Comparison of detection methods for vaginal lactobacilli.

Area of Science:

• Microbiology
• Women's Health
• Genitourinary Health

Background:

• Vaginal lactobacilli are crucial for maintaining a healthy vaginal microbiota and preventing genitourinary infections.
• Different molecular and culture-based methods exist for identifying vaginal lactobacilli, but their concordance is not fully established.

Purpose of the Study:

• To compare the performance of culture-based methods, quantitative PCR (qPCR), and next-generation sequencing (NGS) for detecting vaginal lactobacilli in Estonian women.
• To assess the concordance between these methods for key Lactobacillus species.

Main Methods:

• Vaginal samples from 50 Estonian women of child-bearing age were analyzed.
• Culture-based methods, qPCR, and NGS were employed to identify and quantify vaginal lactobacilli.
• Statistical analysis was performed to evaluate the correlation and concordance between the methods.

Main Results:

• Culture methods identified Lactobacillus crispatus, Lactobacillus jensenii, and Lactobacillus gasseri.
• NGS detected L. crispatus (76%), Lactobacillus iners (52%), L. jensenii (47%), and L. gasseri (33%).
• qPCR detected L. iners (67%) and L. crispatus (64%).
• Good correlation was observed between qPCR and NGS for L. crispatus (R=0.79) and between culture and qPCR for L. crispatus.
• Concordance between culture and NGS was high for L. crispatus (95%), L. jensenii (82%), and L. gasseri (86%).
• Poor correlation was found for L. iners between qPCR and NGS (R=0.13).

Conclusions:

• Culture, qPCR, and NGS methods show general concordance for detecting most vaginal lactobacilli species.
• Lactobacillus iners detection is inconsistent across the compared methods, suggesting limitations in current techniques.
• Standardization of methods, particularly using media suitable for fastidious L. iners, is crucial for accurate vaginal microbiota assessment.