Correlation of H2O2 Production of Lactobacillus species with Nugent Scores of Young Nigerian Women

Abstract

Aim: To correlate H2O2 production of Lactobacillus species with the Nugent scores of young Nigerian women in order to assess their vaginal health. Study Design: Cross-sectional study. Place and Duration of Study: Departments of Medical Microbiology & Parasitology, Biochemistry and Obstetrics and Gynaecology, College of Medicine of the University of Lagos, between May and august 2009. Methodology: Ninety- seven isolates of Lactobacillus from eighty-two women without Bacterial vaginosis (BV) and fifteen women with BV were used for the study. BV was diagnosed using Nugent scoring method. Lactobacilli were isolated using MRS agar and categorized into facultative anaerobes and strict anaerobes. Hydrogen peroxide was detected and measured by titration using dilute sulphuric acid and reaction stopped with potassium permanganate. Results: Out of 97 isolates studied, 76 (78%) were facultative anaerobes, while 21 (22%) were strict anaerobes. The facultative anaerobes were obtained from 11 of 15 women with BV and 65 of 82 women without BV. Forty- nine (50.51%) of the 97 isolates produced H2O2. Forty- four of the H2O2 producers were from women without BV while five were from women with BV. Majority (67%) of the strains obtained from women with BV were non-hydrogen peroxide producing. Proportion of H2O2 producing Lactobacillus by Nugent score were 70%, 43% and 33% in negative, intermediate and BV Nugent scores respectively. There was no significant difference between the mean concentrations of H2O2 production in the various Nugent scores. Conclusion: The overall rate of hydrogen peroxide production was low. While the rates of hydrogen peroxide production correlated with Nugent scores, being highest in negative Nugent scores and lowest with BV scores, the concentration of hydrogen peroxide produced had no association with Nugent scores. The Nigerian women studied might have a relatively high susceptibility rate to vaginal infections.