The inhibitory effect of clindamycin on Lactobacillus in vitro.

OBJECTIVE: To evaluate the in vitro effect of varying concentrations of clindamycin on Lactobocillus spp. METHODS: Concentrations of clindamycin ranging from 1.95-20,000 microg/ml were studied for their effect on the growth of six strains of Lactobacillus. RESULTS: Clindamycin concentrations between 1.95-31.25 microg/ml had no statistically significant effect on growth of lactobacilli (p > 0.05). Concentrations 125 and 250 microg/ml had a bacteriostatic effect. The mean minimum inhibitory concentration (MIC) for studied Lactobacillus strains was determined as 1,000 microg/ml. CONCLUSION: High concentrations of clindamycin achieved in the vagina by intravaginal application might be inhibitory for Lactobacillus.