All reviews of published articles are made public. This includes manuscript files, peer review comments, author rebuttals and revised materials. Note: This was optional for articles submitted before 13 February 2023.
Peer reviewers are encouraged (but not required) to provide their names to the authors when submitting their peer review. If they agree to provide their name, then their personal profile page will reflect a public acknowledgment that they performed a review (even if the article is rejected). If the article is accepted, then reviewers who provided their name will be associated with the article itself.
Thank you for taking action on the last set of requests.
[# PeerJ Staff Note - this decision was reviewed and approved by Valeria Souza, a PeerJ Section Editor covering this Section #]
I would like to reinforce two points made by Reviewer 4:
First, please seek the assistance of an editor to improve the English usage in this manuscript.
Second, given the Reviewer's comments (e.g., "The results have not changed, and show >90% +ve sera in both horses and dogs, and about 5-20% viral RNA +ves by PCR. The numbers are still much higher than have reported for previous studies for dogs. The +ve PCRs still seem to be much higher than have been reported for other studies for influenza hosts, and imply active infection or persistent virus in a relatively high proportion of the animals. The proportion of canine serum +ves are also very high compared to other populations that have been examined."), I would like you to address this and possible limitations of this study in your Discussion section. The Reviewer is allowing for possible diagnostic errors (particularly the potentially low specificity of the test, leading to false positives), and readers will undoubtedly wonder the same. As your manuscript stands, you do not allow for this when you state that "The seroprevalence of 100% obtained in this study in stray dog shows the high incidence of the virus in this animal population."
[# PeerJ Staff Note: The review process has identified that the English language must be improved. PeerJ can provide language editing services - please contact us at [email protected] for pricing (be sure to provide your manuscript number and title) #]
This manuscript is difficult to follow in places, and needs to be edited carefully for English usage. The overall presentation appears to be reasonable.
The experimental design is seeking to detect the presence of influenza viruses in horses and dogs in Mexico. The design of the studies seems reasonable, and the revision addresses many of the comments about the studies. A concern is whether the controls for -ve samples are rigorous enough to exclude possible false positives.
The results have not changed, and show >90% +ve sera in both horses and dogs, and about 5-20% viral RNA +ves by PCR. The numbers are still much higher than have reported for previous studies for dogs. The +ve PCRs still seem to be much higher than have been reported for other studies for influenza hosts, and imply active infection or persistent virus in a relatively high proportion of the animals. The proportion of canine serum +ves are also very high compared to other populations that have been examined.
Please be sure you are using epidemiologic terms correctly. You have studied seroprevalence and swab prevalence, so the statements "The results unveil the incidence of the Influenza A virus in the horse and dog population of the state of Nuevo León" and "The detection of anti-M1 antibodies in stray dogs showed an incidence of 123 (100%) of the sampled population" are not correct. Prevalence is not equivalent to incidence. Please check this throughout the manuscript.
In addition, please provide more information about how owned dogs, stray dogs, and horses were sampled. What were your sampling frames for each of these groups?
no comment'
no comment
no comment
This study unveil the incidence of the Influenza A virus in the horse and dog population of the state of Nuevo León. As well as the impact of the absence of vaccination on these animal populations. This study suggests the constant detection of influenza virus in animal companion in order to investigate its epizootic and zoonotic potential. However, the manuscript needs to be further reorganized and revised, especially the section of “Discussion” and “Introduction”, before publication.
The language is clear and professional.
But no sufficient field backgroud is shown in Introduction and discussion.
Is M gene suitable for analysis of virus typing?
No significant finding was shown.
No comparision among this studies and other published reports.
In this manuscript, the authors performed a surveillance of canine (CIV) and equine
(EIV) influenza virus in Nuevo Leon State, Mexico. Due to analyze the M gene, they considered H1N1 is the major type which is pandemic in this area in dogs and horses. At the same time, higher positive rate in the serological results was shown. However,
1) Not specific and no relative conclusion was conluded.
2) The time about harvesting these samples was not shown, and it is improtant for surveillance of virus.
3) Much information (ex. viral type et., al) in only one figure is absent.
4) No significant finding was shown, and no comparision among this studies and other published reports.
5) Is M gene suitable for analysis of virus typing?
In this manuscript “Genetic and serologic surveillance of canine (CIV) and equine (EIV) influenza virus in Nuevo Leon State, Mexico” by Plata Hipolito et al., the authors evaluated the presence of CIV and EIV in dogs and horses, respectively, from samples collected in 9 municipalities in the state of Nuevo Leon in Mexico using RT-PCR approaches targeting the matrix (M) viral segment. Authors identified the presence of CIV and EIV in several of the analyzed samples, demonstrating the incidence of these viruses in the horse and dog population.
Overall, the experiments are well designed but the authors should include the results from their serological studies.
This is the first genetic and serologic study conduced in Mexico to detect the presence of CIV and EIV in dogs and horses, respectively.
In this manuscript “Genetic and serologic surveillance of canine (CIV) and equine (EIV) influenza virus in Nuevo Leon State, Mexico” by Plata Hipolito et al., the authors evaluated the presence of CIV and EIV in dogs and horses, respectively, from samples collected in 9 municipalities in the state of Nuevo Leon in Mexico using RT-PCR approaches targeting the matrix (M) viral segment. Authors identified the presence of CIV and EIV in several of the analyzed samples, demonstrating the incidence of these viruses in the horse and dog population.
Overall, this manuscript describe the first attempt to detect the presence of CIV and EIV in Mexico and demonstrate the presence of both viruses in the dog and equine populations in several parts in the state of Nuevo Leon in Mexico. There are, however, some general and specific comments that the authors should consider to improve the quality of the manuscript:
General comments:
- After completing the reading of the manuscript, I am not sure what type of CIV or EIV they have identified in this study. Are these CIV H3N8 or H3N2 and EIV H3N8? These are the most common influenza viruses circulating in dogs and horses, respectively; but based on how the manuscript is written, I am not sure what subtypes of influenza viruses they have found. The authors should carefully revised the different sections of the manuscript, including the title, to clearly state what subtype of viruses they have found circulating in dogs and horses.
- The authors indicate and describe conducting some serological studies. However, these data has not been included in the manuscript. The authors should relevant data related to the serology studies in the manuscript.
- Likewise, the authors should provide evidence that the M protein purified from bacteria was produced in sufficient quantity and quality to conduct these serological studies.
- For detection of CIV and EIV, the authors used RT-PCR-based approaches with specific primers targeting the M viral segment. However, it is unclear what subtype of influenza A virus is the target of these primers and whether or not will bind to conserved sequences in H3N8 and H3N2 CIVs, or H3N8 EIV.
Specific comments:
- Please, revise the entire document to clearly state what type of CIVs or EIVs have been identified in this study.
- Please, use the proper nomenclature for the H1N1/2009 influenza A virus. Moreover, it will be important to indicate the origin/source of this H1N1/2009 virus.
- Please, clarify the nature of the primers used for the amplification of the viral M segment and whether or not these primers match the sequence of H3N8 and H3N2 CIVs; and H3N8 EIVs.
- Include the results for the serological studies described in the manuscript. Moreover, provide the results related to the purification of the M1 protein used to detect the presence of CIV and EIV antibodies in dogs and horses, respectively; including quality and quantity of protein preparation.
- Table 1. It is unclear why the authors include some municipalities (e.g. Monterrey, Escobedo, Apodaca and Guadalupe) since samples from these regions have not been used in the study.
- Table 2. The authors should be able to combine Tables 1 and 2 in a single Table. There is redundancy on the information currently provided in Tables 1 and 2.
- Table 3. To me, this is more a Figure than a Table. It will be important to include the name of the viruses used in this amino acid alignment, rather than the reference number. Also, please, include the subtype of viruses (e.g. H1N1, H3N2, H3N8). Finally, include a complete sequence of the M viral coding region.
- Figure 1. Change the accession number but the name of the influenza strains used in this phylogenetic analysis. As indicated above, also include the subtype of viruses (e.g. H1N1, H3N2, H3N8).
Overall an interesting study that seeks to define the prevalence in Mexico of influenza A virus in dogs with respiratory disease or (serology) in stray or feral dogs. Also in trash-collecting horses. The data is based on a nested PCR of the M gene of the influenza viruses, as well as an ELISA based on using a recombinant M1 protein expressed in bacteria. The results are surprising as they report a quite high prevalence of viral RNA, which match the sequence of the human H1N1pandemic virus, and about 100% serological +ves. As mentioned below, these results suggest that there may be contamination in the samples, or cross-reactivity. There is a need for additional controls to ensure that the results are an accurate reflection of the infection status in Mexican animals.
Main issues are technical - to ensure that the results are accurate.
One issue is that the proportion of positives in the serology (or stray dogs) is much higher than has been reported in any other region of the world - where the proportion of +ves tends to be <5%, except in outbreaks or infected colonies. I suggest that an independent test of the sera with a different ELISA test should be carried out to confirm the results seen here with the E. coli-expressed protein.
The high number of +ve PCR results is surprising, even in dogs with respiratory disease, unless there is a major outbreak going on. Human viruses generally do not spread in dogs. To find such high levels in the absence of a documented outbreak seems unlikely. What was the situation in the human population, as this appears to be a human H1N1pandemic virus? Can other sequences be obtained to confirm the origins and serotype of the virus, and to confirm that this was not due to contamination?
In Figure 1, I am not sure what the sequences are that are included - what are the different labels referring to? Such as Zoontic reassortants - of what virus strain? What are contemporary strains? What are ancestral strains - those were from H3N8 viruses in horses, or dogs? What are the outgroup viruses?
All text and materials provided via this peer-review history page are made available under a Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.