Vaginal microbial communities from synchronized heifers and cows with reproductive disorders

Aim: To evaluate changes in the resident microbial population in the cranial vaginal mucosa induced by a progesterone-releasing intravaginal device (PRID) compared to the vaginal microbiota of cows with reproductive disorders. Methods and Results: Vaginal discharge was evaluated by clinical examination and a Vaginitis Diagnosis Score was performed by exfoliative cytology. All samples classified as positive and some classified as negative by clinical evaluation were later diagnosed as positive for vaginitis by cytological analysis. Bacterial diversity profiles were performed by PCR-DGGE and clustered according to the reproductive health status of the specimens, revealing a correspondence between the structures of the communities in the vagina and the clinical profile. Representative bands from each group were sequenced and identified as Ruminococcus sp., Dialister sp., Escherichia sp./Shigella sp., Virgibacillus sp., Campylobacter sp., Helcoccoccus sp., Staphylococcus sp., Bacillus sp., Actinopolymorpha sp., Exiguobacterium sp., Haemophilus sp./Histophilus sp., Aeribacillus sp., Porphyromonas sp., Lactobacillus sp. and Clostridium sp. Conclusion: Our results contribute to the knowledge of the vaginal microbiome in synchronized heifers showing positive or negative clinical vaginitis. Significance and Impact of the Study: This study contributes to the understanding of a dynamic vaginal colonization by bacterial consortiums during the synchronization with a widely used PRID protocol. Also, the results reveal the presence of well-known metritis-related pathogens as well as emerging uterine opportunistic pathogens. The provided information will allow to carry out further studies to elucidate functional roles of these native micro-organisms in the bovine reproductive tract.