Abstract:
Bacterial vaginosis (BV) is a common vaginal condition in women of reproductive age.
During BV development, BV-associated bacteria may form a polymicrobial biofilm, which
predispose women to recurrent BV. The aim of the study was to investigate the growth
forms of Gardnerella spp. and Lactobacillus spp. and to determine the association
between the bacterial growth forms and clinical characteristics [urinary tract infection
(UTI) symptoms, human immunodeficiency virus (HIV) infection and abnormal vaginal
discharge] in women attending a tertiary hospital in Pretoria, South Africa. A first-void
urine specimen was collected from 196 women and BV was diagnosed using the
Nugent scoring and the Ison-Hay criteria (vaginal smear microscopy). Fluorescence in situ
hybridisation (FISH) was performed to classify the growth forms [“dispersed” or “biofilm”].
Bacterial cells were categorized as “dispersed” if cells were scattered separately and
as “biofilm” if bacterial aggregates on the vaginal epithelial cells were observed. BV
was detected in 52 women (52/196; 27%) and in these women, Gardnerella spp. were
predominantly present in biofilms (46/52; 88% for Nugent scoring; and 45/50; 90% for
Ison-Hay criteria), whereas Lactobacillus spp. were predominantly present in a dispersed
form (38/52; 73% for Nugent scoring; and 37/50; 74% for Ison-Hay criteria). The odds
of having BV increased when Gardnerella biofilms were present (p < 0.001), whereas the
opposite was observed for Lactobacillus biofilms (p = 0.001). Neither Gardnerella spp.
or Lactobacillus spp. (both dispersed or biofilms) had an association with the presence of
UTI symptoms, HIV coinfection or abnormal vaginal discharge. In conclusion, this study
demonstrated and confirmed that Gardnerella biofilms are associated with BV and that
Lactobacillus spp. may form biofilms to protect against BV.
