Microbiological quality and risk factors related to sandwiches served in bakeries, Cafés, and sandwich bars in South Korea

The objective of this study was to investigate the microbiological quality of sandwiches produced on site and served in bakeries, cafés, and sandwich bars in South Korea and to determine the major risk factors affecting the sanitation level in each store (n = 1,120). The microbiological quality of the sandwiches was analyzed, and the sanitation level of each store was evaluated as satisfactory or unsatisfactory based on sanitation guidelines. Total coliforms were detected in 906 samples (80.9%), but only 3 samples (0.3%) contained confirmed Escherichia coli contamination. The detection rate was highest for Bacillus cereus (10.0%), followed by Staphylococcus aureus (1.3%) and Salmonella (0.2%). Vibrio parahaemolyticus was not detected in any samples. The microbial contamination level was significantly lower in winter (P < 0.05) and in stores with a higher sanitation grade. Factors related to the microbiological quality of sandwiches were evaluated as the relative risk (RR) of coliform contamination, and the higher risk factors for sandwich contamination were improper holding temperature (RR = 8.75), crosscontamination (RR = 6.30), lack of proper ventilation systems (RR = 6.16), and the absence of clean and/or suitable outer garments (RR = 5.73). Most factors were related to the failure of food handlers to adhere to sanitation guidelines rather than to unsanitary environments. This study provides a comprehensive analysis of the relationship between the microbiological quality of sandwiches served on-site and various risk factors. These results will help researchers establish guidelines for the sanitary management of sandwich shops.