title: Transmission and persistence of methicillin-resistant Staphylococcus aureus in milk, environment, and workers in dairy cattle farms.
abstract: The aim of this study was to determine the presence and persistence of methicillin-resistant Staphylococcus aureus (MRSA) in milk, farm environment, and farmers on 22 dairy cattle farms in Korea during 2008-2009. Genetic relatedness among the MRSA isolates was also investigated. Of 1146 samples examined, 35 of 559 (6.3%) quarter milk samples from 371 cows, four of 86 (4.7%) hand and nose samples from 43 farmers, and 6 of 501 (1.2%) farm environment samples were MRSA positive. Except for three isolates, all MRSA were classified into ST72-spa t324-SCCmec IV with PVL negative, the most predominant clonal type among community-associated MRSA in South Korea. All 35 MRSA-positive milk samples from 19 cows were obtained from a single farm (Farm G) out of 22 (4.5%) farms tested. The farm G was revisited 1 year later and milk samples were collected for examination of MRSA again. Two of six previous MRSA-positive cattle that had been kept on the farm still harbored MRSA genetically identical to MRSA strains, which were isolated from the same farm a year ago. The results of this study provide the evidence of transmission of MRSA among cattle, farm environment, and farmers and also long-term persistence of MRSA in animals.
authors.affiliation: Animal, Plant, and Fisheries Quarantine and Inspection Agency, Gyeonggi-do, Republic of Korea. imsk0049@korea.kr
authors.forename: Suk-Kyung
authors.initials: SK
authors.lastname: Lim
authors.forename: Hyang-Mi
authors.initials: HM
authors.lastname: Nam
authors.forename: Gum-Chan
authors.initials: GC
authors.lastname: Jang
authors.forename: Hee-Soo
authors.initials: HS
authors.lastname: Lee
authors.forename: Suk-Chan
authors.initials: SC
authors.lastname: Jung
authors.forename: Tae-Sun
authors.initials: TS
authors.lastname: Kim
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques / Q000662:veterinary; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology / Q000635:transmission*; D002876:Chromosomes, Bacterial / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D024901:Drug Resistance, Multiple, Bacterial; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D008892:Milk / Q000382:microbiology*; D056910:Republic of Korea; D013203:Staphylococcal Infections / Q000635:transmission* / Q000662:veterinary
chemical_list: D004269:DNA, Bacterial