EFFECT OF METRONIDAZOLE ON THE GROWTH OF VAGINAL LACTOBACILLI IN FEMALE ATHLETES

Abstract

Introduction: To investigate whether Metronidazole prohibits the growth of Lactobacilli strains isolated from vagina of healthy Chinese Zang women of reproductive age. Methods: Strains of Lactobacillus isolated from healthy Chinese Zang women were used as test strains. MRS broth were added a series of concentrations of Metronidazole ranging from 128 to 2000 ug/ml. Optical density was measured at 3-hour interval for 24 hours. Results: When the concentration of Metronidazole was no more than 128ug/ml, no statistically significant differences were found. When the concentration of Metronidazole was more than 512ug/ml, the difference of inhibition of Metronidazole on the growth of lactobacillus strains was found to be statistically significant. In addition, various lactobacillus strains had different response to Metronidazole. When the Metronidazole concentrations were 256ug/ml, Lactobacillus delbrueckii, Lactobacillus jensenii and Lactobacillus vaginalis were inhibited apparently, however Lactobacillus cripatus, Lactobacillus gasseri and Lactobacillus fermentumi were not prohibited significantly. Discussion: High concentrations of Metronidazole inhibited the growth of the six Lactobacillus strains. Lower concentrations did not affect the growth of six Lactobacillus strains. Lactobacillus strains had different response to Metronidazole when the Metronidazole concentrations were between 128 ug/ml and 512ug/ml.