Characterization of methicillin-resistant Staphylococcus aureus from residents and the environment in a long-term care facility.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major public health concern associated with residence in a long-term care facility (LTCF). The aim of this prospective study was to characterize MRSA isolated from residents over a 1-year period and their physical environment over a 2-year period. MRSA was recovered from 17/64 residents (R) of a LTCF and from 42 environmental (E) sites. All isolates carried the mecA gene and lacked the mecC and Panton-Valentine leukocidin (PVL) genes. Thirteen spa types were identified with t032 being the most frequent (41% of total; n = 8R, 16E), followed by t727 (22% of total; n = 13E), and t8783 (10% of total; n = 6E). Five spa types were each represented by single isolates. Thirty-nine isolates were of spa types associated with the multilocus sequence type ST22 (t032, 41%; spa-CC22, 68%) and reflect the predominance of ST22 in Irish hospitals. The uncommon spa types t727, t8783, t1372, t3130, t10038 were present in the environment but not detected in residents and are infrequently observed in Ireland.