Microbiome study of Murrah buffalo mastitis milk with emphasis on Acinetobacter species

Mastitis has been a major challenge in dairy industry incurring heavy loss to dairy farmers. Although targeted antibiotic regime is successful for culturable microbes, the non-culturable and novel microbes are often overlooked. Hence, the present study employed a whole-metagenome profiling to investigate and compare the microbial diversity among the milk samples of healthy and affected buffaloes. 16 Milk samples were collected from Murrah buffaloes and classified into three groups based on the somatic cell count and California Mastitis Test score, i.e., Clinical (3), Sub-clinical (6), and Healthy (7). DNA extraction from milk was followed by Whole Meta-Genome Shotgun (WGS) sequencing to study microbial diversity. The study revealed that Proteobacteria as the most abundant phylum in the clinical mastitis cases, which could be related to the severity of the disease, whereas Firmicutes were strongly associated with the healthy group of buffaloes. The genus Acinetobacter was most abundant in clinical cases (79%) and least in healthy animals (33%). The present study provides important insights into the microbial population and composition in the milk of mastitis-affected buffaloes. The findings will aid in investigating potential therapeutic ways for reducing antibiotic resistance and treatment costs.