Damage to oviduct organ cultures by Gardnerella vaginalis

Gardnerella vaginalis is a Gram-variable coccobacillus found in the lower genital tract, particularly of women. Very large numbers are found in the vagina in bacterial vaginosis. The pathogenicity of G. vaginalis was studied using fallopian tubes and bovine oviducts in organ culture. Whole organisms, whether piliated or not, from broth cultures caused the cilia on ciliated cells in the mucosa of either human or bovine oviducts to stop beating within 3 days or less. Cilia on control tissues kept beating for at least 5 days. Organism-free filtrates from broth cultures, whether frozen and thawed or heat-treated, caused the same effect, indicating the existence of a soluble toxin. Histological sections revealed little damage, but scanning electron microscopy showed damage to the mucosal surface with some loss of ciliated cells. The toxin is not human tissue specific and, therefore, unlikely to be the same as the cytotoxin with haemolytic properties described by others. The toxin could play a part in the development of salpingitis if G. vaginalis organisms gained access to the upper tract in large numbers.