Bacteria assume distinct lifestyles during the planktonic and biofilm
modes of growth. In biofilms, they are more tolerant to antibiotics and can
evade the immune system response more effectively. However, little is
known regarding the molecular determinants involved in biofilm formation
by Gardnerella vaginalis, the predominant species found in the
polymicrobial condition bacterial vaginosis (BV), the most common
vaginal disorder of women in reproductive age.Hence, to gain insight into
the pathogenesis of G. vaginalis, we carried out a comparative
transcriptomic analysis between planktonic and biofilm phenotypes, using
RNA-sequencing. Significant differences were found in the expression of
815 genes. A detailed analysis of the results obtained was performed
based on direct and functional gene interactions. In biofilm bacteria, the
cell envelope appeared to be very active since genes encoding binding
proteins and proteins involved in the synthesis of murein were
significantly up-regulated. In addition, our data showed that G. vaginalis
reflects the typical adaptation to stress and starvation conditions.
Interestingly, genes associated with glucose and carbon metabolism, as
well as oxidoreductase activity were found down-regulated in
biofilms.Furthermore, gene-regulated processes in G. vaginalis biofilms
resulted in a protected form of bacterial growth, characterized by low
metabolic activity, which is appropriate to guarantee long-term survival
during BV recurrence. Therefore, our data suggested that G. vaginalis
adjust its lifestyle during colonization and infection by means of an
extensive change of gene expression
