Clonal Composition of Staphylococcus aureus Isolates at a Brazilian University Hospital: Identification of International Circulating Lineages

Abstract

In only a few instances has the clonal composition of Staphylococcus aureus collections that include methicillinsusceptible S. aureus (MSSA) been extensively characterized. In order to investigate the clonal composition of MSSA and methicillin-resistant S. aureus (MRSA) and examine whether the infections diagnosed at our hospital were related to internationally distributed S. aureus lineages, we collected 89 clinical S. aureus isolates from patients at a public university hospital in Rio de Janeiro, Brazil, from September 1999 to June 2000. All S. aureus isolates were genotyped by pulsed-field gel electrophoresis and multilocus restriction fragment typing (MLRFT), and a subset (n ‫؍‬ 17) was further characterized by multilocus sequence typing (MLST). The 34 MRSA isolates were additionally characterized by SCCmec typing. The MSSA population (n ‫؍‬ 55) was grouped into 18 restriction fragment types (RFTs); of these, five RFTs accounted for 67% (37) of the MSSA isolates. MRSA isolates were clustered into only three RFTs (P ‫؍‬ 0.02). The majority of MSSA RFTs were related to sequence type 30 (ST30) (12 isolates, 22%), ST1, ST188, and ST432 (6 isolates, 11% each). The predominant MRSA RFT comprised 31 (91%) of 34 isolates; four randomly selected isolates of this RFT were ST239, the previously described widely disseminated Brazilian clone. However, a fifth isolate belonging to this RFT was the ST644, a new single locus variant of ST239. By applying MLRFT and MLST, we found evidence for a clonal structure in MSSA isolates and detected the dissemination of MSSA clonal complexes 1, 5, 8, 30, and 45.

New multilocus sequence typing of MRSA in São Paulo, Brazil

“…Thus, we believe that our non-BEC belonging isolates are descendants of a common ancestor, the pediatric clone, first described in Portugal, Poland, Argentina, Colombia, and in New York hospitals' pediatric patients (18,19) or from the pediatric clone NY/Japan that appeared and disseminated in Tokyo and USA hospitals (19). Although in Brazil there was a predominance of BEC in hospitals in several states (3,4,14,20) we found that there was no similarity between this clone and the isolates investigated in the present study. The ST that showed a closely related pattern also had a similar PFGE profile.…”

“…The dissemination of the MRSA clone probably reflects their ability to cause infection and to persist and spread from one region to another, including different continents (5). The predominance of BEC (SCCmec III) in Brazilian hospitals has been well documented (3,4,14). Recent changes in the profile of clonal MRSA isolated in hospitals have been observed, which have increased the number of MRSA isolates belonging to SCCmec type IV (pediatric clone), as shown in the study by Trindade et al (15), who reported a 13% rate of occurrence of MRSA isolates in patients carrying this SCCmec admitted to a São Paulo hospital.…”

“…Pediatric clone samples seem to be associated with nosocomial infections in other Brazilian cities like Rio de Janeiro, Recife, and in Rio Grande do Sul (14) and São Paulo (15). More studies are needed to characterize MRSA clones not belonging to BEC in Brazil genotypically.…”

Staphylococcus aureuscarriage among GPs in the Netherlands

“…[24][25][26][27] Another common MLST CC worldwide is MLST CC45, which was also highly prevalent in the present study. [25][26][27] As the Ridom SpaServer does not detect repeats longer than 24 bases, two isolates with a repeat of 25 base pairs were not type-able, in accordance with European rules for typing justified by SeqNet.org.…”

Antibacterial and antioxidant activities and acute toxicity of Bumelia sartorum Mart., Sapotaceae, a Brazilian medicinal plant

“…Its resistance has been related to the predominance of epidemic PFGE (pulsed field gel eletrophoresis) clones able to expand largely around the world (Feng et al, 2008). Specifically in Brazil, a single PFGE clone A MRSA has been markedly detected as prevalent in several hospitals (Vivoni et al, 2006). The control of MRSA nosocomial infections is, many times, very difficult because of the presence of this prevalent clone.…”