SORDELLI Daniel Oscar
congresos y reuniones científicas
Serotype 5 and 8 capsule polysaccharide (CP5 and CP8) expression in Staphylococcus aureus isolates from patients with chronic bone infection. Abstract P-205
LATTAR, SANTIAGO M.; TUCHSCHERR, LORENA P.N.; CACCURI, ROBERTO L.; BARBAGELATA, MARIA SOL; ALVAREZ, LUCIA P.; BUZZOLA, FERNANDA R.; PREDARI, SILVIA C.; BARBERIS, CLAUDIA; PROCOPIO, ADRIANA; SORDELLI, DANIEL O.
Simposio; 12th International Symposium on Staphylococci and Staphylococcal Infections (ISSSI); 2006
Most clinically relevant S. aureus isolates express either CP5 or CP8. This study was designed to evaluate CP5/CP8 expression by isolates from patients with chronic and acute osteoarticular infection. Sixty-five (52%) expressed CP5, 21 (17%) CP8, and 39 (31%) were non-typeable (NT, non-CP5 and non-CP8). Analysis of blood culture S. aureus isolates revealed that 33 (66%) expressed CP5, 17 (34%) CP8 and none were NT. Further analysis of 72 osteoarticular infection S. aureus showed that 19% of the isolates from patients with acute infection were NT whereas 51% of those from patients with chronic infection were NT (P=0.0068). Further study of 20 NT S. aureus isolates revealed that 11 and 8 exhibited positive amplification for cap5 and cap8 specific genes, respectively, and that one did not show amplification for either cap5 or cap8 genes. No association was found in expression of CP vs. á-haemolysin, â-haemolysin (culture on rabbit and goat blood agar, respectively) or biofilm (culture on Congo red agar) suggesting that mutation in regulatory genes was not the only mechanism responsible for the NT phenotype. Two MRSA clones (STAR-PCR) were detected among the isolates, with no association to CP expression. Our results agree with the hypothesis that NT S. aureus may be positively selected during chronic osteoarticular infection.