Detection of Escherichia coli, Salmonella spp. and Staphylococcus aureus in Ready-to-Eat Food in Al-Ahsa Province, Saudi Arabia

The study aimed to identify and characterize foodborne- Staphylococcus aureus,Escherichia coli and Salmonella spp. in Al-Ahsa Province, Kingdom of Saudi Arabia (KSA), as potential reservoir of human infection and transmitters of antimicrobial resistance. A total of 90 sandwich samples (consist of minced meat and vegetables) were aseptically collected from fast-food cafeterias. Conventional bacteriological techniques were used to isolate Staph. aureus, E. coli and Salmonella spp. For E. coli isolates, molecular analysis was made. Staph. aureus was confirmed from 11.11% of specimens of which 30% were MRSA. MRSA were resistant to erythromycin, nitrofurantoin and Trimethoprim/ Sulfamethoxazole. Non-MRSA were resistant to ciprofloxacin and all Staph. aureus isolates were sensitive to vancomycin which may be a choice for treatment. At a rate of 5.56%, E. coli was confirmed by conventional techniques and VITEK 2 system; E. coli strain O157: H7 was not identified from the isolates. Molecular analysis indicated that 4 strains belonged to Shiga toxigenic E. coli (STEC) family and one strain was Shigella flexneri. Antimicrobial susceptibility analysis of isolates showed two strains (40%) were extended-spectrum β-lactamases (ESBL) positive that were demonstrated to be susceptible to imipenem but resistant to ciprofloxacin. On the other hand, three strains (60%) were identified as ESBL negative which were susceptible to all tested antibiotics. Salmonella spp. were not isolated from any food specimen in the present study. From ready-to-eat food in Al-Ahsa Province, KSA, Staph.aureus MRSA and Non-MRSA were susceptible to vancomycin. Using molecular methods, E. coli and Shig. flexneri were confirmed from food with ESBL positive susceptible to imipenem but resistant to ciprofloxacin.