title: Community-acquired methicillin-resistant Staphylococcus aureus clones circulating in Belgium from 2005 to 2009: changing epidemiology.
abstract: The present study reports the evolution of the demographic characteristics and the molecular epidemiology of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) in Belgium from 2005 to 2009. Four hundred and ten CA-MRSA isolates were prospectively collected and screened for the presence of Panton-Valentin leucocidin (PVL) and toxic shock syndrome toxin 1 (TSST-1) encoding genes, while clinical information were recorded. PVL- and TSST-1-positive isolates were genotyped by pulsed-field gel electrophoresis (PFGE). Staphylococcal cassette chromosome mec (SCCmec) type, spa type and multilocus sequence type (MLST) were determined on representative isolates. One hundred and fifty-nine (39 %) isolates were PVL-positive. PVL-positive isolates were significantly more frequently isolated from skin or soft tissue than PVL-negative isolates, causing mainly subcutaneous abscesses and furuncles. Patients with PVL-positive CA-MRSA were significantly younger than patients with PVL-negative CA-MRSA. Eighty-seven percent of the PVL-positive isolates belonged to a limited number (n = 7) of PFGE types belonging to sequence types (ST) ST80, ST8, ST30, ST5, ST152, ST338 and a new ST, a single-locus variant of ST1. A temporal evolution of the distribution of these PFGE types was observed, characterised by (1) the dissemination of the ST8-SCCmecIV arcA-positive (USA300) genotype and (2) a genetic diversification. Forty-seven (11 %) strains were TSST-1-positive, of which 65 % clustered into four PFGE types, all belonging to ST5. The epidemiology of CA-MRSA in Belgium is changing, as the rapid diffusion of the USA300 clone seems to occur, together with a clonal diversification.
authors.affiliation: Laboratoire de Référence MRSA-Staphylocoques, Service de Microbiologie, Université Libre de Bruxelles (ULB)-Hôpital Erasme, Brussels, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Brauner
authors.forename: M
authors.initials: M
authors.lastname: Hallin
authors.forename: A
authors.initials: A
authors.lastname: Deplano
authors.forename: R
authors.initials: R
authors.lastname: De Mendonça
authors.forename: C
authors.initials: C
authors.lastname: Nonhoff
authors.forename: R
authors.initials: R
authors.lastname: De Ryck
authors.forename: S
authors.initials: S
authors.lastname: Roisin
authors.forename: M J
authors.initials: MJ
authors.lastname: Struelens
authors.forename: O
authors.initials: O
authors.lastname: Denis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001427:Bacterial Toxins / Q000235:genetics; D001530:Belgium / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D024881:Drug Resistance, Bacterial; D004768:Enterotoxins / Q000235:genetics; D005098:Exotoxins / Q000235:genetics; D005260:Female; D006801:Humans; D007223:Infant; D007956:Leukocidins / Q000235:genetics; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D058889:Molecular Typing; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D018089:Superantigens / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004768:Enterotoxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal