Presence of Anaplasma spp. and Their Associated Antibodies in the Swedish Goat Population

Round 1

Reviewer 1 Report

The article is well written and very clear in its content. PCR analysis were conducted on very few samples (only n. 40) considering that in goats Anaplasma excretion does not last for long time in blood...But the results confirm tre presence of the bacteria in goat population and it's an important "start point" to study this disease . I agree with authors when they conclude that more research is needed to undestand better the diffusion of Anaplasmosis in goat population taking into account also more specific serological test (e.g. IFAT for Anaplasma phagocytophilum or other Anaplasma species..), first of all to better investigate the impact of Anaplasma on human health (farmers).

It would be interesting to know if animals go usually to the pasture to explain different seroprevalence levels in different areas of the country if possible.

In the end I'll write down below only one clarification:

line 275: "to detect A. phagocytophilum antibodies in sheep and cattle..."

 

Author Response

Dear reviewer,

We would like to extend our gratitude for your valuable comments and significant contributions to this manuscript. Below you will find our responses.

The article is well written and very clear in its content. PCR analysis were conducted on very few samples (only n. 40) considering that in goats Anaplasma excretion does not last for long time in blood...

Answer: We agree and ideally, we would have liked to analyze more samples. Unfortunately, we were unable to do so due to budgetary constraints.

It would be interesting to know if animals go usually to the pasture to explain different seroprevalence levels in different areas of the country if possible.

Answer: The legislation in Sweden dictates that goats have to be kept on pasture during the summer. We have added this information to the introduction, lines 77-82.

In the end I'll write down below only one clarification:
line 275: "to detect A. phagocytophilum antibodies in sheep and cattle..."

Answer: We have adjusted the sentence according to your comment, thank you, please see line 286.

Reviewer 2 Report

Dear Authors, the manuscript is interesting, even if in my opinion there are some aspects that may be improved.

-    no consideration about the presence of ticks is made during farm inspections. In such a research, noting this information could be useful;

-      the study on the correlation with the use of acaricides is weak as for only six farms included in the study, one lacked this information and precisely the one with the highest prevalence. Therefore it is not possible to know whether this higher prevalence could have any correlation with the use of acaricides;

-      Authors combined different samplings in the same study. This makes the description of the results somewhat fragmented;

 

-      No attempt was made to PCR amplify and sequence the unique  Anaplasma phagocytophilum positive sample.

Author Response

Dear reviewer,

We would like to extend our gratitude for your valuable comments and significant contributions to this manuscript. Below you will find our responses.

No consideration about the presence of ticks is made during farm inspections. In such a research, noting this information could be useful;

Answer: For the samples collected by the authors in 2020, none of the goats were heavily infested with ticks. Unfortunately, a more detailed examination where to check the sampled goats for presence of ticks was not performed, and we agree that this is a limitation. However, we asked the farmers if they had observed ticks on their goats, and we have added this information to the paper – please see lines 104, 233-235 and 313-318.

The study on the correlation with the use of acaricides is weak as for only six farms included in the study, one lacked this information and precisely the one with the highest prevalence. Therefore it is not possible to know whether this higher prevalence could have any correlation with the use of acaricides;

Answer: We agree with your comment, it is very unfortunate that we do not have information on usage of acaricides in herd 6. The reason for this is that these samples were collected by a veterinarian who was not part of the research team, and this person did not ask the farmer about acaricide usage during his/her visit to the farm. 

Authors combined different samplings in the same study. This makes the description of the results somewhat fragmented;

Answer: We agree that the study would have been better if we had used the same sampling strategy throughout. The reason for the variation is that we combine samples that were collected by the second author (FÅ) with samples collected 2019 in a research project aiming to investigate the seroprevalence of other pathogens than Anaplasma spp., thus using a different sampling strategy. Further, we used samples that had been submitted to the National Veterinary Institute in Sweden as part of a control programme for CAE. This information is found in materials and methods, section 2.1.1, 2.1.2 and 2.1.3, as well as figure 1 and 2. Although, use of collected samples from other research projects reduces the number of sampled animals. This is in line with the 3R principle by the use of organs and tissues from the same animal in several different studies or to share with other researchers or other studies.  More information can be found on this webpage.

No attempt was made to PCR amplify and sequence the unique Anaplasma phagocytophilum positive sample.

Answer: We agree that this would have added interesting information to the paper. Unfortunately, we were unable to do so due to budgetary constraints.

Reviewer 3 Report

The mauscript is written very well. In my opinion table 1 is useless. PCRs used by authors were previously published therefore only citations of references should be included without primers sequences. Also description cELISA is too much detailed. Authors declaraited that performed test according with  manufacturer's instruction so details  are useless.

Author Response

Dear reviewer,

We would like to extend our gratitude for your valuable comments and significant contributions to this manuscript. Below you will find our responses.

In my opinion table 1 is useless. PCRs used by authors were previously published therefore only citations of references should be included without primers sequences.

Answer: Thank you for your comment. We understand your point, but in our opinion, table 1 gives a nice overview and makes it easy for the reader to find information on which primers we used. We would therefore like to keep the table. We would however be willing to remove it if deemed necessary.

Also description cELISA is too much detailed. Authors declaraited that performed test according with  manufacturer's instruction so details  are useless.

Answer: We have shortened the description.

Reviewer 4 Report

Overall, the manuscript is in good shape but it also contains parts which seems difficult to understand for the readers. Thus, I  advise the authors of this manuscript to try all what is possible to make more easier for the readers. 

Authors should modify the title of the manuscript (avoid the word selection):

For instance : Presence of Anaplasma spp. in Swedish goat population.

Authors need to correctly use the words anaplasmosis and Anaplasma spp. as appropriate and shouldn't be used interchangeably.

For additional comment see the attached file.    

Comments for author File: Comments.pdf

Author Response

Dear reviewer,

We would like to extend our gratitude for your valuable comments and significant contributions to this manuscript. Below you will find our responses.

Authors should modify the title of the manuscript (avoid the word selection): For instance : Presence of Anaplasma spp. in Swedish goat population.

Answer: Thank you for your comment. As the paper also investigates presence of antibodies, we added “and its associated antibodies” to the title. We also deleted “in a selection”. We hope that you are happy with the change.

Authors need to correctly use the words anaplasmosis and Anaplasma spp. as appropriate and shouldn't be used interchangeably.

Answer: We use the term anaplasmosis to describe the disease, and Anaplasma spp. when we talk about the pathogens. We have read through the paper and made some changes. We hope that you are happy with this. If not, can you please specify where in the manuscript we have used the wrong term?

Authors should try all their best to significantly improve the English language of the Manuscript. Misspellings, many types of mistakes and all other sorts of errors in the paper should be carefully rechecked and recorrected.

Answer: The manuscript was reviewed by an English language editor just before it was submitted to Animals. The editor’s native language is (British) English. We have gone through the paper again ourselves and we have made minor corrections. Can you please specify where in the paper you have found errors?

Keywords: The number of words/phrases need to be reduced to meet the requirments by this jurnal.

Answer: This information is taken from the authors instructions on Animals homepage: “Three to ten pertinent keywords need to be added after the abstract”. We have included nine keywords, which therefore is in line with the author instructions.

Authors should provide sufficient explanation for the absene of A. marginale, A. ovis and A. centrale using cELISA.

Answer: We are not entirely sure if we understand your question, but we have added information on the fact that A.marginale, A.centrale and A.ovis generally are found in tropical and subtropical areas and that most of the tick vector species are not present in Sweden, please see lines 282-285.

Authors should provide sufficient explanation for the finding inidcated on the sentnence “The proportion of seropositive goats was significantly higher in South Sweden (50%) than in Central Sweden (13.8%) (OR 6.25, 95% CI 1.59-24.6, p=0.009), while no goats sampled in North Sweden were seropositive.).”

Answer: Thank you for your comment. Is your question why we did not test whether the seropositivity rate in South Sweden was significantly higher than in North Sweden? We did logistic regression here, to obtain an odds ratio. Logistic regression cannot be easily performed if the independent variable (North Sweden) has 0 observations (none of the goats were seropositive). There are statistical methods to get around this, but we decided not to do that since the number of seropositive goats will be significantly higher in South Sweden compared to North Sweden, as it is significantly higher in South compared to Central Sweden. Please do let us know if we need to clarify this in the manuscript. 

Authors should insert reference for the sentnence “A plausible reason for this finding is that the climatic conditions in South Sweden are generally more favourable for ticks, with the region’s shorter winters and higher ambient temperatures.”

Answer: We apologize for this oversight. A reference has been added.

Authors need to avoid reduce the number of old references.

Answer: We are not entirely sure that we understand your point. Can you please clarify? We have not reduced the number of references in this updated version.