[Activity of the amoxicillin-clavulanic acid (augmentin) combination on strains of hospital isolates].

All strains of Staphylococcus aureus and Gram negative bacilli (Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter) isolated from 01.01 to 03.31.83 were studied using agar diffusion with augmentin-impregnated discs (amoxicillin 20 micrograms + clavulanic acid 10 micrograms). Augmentin is active against penicillinase-producing Staphylococci susceptible to methicillin, whereas methicillin-resistant strains are also resistant to augmentin. According to the susceptibility of strains to amoxicillin, carbenicillin and cefalotin, Enterobacteriaceae can be divided into five main phenotypes, of which four are resistant. "RSR" and "RRR" phenotypes, which are cephalosporinase producers, are chiefly found among Enterobacter, Serratia, Citrobacter and indole + Proteus; in these groups a change in inhibition diameters indicating activity of augmentin is observed only in a significant number of Proteus vulgaris strains. "RRS" and "RRI" strains are penicillinase producers found mainly among E. coli, Klebsiella pneumoniae and oxytoca, and Proteus mirabilis; they emerge as very susceptible to augmentin. Pseudomonas aeruginosa is never susceptible to augmentin. Augmentin is slightly more active than amoxicillin on some Acinetobacter strains but the difference is too inconsiderable to be of clinical significance.