Effect of subminimal inhibitory concentrations of clindamycin, streptomycin, chloramphenicol, erythromycin and clavulanic acid on the penicillinase production of Staphylococcus aureus, Bacillus cereus and Pseudomonas fluorescens

ABSTRACT

The influence of subminimal inhibitory concentrations of clindamycin, streptomycin, chloramphenicol, erythromycin and clavulanic acid on the penicillinase production of Staphylococ-cus aureus, Bacillus cereus and Pseudomonas fluorescens were tested. Results revealed that the penicillinase activity can be inhibited by subminimal inhibitory concentrations of these antibiotics. The maximal inhibitory effect was generally induced by concentrations ranging from 1/2 to 1/32 the minimal inhibitory concentrations of clmdamycin and clavulanic acid. Results also revealed that the clindamycin or clavulanic acid produced synergy when combined with penicillin G [Na] against three strains tested in vitro