Determination of some virulence factors in Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium isolated from meat and milk products.

摘要

The aim of this work is to characterize Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium isolated from meat and milk products in Ankara, Turkey. A total of 40 S. aureus, 55 E. faecalis and 30 E. faecium isolates were isolated from raw calf meat (minced), chicken drumsticks, raw milk, ice cream and white cheese samples. A high proportion of S. aureus isolates had slime formation (80%), biofilm formation (70%), deoxyribonuclease (DNase) activity (53%), hemolytic activity (40%), protease production (80%) and lipase production (45%). The frequency of positive slime formation, DNase activity, hemolysis and protease production for E. faecalis isolates was 36, 5, 7 and 16%, and for E. faecium isolates was 50, 10, 13 and 6%. Neither biofilm formation nor lipase production was detected in Enterococcus isolates. It was found that S. aureus isolates were resistant to penicillin (77%), ampicillin (67%), erythromycin (30%), tetracycline (25%), chloramphenicol (20%) and gentamicin (17%), but they were sensitive to vancomycin and teicoplanin. All Enterococcus spp. isolates were sensitive to ampicillin, chloramphenicol, teicoplanin, tetracycline and vancomycin, but they were resistant to erythromycin (47%), gentamicin (14%) and penicillin (4%). Practical Applications. A number of factors contribute to the virulence of Staphylococcus aureus and enterococci, including slime, biofilm, deoxyribonuclease, hemolysin, protease and lipase production. Our results suggest that the determination of these traits in food isolates of S. aureus and enterococci could be valuable tests for the meat and dairy industry. Antimicrobial resistance is an important public health concern worldwide. Thus, antibiotic resistance can also be used as adjunct test in the food industry. In the absence of control measures, virulent and antibiotic-resistant organisms might be transmitted to humans by the consumption of meat, milk and their product