Document Type : Original Article
Authors
1
Bacteriology, Immunology and Mycology Department Faculty Veterinary Medicine, menoufia university, Egypt
2
Anatomy Department Faculty of Veterinary Medicine Shebin El-com Menofia University, Egypt
3
Bacteriology, Immunology and Mycology Department Faculty of Veterinary Medicine, Benha University, Egypt
4
Animal Health Research Institute, Tanta Branch, Egypt
5
Department of Food Hygiene and Control, Faculty ofVeterinary Medicine, Menoufia University
Abstract
Coagulase positive Staphylococcus aureus (S. aureus) is one of the most common etiological pathogens, causing intramammary infection in dairy herds leading to severe economic losses in dairy industry,So this study aimed for the sampling, isolation ,biochemical and genotypic characterization of coagulase positive Staphylococcus aureus from raw milk (cow and buffalo)and dairy products . A total of 100 random samples of raw milk(cow and buffalo), kareish cheese, baladi yogurt (25 of each) were collected from different shops and supermarkets , all samples examined bacteriologically for characterization of coagulase positive Staphylococcus aureus. A total of 52 isolates of S.aureus was recovered 21/25 ( 84%), 17/25 (68% ), 8/25 (32%), 6/25 ( 24%)from raw cow milk, raw buffalo milk, kareish cheese, baladi yogurt , respectively, then the positive isolates examined for their coagulase activity and for their resistance to different types of antibiotics and results of some strains were highly resistant to penicillin (80%) followed by clindamycin (60%) , erythromycin (53%) and other strains were highly sensitive for gentamicin(100%) ,norfloxacin (93%) ,vancomycin (86%) and linezolid (60%). Then Polymerase chain reaction (PCR) was applied on positive strains of S.aureus to detect their virulence genes staphylococcal protein A (SpA) and coagulase gene (coa) which were detected with percentage (100%)of tested isolates, and beta- lactam resistance gene (blaZ) was found in (33%) of examined s.aureus strains.
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