Investigating the presence of environmental Listeria in butcher shop utensils and surfaces using petrifilms

Foodborne illnesses persist as a substantial global public health threat, with Listeria monocytogenes being especially alarming due to its high fatality rate and ability to survive in food-processing settings. This study used a mix of culture-based, biochemical, and molecular techniques to examine the incidence of environmental Listeria in butcher shops in Mosul, Iraq. Eighty swab samples (sterile polyurethane foam PUR-Blue™ swabs) were collected from knives, hooks, cutting boards, and refrigerator inner surfaces across 20 butcher shops. Using 3M™ Petrifilm™ plates, 24% of the samples showed signs of presumptive Listeria spp. The API Listeria system showed different biochemical reactions during verification, and PCR amplification of the iap gene confirmed L. monocytogenes in 15% of the total samples. Knives and hooks had the most contamination, with 37% and 26% of positive detections, respectively. Cutting boards had 21%, and refrigerator surfaces had 16%. The results showed how everyday utensils can lead to cross-contamination and highlighted L. monocytogenes as a continuing public health risk in stores that sell meat. The phylogenetic analysis showed that the Mosul isolate (PX204934) clustered closely with the Baghdad isolates (MN960572 and MN960575), indicating a common regional lineage. Improved sanitation, regular monitoring, and proper staff training are important to reduce environmental contamination and prevent L. monocytogenes from entering the food chain.