{"title":"Association of infrastructure and operations with antibiotic resistance potential in the dairy environment in India","authors":"Harshita Singh , Kenyum Bagra , Sourabh Dixit , Awanish Kumar Singh , Gargi Singh","doi":"10.1016/j.prevetmed.2025.106497","DOIUrl":null,"url":null,"abstract":"<div><div>The dairy industry in developing countries is often associated with inappropriate use of antibiotics and the subsequent contamination of the environment with co-selectors of antibiotic resistance. However, the specific factors in dairy farm environments that influence antibiotic resistance levels and the subsequent exposure risks to farm workers are unknown. We examined the link between the infrastructure and operations of the dairy farm and the antibiotic resistance potential in India, which is the highest producer and consumer of dairy products globally. We sampled sixteen dairy farms in the Dehradun district, India, that varied in their herd size, infrastructure, and operational features during winter, summer, and monsoon. We collected samples of dung, manure, wastewater, manure-amended, and control soil from these farms. We quantified six antibiotic resistance genes (ARGs) (<em>sul</em>1, <em>sul</em>2, <em>par</em>C, <em>mcr</em>5, <em>erm</em>F, and <em>tet</em>W), an integron integrase gene cassette (<em>int</em>I1), and 16S rRNA gene copies as an indicator for total bacterial count. We observed that the infrastructure and the operations of the dairy farms were significantly associated with antibiotic resistance potential in the dairy environment. For example, with increased ventilation and exposure to external weather, the levels of <em>sul</em>2 (x͂=10<sup>−1.63</sup>) and <em>par</em>C (x͂=10<sup>−4.24</sup>) in manure increased. When farmers administered antibiotics without veterinary consultation, the relative levels of <em>int</em>I1 (x͂=10<sup>−2.36</sup>), <em>sul</em>2 (x͂=10<sup>−1.58</sup>), and <em>tet</em>W (x͂=10<sup>−3.04</sup>) in manure were lower than the cases where professional advice was sought. Small-scale farms had lower relative ARG levels than medium- and large-scale farms, except for <em>mcr</em>5 (x͂=10<sup>−3.98</sup>) in wastewater. In different sample types, the relative ARG levels trended as manure-amended soil (x͂=10<sup>−2.34</sup>) > wastewater (x͂=10<sup>−2.90</sup>)> manure (x͂=10<sup>−3.39</sup>)> dung (x͂=10<sup>−2.54</sup>). ARGs correlated with the marker for horizontal gene transfer, <em>int</em>I1, which exacerbates overall antibiotic resistance levels. Exposure assessment showed that the agriculture farm workers working in manure-amended agriculture farms are exposed to higher antibiotic resistance potential than dairy farm workers, who manually handle dung. Our study showed that the link between the dairy infrastructure (ventilation and floor type) and operations (scale of operation and veterinary consultation) and the antibiotic resistance potential in the dairy farm environment was statistically significant. This knowledge paves the way for designing interventions that can minimize the antibiotic resistance potential on dairy farms and in affected environments and thus reduce the public health burden of antibiotic-resistant infections in the dairy industry and dairy workers in India.</div></div>","PeriodicalId":20413,"journal":{"name":"Preventive veterinary medicine","volume":"239 ","pages":"Article 106497"},"PeriodicalIF":2.2000,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Preventive veterinary medicine","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167587725000820","RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"VETERINARY SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
The dairy industry in developing countries is often associated with inappropriate use of antibiotics and the subsequent contamination of the environment with co-selectors of antibiotic resistance. However, the specific factors in dairy farm environments that influence antibiotic resistance levels and the subsequent exposure risks to farm workers are unknown. We examined the link between the infrastructure and operations of the dairy farm and the antibiotic resistance potential in India, which is the highest producer and consumer of dairy products globally. We sampled sixteen dairy farms in the Dehradun district, India, that varied in their herd size, infrastructure, and operational features during winter, summer, and monsoon. We collected samples of dung, manure, wastewater, manure-amended, and control soil from these farms. We quantified six antibiotic resistance genes (ARGs) (sul1, sul2, parC, mcr5, ermF, and tetW), an integron integrase gene cassette (intI1), and 16S rRNA gene copies as an indicator for total bacterial count. We observed that the infrastructure and the operations of the dairy farms were significantly associated with antibiotic resistance potential in the dairy environment. For example, with increased ventilation and exposure to external weather, the levels of sul2 (x͂=10−1.63) and parC (x͂=10−4.24) in manure increased. When farmers administered antibiotics without veterinary consultation, the relative levels of intI1 (x͂=10−2.36), sul2 (x͂=10−1.58), and tetW (x͂=10−3.04) in manure were lower than the cases where professional advice was sought. Small-scale farms had lower relative ARG levels than medium- and large-scale farms, except for mcr5 (x͂=10−3.98) in wastewater. In different sample types, the relative ARG levels trended as manure-amended soil (x͂=10−2.34) > wastewater (x͂=10−2.90)> manure (x͂=10−3.39)> dung (x͂=10−2.54). ARGs correlated with the marker for horizontal gene transfer, intI1, which exacerbates overall antibiotic resistance levels. Exposure assessment showed that the agriculture farm workers working in manure-amended agriculture farms are exposed to higher antibiotic resistance potential than dairy farm workers, who manually handle dung. Our study showed that the link between the dairy infrastructure (ventilation and floor type) and operations (scale of operation and veterinary consultation) and the antibiotic resistance potential in the dairy farm environment was statistically significant. This knowledge paves the way for designing interventions that can minimize the antibiotic resistance potential on dairy farms and in affected environments and thus reduce the public health burden of antibiotic-resistant infections in the dairy industry and dairy workers in India.
期刊介绍:
Preventive Veterinary Medicine is one of the leading international resources for scientific reports on animal health programs and preventive veterinary medicine. The journal follows the guidelines for standardizing and strengthening the reporting of biomedical research which are available from the CONSORT, MOOSE, PRISMA, REFLECT, STARD, and STROBE statements. The journal focuses on:
Epidemiology of health events relevant to domestic and wild animals;
Economic impacts of epidemic and endemic animal and zoonotic diseases;
Latest methods and approaches in veterinary epidemiology;
Disease and infection control or eradication measures;
The "One Health" concept and the relationships between veterinary medicine, human health, animal-production systems, and the environment;
Development of new techniques in surveillance systems and diagnosis;
Evaluation and control of diseases in animal populations.