Transmission and persistence of methicillin-resistant Staphylococcus aureus in milk, environment, and workers in dairy cattle farms

Foodborne Pathog Dis. 2013 Aug;10(8):731-6. doi: 10.1089/fpd.2012.1436. Epub 2013 Jun 8.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Typing Techniques / veterinary
  • Cattle
  • Cattle Diseases / microbiology
  • Cattle Diseases / transmission*
  • Chromosomes, Bacterial / genetics
  • DNA, Bacterial / genetics
  • DNA, Bacterial / isolation & purification
  • Drug Resistance, Multiple, Bacterial
  • Food Contamination / analysis
  • Food Microbiology
  • Humans
  • Methicillin-Resistant Staphylococcus aureus / genetics
  • Methicillin-Resistant Staphylococcus aureus / growth & development
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification*
  • Microbial Sensitivity Tests / veterinary
  • Milk / microbiology*
  • Republic of Korea
  • Staphylococcal Infections / transmission*
  • Staphylococcal Infections / veterinary

Substances

  • DNA, Bacterial