Dupont D, Mahjuob-Messai F, Francois M, Doit C, Mariani-Kurkdjian P, Bidet P, et al. Evolving microbiology of complicated acute otitis media before and after introduction of the pneumococcal conjugate vaccine in France. Diagnostic Microbiology and Infectious Disease. 2010;68:89–92. doi: 10.1016/j.diagmicrobio.2010.04.012. pmid:20727478
  15. 15. Moher D, Liberati A, Tetzlaff J, Altman D, PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 2009;6(7).
  16. 16. Arguedas A, Dagan R, Soley C, Loaiza C, Knudsen K, Porat N, et al. Microbiology of otitis media in Costa Rican children, 1999 through 2001. Pediatr Infect Dis J. 2003;22(12):1063–8. pmid:14688566
  17. 17. Aguilar L, Alvarado O, Soley C, Abdelnour A, Dagan R, Arguedas A. Microbiology of the middle ear fluid in Costa Rican children between 2002 and 2007. Int J Pediatr Otorhinolaryngol 2009;73:1407–11. doi: 10.1016/j.ijporl.2009.07.005. pmid:19683349
  18. 18. Harimaya A, Takada R, Hendolin PH, Fujii N, Ylikoski J, Himi T. High incidence of Alloiococcus otitidis in children with otitis media, despite treatment with antibiotics. J Clin Microbiol. 2006;44(3):946–9. pmid:16517881
  19. 19. Stol K, Verhaegh SJ, Graamans K, Engel JA, Sturm PD, Melchers WJ, et al. Microbial profiling does not differentiate between childhood recurrent acute otitis media and chronic otitis media with effusion. Int J Pediatr Otorhinolaryngol 2013;77(4):488–93. doi: 10.1016/j.ijporl.2012.12.016. pmid:23369612
  20. 20. Leskinen K, Hendolinb P, Virolainen-Julkunen A, Ylikoski J, Jeroa J. Alloiococcus otitidis in acute otitis media. International Journal of Pediatric Otorhinolaryngology. 2004;68:51–6. pmid:14687687
  21. 21. Heikkinen T, Thint M, Chonmaitree T. Prevalence of various respiratory viruses in the middle ear during acute otitis media. Engl J Med. 1999;340(4):260–4.
  22. 22. Rodriguez W, Schwartz R, Thorne M. Increasing incidence of penicillin- and ampicillin-resistant middle ear pathogens. Pediatr Infect Dis J. 1995;14(12):1075–8. pmid:8745021
  23. 23. Patel JA, Nguyen DT, Revai K, Chonmaitree T. Role of respiratory syncytial virus in acute otitis media: implications for vaccine development. Vaccine. 2007;25(9):1683–9. pmid:17156899
  24. 24. Grubb MS, Spaugh DC. Microbiology of acute otitis media, Puget Sound region, 2005–2009. Clinical Pediatrics. 2010;49(8):727–30. doi: 10.1177/0009922810361365. pmid:20185479
  25. 25. Kaur R, Adlowitz DG, Casey JR, Zeng M, Pichichero ME. Simultaneous assay for four bacterial species including Alloiococcus otitidis using multiplex-PCR in children with culture negative acute otitis media. Pediatr Infect Dis J. 2010;29(8):741–5. doi: 10.1097/INF.0b013e3181d9e639. pmid:20335823
  26. 26. Casey JR, Kaur R, Friedel VC, Pichichero ME. Acute otitis media otopathogens during 2008 to 2010 in Rochester, New York. Pediatr Infect Dis J 2013;32(8):805–9. doi: 10.1097/INF.0b013e31828d9acc. pmid:23860479
  27. 27. MacLoughlin GJF, Barreto DG, Torre Cdl, Pinetta EA, Castillo Fd, Palma L. Cefpodoxime proxetil suspension compared with cefaclor suspension for treatment of acute otitis media in paediatric patients. Journal of Antimicrobial Chemotherapy. 1996;37:565–73. pmid:9182113
  28. 28. Commisso R, Romero-Orellano F, Montanaro PB, Romero-Moroni F, Romreo-Diaz R. Acute otitis media: bacteriology and bacterial resistance in 205 pediatric patients. International Journal of Pediatric Otorhinolaryngology. 2000;56:23–31. pmid:11074112
  29. 29. Sih TM. Acute otitis media in Brazilian children: analysis of microbiology and antimicrobial susceptibility. The Annals of Otology, Rhinology & Laryngology. 2001;110(7):662–6.
  30. 30. Rosenblut A, Santolaya ME, Gonzalez P, Corbalan V, Avendano LF, Martinez MA, et al. Bacterial and viral etiology of acute otitis media in Chilean children. The Pediatric Infectious Disease Journal. 2001;20(5):501–7. pmid:11368107
  31. 31. Rosenblut A, Santolaya ME, Gonzalez P, Borel C, Cofre J. Penicillin resistance is not extrapolable to amoxicillin resistance in Streptococcus pneumoniae isolated from middle ear fluid in children with acute otitis media. The Annals of Otology, Rhinology & Laryngology. 2006;115(3):186–90.
  32. 32. Arguedas A, Loaiza C, Perez A, Vargas F, Herrera M, Rodriguez G, et al. Microbiology of acute otitis media in Costa Rican children. Pediatr Infect Dis J. 1998;17(8):680–9. pmid:9726340
  33. 33. Trujillo H, Callejas R, Mejia GI, Castrillon L. Bacteriology of middle ear fluid specimens obtained by tympanocentesis from 111 Colombian children with acute otitis media. Pediatr Infect Dis J. 1989;8(6):361–3. pmid:2787494
  34. 34. Sierra A, Lopes P, Zapata MA, Vanegas B, Castrejon MM, DeAntonio R, et al. Non-typeable Haemophilus influenzae and Streptococcus pneumonia as primary causes of acute otitis media in colombian children: a prospective study. BMC Infectious Diseases. 2011;11(4):1–11.
  35. 35. Parra MM, Aguilar GM, Echaniz-Aviles G, Rionda RG, Estrada MdLA, Cervantes Y, et al. Bacterial etiology and serotypes of acute otitis media in Mexican children. Vaccine. 2011;29:5544–9. doi: 10.1016/j.vaccine.2011.04.128. pmid:21596081
  36. 36. Naranjo L, Suarez JA, DeAntonio R, Sanchez F, Calvo A, Spadola E, et al. Non-capsulated and capsulated Haemophilus influenzae in children with acute otitis media in Venezuela: a prospective epidemiological study. BMC Infectious Diseases. 2012;12(40):1–10.
  37. 37. del Castillo F, Garcia-Perea A, Baquero-Artigao F. Bacteriology of acute otitis media in Spain: a prospective study based on tympanocentesis. Pediatr Infect Dis J. 1996;15(6):541–3.
  38. 38. Karma PH, Pukander JS, Sipilä MM, Vesikari TH, Grönroos PW. Middle ear fluid bacteriology of acute otitis media in neonates and very young infants. Int J Pediatr Otorhinolaryngol. 1987;14(2–3):141–50. pmid:3125118
  39. 39. Kilpi T, Herva E, Kaijalainen T, Syrjanen R, Takala AK. Bacteriology of acute otitis media in a cohort of Finnish children followed for the first two years of life. Pediatr Infect Dis J. 2001;20:654–62. pmid:11465836
  40. 40. Ruohola A, Meurman O, Nikkari S, Skottman T, Salmi A, Waris M, et al. Microbiology of acute otitis media in children with tympanostomy tubes: prevalences of bacteria and viruses. Clin Infect Dis 2006;43:1417–22. pmid:17083014
  41. 41. Grevers G, Wiedemann S, Bohn J, Blasius R, Harder T, Kroeniger W, et al. Identification and characterization of the bacterial etiology of clinically problematic acute otitis media after tympanocentesis or spontaneous otorrhea in German children. BMC Infect Dis. 2012;12(1):312.
  42. 42. Leibovitz E, Piglansky L, Raiz S, Greenberg D, Yagupsky P, Press J, et al. Bacteriologic efficacy of a three-day intramuscular ceftriaxone regimen in nonresponsive acute otitis media. Pediatr Infect Dis J. 1998;17(12):1126–31. pmid:9877360
  43. 43. Turner D, Leibovitz E, Aran A, Piglansky L, Raiz S, Leiberman A, et al. Acute otitis media in infants younger than two months of age: microbiology, clinical presentation and therapeutic approach. Pediatr Infect Dis J. 2002;21:669–74. pmid:12237601
  44. 44. Polachek A, Greenberg D, Lavi-Givon N, Broides A, Leiberman A, Dagan R, et al. Relationship among peripheral leukocyte counts, etiologic agents and clinical manifestations in acute otitis media. Pediatr Infect Dis J. 2004;23(5):406–13. pmid:15131462
  45. 45. Sugita R, Kawamura S, Ichikawa G, Goto S, Fujimaki Y. Studies of anaerobic bacteria in chronic otitis media. Laryngoscope. 1981;91(5):816–21. pmid:7231031
  46. 46. Sagai S, Suetake M, Yano H, Yoshida M, Ohyama K, Endo H, et al. Relationship between respiratory syncytial virus infection and acute otitis media in children. Auris Nasus Larynx 2004;31(4):341–5. pmid:15571905
  47. 47. Suzuki A, Watanabe O, Okamoto M, Endo H, Yano H, Suetake M, et al. Detection of Human Metapneumovirus From Children With Acute Otitis Media. The Pediatric Infectious Disease Journal. 2005;24(7):665–7.
  48. 48. Yano H, Okitsu N, Hori T, Watanabe O, Kisu T, Hatagishi E, et al. Detection of respiratory viruses in nasopharyngeal secretions and middle ear fluid from children with acute otitis media. Acta Oto-Laryngologica. 2009;129:19–24. doi: 10.1080/00016480802032777. pmid:18607974
  49. 49. Tseng T-C, Chen L-C, Wang P-C, Huang C-H, Chen Y-H. Clinical report on the bacteriology of acute otitis media in childhood. FJJM. 2007;5(1):1–8.
  50. 50. Intakorn P, Sonsuwan N, Noknu S, Moungthong G, Pircon J-Y, Dyke MKV, et al. Haemophilus influenzae type b as an important cause of culture-positive acute otitis media in young children in Thailand: a tympanocentesis-based, multi-center, cross-sectional study. BMC Pediatrics. 2014;14(157):1–9.
  51. 51. Oğuz F, Unüvar E, Süoğlu Y, Erdamar B, Dündar G, Katircioğlu S, et al. Etiology of acute otitis media in childhood and evaluation of two different protocols of antibiotic therapy: 10 days cefaclor vs. 3 days azitromycin. Int J Pediatr Otorhinolaryngol. 2003;67(1):43–51. pmid:12560149
  52. 52. Guven M, Bulut Y, Sezer T, Aladag I, Eyibilen A, Etikan I. Bacterial etiology of acute otitis media and clinical efficacy of amoxicillin—clavulanate versus azithromycin. International Journal of Pediatric Otorhinolaryngology. 2006;70(70):915–23.
  53. 53. Bulut Y, Guven M, Otlu B, Yenisehirli G, Aladag I, Eyibilen A, et al. Acute otitis media and respiratory viruses. Eur J Pediatr. 2007;166:223–8. pmid:16967296
  54. 54. Huebner RE, Wasas AD, Hockman M, Klugman KP. Bacterial aetiology of non-resolving otitis media in South African children. The journal of Laryngology & Otology. 2003;117:169–72.
  55. 55. Couloigner V, Levy C, Francois M, Bidet P, Hausdorff WP, Pascal T, et al. Pathogens implicated in acute otitis media failures after 7-valent pneumococcal conjugate vaccine implementation in France: distribution, serotypes, and resistance levels. Pediatr Infect Dis J. 2012;31:154–8. doi: 10.1097/INF.0b013e3182357c8d. pmid:21983212
  56. 56. Wiertsema SP, Kirkham LS, Corscadden KJ, Mowe EN, Bowman JM, Jacoby P, et al. Predominance of nontypeable Haemophilus influenzae in children with otitis media following introduction of a 3 + 0 pneumococcal conjugate vaccine schedule. Vaccine. 2011;29:5163–70. doi: 10.1016/j.vaccine.2011.05.035. pmid:21621576
  57. 57. Thornton RB, Wiertsema SP, Kirkham LS, Rigby PJ, Vijayasekaran S, Coates HL, et al. Neutrophil extracellular traps and bacterial biofilms in middle ear effusion of children with recurrent acute otitis media—a potential treatment target. PLoS One. 2013;8:e53837. doi: 10.1371/journal.pone.0053837. pmid:23393551
  58. 58. Mills N, Best E, Murdoch D, Souter M, Neeff M, Anderson T, et al. What is behind the ear drum? The microbiology of otitis media and the nasopharyngeal flora in children in the era of pneumococcal vaccination. J Paediatr Child Health. 2015;51(3):300–6. doi: 10.1111/jpc.12710. pmid:25175818
  59. 59. Pereira MBR, Pereira MR, Cantarelli V, Costa SS. Prevalence of bacteria in children with otitis media with effusion. Jornal de Pediatria. 2004;80(1):41–8. pmid:14978548
  60. 60. Post JC, Preston RA, Aul JJ, Larkins-Pettigrew M, Rydquist-White J, Anderson KW, et al. Molecular analysis of bacterial pathogens in otitis media with effusion. JAMA. 1995;273(20):1598–604. pmid:7745773
  61. 61. Sipilä P, Jokipii AM, Jokipii L, Karma P. Bacteria in the middle ear and ear canal of patients with secretory otitis media and with non-inflamed ears. Acta Otolaryngol. 1981;92(1–2):123–30. pmid:7315245
  62. 62. Sriwardhana KB, Howard AJ, Dunkin KT. Bacteriology of otitis media with effusion. J Laryngol Otol 1989;103(3):253–6. pmid:2495334
  63. 63. Diamond C, Sisson PR, Kearns AM, Ingham HR. Bacteriology of chronic otitis media with effusion. J Laryngol Otol. 1989;103(4):369–71. pmid:2497219
  64. 64. Jero J, Karma P. Bacteriological findings and persistence of middle ear effusion in otitis media with effusion. Acta Otolaryngol Suppl. 1997;529:22–6. pmid:9288259
  65. 65. Leskinen K, Hendolin P, Virolainen-Julkunen A, Ylikoski J, Jero J. The clinical role of Alloiococcus otitidis in otitis media with effusion. International Journal of Pediatric Otorhinolaryngology. 2002;66:41–8. pmid:12363421
  66. 66. Hendolin PH, Kärkkäinen U, Himi T, Markkanen A, Ylikoski J. High incidence of Alloiococcus otitis in otitis media with effusion. Pediatr Infect Dis J 1999;18(10):860–5. pmid:10530580
  67. 67. Martínez IM, Ramos MA, Masgoret PE. Bacterial implication in otitis media with effusion in the childhood. Acta Otorrinolaringol Esp. 2007;58(9):408–12. pmid:17999905
  68. 68. Daniel M, Imtiaz-Umer S, Fergie N, Birchall JP, Bayston R. Bacterial involvement in otitis media with effusion. Int J Pediatr Otorhinolaryngol. 2012;76(10):1416–22. doi: 10.1016/j.ijporl.2012.06.013. pmid:22819485
  69. 69. Gok U, Bulut Y, Keles E, Yalcin S, Doymaz MZ. Bacteriological and PCR analysis of clinical material aspirated from otitis media with effusions. Int J Pediatr Otorhinolaryngol. 2001;60(1):49–54. pmid:11434953
  70. 70. Jung H, Lee SK, Cha SH, Byun JY, Park MS, Yeo SG. Current bacteriology of chronic otitis media with effusion: high rate of nosocomial infection and decreased antibiotic sensitivity. J Infect 2009;59(5):308–16. doi: 10.1016/j.jinf.2009.08.013. pmid:19715725
  71. 71. Park C-W, Han J-H, Jeong J-H, Cho S-H, Kang M-J, Tea K, et al. Detection rates of bacteria in chronic otitis media with effusion in children. J Korean Med Sci. 2004;19:735–8. pmid:15483353
  72. 72. Kurono Y, Tomonaga K, Mogi G. Staphylococcus epidermidis and Staphylococcus aureus in otitis media with effusion. Arch Otolaryngol Head Neck Surg 1988;114(11):1262–5. pmid:3262358
  73. 73. Shishegar M, Faramarzi A, Kazemi T, Bayat A, Motamedifar M. Polymerase chain reaction, bacteriologic detection and antibiogram of bacteria isolated from otitis media with effusion in children, shiraz, iran. Iran J Med Sci. 2011;36(4):273–80. pmid:23115412
  74. 74. Khoramrooz SS, Mirsalehian A, Emaneini M, Jabalameli F, Aligholi M, Saedi B, et al. Frequency of Alloicoccus otitidis, Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae in children with otitis media with effusion (OME) in Iranian patients. Auris Nasus Larynx. 2012;39:369–73. doi: 10.1016/j.anl.2011.07.002. pmid:21868180
  75. 75. Matar GM, Sidani N, Fayad M, Hadi U. Two-step PCR-based assay for identification of bacterial etiology of otitis media with effusion in infected Lebanese children. J Clin Microbiol. 1998;36(5):1185–8. pmid:9574673
  76. 76. Nasser SC, Moukarzel N, Nehme A, Haidar H, Kabbara B, Haddad A. Otitis media with effusion in lebanese children: prevalence and pathogen susceptibility. The journal of Laryngology & Otology. 2011;125:928–33.
  77. 77. el-Shamy HA. Bacteriology of chronic secretory otitis media in children. J Egypt Public Health Assoc. 1993;68:495–505. pmid:7775877
  78. 78. Aly BH, Hamad MS, Mohey M, Amen S. Polymerase Chain Reaction (PCR) Versus Bacterial Culture in Detection of Organisms in Otitis Media with Effusion (OME) in Children. Indian J Otolaryngol Head Neck Surg. 2012;64(1):51–5. doi: 10.1007/s12070-011-0161-6. pmid:23449820
  79. 79. Stuart J, Butt H, Walker P. The microbiology of glue ear in Australian Aboriginal children. J Paediatr Child Health. 2003;39(9):665–7. pmid:14629496
  80. 80. Watson P, Voss L, Barber C, Aickin R, Bremner D, Lennon D. The microbiology of chronic otitis media with effusion in a group of Auckland children. N Z Med J. 1996;109(1022):182–4. pmid:8657383
  81. 81. Block SL, Hedrick J, Harrison CJ, Tyler R, Smith A, Findlay R, et al. Pneumococcal serotypes from acute otitis media in rural Kentucky. Pediatr Infect Dis J. 2002;21:859–65. pmid:12352810
  82. 82. Bluestone CD, Stephenson JS, Martin LM. Ten-year review of otitis media pathogens. Pediatr Infect Dis J. 1992;11(8):s7–s11. pmid:1513611
  83. 83. Dagan R, Johnson CE, McLinn S, Abughali N, Feris J, Leibovitz E, et al. Bacteriologic and clinical efficacy of amoxicillin/clavulanate vs. azithromycin in acute otitis media. Pediatr Infect Dis J. 2000;19(2):95–104. pmid:10693993
  84. 84. Chiu NC, Lin HY, Hsu CH, Huang FY, Lee KS, Chi H. Epidemiological and microbiological characteristics of culture-proven acute otitis media in Taiwanese children. J Formos Med Assoc. 2012;111(10):536–41. doi: 10.1016/j.jfma.2011.07.015. pmid:23089688
  85. 85. Leibovitz E, Piglansky L, Raiz S, Greenberg D, Hamed KA, Ledeine JM, et al. Bacteriologic and clinical efficacy of oral gatifloxacin for the treatment of recurrent/nonresponsive acute otitis media: an open label, noncomparative, double tympanocentesis study. Pediatr Infect Dis J 2003;22(11):943–9. pmid:14614364
  86. 86. Ben-Shimol S, Greenberg D, Givon-Lavi N, Elias N, Glikman D, Rubinstein U, et al. Rapid reduction in invasive pneumococcal disease after introduction of PCV7 into the National Immunization Plan in Israel. Vaccine. 2012;30(46):6600–7. doi: 10.1016/j.vaccine.2012.08.012. pmid:22939907
  87. 87. Jones SA, Groome M, Koen A, Van NN, Sewraj P, Kuwanda L, et al. Immunogenicity of seven-valent pneumococcal conjugate vaccine administered at 6, 14 and 40 weeks of age in South african infants. PLoS One. 2013;8(8):e72794. doi: 10.1371/journal.pone.0072794. pmid:24015277
  88. 88. Abdelnour A, Soley C, Guevara S, Porat N, Dagan R, Arguedas A. Streptococcus pneumoniae Serotype 3 among Costa Rican Children with Otitis Media: clinical, epidemiological characteristics and antimicrobial resistance patterns. BMC Pediatrics. 2009;9(52):1–6.
  89. 89. Lee LH, Gu X, Nahm MH. Towards New Broader Spectrum Pneumococcal Vaccines: The Future of Pneumococcal Disease Prevention. Vaccines. 2014;2:112–28. doi: 10.3390/vaccines2010112. pmid:26344470
  90. 90. Gomez-Barreto D, Monteros LEEdl, Lopez-Enriquez C, Suarez RR, Torre Cdl. Streptococcus pneumoniae serotypes isolated from middle ear of Mexican children diagnosed with acute otitis media. salud pública de méxico. 2011;53(3):207–11. pmid:21829885
  91. 91. Guevara S, Abdelnour A, Soley C, Porat N, Dagan R, Arguedas A. Streptococcus pneumoniae serotypes isolated from the middle ear fluid of Costa Rican children following introduction of the heptavalent pneumococcal conjugate vaccine into a limited population. Vaccine. 2012;30(26):3857–61. doi: 10.1016/j.vaccine.2012.04.010. pmid:22521846
  92. 92. Arguedas A, Dagan R, Guevara S, Porat N, Soley C, Perez A, et al. Middle ear fluid Streptococcus pneumoniae serotype distribution in Costa Rican children with otitis media. The Pediatric Infectious Disease Journal. 2005;24(7):631–4. pmid:15999006
  93. 93. Centers for Disease Control and Prevention. Preventing Pneumococcal Disease Among Infants and Young Children. 2000.
  94. 94. McEllistrem MC, Adams JM, Patel K, Mendelsohn AB, Kaplan SL, Bradley JS, et al. Acute otitis media due to penicillin-nonsusceptible Streptococcus pneumoniae before and after the introduction of the pneumococcal conjugate vaccine. Clin Infect Dis. 2005;40(12):1738–44. pmid:15909260
  95. 95. Gomes HDC, Muscat M, Monnet DL, Giesecke J, Lopalco PL. Use of seven-valent pneumococcal conjugate vaccine (PCV7) in Europe, 2001–2007. EUROSURVEILLANCE. 2009;14(12):1–6.
  96. 96. Stamboulidis K, Chatzaki D, Poulakou G, Ioannidou S, Lebessi E, Katsarolis I, et al. The impact of the heptavalent pneumococcal conjugate vaccine on the epidemiology of acute otitis media complicated by otorrhea. Pediatr Infect Dis J. 2011;30:551–5. doi: 10.1097/INF.0b013e31821038d9. pmid:21297521
  97. 97. Gene A, Garcia-Garcia JJ, Domingo A, Palacin PWyE. Etiology of acute otitis media in a children's hospital and antibiotic sensitivity of the bacteria involved. Enferm Infecc Microbiol Clin. 2004;22(7):377–80. pmid:15355766
  98. 98. Fenoll A, Aguilar L, Vicioso M-D, Robledo O, Granizo J-J. Increase in serotype 19A prevalence and amoxicillin non-susceptibility among paediatric Streptococcus pneumoniae isolates from middle ear fluid in a passive laboratory-based surveillance in Spain, 1997–2009. BMC Infectious Diseases. 2011;11(239):1–8.
  99. 99. Alonso M, Marimon JM, Ercibengoa M, Pérez-Yarza EG, Pérez-Trallero E. Dynamics of Streptococcus pneumoniae serotypes causing acute otitis media isolated from children with spontaneous middle-ear drainage over a 12-year period (1999–2010) in a region of northern Spain. PLoS One. 2013;8(1):e54333. doi: 10.1371/journal.pone.0054333. pmid:23349853
  100. 100. Lu C-Y, Santosham M, Members A. Survey of national immunization programmes and vaccine coverage rates in Asia Pacific countries. Vaccine. 2012;30:2250–5. doi: 10.1016/j.vaccine.2011.10.070. pmid:22075085
  101. 101. Tyo KR, Rosen MM, Zeng W, Yap M, Pwee KH, Ang LW, et al. Cost-effectiveness of conjugate pneumococcal vaccination in Singapore: comparing estimates for 7-valent, 10-valent, and 13-valent vaccines. Vaccine. 2011;29:6686–94. doi: 10.1016/j.vaccine.2011.06.091. pmid:21745516
  102. 102. Porat N, Amit U, Givon-Lavi N, Leibovitz E, Dagan R. Increasing Importance of Multidrug-Resistant Serotype 6A Streptococcus pneumoniae Clones in Acute Otitis Media in Southern Israel. The Pediatric Infectious Disease Journal. 2010;29(2):126–30. doi: 10.1097/INF.0b013e3181b78e6e. pmid:19927039
  103. 103. Somech I, Dagan R, Givon-Lavi N, Porat N, Raiz S, Leiberman A, et al. Distribution, dynamics and antibiotic resistance patterns of Streptococcus pneumoniae serotypes causing acute otitis media in children in southern Israel during the 10 year-period before the introduction of the 7-valent pneumococcal conjugate vaccine. Vaccine. 2011;29(25):4202–9. doi: 10.1016/j.vaccine.2011.03.103. pmid:21497634
  104. 104. Kim SY, Lee G, Goldie SJ. Economic evaluation of pneumococcal conjugate vaccination in The Gambia. BMC Infect Dis. 2010;10(260):1–18.
  105. 105. Ako-Nai AK, Oluga FA, Onipede AO, Adejuyigbe EA, Amusa YB. The characterization of bacterial isolates from acute otitis media in Ile-Ife, southwestern Nigeria. Journal of Tropical Pediatrics. 2002;48:15–23. pmid:11866331
  106. 106. Akinjogunla OJ, Eghafona NO, Enabulele IO. Aetiologic Agents of Acute Otitis Media (AOM): Prevalence, Antibiotic Susceptibility, β-Lactamase (βL) and Extended Spectrum β-Lactamase (ESBL) Production. Journal of Microbiology, Biotechnology and Food Sciences. 2011;1(3):333–53.
  107. 107. Giele C, Moore H, Bayley K, Harrison C, Murphy D, Rooney K, et al. Has the seven-valent pneumococcal conjugate vaccine had an impact on invasive pneumococcal disease in Western Australia? Vaccine. 2007;25(13):2379–84. pmid:17064825
  108. 108. Watson M, Brett M, Brown M, Stewart MG, Warren S, Network ftNSWP. Pneumococci responsible for invasive disease and discharging ears in children in Sydney, Australia. journal of medical microbiology. 2007;56:819–23. pmid:17510269
  109. 109. Dawson VM, Coelen RJ, Murphy S, Graham D, Dyer H, Sunderman J. Microbiology of chronic otitis media with effusion among Australian Aboriginal children: role of Chlamydia trachomatis. Aust J Exp Biol Med Sci. 1985;63:99–107. pmid:4040361
  110. 110. Gibney KB, Morris PS, Carapetis JR, Skull SA, Smith-Vaughan HS, Stubbs E, et al. The clinical course of acute otitis media in high-risk Australian Aboriginal children: a longitudinal study. BMC Pediatr. 2005;5(16):1–8.
  111. 111. Leach AJ, Morris PS. The burden and outcome of respiratory tract infection in Australian and Aboriginal children. Pediatr Infect Dis J. 2007;26(10):S4–S7. pmid:18049380
  112. 112. Walls T, Best E, Murdoch D, Mills N. Vaccination to prevent otitis media in New Zealand. N Z Med J. 2011;124(1340):6–9. pmid:21952379
  113. 113. Hamamoto Y, Gotoh Y, Nakajo Y, Shimoya S, Kayama C, Hasegawa S, et al. Impact of antibiotics on pathogens associated with otitis media with effusion. J Laryngol Otol. 2005;119(11):862–5. pmid:16354337
  114. 114. Kalcioglu MT, Oncel S, Durmaz R, Otlu B, Miman MC, Ozturan O. Bacterial etiology of otitis media with effusion; focusing on the high positivity of Alloiococcus otitidis. New Microbiol. 2002;25(1):31–5. pmid:11837388
  115. 115. Neumark T, Ekblom M, Brudin L, Groth A, Eliasson I, Molstad S, et al. Spontaneously draining acute otitis media in children: An observational study of clinical findings, microbiology and clinical course. Scandinavian Journal of Infectious Diseases. 2011;43:891–8. doi: 10.3109/00365548.2011.591820. pmid:21736512
  116. 116. Beswick AJ, Lawley B, Fraise AP, Pahor AL, Brown NL. Detection of Alloiococcus otitis in mixed bacterial populations from middle-ear effusions of patients with otitis media. Lancet. 1999;354(9176):386–9. pmid:10437868
  117. 117. Holder RC, Kirse DJ, Evans AK, Peters TR, Poehling KA, Swords WE, et al. One third of middle ear effusions from children undergoing tympanostomy tube placement had multiple bacterial pathogens. BMC Pediatrics. 2012;12(87):1–7.
  118. 118. Güvenç MG, Midilli K, Inci E, Kuşkucu M, Tahamiler R, Ozergil E, et al. Lack of Chlamydophila pneumoniae and predominance of Alloiococcus otitidis in middle ear fluids of children with otitis media with effusion. Auris Nasus Larynx. 2010;37(3):269–73. doi: 10.1016/j.anl.2009.09.002. pmid:19879704
  119. 119. Ashhurst-Smith C, Hall ST, Walker P, Stuart J, Hansbro PM, Blackwell CC. Isolation of Alloiococcus otitidis from Indigenous and non-Indigenous Australian children with chronic otitis media with effusion. FEMS immunology and medical microbiology. 2007;51(1):163–70. pmid:17666076
  120. 120. Morris PS, Leach AJ. acute and chronic otitis media. Pediatr Clin N Am. 2009;56:1383–99.
  121. 121. Ashhurst-Smith C, Hall S, Burns C, Stuart J, Blackwell C. Induction of inflammatory responses from THP-1 cells by cell-free filtrates from clinical isolates of Alloiococcus otitidis. Innate Immun. 2014;20(3).
  122. 122. Ashhurst-Smith C, Hall ST, Burns CJ, Stuart J, Blackwell CC. In vitro inflammatory responses elicited by isolates of Alloiococcus otitidis obtained from children with otitis media with effusion. Innate Immun. 2014;3:Abstract.
  123. 123. Palmu AA, Jokinen JT, Kaijalainen T, Leinonen M, Karma P, Kilpi TM. Association of clinical signs and symptoms with pneumococcal acute otitis media by serotype—implications for vaccine effect. Clin Infect Dis. 2005;40(1):52–7. pmid:15614692
  124. 124. Rodriguez WJ, Schwartz RH. Streptococcus pneumoniae causes otitis media with higher fever and more redness of tympanic membranes than Haemophilus influenzae or Moraxella catarrhalis. Pediatr Infect Dis J. 1999;18(10):942–4. pmid:10530598
  125. 125. Courter JD, Baker WL, Nowak KS, Smogowicz LA, Desjardins LL, Coleman CI, et al. Increased clinical failures when treating acute otitis media with macrolides: a meta-analysis. Ann Pharmacother 2010;44:471–8. doi: 10.1345/aph.1M344. pmid:20150506
  126. 126. Pichichero ME, Casey JR. Emergence of a Multiresistant Serotype 19A Pneumococcal Strain Not Included in the 7-Valent Conjugate Vaccine as an Otopathogen in Children. JAMA. 2007;298(15):1772–8. pmid:17940232
  127. 127. Nuorti JP, Whitney CG. Prevention of Pneumococcal Disease Among Infants and Children—Use of 13-Valent Pneumococcal Conjugate Vaccine and 23-Valent Pneumococcal Polysaccharide Vaccine: Recommendations of the Advisory Committee on Immunization Practices (ACIP). Morbidity and Mortality Weekly Report (CDC). 2010;59:1–18.
  128. 128. Jefferies JMC, Macdonald E, Faust SN, Clarke SC. 13-valent pneumococcal conjugate vaccine (PCV13). Human Vaccines. 2011;7(10):1012–8. doi: 10.4161/hv.7.10.16794. pmid:21941097
  129. 129. Newall AT, Creighton P, Philp DJ, Wood JG, MacIntyre CR. The potential cost-effectiveness of infant pneumococcal vaccines in Australia. Vaccine. 2011;29:8077–85. doi: 10.1016/j.vaccine.2011.08.050. pmid:21864617
  130. 130. Smith-Vaughan HC, Binks MJ, Marsh RL, Kaestli M, Ward L, Hare KM, et al. Dominance of Haemophilus influenzae in ear discharge from Indigenous Australian children with acute otitis media with tympanic membrane perforation. BMC Ear Nose Throat Disord. 2013;13(1):1–9.
  131. 131. Palmu AA, Herva E, Savolainen H, Karma P, Mäkelä PH, Kilpi TM. Association of clinical signs and symptoms with bacterial findings in acute otitis media. Clin Infect Dis. 2004;38(2):234–42. pmid:14699456
  132. 132. Barkai G, Leibovitz E, Givon-Lavi N, Dagan R. Potential contribution by nontypable Haemophilus influenzae in protracted and recurrent acute otitis media. Pediatr Infect Dis J. 2009;28:466–71. pmid:19504729
  133. 133. Livermore DM. b-Lactamases in Laboratory and Clinical Resistance. CLINICAL MICROBIOLOGY REVIEWS. 1995;8(4):557–84. pmid:8665470
  134. 134. Wilke MS, Lovering AL, Strynadka NCJ. b-Lactam antibiotic resistance: a current structural perspective. Current Opinion in Microbiology. 2005;8:525–33. pmid:16129657
  135. 135. Yano H, Yamazaki Y, Qin L, Okitsu N, Yahara K, Irimada M, et al. Improvement rate of acute otitis media caused by Haemophilus influenzae at 1 week is significantly associated with time to recovery. J Clin Microbiol. 2013;51(11):3542–6. doi: 10.1128/JCM.01108-13. pmid:23966504
  136. 136. Tristram S, Jacobs M, Appelbaum P. Antimicrobial resistance in Haemophilus influenzae. Clin Microbiol Rev. 2007;20(2):368–89. pmid:17428889
  137. 137. Tomic V, Dowzicky M. Regional and global antimicrobial susceptibility among isolates of Streptococcus pneumoniae and Haemophilus influenzae collected as part of the Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) from 2009 to 2012 and comparison with previous years of T.E.S.T. (2004–2008). Ann Clin Microbiol Antimicrob 2014;13(52):1–8.
  138. 138. Agrawal A, Murphy TF. Haemophilus influenzae Infections in the H. influenzae Type b Conjugate Vaccine Era. JOURNAL OF CLINICAL MICROBIOLOGY. 2011;49(11):3728–32. doi: 10.1128/JCM.05476-11. pmid:21900515
  139. 139. Murphy TF. Vaccine development for non-typeable Haemophilus influenzae and Moraxella catarrhalis: progress and challenges. Expert Rev Vaccines. 2005;4(6):843–53. pmid:16372880
  140. 140. Ruiz-Palacios GM, Guerrero ML, Hernández-Delgado L, Lavalle-Villalobos A, Casas-Muñoz A, Cervantes-Apolinar Y, et al. Immunogenicity, reactogenicity and safety of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in Mexican infants. Hum Vaccin. 2011;7(11):1137–45. doi: 10.4161/hv.7.11.17984. pmid:22048109
  141. 141. Lagos RE, Muñoz AE, Levine MM, Lepetic A, François N, Yarzabal JP, et al. Safety and immunogenicity of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in Chilean children. Hum Vaccin. 2011;7(5):511–22. pmid:21441782
  142. 142. Dicko A, Santara G, Mahamar A, Sidibe Y, Barry A, Dicko Y, et al. Safety, reactogenicity and immunogenicity of a booster dose of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in Malian children. Hum Vaccin Immunother. 2013;9(2):382–8. pmid:23291945
  143. 143. van den Bergh MR, Spijkerman J, François N, Swinnen K, Borys D, Schuerman L, et al. Immunogenicity, safety, and reactogenicity of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine and DTPa-IPV-Hib when coadministered as a 3-dose primary vaccination schedule in The Netherlands: a randomized controlled trial. Pediatr Infect Dis J 2011;30(9):e179–e8.
  144. 144. Kim CH, Kim JS, Cha SH, Kim KN, Kim JD, Lee KY, et al. Response to primary and booster vaccination with 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine in Korean infants. Pediatr Infect Dis J. 2011;30(12):e235–e43. doi: 10.1097/INF.0b013e31822a8541. pmid:21817957
  145. 145. Lim FS, Koh MT, Tan KK, Chan PC, Chong CY, Shung YYW, et al. A randomised trial to evaluate the immunogenicity, reactogenicity, and safety of the 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) co-administered with routine childhood vaccines in Singapore and Malaysia. BMC Infect Dis. 2014;14(530):1–13.
  146. 146. Smith-Vaughan HC, Chang AB, Sarovich DS, Marsh RL, Grimwood K, Leach AJ, et al. Absence of an important vaccine and diagnostic target in carriage- and disease-related nontypeable Haemophilus influenzae. Clin Vaccine Immunol. 2014;21(2):250–2. doi: 10.1128/CVI.00632-13. pmid:24285816
  147. 147. Verduin CM, Hol C, Fleer A, Dijk Hv, van Belkum A. Moraxella catarrhalis: from Emerging to Established Pathogen. CLINICAL MICROBIOLOGY REVIEWS. 2002;15(1):125–44. pmid:11781271
  148. 148. Coffey JDJ, Martin AD, Booth HN. Neisseria catarrhalis in exudate otitis media. Arch Otolaryngol. 1967;86(4):403–6. pmid:6041112
  149. 149. Broides A, Dagan R, Greenberg D, Givon-Lavi N, Leibovitz E. Acute otitis media caused by Moraxella catarrhalis: epidemiologic and clinical characteristics. Clin Infect Dis 2009;49:1641–7. doi: 10.1086/647933. pmid:19886799
  150. 150. Tan TT, Riesbeck K. Current progress of adhesins as vaccine candidates for Moraxella catarrhalis. Expert Rev Vaccines. 2007;6(6):949–56. doi: 10.1586/14760584.6.6.949. pmid:18377357
  151. 151. Mawas F, Ho MM, Corbel MJ. Current progress with Moraxella catarrhalis antigens as vaccine candidates. Expert Rev Vaccines. 2009;8(1):77–90. doi: 10.1586/14760584.8.1.77. pmid:19093775
  152. 152. Smidt M, Bättig P, Verhaegh SJ, Niebisch A, Hanner M, Selak S, et al. Comprehensive antigen screening identifies Moraxella catarrhalis proteins that induce protection in a mouse pulmonary clearance model. PLoS One. 2013;8(5):1–15.
  153. 153. Segal N, Givon-Lavi N, Leibovitz E, Yagupsky P, Leiberman A, Dagan R. Acute Otitis Media Caused by Streptococcus pyogenes in Children. Clinical Infectious Diseases. 2005;41:35–41. pmid:15937760
  154. 154. Roland PS. controversial etiopathologic agents in otitis media. Ear, Nose & Throat Journal. 2007;86(11):2–4.
  155. 155. Harimaya A, Fujii N, Himi T. Preliminary study of proinflammatory cytokines and chemokines in the middle ear of acute otitis media due to Alloiococcus otitidis. Int J Pediatr Otorhinolaryngol. 2009;73(5):677–80. doi: 10.1016/j.ijporl.2008.12.033. pmid:19185927
  156. 156. Marsh RL, Binks MJ, Beissbarth J, Christensen P, Morris PS, Leach AJ, et al. Quantitative PCR of ear discharge from indigenous Australian children with acute otitis media with perforation supports a role for Alloiococcus otitidis as a secondary pathogen. BMC Ear, Nose and Throat Disorders. 2012;12(11).
  157. 157. Cripps AW, Otczyk DC. Prospects for a vaccine against otitis media. Expert Rev Vaccines. 2006;5(4):517–34. pmid:16989632
  158. 158. Niittynen L, Pitkäranta A, Korpela R. Probiotics and otitis media in children. Int J Pediatr Otorhinolaryngol. 2012;76(4):465–70. doi: 10.1016/j.ijporl.2012.01.011. pmid:22305688