Gardnerella vaginalis

Gardnerella vaginalis is a Gram-variable bacteria species and the main causative agent of bacterial vaginosis, a common vaginal infection. It was first identified by the American bacteriologist Herman L. Gardner in 1955.

Taxonomy

Gardnerella vaginalis is a small, non-motile, non-spore-forming, facultative anaerobic bacteria. It is classified under the phylum Actinobacteria, class Actinobacteria, order Bifidobacteriales, and family Bifidobacteriaceae.

Morphology

The bacteria are pleomorphic, meaning they can change their shape or size in response to environmental conditions. They are typically rod-shaped but can also appear coccobacillary. They are Gram-variable, which means they do not consistently stain either positive or negative with Gram stain.

Pathogenesis

Gardnerella vaginalis is associated with bacterial vaginosis, a condition characterized by an overgrowth of certain bacteria in the vagina. The bacteria adhere to the vaginal epithelial cells, forming a biofilm that protects them from the immune system and antibiotics. They produce a variety of virulence factors, including cytolysins, sialidases, and proteases, which contribute to the symptoms of bacterial vaginosis.

Diagnosis and Treatment

Diagnosis of bacterial vaginosis typically involves a physical examination, a review of medical history, and laboratory tests. The presence of Gardnerella vaginalis can be confirmed through microscopy, culture, or polymerase chain reaction (PCR). Treatment usually involves antibiotics, such as metronidazole or clindamycin.

Epidemiology

Bacterial vaginosis is the most common vaginal infection in women of reproductive age. However, Gardnerella vaginalis can also be found in healthy women, suggesting that its presence alone is not sufficient to cause disease.

See also

• Bacterial vaginosis
• Gram stain
• Bifidobacteriaceae