A 24 hour plastic envelope method for isolating and identifying Gardnerella vaginalis (PEM-GVA).

A new plastic envelope culture test that is selective for Gardnerella vaginalis was compared with a conventional method. Vaginal specimens from 92 women were cultured. Results from both methods were compared with the results of pelvic examinations and clinic screening tests used to diagnose bacterial vaginosis (BV). G vaginalis was isolated more often in the envelope than by the conventional method from patients with BV and those without, though the difference was not significant. Isolation and identification of G vaginalis was completed in 18-24 hours by the envelope method; the conventional method took a mean of 72 hours (range two to six days). Polymorphonuclear leucocytes (PMNLs) occurred significantly more in specimens from the patients without BV than from those with BV. Both clue cells and a positive amine test reaction were found significantly more in specimens from patients with BV than from those without BV. Clue cells and G vaginalis isolation correlated best with BV (in 47 women), followed by clue cells and positive amine test results (in 39). Adherence of G vaginalis in the envelope also correlated more with BV, clue cells, and positive amine test results (32) than with patients without BV (14). When there were no clue cells and amine test results were negative the results correlated totally with a prediction of no BV. The use of the rapid envelope culture test would have confirmed BV in 20% of the cases where clue cell and amine test results were discordant.