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.
I agree with the two expert reviewers that your manuscript has considerably improved by the revision. It is now acceptable for publication in the hournal.
The manuscript has definitely improved upon revision. The revised manuscript reads well with a clear methodology, discussion of obtained results, and conclusion.
The authors made all the suggested changes and significantly improved the manuscript. I approve the manuscript for publication.
Dear Dr. Ofoedu,
I agree with the issues raised by the two expert reviewers. Please revise your manuscript accordingly. I am looking forward to receiving your revised manuscript.
[# PeerJ Staff Note: Please ensure that all review comments are addressed in a rebuttal letter and any edits or clarifications mentioned in the letter are also inserted into the revised manuscript where appropriate. It is a common mistake to address reviewer questions in the rebuttal letter but not in the revised manuscript. If a reviewer raised a question then your readers will probably have the same question so you should ensure that the manuscript can stand alone without the rebuttal letter. Directions on how to prepare a rebuttal letter can be found at: https://peerj.com/benefits/academic-rebuttal-letters/ #]
[# 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@example.com for pricing (be sure to provide your manuscript number and title) #]
1. The work presented in this manuscript is interesting, and relevant. The authors have determined the bacterial load on the Nigerian currency notes ₦1000, ₦500, ₦200, ₦100, ₦50, ₦20, ₦10, and ₦5 recovered from local fruit, vegetable, meat, fish, and grain sellers in Nigeria.
2. Please check the manuscript for grammatical errors.
1.The authors have mentioned that the samples were inoculated on nutrient agar plates and incubated at 37°C for 24 hours. Were these samples also inoculated on other media such as Brain Heart Infusion Agar, Tryptic Soy Agar, Blood Agar, or Mac Conkey’s Agar? Additionally, were the nutrient agar plates incubated at different temperatures and for different time-periods? Using two to four different media and different incubation conditions will increase the accuracy and reduce the bias as compared to using a single medium and incubation conditions.
2.The samples were prepared by immersing the notes in 100 mL Ringer’s solution, the beaker was shaken, the notes removed, and the solution was used as the sample for inoculation. Were these notes inoculated on the agar plates or observed microscopically after sample preparation? It would be interesting to know if the method used efficiently detaches all the bacteria from the surface of the notes or if additional steps are required for successful bacterial detachment.
3.The authors only mention using microbiological techniques for the identification of bacterial isolates. Was 16S rRNA sequencing or MALDI or a similar technique performed for the same? Using one of these molecular techniques in addition to the microbiological techniques is recommended for accurate identification of the bacterial isolates.
1. Please check the mean values in Tables 2, 3, and 5.
2. It would be interesting if the authors add a short section comparing the results of the presented study with other similar studies.
3. Figures 2 and 3 contain an additional light orange legend, please clarify what it indicates.
Ofoedu et al, report about the degree of bacterial contamination and its dependency on the food vendor type and currency denomination(s). For this purpose, the authors have performed microbiology experiments. Similar information related to Nigerian currency and bacterial contamination has been published earlier, but the authors provided additional information about its relation to the food vendors. This information is useful, however, there are important questions that need to be addressed.
There are several aspects that require revision and/or clarification.
1. The authors have described, (line 163-164) 100 ml sterile ringer solution was used to immerse each Naira. It would be better if the composition of the ringer’s solution used in this study is also provided. Or details, if it was purchased?
2. When the authors provided duplicate values, are these values of the same samples (replicates), it’s not easy to understand from the method description.
3. The author should describe why only nutrient agar was used for the experiment?
4. I would like to appreciate the amount of work the authors did, characterize >250 samples for each fruit seller/each currency denomination. It’s a lot of work just to characterize the viable colony-forming unit by gram staining and growth media cultivation experiments.
1. The author mentioned the use of Mannitol salt and Eosin methylene blue media to characterize the isolates, however, there is no information presented in data, how many were pathogenic and non-pathogenic strains of staphylococcus.
2. Line-203: The TVC for the fruit seller is mentioned wrong, it should be 3X103-2.2X105, (according to the supplementary data provided).
3. I would like the authors to explain, if the TVC of ₦10 (2nd seller) is 1X103 then, how it is possible to have higher CFU/ml (1.1 for E.coli)?
1. The English language should be improved to ensure easy understanding for the international audience.
2. For eg. Line 160- The wire loops were sterilized by flaming, need to be removed and rewritten. The whole paragraph of preparation of materials /samples should be modified.
3. Some details are unnecessary, for eg. Line 174- “in an invert position”.
4. The authors need to cross-check all the values from all the tables, the data described in the table is confusing.
5. The time duration matters for bacterial transmission via currency note. Hence, the author should describe the time difference/duration between the sample collection and sample processing.
6. In the case of Meat, fish sellers, the sampling should have been done on blood agar. To provide rich nutrients for pathogenic strains that might be present.
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.