Performance assessment of a food safety management system in meat processing plants and the local market of Tehran: A microbial source tracking study

Foodborne diseases are a major public health concern worldwide, and they can be prevented by implementing a food safety management system (FSMS) in the food chain. Coliforms and Escherichia coli are commonly used as indicators of foodborne pathogens and hygiene conditions in food products. This study aimed to assess the FSMS performance in three meat processing plants and the local market of Tehran by detecting coliforms and Escherichia coli in hamburger samples and evaluating the main sources of contamination in final products. A total of 107 samples were collected from raw materials, hands of food handlers, contact surfaces of food processing equipment, and products of the three plants. In addition, 45 hamburger samples were purchased from the local market. Polymerase chain reaction analysis was performed on the positive samples to confirm the presence of Escherichia coli O157:H7. Frequency (percentage), and mean (standard deviation) were used to describe the data. Approximately 38 % (41/107) of the samples from the three plants were contaminated with coliform bacteria and Escherichia coli, and only one sample was contaminated with E. coli O157:H7, which originated from the raw meat in plant C. Moreover, 80 % (36/45) of hamburger samples collected from the local market contained coliforms lower than 102 CFU/g and E. coli lower than 10 CFU/g, and none of them were contaminated with E. coli O157:H7. The results showed that the three plants were significantly different in terms of the number of coliforms and E. coli (p<0.05). Regarding the number of coliforms and E. coli, plant C had the highest, and plant B had the lowest value.  Implementation of FSMS in the food chain reduces microbial contamination. There is no safety concern about Escherichia coli O157:H7 contamination in hamburgers marketed in Tehran.