Fig 1.
Flow chart of urine sample screening and selection of priority pathogens.
A total of 3,026 urine samples were collected from outpatients or patients hospitalized for ≤48 hours. Of these, 1,786 samples yielded negative or contaminated cultures (≥3 organisms), and 291 showed non-significant bacteriuria (<10⁵ CFU/mL). Significant bacteriuria (≥10⁵ CFU/mL) was identified in 949 samples, which were clinically classified as cystitis (589 cases) or pyelonephritis (360 cases). Based on Global Antimicrobial Resistance Surveillance System (GLASS) criteria, 200 isolates were selected as priority pathogens for antimicrobial resistance surveillance in community-acquired urinary tract infections, comprising 124 E. coli and 76 K. pneumoniae isolates. CFU, colony-forming units; AMR, antimicrobial resistance; GLASS, Global Antimicrobial Resistance Surveillance System.
Table 1.
Univariate and multivariate logistic regression analyses of cystitis and pyelonephritis according to sociodemographic, clinical, and seasonal factors.
Table 2.
General characteristics of patients with community-acquired UTIs due to E. coli and K. pneumoniae isolates, stratified by β-lactamase production.
Table 3.
Comparison of resistance rates to commonly used antibiotics between ESBL-producing and non-ESBL-producing Escherichia coli and Klebsiella pneumoniae isolates from community-acquired urinary tract infections.
Table 4.
Comparison of resistance rates to commonly used antibiotics between AmpC-producing and non-AmpC-producing Escherichia coli and Klebsiella pneumoniae isolates from community-acquired urinary tract infections.
Fig 2.
Distribution of β-lactamase-encoding genes in E. coli and K. pneumoniae.
This figure illustrates the distribution of beta-lactamase gene combinations identified in E. coli and K. pneumoniae isolates. A total of 35 E. coli and 33 K. pneumoniae isolates producing Extended-Spectrum β-lactamase (ESBL) were analyzed. In E. coli, the most frequent gene combinations included bla-CTX-M-gp1 alone or associated with bla-TEM, whereas in K. pneumoniae, profiles combining bla-SHV, bla-CTX-M-gp1, and bla-TEM were predominant. Carbapenemase genes were investigated in K. pneumoniae and the bla-OXA-48 gene was detected in one isolate. AmpC β-lactamase genes were assessed in 14 K. pneumoniae isolates, in which bla-CMY-2 and bla-ACT-1 were identified, while no AmpC genes were detected in E. coli. Some isolates showed no β-lactamase gene detected by the panel used.
Fig 3.
Distribution of E. coli phylogenetic groups.
This figure shows the distribution of phylogenetic groups among 35 ESBL-positive E. coli isolates. Group A was the most prevalent, followed by groups B2 and F. A smaller proportion of isolates belonged to group E or D.