Assessment of Conventional and Molecular Features of Staphylococcus aureus Isolated from Bovine Milk Samples and Contact Dairy Workers

A total of 384 apparently normal quarter foremilk samples, collected from 96 machine milking lactating Friesian cows from Aswan governorate, were cultivated on Baird Parker media. 52 swabs collected from contact dairy workersʹ hands or faces were streaked on mannitol salt egg yolk agar (MSEY agar). Isolated Staphylococcus aureus strains were examined for coagulase slide test, Catalase and DNAase test. Staphylococcus aureus isolates were tested by a two multiplex PCR assays one of them was to detect 16SrRNA gene and coagulase (coa) gene. The second multiplex PCR was to clarify presence of S. aureus entertoxins type A (SEA) andB (SEB) in positive coagulase S. aureus. For bovine milk, a prevalence rate of 39.7 % and 34.1 of California mastitis test (CMT) and Somatic cell count (SSC) was detected, respectively. Whereas, coagulase test was positive in 33.55 and 56.52% of bovine milk and contact daily workers in the same sequence, 16Sr-RNA gene was positive in 49.61 and 82.6% of bovine milk and daily workers, respectively. While coagulase (coa) gene was positive in 40.45 and 69.56 % of milk and daily workers, respectively. SEA was positive in 21.37 and 43.47 % of milk and dairy workers in the same manner, respectively. While SEB was positive in 20.61 and 34.78% in the same sequence, respectively. In conclusion testing milk (by CMT, SCC and microbial isolation) for detection of subclinical mastitis is an essential part of daily evaluation record of each daily farm and detection of S. aureus by PCR as well as entertoxins identification found to be rapid, sensitive and accurate. Special concern should be directed to elucidate the kinetic transfer of S. aureus between animals and human. Detection of S.aureus entertoxin A and B were found to easy and rapid by using PCR.