mastitis in dairy cattle.

has recently been identified increasingly in dairy cows causing huge economic losses to the dairy industry. is a causative agent for mastitis, pneumonia, endometritis, endocarditis, arthritis, otitis media, and many other clinical symptoms in cattle. However, some infected cows are asymptomatic or may not shed the pathogen for weeks to years. This characteristic of , along with the lack of adequate testing and identification methods in many parts of the world until recently, has allowed the to be largely undetected despite its increased prevalence in dairy farms. Due to growing levels of antimicrobial resistance among wild-type isolates and lack of cell walls in mycoplasmas that enable them to be intrinsically resistant to beta-lactam antibiotics that are widely used in dairy farms, there is no effective treatment for mastitis. Similarly, there is no commercially available effective vaccine for mastitis. The major constraint to developing effective intervention tools is limited knowledge of the virulence factors and mechanisms of the pathogenesis of mastitis. There is lack of quick and reliable diagnostic methods with high specificity and sensitivity for . This review is a summary of the current state of knowledge of the virulence factors, pathogenesis, clinical manifestations, diagnosis, and control of mastitis in dairy cows.