Comparison between a novel molecular tool and conventional methods for diagnostic classification of bacterial vaginosis: is integration of the two approaches necessary for a better evaluation?

The etiological cause of bacterial vaginosis (BV) is the change of the vaginal ecosystem characterized by a decrease of lactobacilli and an increase of other germs, such as Gardnerella vaginalis and Atopobium vaginae. Molecular tools have revolutionized the diagnosis of these conditions. The aim of this paper was to compare results obtained from 158 vaginal swabs collected from women aged between 18 and 59 years old and subjected to microscopic evaluation (Nugent Score), culture and to the multiparametric molecular assay Vaginitis and Vaginosis Multiplex-Tandem (MT) PCR (AU27117) - Nuclear Laser Medicine. In 50 samples we also used matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for bacterial microbiome identification. Our results showed a moderate concordance between traditional and molecular methods for diagnosis of candidiasis and a lower concordance for BV and normal flora. MALDI TOF MS allowed us to discriminate more than 10 species of lactobacilli with a greater abundance of Lactobacillus gasseri, Lactobacillus paracasei spp. paracasei, Lactobacillus pentosus and Lactobacillus crispatus in BV and altered flora. This work underlined how the integration of different assays and metagenomics studies can greatly expand our current understanding of vaginal microbial diversity, providing more reliable diagnostic criteria for BV and its intermediate condition diagnosis.