Impact of artificial feeding on the developmental cycle of two triatomine species

Raquel Aparecida Ferreira; Ana Carolina Corrêa Nascimento; Natalya Lorena da Silva Santos; Liléia Gonçalves Diotaiuti; Eduardo Fernandes e Silva; Silvia Ermelinda Barbosa

doi:10.1371/journal.pone.0323090

Peer Review History

Original SubmissionSeptember 20, 2024
20 Sep 2024 Author Response Transfer Alert This paper was transferred from another journal. As a result, its full editorial history (including decision letters, peer reviews and author responses) may not be present. https://doi.org/10.1371/journal.pone.0323090.r001
9 Dec 2024 Decision Letter - Pedro L. Oliveira, Editor PONE-D-24-41986Impact of artificial feeding on the developmental cycle of two triatomine speciesPLOS ONE Dear Dr. Ferreira, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. As there was some difficult in securing two reviews for your paper, I decided to go further with this single review. As you will see, the reviewer felt that the paper contributes to the field, but needs relevant changes pointed out in his review. One point that could help improve the paper's impact would be going further than just stating, as mentioned in the review, that in vitro is not the best way for triatomine rearing. In this sense, the review has several sound suggestions. Also, specific comments 4 and 6 are particularly critical, as methodological correctness is an essential for acceptance in PLos One. Please submit your revised manuscript by Jan 23 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. 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Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Partly ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: No ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: General comment The manuscript submitted by Ferreira and co-workers presents a detailed analysis of the effect of three feeding conditions on different parameters in two species of triatomine bugs with public health relevance as vectors of Chagas disease. Mass-rearing of triatomine bugs is a key activity in basic and applied research on triatomine biology, parasite studies and infection diagnosis. Optimising the effort and cost of such a demanding task is essential in order to supply large numbers of insects on a regular basis. In vitro feeding is a technique that has been used for several decades to rear haematophagous arthropods, with varying degrees of success depending on the species. In the case of triatomines, much work has been done to find the most appropriate conditions and the method has been successfully adopted for rearing small to medium sized laboratory populations. Large-scale rearing as required, for example in reference centres or diagnostic units, usually involves feeding bugs on live hosts, which requires specific infrastructure and personnel. Modern ethical guidelines on animal care and welfare require the search for alternatives to feeding insects on live hosts. The aim of the present manuscript is to provide a comparison of biological parameters that could be relevant for mass rearing, in bugs reared in vivo, in vitro and alternating both conditions. Even though, the study has been conducted at a small scale, the data collected could be of interest; yet, some points deserve further attention by the authors. The aim of the present manuscript is providing a comparison on biological parameters, in bugs reared in vivo, in vitro and alternating both conditions. Specific points 1) Line 56 “Vinchuca” is not the only vernacular Spanish name given to triatomines. “Chinche besucona”, “chinche”, “pito” and also employed, depending on the country. Please, check and complete. 2) Lines 60-61. The feasibility of rearing triatomines in vitro has long been demonstrated. Please rephrase to make it clear that you are interested in large-scale rearing. 3) Lines 68-70. Please rephrase, it seems impractical for your needs and under your conditions, but it has been used successfully for decades. 4) Lines 169-175. As indicated in several cited references, it is crucial to precise the treatment and conditioning of the blood used for in vitro feeding. Parameters as how long after extraction blood was proposed to bugs, how was it stored in between, the exact composition and amount of anticoagulant solutions, the exact nature and treatment of latex membranes, the type of artificial feeder used, the exact temperature of the blood (and not that of the water bath) are just some of them. 5) The authors repeatedly point out that previous reports on in vitro feeding of triatomines do not follow the bugs over several generations, as an argument to justify the need for their study. However, the manuscript only presents what happens along a single generation, so the previous criticism applies to them. My advice would be to provide solid arguments justifying the rationale for a study in 2024 that is not much different from many others done decades ago. 6) A major inconsistency that seems unjustified in the current version is why the authors chose to use different species as blood donors and for live host feeding. Why not use the same blood? This would have revealed differences in the methods, whereas in the present experiment the effect of donor and method cannot be distinguished. This reason is probably practical, but needs to be explained. 7) Some sections of the manuscript are inappropriately long. The detailed description of the statistical treatment of the data is interesting, but can be presented in supplementary material. The results section is also unnecessarily long, but for a different reason: there is redundancy in the information presented in the tables and in the text. 8) The discussion focuses on the advantages of in vivo over in vitro feeding, which, as the authors say in the introduction, is now well acknowledged. Simply stating that in vitro is not the best and that this strategy might be potentially problematic for mass rearing is much less than most educated readers of PLoS One would expect. In the opinion of this reviewer, this study provides an interesting opportunity to discuss the trade-off that scientists face today, i.e. optimising efforts and resources to advance public health science versus animal welfare regulations. In particular in Chagas endemic countries, where the need of advances is high and the resources usually limited. This problematic goes beyond Brazilian legislation and triatomine rearing. ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean? ). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy . Reviewer #1: No ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/ . PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org . Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0323090.r002
Revision 1
7 Mar 2025 Author Response Dear reviewers, we appreciate your suggestions and have accepted almost all of them. Below are the point-by-point responses. 1) Line 56 “Vinchuca” is not the only vernacular Spanish name given to triatomines. “Chinche besucona”, “chinche”, “pito” and also employed, depending on the country. Please, check and complete. Authors: The names were added as suggested by the reviewer 2) Lines 60-61. The feasibility of rearing triatomines in vitro has long been demonstrated. Please rephrase to make it clear that you are interested in large-scale rearing. Authors: Changes were made as suggested. 3) Lines 68-70. Please rephrase, it seems impractical for your needs and under your conditions, but it has been used successfully for decades. Authors: Changes were made as suggested. 4) Lines 169-175. As indicated in several cited references, it is crucial to precise the treatment and conditioning of the blood used for in vitro feeding. Parameters as how long after extraction blood was proposed to bugs, how was it stored in between, the exact composition and amount of anticoagulant solutions, the exact nature and treatment of latex membranes, the type of artificial feeder used, the exact temperature of the blood (and not that of the water bath) are just some of them. Authors: Thank you for your comments. Please note that the information has been added in lines 206-221. The blood used in the artificial feedings was 10% citrated rabbit blood (25g P.A. citrate, 8g citric acid, and 24.5g glucose). This blood is collected, prepared, and sterilized at the Institute of Science and Technology in Biomodels (ICTB)/Fiocruz. It is packaged in an autoclavable glass bottle with a rubber cap, sealed, and distributed chilled on dry ice to the laboratories. In the laboratory, the blood is immediately stored at -20°C and used within 10 days of being collected. The artificial feeding device used consisted of a glass apparatus, made by a craftsman in the shape of a baby bottle, with an external compartment for circulating water heated by an attached water bath and an internal compartment containing the blood. The water temperature was set at 40°C, and the blood temperature in the bottles remained at 39.5°C. The membrane used to cover the feeding bottle was a latex membrane. These were obtained from natural latex gloves, which were cut into 10x10 cm pieces and washed with Type I water to remove dust. The dried latex membrane was used to seal the mouth of the glass apparatus with the help of an elastic band, simulating the skin of a live animal that was pierced by the insect's mouthparts during feeding (Lazzari, 2014). 5) The authors repeatedly point out that previous reports on in vitro feeding of triatomines do not follow the bugs over several generations, as an argument to justify the need for their study. However, the manuscript only presents what happens along a single generation, so the previous criticism applies to them. My advice would be to provide solid arguments justifying the rationale for a study in 2024 that is not much different from many others done decades ago. Authors: The passage between lines 110 and 113 was moved to lines 131–135. The sentence, 'One of these gaps involves the effectiveness and suitability of rearing insects exclusively with artificial feeders over multiple generations in an insectary,' between lines 115 and 118, was removed from the manuscript. Additionally, the aspect highlighted by the reviewer was revised throughout the manuscript (lines 573–580; 587–591; 594-598;764–776), and minor changes were made to the writing of the last paragraph of the introduction. We hope these adjustments have met your expectations. 6) A major inconsistency that seems unjustified in the current version is why the authors chose to use different species as blood donors and for live host feeding. Why not use the same blood? This would have revealed differences in the methods, whereas in the present experiment the effect of donor and method cannot be distinguished. This reason is probably practical, but needs to be explained. Authors: We understand the reviewer's questions and hope to clarify this point. It is important to note that working with live animals has not been an easy task in the scientific environment, particularly in Brazil. This work is the result of various questions and recommendations from the Ethics Committee on the Use of Animals. The license obtained from CEUA to keep triatomines in an insectary, after a 2.5-year process, does not allow us to breed rabbits at our institution to be used as a source of blood for the triatomines. For this reason, we use the license granted to ICTB/Fiocruz (as mentioned in question 4). ICTB is the technical-scientific unit of Fiocruz responsible for studies, development, and production in Laboratory Animal Science. They prepare and supply blood from other animals, such as rodents and lagomorphs, to other Fiocruz units. Although we have a license to use chickens to provide blood for feeding triatomines kept in the institutional insectary, we lack the expertise and equipment at our institution to prepare the blood, monitor the health of the animals, and carry out pre-clinical analyses on animals bred to ensure quality control of the blood for use in the artificial feeder. Therefore, for practical reasons, the same blood donors were not used in the tests in this study. 7) Some sections of the manuscript are inappropriately long. The detailed description of the statistical treatment of the data is interesting, but can be presented in supplementary material. The results section is also unnecessarily long, but for a different reason: there is redundancy in the information presented in the tables and in the text. Authors: We appreciate your suggestions. Regarding the statistical analyses, we have removed the paragraph describing the GEE test from the manuscript. However, due to the complexity of the analyses and models employed, we believe that the details and description of the criteria used in decision-making should remain in the manuscript. Regarding the results section, we completely agree with the reviewer and have removed the redundant information. 8) The discussion focuses on the advantages of in vivo over in vitro feeding, which, as the authors say in the introduction, is now well acknowledged. Simply stating that in vitro is not the best and that this strategy might be potentially problematic for mass rearing is much less than most educated readers of PLoS One would expect. In the opinion of this reviewer, this study provides an interesting opportunity to discuss the trade-off that scientists face today, i.e. optimising efforts and resources to advance public health science versus animal welfare regulations. In particular in Chagas endemic countries, where the need of advances is high and the resources usually limited. This problematic goes beyond Brazilian legislation and triatomine rearing. Authors: We appreciate your comments. We have expanded the discussion, addressing the points highlighted by the reviewer. A paragraph was added between lines 573 and 580, and a sentence was added between lines 587-591 and 594-598. Finally, in the last paragraph, lines 774-776 were added, and the ending of this paragraph was rewritten. We hope that these additions are sufficient, as we do not intend to engage in discussions that involve, including, philosophical aspects, which would be more appropriate for another type or format of manuscript. Attachments Attachment Submitted filename: Response to Reviewers.docx https://doi.org/10.1371/journal.pone.0323090.r003
2 Apr 2025 Decision Letter - Pedro L. Oliveira, Editor Impact of artificial feeding on the developmental cycle of two triatomine species PONE-D-24-41986R1 Dear Dr. Ferreira, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice will be generated when your article is formally accepted. Please note, if your institution has a publishing partnership with PLOS and your article meets the relevant criteria, all or part of your publication costs will be covered. Please make sure your user information is up-to-date by logging into Editorial Manager at Editorial Manager® and clicking the ‘Update My Information' link at the top of the page. If you have any questions relating to publication charges, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Pedro L. Oliveira Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #1: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: Thank you for having adequately addressed my comments. In the opinion of this reviewer, the manuscript has been improved in the new version. ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean? ). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy . Reviewer #1: No ******** https://doi.org/10.1371/journal.pone.0323090.r004
Formally Accepted
Acceptance Letter - Pedro L. Oliveira, Editor PONE-D-24-41986R1 PLOS ONE Dear Dr. Ferreira, I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now being handed over to our production team. At this stage, our production department will prepare your paper for publication. This includes ensuring the following: * All references, tables, and figures are properly cited * All relevant supporting information is included in the manuscript submission, * There are no issues that prevent the paper from being properly typeset You will receive further instructions from the production team, including instructions on how to review your proof when it is ready. Please keep in mind that we are working through a large volume of accepted articles, so please give us a few days to review your paper and let you know the next and final steps. Lastly, if your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. If we can help with anything else, please email us at customercare@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Pedro L. Oliveira Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0323090.r005

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