Gram stain: negative (sometimes positive) Cell shape: pleomorphic rods Arrangement: Oxygen requirements: aerotolerant anaerobes Other: non-motile. The organism has a cell wall structurally similar to that of a gram + cell, however, the wall is quite thin and therefore gives a gram - staining reaction. Bergey's Manual actually lists this bacteria under both categories!
Habitat: common inhabitant of female vaginal canals and male urethras.
Pathogenicity: Probably sexually transmitted, but vaginosis only occurs when vaginal pH increases to above 5 and there are decreased numbers of normal flora lactobacilli. Causes a pronounced fishy odor and copious frothy discharge. May act synergistically with other bacteria to cause inflammation.
Diagnosis: increased pH, discharge, odor, presence of "clue cells" - sloughed off vaginal cells covered with organism.
Treatment: metronidazole, which kills anaerobes and permits growth of lactobacilli.
Gardnerella vaginalis
