Clonal analysis of Staphylococcus aureus isoaltes carrying the cap5 compared with those carrying the cap8 allele

LATTAR SM, TUCHSCHERR LPN, CENTRON D, CERQUETTI C, BUZZOLA FR AND SORDELLI DO.

San Miguel de Tucumán, Argentina

Conferencia; 45th Annual Meeting Argentine Society for Biochemistry and Molecular Biology Research; 2009

Most S. aureus isolates from humans produce capsular polysaccharide (CP) of serotypes 5 (CP5) or 8 (CP8).The present study was conducted using those 99 isolates to ascertain the presence of selected genes (pvl, agr, mecA, agr, hla, hlb), slime production and.Twenty-seven SmaI PFGE types were defined arbitrarily (85% similitude). All isolates bearing the cap5 and cap8 alleles were distributed into two SmaI PFGE clusters. Isolates with pulsotypes A through M carried the cap5 allele whereas isolates of pulsotypes M through AA carried the cap8 allele.A significantly (p=0.0005) higher proportion of MRSA isolates bearing the cap5 allele (37/47) was found, compared with those bearing the cap8 allele (n=10/47). The hla and the lukS-PV/lukF-PV genes was also significantly (p<0.0001 and p= 0.0001, respectively) associated to the presence of the cap5 allele. No significant association was found between disease course and pulsotype, meticilin-resistance, agr type or presence of the lukS-PV/lukF-PV, hla or hlb genes. Whereas agr I isolates were evenly distributed among strains bearing cap5 and cap8, most agr group II isolates carried the cap5 allele and most agr group III isolates carried the cap8 allele. Our results are consistent with an increased fitness of S. aureus bearing the cap5 allele in patients with osteomyelitis. Two S. aureus genomovars, namely Cap5 and Cap8, is suggested.