Molecular detection of Streptococcus uberis and Streptococcus agalactiae in the mastitic cows milks in Isfahan province

Mastitis is one of the most prevalent and important diseases in dairy cow herds. It is an inflammatory disease of mammary gland which is caused by many infectious agents. Streptococcus uberis and Streptococcus agalactiae have been frequently isolated from bovine mastitic milk. This research was carried out to study the prevalence of Streptococcus uberis and Streptococcus agalactiae in the milk of cows with clinical mastitis in industrial dairy farms around the province of Isfahan. In total, 123 milk samples were collected from cows with clinical mastitis and then, were immediately transferred to the laboratory. Mastitic milks were confirmed using California Mastitis Test and then, all samples were tested using microbial and biochemical tests. Finally, all 123 samples were tested using PCR. Culture results showed that 16% and 7.31% of the milk samples were positive for Streptococcus agalactiae and Streptococcus uberis, respectively. The PCR showed that 19.51% and 10.56% of the samples were infected with Streptococcus agalactiae and Streptococcus uberis, respectively. Discussion and This study showed that the Polymerase Chain Reaction has a higher accuracy and safety than the culture method. Therefore, we recommend the use of Polymerase Chain Reaction for inspection of microbial quality of milk samples.