Metagenomic approach to study the bacterial community in clinical and subclinical mastitis in buffalo

- Mastitis is an inflammatory disease of the mammary gland.
- Very few reports are there on epidemiological and bacteriological of buffalo mastitis.
- 16S rRNA gene amplicon sequencing was done to investigate bacterial diversity.
- Comparative evaluation of microbial community among two breeds of buffalo
- Significant differences were there in the microbiota in clinical and subclinical samples.

Mastitis is an inflammatory disease of the mammary gland, which occurs mainly because of infection. Infectious mastitis imposes significant economic losses throughout the world. Metagenomic approach was used to investigate bacterial diversity using 16S rRNA gene amplicon sequencing of clinical and subclinical mastitis affected buffalo milk. The data were analyzed using best hit approach through MG-RAST having 95% of the total reads assigned to bacteria. However, about 4% of all analyzed sequences were found to be not assigned to any known bacterial group which suggests that the disease may involve a community of not yet described bacterial groups. Sequences predominantly aligned with the phyla 57% Firmicutes followed by 16% Proteobacteria. At the family level, Staphylococcaceae and Enterococcaceae were predominated in samples from subclinical mastitis, whereas Streptococcaceae was predominated in samples from clinical mastitis. Reads were also assigned to uncultured bacterium indicating that they may also be associated with the etiology of mastitis. Thus the use of metagenomic pyrosequencing of the 16S rRNA may be considered to be an important tool to advance our knowledge regarding the pathogenesis of mastitis in buffalo.