Identifying the Bacteria Causing Ovine Gangrenous Mastitis and Detection of Staphylococcus aureus in Gangrenous Milk by PCR

Summary The objective of this study was to identify bacteria causing gangrenous ovine mastitis as well as to detect and genotype Staphylococcus aureus in milk samples by using polymerase chain reaction (PCR) amplification and restriction fragment length polymorphism (RFLP) of coagulase gene. A total of 264 milk samples were collected from Awassi sheep with gangrenous mastitis raised in Sanliurfa province of Turkey. By using bacteriological examination Staphylococcus aureus (75%), Mannheimia haemolytica (7.2%), coagulase negative staphylococci (6.43%), Escherichia coli (4.55%), Corynebacterium spp. (0.76%) and Actinomyces pyogenes (0.76%) were identified. Bacterial DNA was isolated from 155 randomly selected milk sample. By PCR amplification of coagulase gene S. aureus was detected in 91.6% of the milk samples. Three different amplicons of 420 (0.7%), 580 (65.3%) and 780 (34%) bp band sizes, each showing a specific RFLP profile were observed. In conclusion, S. aureus was found to be mostly responsible for gangrenous mastitis in sheep raised in this region. S. aureus in milk samples could be more rapidly detected by PCR method. Two coa genotype of S. aureus were found to be common suggesting that limited number of strains were responsible for most cases of gangrenous mastitis in the region under the study.