Contamination level and characterization of Staphyloccocus aureus associated with ready-to-eat foods, food handlers, and environmental factors

Aims: Although several major food poisoning outbreaks caused by Staphylococcus aureus have been reported, monitoring of this pathogen is often neglected. The objectives of this study were to assess the contamination level of S. aureus and characterize the S. aureus isolated in ready-to-eat (RTE), food handlers, food contact surfaces, and table cleaning cloths (TCC). Methodology and results: A total of 150 RTE foods, 59 food contact surfaces (FCS) and 34 table cleaning cloths (TCC) from food premises were examined. The contamination level of S. aureus in RTE foods was at acceptable level. However, more than 10% of the FCS and TCC were contaminated with high levels of S. aureus (>1.0 Log CFU/cm(2), >2.7 Log CFU/piece). Eighty-one isolated S. aureus including those isolated from hands of food handlers were further characterized by antimicrobial susceptibility testing, virulotyping and PFGE. Out of 81 isolates, only three were multidrug resistant. More than 96% (n = 78) of the S. aureus harboured at least one virulence gene. Almost half of the isolates carried at least one staphylococcal enterotoxin in which SEC was the most common enterotoxin detected. Conclusion, significance and impact of study: The PFGE analysis showed that the S. aureus could be disseminated via the FCS, TCC and the hands of food handlers. Therefore, this study reiterates the importance of proper hand washing, sanitation of FCS and TCC, as well as continuous monitoring on S. aureus in food and the food handlers.