Molecular and conventional detection of Salmonella spp. and Helicobacter pylori in licensed and individually prepared foods in the city of Al-Kut, Iraq

Background: A wide range of licensed foods (LFs) and foods prepared by individuals (FPIs) in local stores and restaurants have been frequently blamed for food poisoning in many consumers. To the best of our knowledge, no data are available on the status of contamination in these foods. Aim: This study was conducted to estimate the contamination levels and detect some bacterial pathogens in different food sources prepared by individuals in local stores and restaurants in Al-Kut City, Iraq. Methods: Food samples were subjected to microscopic examination and counting. These samples were also examined for the presence of Salmonella spp. and Helicobacter pylori using Quantitative Reverse Transcription Polymerase Chain Reaction. The ureC gene of H. pylori was detected by quantitative reverse transcription polymerase chain reaction using published primers. Deoxyribonucleic Acid was extracted using a commercial kit and amplified using SYBR Green (a DNA-binding fluorescent dye) Green chemistry. Results: The results revealed high bacterial and fungal contamination as discovered by the microscopic method. Furthermore, these samples showed a significant (p < 0.05) presence of Salmonella spp. in many food samples at different rates ranging from 76% to 80%, especially in FPIs. In addition, these samples showed a significant (p < 0.05) presence of H. pylori, as it ranged from 12% to 17% of the FPIs. The ureC gene of H. pylori was detected in 16% of the food samples by quantitative polymerase chain reaction. The highest positivity was recorded in cheese (22%) and cream cheese (18%), while lower rates were found in juices (10%) and yogurt (12%). The difference between cheese products and juices was statistically significant (p < 0.05). These findings confirm that unprocessed dairy products are more contaminated with H. pylori ureC than other foods. Conclusion: The results suggest that high levels of contamination in different food samples need control procedures for better protection against food-borne diseases.