Livestock-associated Methicillin-Resistant Staphylococcus aureus Sequence Type 398 in Humans, Canada

摘要

Rates of colonization with livestock-associated methicil-lin-resistant Staphylococcus aureus (MRSA) sequence type 398 have been high for pigs and pig farmers in Canada, but prevalence rates for the general human population are un-known. In this study, 5 LA-MRSA isolates, 4 of which were obtained from skin and soft tissue infections, were identifi ed from 3,687 tested MRSA isolates from persons in Manitoba and Saskatchewan, Canada. Further molecular character-ization determined that these isolates all contained staphy-lococcal cassette chromosome (SCC) mecV, were negative for Panton-Valentine leukocidin, and were closely related by macrorestriction analysis with the restriction enzyme Cfr91. The complete DNA sequence of the SCCmec region from the isolate showed a novel subtype of SCCmecV harboring clustered regularly interspaced short palindromic repeats and associated genes. Although prevalence of livestock-as-sociated MRSA seems to be low for the general population in Canada, recent emergence of infections resulting from this strain is of public health concern