Detection of Antibiotic-Resistant Airborne Bacteria in Restaurant Environments in Riyadh City

The spread of bacteria that cause illness is a critical problem facing the restaurant industry worldwide. These bacteria can proliferate in various restaurants areas through airborne transmission mechanisms, increasing the risk of food contamination. In this study, our aim was to detect the presence of potential foodborne pathogenic bacteria-Escherichia coli, Staphylococcus aureus, and aerobic bacteria-in aerosols of different restaurants zones in Riyadh city in the Kingdom of Saudi Arabia. We focused on 3 important zones: preparation (Zone A), food packaging (Zone B), and handwashing (Zone C). The bacteria of interest were isolated, identified, and characterized by using selective media, biochemical, and antibiotic susceptibility tests. The results showed that all 40 of the studied restaurants were contaminated with aerobic bacteria, with a total count of 3,978 colony-forming units (CFU) in Zone C, 1,323 in Zone B, and 525 in Zone A. E coli was identified as the most prevalent illness-causing bacteria in Zone A-derived aerosols (721 CFU), while S aureus had the highest occurrence in aerosols in Zone C (528 CFU). Pertaining to the antibiotic resistance phenotype of assessed isolates, our findings revealed that Zone C-derived E coli isolates showed resistance ranging from 25% to 100% toward 8 of the 15 tested antibiotics. S aureus isolates originating from Zone B exhibited between 25% and 75% resistance to 2 antibiotics, while isolates from Zone C showed resistance ranging from 5.88% to 47.05% to 4 antibiotics. Findings from this study illustrate that restaurants' aerosols are highly contaminated with different antibiotic-resistant bacteria, which increases the risk of food poisoning and threats food security.