Histological and microbiological aspects of the vagina in captive howler monkeys (Alouatta caraya)

The histology and the glycogen content of the vaginal epithelium was studied in 15 adult Alouatta caraya monkeys. The histological sections revealed a thin epithelium without cornification. The application of the PAS-amylase method showed absence of glycogen. The microbial flora of the vagina was examined in eight adult Alouatta caraya. The vaginal smears showed a mixed flora with a predominance of Gram+cocci. Haemolytic streptococci were found in 100% of the tested monkeys. Other cocci, such as Staphylococcus albus, Streptococcus faecalis and Micrococcus sp. were less frequent. Of the fecal organisms, Proteus sp. was the most frequently isolated. Neither ureaplasms nor any species of Lactobacillus could be isolated. Positive cultures for nonpathogenic yeasts was a common feature. The relation between the absence of glycogen in the vaginal epithelium and the impossibility to isolate lactobacilli is discussed.