Pili on Gardnerella vaginalis studied by electronmicroscopy

Area of Science:

• Microbiology
• Bacteriology
• Electron Microscopy

Background:

• Gardnerella vaginalis is a bacterium associated with bacterial vaginosis.
• The presence and function of pili in Gardnerella vaginalis are not fully understood.
• Pili are hair-like appendages on bacterial surfaces involved in adhesion and other functions.

Purpose of the Study:

• To investigate the presence of pili in recently isolated and laboratory strains of Gardnerella vaginalis.
• To determine if pili expression is affected by laboratory cultivation.

Main Methods:

• Electron microscopy was used to examine fourteen recently isolated strains and two laboratory strains of Gardnerella vaginalis.
• The degree of pilation was assessed in freshly isolated strains and after repeated subculturing.

Main Results:

• All recently isolated Gardnerella vaginalis strains from both male and female subjects were heavily pilated.
• Laboratory strains showed significantly fewer pili, with many organisms lacking them entirely.
• Repeated subculturing of a freshly isolated strain led to a decrease in pilation, suggesting gradual pili loss.

Conclusions:

• Piliation is a common characteristic of freshly isolated Gardnerella vaginalis.
• Laboratory cultivation, particularly multiple subcultures, leads to a loss of pili in Gardnerella vaginalis.
• The observed loss of pili is likely due to a gradual degradation rather than selection of non-pilated variants.