The protective bacterium in the normal vagina is:
Vagina has inhabitant bacteria called as Doderleins bacteria which is a lactobaccilli, and converts the glycogen present in vaginal epithelium into lactic acid.
Thus, pH of the vagina is acidic
The pH of the vagina in an adult woman is 4 -5.5 with an average of 4.5.
The pH of vagina varies with age — for further details see preceding text.
Peptostreptococcus
Lactobacillus
Gardenella vaginalis
E. coli