Limits...
Using an in-vitro biofilm model to assess the virulence potential of bacterial vaginosis or non-bacterial vaginosis Gardnerella vaginalis isolates.

Castro J, Alves P, Sousa C, Cereija T, França Â, Jefferson KK, Cerca N - Sci Rep (2015)

Bottom Line: Gardnerella vaginalis is the most common species found in bacterial vaginosis (BV).In an effort to better understand the differences between G. vaginalis isolated from women with a positive (BV) versus a negative (non-BV) diagnosis of BV, we compared the virulence potential of 7 BV and 7 non-BV G. vaginalis isolates and assessed the virulence factors related to biofilm formation, namely: initial adhesion and cytotoxic effect, biofilm accumulation, susceptibility to antibiotics, and transcript levels of the known vaginolysin, and sialidase genes.Our results showed that non-BV strains were less virulent than BV strains, as suggested by the lower cytotoxicity and initial adhesion to Hela cells.

View Article: PubMed Central - PubMed

Affiliation: 1] Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal [2] Instituto de Ciências Biomédicas Abel Salazar (ICBAS), University of Porto, Rua de Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.

ABSTRACT
Gardnerella vaginalis is the most common species found in bacterial vaginosis (BV). However, it is also present in a significant proportion of healthy women and G. vaginalis vaginal colonization does not always lead to BV. In an effort to better understand the differences between G. vaginalis isolated from women with a positive (BV) versus a negative (non-BV) diagnosis of BV, we compared the virulence potential of 7 BV and 7 non-BV G. vaginalis isolates and assessed the virulence factors related to biofilm formation, namely: initial adhesion and cytotoxic effect, biofilm accumulation, susceptibility to antibiotics, and transcript levels of the known vaginolysin, and sialidase genes. Furthermore, we also determined the ability of G. vaginalis to displace lactobacilli previously adhered to HeLa cells. Our results showed that non-BV strains were less virulent than BV strains, as suggested by the lower cytotoxicity and initial adhesion to Hela cells. Significant differences in expression of known virulence genes were also detected, further suggesting a higher virulence potential of the BV associated G. vaginalis. Importantly, we demonstrated that BV associated G. vaginalis were able to displace pre-coated vaginal protective lactobacilli and we hypothesize this to be a trigger for BV development.

No MeSH data available.


Related in: MedlinePlus

Initial adhesion of non-BV and BV G. vaginalis isolates to HeLa cells.Adhesion was microscopically quantified and expressed as the average ± SD number of bacteria per epithelial cell. *Denotes significance differences between the 2 groups of G. vaginalis strains at same conditions (one-way ANOVA, p < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4481526&req=5

f1: Initial adhesion of non-BV and BV G. vaginalis isolates to HeLa cells.Adhesion was microscopically quantified and expressed as the average ± SD number of bacteria per epithelial cell. *Denotes significance differences between the 2 groups of G. vaginalis strains at same conditions (one-way ANOVA, p < 0.05).

Mentions: After isolating 7 BV and 7 non-BV associated strains of G. vaginalis (Supplementary Table S1) we first determined the ability of all strains to adhere to a monolayer of HeLa epithelial cells. As can be seen in Fig. 1, variations in adhesion were observed among the 14 isolates, with statistical differences between the 2 groups (p < 0.05). Importantly, BV isolates showed a greater ability to adhere to epithelial cells than non-BV isolates, with an average of 14.83 and 2.89 bacteria per HeLa cell, respectively. Cytotoxicity was also quantified in order to determine the capacity of the 2 groups of bacteria to induce cytotoxic changes in cell morphology on HeLa cells. Similar to the initial adhesion assays, BV isolates had a higher cytotoxicity score than non-BV isolates (p < 0.05; Fig. 2), which were only capable of causing slight morphological changes in HeLa monolayer.


Using an in-vitro biofilm model to assess the virulence potential of bacterial vaginosis or non-bacterial vaginosis Gardnerella vaginalis isolates.

Castro J, Alves P, Sousa C, Cereija T, França Â, Jefferson KK, Cerca N - Sci Rep (2015)

Initial adhesion of non-BV and BV G. vaginalis isolates to HeLa cells.Adhesion was microscopically quantified and expressed as the average ± SD number of bacteria per epithelial cell. *Denotes significance differences between the 2 groups of G. vaginalis strains at same conditions (one-way ANOVA, p < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4481526&req=5

f1: Initial adhesion of non-BV and BV G. vaginalis isolates to HeLa cells.Adhesion was microscopically quantified and expressed as the average ± SD number of bacteria per epithelial cell. *Denotes significance differences between the 2 groups of G. vaginalis strains at same conditions (one-way ANOVA, p < 0.05).
Mentions: After isolating 7 BV and 7 non-BV associated strains of G. vaginalis (Supplementary Table S1) we first determined the ability of all strains to adhere to a monolayer of HeLa epithelial cells. As can be seen in Fig. 1, variations in adhesion were observed among the 14 isolates, with statistical differences between the 2 groups (p < 0.05). Importantly, BV isolates showed a greater ability to adhere to epithelial cells than non-BV isolates, with an average of 14.83 and 2.89 bacteria per HeLa cell, respectively. Cytotoxicity was also quantified in order to determine the capacity of the 2 groups of bacteria to induce cytotoxic changes in cell morphology on HeLa cells. Similar to the initial adhesion assays, BV isolates had a higher cytotoxicity score than non-BV isolates (p < 0.05; Fig. 2), which were only capable of causing slight morphological changes in HeLa monolayer.

Bottom Line: Gardnerella vaginalis is the most common species found in bacterial vaginosis (BV).In an effort to better understand the differences between G. vaginalis isolated from women with a positive (BV) versus a negative (non-BV) diagnosis of BV, we compared the virulence potential of 7 BV and 7 non-BV G. vaginalis isolates and assessed the virulence factors related to biofilm formation, namely: initial adhesion and cytotoxic effect, biofilm accumulation, susceptibility to antibiotics, and transcript levels of the known vaginolysin, and sialidase genes.Our results showed that non-BV strains were less virulent than BV strains, as suggested by the lower cytotoxicity and initial adhesion to Hela cells.

View Article: PubMed Central - PubMed

Affiliation: 1] Centre of Biological Engineering, LIBRO - Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal [2] Instituto de Ciências Biomédicas Abel Salazar (ICBAS), University of Porto, Rua de Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.

ABSTRACT
Gardnerella vaginalis is the most common species found in bacterial vaginosis (BV). However, it is also present in a significant proportion of healthy women and G. vaginalis vaginal colonization does not always lead to BV. In an effort to better understand the differences between G. vaginalis isolated from women with a positive (BV) versus a negative (non-BV) diagnosis of BV, we compared the virulence potential of 7 BV and 7 non-BV G. vaginalis isolates and assessed the virulence factors related to biofilm formation, namely: initial adhesion and cytotoxic effect, biofilm accumulation, susceptibility to antibiotics, and transcript levels of the known vaginolysin, and sialidase genes. Furthermore, we also determined the ability of G. vaginalis to displace lactobacilli previously adhered to HeLa cells. Our results showed that non-BV strains were less virulent than BV strains, as suggested by the lower cytotoxicity and initial adhesion to Hela cells. Significant differences in expression of known virulence genes were also detected, further suggesting a higher virulence potential of the BV associated G. vaginalis. Importantly, we demonstrated that BV associated G. vaginalis were able to displace pre-coated vaginal protective lactobacilli and we hypothesize this to be a trigger for BV development.

No MeSH data available.


Related in: MedlinePlus