Evaluation of the microbial burden of grilled food and hummus from restaurants in Al-Ahsa region of Saudi Arabia

Abstract Background The quality of food preparation is considered a public health concern. The present study aimed to evaluate the microbiological quality of grilled food and hummus. Materials and methods The study was conducted in Al-Ahsa Governorate, Saudi Arabia. Restaurants were categorized into traditional and non-traditional. Grilled food (meat and chicken) and hummus were collected without prior arrangement with the restaurant staff. All samples were examined for the total aerobic count and the presence of Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Salmonella spp. Staphylococcal enterotoxin and serotypes, antimicrobial susceptibilities and the PCR detection of virulence genes of E. coli and Salmonella spp. were determined. The culture of hands of food handlers was performed by direct swabbing. Results A total of 83 samples, including food and hand swabs, were collected from six traditional and four non-traditional restaurants. All samples cultured yielded acceptable total aerobic count. Of the 83 samples, 36 (43%) tested positive for the targeted organisms. Among these, 38% were hand swabs, 25% were hummus, 19% were meat tikka, and 6% each were meat kebab, chicken tikka, and chicken kebab. In total, E. coli, K. pneumoniae, Salmonella spp., and S. aureus were cultured from 29, 10, 20, to 13% of the collected samples, respectively. All S. aureus isolates (11) were positive for enterotoxin. E. coli isolates (24) were enteropathogenic with different serotypes, and the stx1, stx2 and eaeA genes were detected. Ten Salmonella isolates with different serotypes were positive for invA gene, and most also harboured hilA and fimH genes. Thirty seven percent of hands grew at least one of the targeted organisms, including one Salmonella. Methicillin-resistant S. aureus (MRSA) was isolated from the hand of a food handler, and ciprofloxacin resistance was detected in 30% of the Salmonella spp. tested. Conclusion We found that food served in local restaurants contained potential pathogens or toxin. Random inspection, including bacterial cultures, and more rigorous rules may be required to improve food production standards. Clinical trial number Not applicable.