Bovine mastitis, a worldwide impact disease: Prevalence, antimicrobial resistance, and viable alternative approaches

Bovine mastitis is globally considered one of the most important diseases within dairy herds, mainly due to the associated economic losses. The most prevalent etiology are bacteria, classified into contagious and environmental, with Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, Escherichia coli and Klebsiella pneumoniae being the most common pathogens associated with mastitis cases. To date these pathogens are resistant to the most common active ingredients used for mastitis treatment. According to recent studies resistance to new antimicrobials has increased, which is why developing of alternative treatments is imperative. Therefore the present review aims to summarize the reports about bovine mastitis along 10 years, emphasizing bacterial etiology, its epidemiology, and the current situation of antimicrobial resistance, as well as the development of alternative treatments for this pathology. Analyzed data showed that the prevalence of major pathogens associated with bovine mastitis varied according to geographical region. Moreover, these pathogens are classified as multidrug-resistant, since the effectiveness of antimicrobials on them has decreased. To date, several studies have focused on the research of alternative treatments, among them vegetal extracts, essential oils, or peptides. Some other works have reported the application of nanotechnology and polymers against bacteria associated with bovine mastitis. Results demonstrated that these alternatives may be effective on bacteria associated with bovine mastitis.