Understanding mastitis: Microbiome, control strategies, and prevalence – A comprehensive review

Mastitis significantly affects the udder tissue in dairy cattle, leading to inflammation, discomfort, and a decline in both milk yield and quality. The condition can be attributed to an array of microbial agents that access the mammary gland through multiple pathways. The ramifications of this ailment are not merely confined to animal welfare but extend to the financial viability of the livestock industry. This review offers a historical lens on mastitis, tracing its documentation back to 1851, and examines its global distribution with a focus on regional differences in prevalence and antimicrobial resistance (AMR) patterns. Specific microbial genes and communities implicated in both mastitis and AMR are explored, including Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysagalactiae, Streptococcus uberis Escherichia coli, Klebsiella pneumoniae, Mycoplasma bovis, Corynebacterium bovis, among others. These microorganisms have evolved diverse strategies to elude host immune responses and neutralize commonly administered antibiotics, complicating management efforts. The review aims a comprehensive overview of the current knowledge and research gaps on mastitis and AMR, and to highlight the need for a One Health approach to address this global health issue. Such an approach entails multi-disciplinary cooperation to foster judicious antibiotic use, enhance preventive measures against mastitis, and bolster surveillance and monitoring of AMR in pathogens responsible for mastitis.