Bacteriocin susceptibility of Gardnerella vaginalis and its relationship to biotype, genotype, and metronidazole susceptibility.
OBJECTIVE
Our purpose was to investigate the bacteriocin susceptibility of Gardnerella vaginalis and its relationship to biotype, genotype, and resistance to metronidazole.


METHODS
Bacteriocin susceptibility of 36 G vaginalis clinical isolates was tested against a vaginal strain of Lactobacillus acidophilus by a growth-inhibition method. The relationship to biotype, genotype, and resistance to metronidazole were analyzed by the chi2 test and Fisher exact test.


RESULTS
Eight G vaginalis strains (22%) were bacteriocin-resistant. Biotypes 5 and 7 were found to be the most frequent among these resistant strains. Eight (42%) of the 19 isolates classified as biotype 5, 6, or 7 were bacteriocin-resistant compared with none of the isolates that were classified as other biotypes (P <.01). Biotype 5 was found in higher prevalence among the isolates resistant to bacteriocin (62%) than among the susceptible isolates (14%) (P =.01). Genotype B was found more frequently among the bacteriocin-resistant strains, but this finding was not statistically significant (P =.71). Seven (88%) bacteriocin-resistant strains were also resistant to metronidazole.


CONCLUSIONS
An association between biotype and an increased resistance to bacteriocin was found. The ability of G vaginalis to resist the antibacterial activity of Lactobacillus bacteriocin may be a pivotal factor in understanding bacterial vaginosis.
Simoes
J A
JA
Department of Obstetrics and Gynecology, Rush Medical College, Chicago, Ill, USA.
Aroutcheva
A
A
Heimler
I
I
Shott
S
S
Faro
S
S
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001430:Bacteriocins / Q000494:pharmacology*; D006194:Gardnerella vaginalis / Q000145:classification / Q000187:drug effects*; D005838:Genotype; D008795:Metronidazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010865:Pilot Projects
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D008795:Metronidazole