A multiplex polymerase chain reaction-based diagnostic method for bacterial vaginosis

Abstract

Objective: To develop a polymerase chain reaction (PCR)-based diagnostic method for bacterial vaginosis using bacterial vaginosis-associated anaerobes.

Methods: A multiple PCR assay was developed using primers specific to 16S ribosomal deoxyribonucleic acid (DNA) (Mobiluncus mulieris and Mobiluncus curtisii), nanH (Bacteroides fragilis), and an internal spacer region of ribosomal DNA (Gardnerella vaginalis). The vaginal swabs from pregnant and nonpregnant women were examined by Gram stain-based Nugent scoring system. One hundred seventy-two samples of 853 Gram stain-interpretable samples were randomly selected and subjected to multiplex PCR assay.

Results: The sensitivity of the PCR assay ranged from 10 to 10 colony-forming units per vaginal swab. The prevalence of the bacterial vaginosis, intermediate, and normal categories was found by Nugent scoring system to be 21.6% (184/853), 26.0% (222/853), and 52.4% (447/853), respectively. By the multiplex PCR-based diagnostic method, 20.3% (35/172) of the samples were identified as bacterial vaginosis. The diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of multiplex PCR in comparison with Gram stain examination were 78.4% (95% confidence interval [CI] 65.1%, 91.6%), 95.6% (95% CI 92.1%, 99.0%), 82.9% (95% CI 70.4%, 95.4%), and 94.2% (95% CI 90.3%, 98.1%), respectively.

Conclusion: This multiplex PCR can be used as a diagnostic or screening test for bacterial vaginosis.