The microbiome of Escherichia coli and culture-negative nonsevere clinical mastitis:

Culture-negative and Escherichia coli cases are uncommonly treated in pathogen-based protocols for nonsevere clinical mastitis (CM). High-throughput sequencing might reveal missed treatment opportunities in regards to the presence of other pathogens and can provide information on microbial diversity. We wished to explore the milk microbiome and its association with milk production and postevent linear score (LS) for cows with CM characterized as negative or E. coli by culture. Our first objective was to explore the microbiome of cows with E.coli CM to determine if microbial profiles differ between cows that had positive (no drop in milk production or a next-test LS of <4.0) or negative (a drop in milk production or a next test LS of ~4.0) outcomes when not treated. Our second objective was to explore the microbiome of cows with culture-negative CM to determine if microbial profiles differ between cows that had positive or negative outcomes. Characterizing these associations will improve our understanding of CM, allowing for more effective treatment strategies.