Detection of virulence associated genes in Streptococcus agalactiae isolated from bovine mastitis

Mastitis is one of the most expensive diseases in the dairy industry. It causes heavy monetary losses by decreasing milk production and treatment cost. Streptococcus agalactiae, the cause of contagious bovine mastitis, possesses various virulence factors that contribute to pathogenicity.

The main aim of the study was to evaluate the distribution of virulence genes of S. agalactiae.

In the current work, 98 Streptococcus species were isolated from 320 milk samples, collected from Veterinary Clinical Complex, Junagadh. Out of the isolates, 42 S. agalactiae isolates were used for virulence genes detection.

All Streptococcus spp. were confirmed at genus level by targeting tuf gene, and S. agalactiae was identified at species level by targeting 16S rRNA gene. For virulence gene detection, scpB, cfb, and cylE genes were targeted. Of 42 S. agalactiae isolates, 15, 16, and 10 isolates possessed scpB, cfb, and cylE genes, respectively.

This study aids us to know virulence characteristics and mechanisms responsible for the development of new strains in mastitis epidemiology in response to prevention and control strategies.