MULTIFUNCTIONAL CHITOSAN MICROPARTICLES FOR TREATMENT OF BOVINE METRITIS

Bovine metritis is an acute inflammatory uterine disease caused by polymicrobial infections of Gram-negative anaerobes in the uterus and impaired immune function after calving. The principal pathogens associated with bovine metritis are Fusobacterium necrophorum, Bacteroides pyogenes, and Porphyromonas levii, which act synergistically to grow and infect the uterus. We have previously developed chitosan microparticles (CM) as an alternative antimicrobial agent for use in food animals. In clinical trials, we have confirmed that CM significantly alter the uterine microbiota of dairy cows with metritis toward reduced uterine pathogens. However, the therapeutic efficacy of CM was lower than traditional antibiotics, and cows treated with CM were at increased risk of culling due to inflammatory conditions in the uterus. Our long-term goal is to develop a safe and effective alternative to antibiotics for the treatment of bovine metritis. The overall objectives are to (i) develop CM with targeted-antibacterial, anti-inflammatory, and immunomodulatory properties, (ii) elucidate the mechanisms by which CM interact with host cells and the uterine pathogens in vitro, and (iii) determine the in vivo efficacy of CM to treat metritis.