Comparison between patients under hemodialysis with community-onset bacteremia caused by community-associated and healthcare-associated methicillin-resistant Staphylococcus aureus strains

[[abstract]]Background/Purpose(s): Patients receiving hemodialysis infected with methicillin-resistantStaphylococcus aureus (MRSA) have been considered to have healthcare-associated (HA) infec-tions, but strains with community-associated (CA) characteristics have also been identi?ed inthis population. The authors compared infections of the two strains among patients with end-stage renal disease.Methods: From January 2004 to December 2008 the authors analyzed the demographic andmicrobiologic data of 57 patients with community-onset (defined as a positive culture obtained 48 hours after admission) MRSA bacteremia and end-stage renal disease at a 2900-bedtertiary medical center. MRSA isolate with staphylococcal cassette chromosome mec (SCCmec)type II/III was classi?ed as HA strains, and SCCmec type IV/V as CA strains.Results: Forty-seven patients (82%) had HA-MRSA strains and 10 patients (18%) had CA-MRSAstrains. The major clones of HA-MRSA were sequence type (ST) 5 with SCCmec type II andstaphylococcal protein A (spa) t002 as well as ST239 carrying SCCmec type III and spa t037.The CA-MRSA strains were predominantly ST59, more susceptible to non- b -lactam antimicro-bial agents, and had a higher percentage of carrying the Panton-Valentine leukocidin genein comparision with the HA-MRSA strains. Patients infected with HA-MRSA isolates had a higheroverall mortality (57.4%, p Z 0.012). In multivariate analysis, male patients were more likelyto be infected with HA-MRSA isolates than CA-MRSA strains (p Z 0.037), and a history ofreceiving urinary catheterization within 1 year prior to bacteremia onset (p Z 0.047) is anindependent risk factor to acquiring HA-MRSA strains.Conclusion: Patients undergoing dialysis and infected with HA-MRSA strains had highermortality rates and were more commonly associated with urinary catheterization within 1 yearbefore bacteremia