Heterogeneous resistance to vancomycin and teicoplanin among Staphylococcus spp. isolated from bacteremia.
This study evaluated the BHIA screening method with 4 or 6 mug/mL of vancomycin to detect glycopeptides heteroresistant staphylococci strains isolated from bacteremia. A total of 213 staphylococci strains were isolated from 106 patients between October/2001 and November/2002 in a tertiary hospital in Rio de Janeiro city. Fifty-seven (53.8%) patients presented Staphylococcus aureus, while coagulase-negative staphylococci (CNS) were isolated from 49 (46.2%). Resistance rates for oxacillin of 26.3% and 81.6% were found for the staphylococci isolates, respectively. Thirteen CNS isolated from nine (8.5%) patients grew on agar screening with 4 mug/mL of vancomycin and showed heterogeneous profiles of resistance for vancomycin and teicoplanin by the population analysis profile method. Only 30.8% of them grew at the concentration 6 mug/mL. Bacterial infection and use of antimicrobial therapy were common among these patients. Alert about the emergence of oxacillin-resistant staphylococci presenting heteroresistance to glycopeptides is important in order to achieve judicious use of antimicrobials. Vancomycin agar screening test could help to confirm the presence of these isolates in hospitals.
Nunes
Ana Paula Ferreira
AP
Department of Pathology, Federal University of Espírito Santo, Vitoria, ES.
Schuenck
Ricardo Pinto
RP
Bastos
Carla Callegário Reis
CC
Magnanini
Mônica Maria F
MM
Long
Jacinta B
JB
Iorio
Natália Lopes Pontes
NL
Santos
Kátia Regina Netto Dos
KR
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016470:Bacteremia / Q000382:microbiology; D003470:Culture Media; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D015203:Reproducibility of Results; D013203:Staphylococcal Infections / Q000382:microbiology; D013210:Staphylococcus / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D017334:Teicoplanin / Q000494:pharmacology*; D014640:Vancomycin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D003470:Culture Media; D017334:Teicoplanin; D014640:Vancomycin