Investigation of Biofilm Formation Ability and Antibiotic Resistance of <i>Staphylococcus aureus</i> Isolates from Food Products

<i>Staphylococcus aureus</i> is one of the major causes of foodborne diseases and its presence in food products may poses a public health challenge. The aims of this study were to assess <i>in vitro</i> the capacity of <i>S. aureus</i> isolates from foods to form biofilm and to determine their antibiotic susceptibility. A total of 80 <i>S. aureus</i> isolates were characterized. The slime production ability was evaluated by congo-red agar (CRA) and the biofilm formation was carried out by microtiter-plate method (MPM). Resistance of isolates to eight antibiotics was determined using disc diffusion method. Sixty-four (80%) of the isolates were slime producers on congo-red agar. However, all isolates were biofilm producers on microtiter-plate method. The highest resistance profiles were ascribed to penicillin G (91.25%) and tetracycline (41.25%). Twelve isolates were methicillin-resistant (MRSA) harboring the <i>mecA</i> gene. All of these MRSA isolates were negative for the genes of the Panton Valentine leukocidine (<i>lukF/S</i>-PV). Typing of the MRSA isolates indicated that they belonged to three spa-types including t024, t450 and t688. The presence of biofilm producers and multidrug resistant isolates (MRSA) in food samples can represent a risk for public health. Therefore, an efficient control and effective measures were needed along the production chain to ensure the food safety.