Surveillance of Gram positive cocci susceptibility to betalactamics, glycopeptides and other antimicrobials

Background: During the last decade, there has been a progressive increase i n the resistance of gram (+) cocci to betalactamics and other antimicrobial s. Therefore, vancomycin and teicoplanin have incorporated as alternative a ntimicrobial drugs. Aim: To assess the susceptibility of gram (+) cocci to different antimicrobials including vancomycin ans teicoplanin. Material and methods: We studied 447 strains of gram (+) cocci coming from ambulatory a nd hospitalized patients. These included 308 Enterococcus sp strains, 99 St aphycoccus aureus strains and 40 coagulase negative Staphylococci strains. Enterococci susceptibility was measured using minimal inhibitory concentrat ions in agar and that of Staphylococci, through diffusion. Susceptibility t o vancomycin and teicoplanin was measured using minimal inhibitory concentr ations in all strains. Results: Enterococcus faecalis was 100% susceptible to ampicillin, penicillin, vancomycin and teicoplanin, 23% susceptible to t etracyclin and 47% to chloramphenicol. Susceptibility of E faecium was 61% to penicillin, 49% to chloramphenicol, 41% to tetracyclin, 100% to vancomyc in and teicoplanin. Of 19 Enterococcus spp strains, 90% were susceptible to ampicillin, 80% to penicillin, 55% to chloramphenicol and 45% to tetracycl in. Only one E casseiflavus strain had a low level resistance to vancomycin and was susceptible to teicoplanin. No Staphylococcus aureus strain was re sistant to vancomycin or teicoplanin. Conclusion: A permanent surveillance of gram (+) cocci antimicrobial susceptibility is required to update therap eutic schemes.