{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T17:19:20Z","timestamp":1787764760361,"version":"build-2784847793"},"reference-count":37,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T00:00:00Z","timestamp":1787702400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Vet. Sci."],"abstract":"\n Background<\/jats:title>\n Bovine mastitis is one of the most economically important infectious diseases affecting the global dairy industry. In the Jaffna district of Northern Sri Lanka, information on mastitis prevalence, bacterial aetiology, and antimicrobial resistance remains limited, constraining evidence-based disease management.<\/jats:p>\n <\/jats:sec>\n \n Objectives<\/jats:title>\n To determine the California Mastitis Test (CMT)-based prevalence of bovine mastitis in the Jaffna district, identify causative bacterial pathogens, evaluate antibiotic susceptibility patterns, and assess farm-level risk factors associated with mastitis occurrence.<\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n A cross-sectional study was conducted from April to September 2024 across all 15 veterinary ranges of Jaffna district. A total of 200 milk samples from lactating dairy cattle were screened using the CMT. Positive samples were cultured, and bacterial isolates were identified through Gram staining and standard biochemical tests. Antibiotic susceptibility testing was performed using the Kirby-Bauer disk diffusion method against eight antibiotics following CLSI (2021) guidelines, and Multiple Antibiotic Resistance (MAR) indices were calculated. A structured questionnaire administered to 200 farmers collected data on management, breed, hygiene, and milking practices. Associations between risk factors and mastitis occurrence were analysed using chi-square tests and binary logistic regression.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n The overall prevalence of bovine mastitis was 10.0% (20\/200), with all CMT-positive samples yielding bacterial growth.\n Staphylococcus aureus<\/jats:italic>\n was the predominant isolate (50%), followed by\n Streptococcus agalactiae<\/jats:italic>\n (30%),\n Escherichia coli<\/jats:italic>\n (10%), and\n Klebsiella<\/jats:italic>\n spp. (10%). Enrofloxacin showed the highest susceptibility (90%; MAR\u202f=\u202f0.14), followed by Doxycycline (60%) and Ciprofloxacin (55%), whereas Oxytetracycline exhibited the lowest efficacy (15%; MAR\u202f=\u202f0.45). Semi-intensive farming (aOR\u202f=\u202f1.72;\n p<\/jats:italic>\n \u202f=\u202f0.05), European crossbred cattle (aOR\u202f=\u202f3.12;\n p<\/jats:italic>\n \u202f&lt;\u202f0.05), milk yield &gt;10\u202fL\/day (aOR\u202f=\u202f2.45;\n p<\/jats:italic>\n \u202f=\u202f0.036), absence of post-milking teat dipping (aOR\u202f=\u202f2.67;\n p<\/jats:italic>\n \u202f&lt;\u202f0.05), and non-use of gloves during milking (aOR\u202f=\u202f2.90;\n p<\/jats:italic>\n \u202f&lt;\u202f0.05) were significant risk factors.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n \n Bovine mastitis remains a significant challenge in Jaffna district, with\n S. aureus<\/jats:italic>\n as the dominant pathogen. Enrofloxacin was the most effective antibiotic, while high resistance to Oxytetracycline highlights concerns regarding antimicrobial resistance. Improved milking hygiene and antibiogram-guided treatment strategies are recommended.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fvets.2026.1908298","type":"journal-article","created":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T16:33:45Z","timestamp":1787762025000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Prevalence of bovine mastitis and antibiotic susceptibility patterns of bacterial isolates in the Jaffna District, Sri Lanka"],"prefix":"10.3389","volume":"13","author":[{"given":"Kalaivizhi","family":"Varathanathan","sequence":"first","affiliation":[{"name":"Department of Animal Science, Faculty of Agriculture, Eastern University of Sri Lanka","place":["Chenkaladi, Sri Lanka"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Croos","family":"Antony Niroshan Rajeev","sequence":"additional","affiliation":[{"name":"Department of Animal Science, Faculty of Agriculture, University of Jaffna","place":["Kilinochchi, Sri Lanka"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Susantha","family":"Piratheepan","sequence":"additional","affiliation":[{"name":"Department of Animal Science, Faculty of Agriculture, University of Jaffna","place":["Kilinochchi, Sri Lanka"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thasanthan","family":"Loganathan","sequence":"additional","affiliation":[{"name":"Department of Radiography\/Radiotherapy, Faculty of Allied Health Sciences, University of Peradeniya","place":["Peradeniya, Sri Lanka"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,26]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"18","DOI":"10.1080\/01652176.2007.9695224","article-title":"Economic effects of bovine mastitis and mastitis management: a review","volume":"29","author":"Halasa","year":"2007","journal-title":"Vet Q"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"475","DOI":"10.1051\/vetres:2003027","article-title":"Production effects related to mastitis and mastitis economics in dairy cattle herds","volume":"34","author":"Seegers","year":"2003","journal-title":"Vet Res"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"10381","DOI":"10.3168\/jds.2017-13023","article-title":"A 100-year review: mastitis detection, management, and prevention","volume":"100","author":"Ruegg","year":"2017","journal-title":"J Dairy Sci"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"5649","DOI":"10.1073\/pnas.1503141112","article-title":"Global trends in antimicrobial use in food animals","volume":"112","author":"Van Boeckel","year":"2014","journal-title":"Proc Natl Acad Sci USA"},{"key":"ref5","volume-title":"Sri Lanka Statistical Year Book 2019 Department of Census and Statistics","year":"2019"},{"key":"ref6","volume-title":"Annual Report of the Department of Animal Production and Health 2023 Department of Animal Production and Health","year":"2023"},{"key":"ref7","first-page":"78","article-title":"Post-war agricultural recovery in Northern Province, Sri Lanka","volume":"28","author":"Thiruchelvam","year":"2017","journal-title":"Trop Agric Res"},{"key":"ref8","volume-title":"Economic impact of Bovine Mastitis in Sri Lanka. Annual Report of the Department of Animal Production and Health","author":"Chandrasri","year":"2009"},{"key":"ref9","volume-title":"Veterinary Microbiology and Microbial Disease","author":"Quinn","year":"2004"},{"key":"ref10","first-page":"295","article-title":"Prevalence of bovine subclinical mastitis and antibiogram of isolated bacteria","volume":"9","author":"Shahid","year":"2011","journal-title":"J Bangladesh Agri Univ"},{"key":"ref11","first-page":"143","article-title":"Prevalence and risk factors of subclinical mastitis in lactating cows","volume":"12","author":"Kayesh","year":"2014","journal-title":"Bangladesh J Vet Med"},{"key":"ref12","first-page":"98","article-title":"Comparison of indirect methods for detection of sub-clinical mastitis in dairy cows","volume":"13","author":"Sharma","year":"2010","journal-title":"Bulg J Vet Med"},{"key":"ref13","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1186\/1751-0147-53-36","article-title":"Etiology and antimicrobial susceptibility of udder pathogens from subclinical mastitis in dairy cows in Sweden","volume":"53","author":"Persson","year":"2011","journal-title":"Acta Vet Scand"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"165","DOI":"10.1128\/aem.46.1.165-170.1983","article-title":"Multiple antibiotic resistance indexing of Escherichia coli to identify high-risk sources of fecal contamination in foods","volume":"46","author":"Krumperman","year":"1983","journal-title":"Appl Environ Microbiol"},{"key":"ref15","first-page":"10","article-title":"Prevalence and etiology of subclinical mastitis in cattle in Pakistan","volume":"27","author":"Hameed","year":"2007","journal-title":"Pak Vet J"},{"key":"ref16","first-page":"157","article-title":"Prevalence and risk factors of sub-clinical mastitis in cows","volume":"7","author":"Rahman","year":"2009","journal-title":"Bangladesh J Vet Med"},{"key":"ref17","first-page":"55","article-title":"Prevalence of bovine mastitis in southern Sudan","volume":"3","author":"Madut","year":"2009","journal-title":"Res J Dairy Sci"},{"key":"ref18","first-page":"673","article-title":"Subclinical mastitis: prevalence and associations between indicators","volume":"2","author":"Dohoo","year":"1984","journal-title":"Prev Vet Med"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"270","DOI":"10.1186\/s12917-016-0905-3","article-title":"Bovine mastitis: prevalence, risk factors and isolation of Staphylococcus aureus in dairy herds at Hawassa milk shed, South Ethiopia","volume":"12","author":"Abebe","year":"2016","journal-title":"BMC Vet Res"},{"key":"ref20","doi-asserted-by":"publisher","first-page":"181","DOI":"10.1080\/01652176.2002.9695135","article-title":"Factors in early pathogenesis of bovine Staphylococcus aureus mastitis","volume":"24","author":"Kerro Dego","year":"2002","journal-title":"Vet Q"},{"key":"ref21","volume-title":"Current Concepts of Bovine Mastitis","year":"1996"},{"key":"ref22","volume-title":"Mastitis Management in Florida Dairy Herds","author":"Bray","year":"1986"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"958","DOI":"10.3168\/jds.S0022-0302(94)77032-6","article-title":"Coagulase-positive Staphylococcus intramammary infections in primiparous dairy cows","volume":"77","author":"Roberson","year":"1994","journal-title":"J Dairy Sci"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"1655","DOI":"10.3168\/jds.S0022-0302(99)75394-4","article-title":"Incidence of clinical mastitis in dairy herds grouped in three categories by bulk milk somatic cell counts","volume":"82","author":"Barkema","year":"1999","journal-title":"J Dairy Sci"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"489","DOI":"10.1016\/S0749-0720(15)30616-2","article-title":"Environmental mastitis","volume":"9","author":"Smith","year":"1993","journal-title":"Vet Clin North Am Food Anim Pract"},{"key":"ref26","doi-asserted-by":"publisher","first-page":"73","DOI":"10.3329\/bjvm.v9i1.11216","article-title":"Prevalence of subclinical mastitis in dairy cows in selected areas of Bangladesh","volume":"9","author":"Islam","year":"2011","journal-title":"Bangladesh J Vet Med"},{"key":"ref27","doi-asserted-by":"publisher","first-page":"289","DOI":"10.1038\/nrmicro862","article-title":"Antimicrobial pharmacodynamics: critical interactions of \u2018bug and drug\u2019","volume":"2","author":"Drusano","year":"2004","journal-title":"Nat Rev Microbiol"},{"key":"ref28","first-page":"1153","article-title":"Novel antibacterial agents for serious gram-positive infections","volume":"25","author":"Rybak","year":"2005","journal-title":"Pharmacotherapy"},{"key":"ref29","volume-title":"Global Action Plan on Antimicrobial Resistance","year":"2015"},{"key":"ref30","first-page":"31","article-title":"Seasonal variation of bulk milk somatic cell counts in UK dairy herds","volume":"79","author":"Green","year":"2007","journal-title":"Prev Vet Med"},{"key":"ref31","doi-asserted-by":"publisher","first-page":"22","DOI":"10.1186\/1751-0147-48-22","article-title":"A study of bovine mastitis, milking procedures and management practices on 25 Estonian dairy herds","volume":"48","author":"Haltia","year":"2006","journal-title":"Acta Vet Scand"},{"key":"ref32","first-page":"137","article-title":"Calculated milk production losses associated with elevated somatic cell counts in dairy cows","volume":"37","author":"Hortet","year":"1998","journal-title":"Prev Vet Med"},{"key":"ref33","first-page":"2017","article-title":"Influence of premilking teat preparation and attachment delay on milking performance","volume":"74","author":"Rasmussen","year":"1991","journal-title":"J Dairy Sci"},{"key":"ref34","volume-title":"Managing calving cows to prevent mastitis","author":"Durst","year":"2011"},{"key":"ref35","first-page":"253","article-title":"Prevalence of bovine sub-clinical mastitis in Trinidad","volume":"35","author":"St Rose","year":"2003","journal-title":"Trop Anim Health Prod"},{"key":"ref36","doi-asserted-by":"publisher","first-page":"237","DOI":"10.4142\/jvs.2007.8.3.237","article-title":"Effect of mastitis on raw milk compositional quality","volume":"8","author":"Ogola","year":"2007","journal-title":"J Vet Sci"},{"key":"ref37","volume-title":"Performance Standards for Antimicrobial Disk Susceptibility Tests","year":"2021"}],"container-title":["Frontiers in Veterinary Science"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fvets.2026.1908298\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T16:33:49Z","timestamp":1787762029000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fvets.2026.1908298\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,26]]},"references-count":37,"alternative-id":["10.3389\/fvets.2026.1908298"],"URL":"https:\/\/doi.org\/10.3389\/fvets.2026.1908298","relation":{},"ISSN":["2297-1769"],"issn-type":[{"value":"2297-1769","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,26]]},"article-number":"1908298"}}