Screening virulence properties of staphylococci isolated from meat and meat products

Abstract

Virulence properties (biofilm formation, antibiotic susceptibility, production of extracellular enzymes and the presence of toxin genes) of staphylococci isolated from various meat and meat products were investigated. 22 Staphylococcus spp. (S. aureus n = 9, S. haemolytlcus n = 4, S. cohnii n = 3, S. saprophytics n = 3, S. hominis n = 1, S. simulans n = 1 and S. warneri n = 1) were isolated from 120 meat and meat product samples. 10 strains were biofilmformers. Although none of the strains was resistant to vancomycin, oxacillin, teicoplanin, ofloxacin and gentamicin, 8 strains were found to be resistant to penicillin and one strain was found to be resistant to erythromycin. In addition, all strains were negative for the mecA PCR. 8 strains showed lipolytic activity against Tween 80,10 strains against Tween 20, and 18 strains against tributyrin. Moreover, 9 strains showed proteolytic activity against casein, 11 strains against milk and 17 strains against skim milk containing media. Mostly S. aureus strains showed positive results for icaA-SA, nuc, geh, sspA, sspB, aur, serine protease gene, hla, hlb, set1, and etb. However, 7 of coagulase-negative staphylococci strains were found to carry see gene. As both prevalence and concentration of this bacterium were low, and no isolate contained all virulence factors, it is concluded that common hygiene and process control measures should be sufficient to control meatborne staphylococcal intoxication.