Which organism is the most common indicator of bacterial vaginosis?

• A. Eikenella
• B. Capnocytophaga
• C. Gardnerella
• D. Listeria

Answer: (C)

Gardnerella vaginalis is the organism most consistently linked with bacterial vaginosis. BV represents a shift from a Lactobacillus-dominated vaginal flora to a diverse, anaerobe-rich community, and Gardnerella is the hallmark organism repeatedly identified in these cases. Because of its strong association and role in the typical biofilm on the vaginal epithelium, Gardnerella vaginalis serves as the primary indicator in diagnostic schemes (for example, higher Nugent scores correlate with Gardnerella morphotypes). The other organisms listed are not characteristic markers of BV—Eikenella and Capnocytophaga are more commonly linked to oral or other contexts, and Listeria is a well-known systemic pathogen not associated with BV.