Distribution of lactic acid bacteria in vaginal samples from Cameroonian women

BACKGROUND: Numerous bacteria coexist in the human body and constitute the 'normal microbiota'. Data on the normal vaginal microbiota are limited in Africa, particularly in Cameroon. This study aimed to determine the distribution of lactic acid bacteria (LAB) isolated from vaginal samples of Cameroonian women. METHODS: This cross-sectional analytical study was conducted in Douala, Cameroon, from March 2024 to March 2025. It included non-menopausal women aged 18 to 50 years without gynaecological infections. Vaginal swabs were cultured on MRS and M17 media and identified by MALDI-TOF mass spectrometry at the Pasteur Centre for lactic acid bacteria, and by API mini-galleries for pathogenic organisms. Microbiota typing was performed using the Nugent scoring system. Descriptive and inferential statistics were conducted using SPSS v25.0, XLSTAT, and the VITEK MS Knowledge Base. Logistic regression and Poisson regression were applied where appropriate; significance was set at p < 0.05. RESULTS: A total of 783 participants were enrolled; the majority were aged 29-39 years (44.2%). Microbiota type IV (depleted) was the most prevalent (48.1%). Overall, 67.6% of samples harboured pathogenic bacteria, while 32.4% yielded LAB. Among 260 LAB isolates, Enterococcus spp. dominated (59.2%), mainly E. faecalis (33.5%) and E. faecium (22.3%). Bacteria belonging to the former Lactobacillus group accounted for only 18.8% of all LAB. Age (p = 0.019), region of origin (p = 0.012), and marital status (p = 0.011) were significantly associated with LAB prevalence. CONCLUSION: The distribution of vaginal lactic acid bacteria in Cameroonian women depends on age, marital status, and region of origin. The predominance of Enterococcus spp. over canonical lactobacilli represents a distinctive microbiological signature, potentially reflecting biogeographical and socio-cultural adaptations, which calls for region-specific approaches to vaginal health management.