Changes in vaginal bacterial flora during the oestrous cycle of the mouse

Abstract

The vaginal bacterial flora of MF1 mice was studied using bacteriological culturing techniques, light microscopy and scanning electron microscopy, and results related to stage in oestrous cycle as determined by cytological smears. Total viable bacterial numbers at metoestrus and dioestrus were lower than at oestrus and proestrus. Bacteria of the genera Streptococcus, Lactobacillus, Corynebacterium, Staphylococcus and Actinomyces were consistently isolated at all stages of the cycle, although at proestrus and oestrus the Streptococcus and Lactobacillus mainly contributed to the increase in bacterial numbers. These results are associated with vaginal cellular changes at various stages of the oestrous cycle. Metabolic end-products produced by the vaginal bacterial flora may contribute in signalling the sexual status of the mice to receptive males. ©1991 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.