Livestock-Associated Methicillin-Resistant Staphylococcus aureus Identified in Korean Pig Farms

Strategic Insights -

Research conducted at Inje University in South Korea has identified the presence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in several pig farms across the country. The study, published in the International Journal of Food Microbiology, found that 96 MRSA isolates were obtained from 17 farms, with all isolates exhibiting multidrug resistance. The research also highlighted the emergence of a novel SCCmec variant, which was found in a distinct cluster of six isolates from two separate farms purchasing pigs from the same breeding company.

Key Takeaways:

  • LA-MRSA was identified in 96 MRSA isolates from 17 pig farms in Korea, with all isolates exhibiting multidrug resistance.
  • The dominant lineage of LA-MRSA was CC398 (ST398, spa type t571, SCCmec type V), which has not been reported in Korea previously.
  • Thirty-five isolates carried an SCCmec type III + V combination, which has not been reported in Korea.
  • Whole-genome sequencing analysis of 28 representative isolates identified six clonal clusters and seven singletons, with potential inter-farm transmission observed in four clusters spanning different provinces.
  • Enhanced surveillance, biosecurity measures, and antimicrobial stewardship are necessary to mitigate the spread of LA-MRSA within pig farms and its potential impact on public health.

Statistics:

  • 1515 samples were collected from 74 pig farms nationwide, yielding 96 MRSA isolates from 17 farms.
  • 35 isolates carried an SCCmec type III + V combination.
  • 28 representative isolates were analyzed using whole-genome sequencing, identifying six clonal clusters and seven singletons.
  • 96% of MRSA isolates exhibited multidrug resistance.
  • Six isolates from two separate farms purchased pigs from the same breeding company and carried a novel SCCmec variant.

Sources:

  • Clonal distribution of livestock-associated methicillin-resistant Staphylococcus aureus in pig farms of Korea: Emergence of a novel variant staphylococcal chromosome cassette mec. International Journal of Food Microbiology, 2025;441:111341.
  • International Journal of Food Microbiology, www.journals.elsevier.com/international-journal-of-food-microbiology/
  • Inje University, Dept. of Digital Anti-aging and Healthcare, Gimhae 50834, South Korea.