[Surveillance of gram positive cocci susceptibility to betalactams, glycopeptides, and other antimicrobials].

BACKGROUND

During the last decade, there has been a progressive increase in the resistance of gram (+) cocci to betalactamics and other antimicrobials. Therefore, vancomycin and teicoplanin have incorporated as alternative antimicrobial drugs.

AIM

To assess the susceptibility of gram (+) cocci to different antimicrobials including vancomycin and teicoplanin.

MATERIAL AND METHODS

We studied 447 strains of gram (+) cocci coming from ambulatory and hospitalized patients. These included 308 Enterococcus sp strains, 99 Staphylococcus aureus strains and 40 coagulase negative Staphylococci strains. Enterococci susceptibility was measured using minimal inhibitory concentrations in agar and that of Staphylococci, through diffusion. Susceptibility to vancomycin and teicoplanin was measured using minimal inhibitory concentrations in all strains.

RESULTS

Enterococcus faecalis was 100% susceptible to ampicillin, penicillin, vancomycin and teicoplanin, 23% susceptible to tetracyclin and 47% to chloramphenicol. Susceptibility of E faecium was 61% to penicillin, 49% to chloramphenicol, 41% to tetracyclin, 100% to vancomycin and teicoplanin. Of 19 Enterococcus spp strains, 90% were susceptible to ampicillin, 80% to penicillin, 55% to chloramphenicol and 45% to tetracyclin. Only one E casseiflavus strain had a low level resistance to vancomycin and was susceptible to teicoplanin. No Staphylococcus aureus strain was resistant to vancomycin or teicoplanin.

CONCLUSIONS

A permanent surveillance of gram (+) cocci antimicrobial susceptibility is required to update therapeutic schemes.