title: Comparison of community-associated and health care-associated methicillin-resistant Staphylococcus aureus in Canada: results of the CANWARD 2007-2009 study.
abstract: This study assessed the demographics, antimicrobial susceptibility, and molecular epidemiology of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and health care-associated MRSA (HA-MRSA) in Canadian hospitals between 2007 and 2009. Among 3589 S. aureus, 889 (24.8%) were MRSA; 224 (25.2%) were CA-MRSA genotypes and 644 (72.4%) were HA-MRSA genotypes. The prevalence of CA-MRSA genotypes increased from 19.5% in 2007 to 31.9% in 2009 (P < .001). CMRSA10/USA300 (73.7%) was the predominant CA-MRSA epidemic type; the most common HA-MRSA epidemic type was CMRSA2/USA100/800 (83.5%). CA-MRSA genotypes carried SCCmec type IVa (98.2%) and were largely agr type I (73.2%). Most HA-MRSA genotypes were SCCmec type II (81.2%) and agr type II (83.4%). Panton-Valentine leukocidin was detected in 201/224 (89.7%) CA-MRSA genotypes and 3/644 (0.5%) HA-MRSA genotypes. An increase in vancomycin minimum inhibitory concentration (MIC) was observed in HA-MRSA genotypes overall, with 1.3% (4/305) of strains in 2007 and 4.6% (7/152) in 2009 exhibiting vancomycin MICs of 2 μg/mL. No MRSA resistance occurred with linezolid, daptomycin, or tigecycline. In conclusion, CA-MRSA genotypes represented 25.2% of all MRSA and continue to increase in prevalence in Canadian hospitals.
authors.affiliation: Department of Clinical Microbiology, Health Sciences Centre/Diagnostic Services of Manitoba, Winnipeg, Manitoba R3A 1R9, Canada. knichol@hsc.mb.ca
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Nichol
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Adam
authors.forename: Zafar
authors.initials: Z
authors.lastname: Hussain
authors.forename: Michael R
authors.initials: MR
authors.lastname: Mulvey
authors.forename: Melissa
authors.initials: M
authors.lastname: McCracken
authors.forename: Laura F
authors.initials: LF
authors.lastname: Mataseje
authors.forename: Kristjan
authors.initials: K
authors.lastname: Thompson
authors.forename: Sara
authors.initials: S
authors.lastname: Kost
authors.forename: Philippe R S
authors.initials: PR
authors.lastname: Lagacé-Wiens
authors.forename: Daryl J
authors.initials: DJ
authors.lastname: Hoban
authors.forename: George G
authors.initials: GG
authors.lastname: Zhanel
mesh_terms: D000081:Acetamides / Q000494:pharmacology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000032:analysis; D002170:Canada / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000235:genetics / Q000382:microbiology*; D003428:Cross Infection / Q000453:epidemiology / Q000235:genetics / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D017576:Daptomycin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005098:Exotoxins / Q000032:analysis; D005260:Female; D006761:Hospitals; D006801:Humans; D007223:Infant; D007956:Leukocidins / Q000032:analysis; D000069349:Linezolid; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008911:Minocycline / Q000031:analogs & derivatives / Q000494:pharmacology; D023303:Oxazolidinones / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D000078304:Tigecycline; D020713:Vancomycin Resistance
chemical_list: D000081:Acetamides; D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D005098:Exotoxins; D007956:Leukocidins; D023303:Oxazolidinones; C078284:Panton-Valentine leukocidin; D000078304:Tigecycline; D008911:Minocycline; D000069349:Linezolid; D017576:Daptomycin