Comparative study of the microbiological status of street, lower-mid, higher-mid and high level fast food shops and detection of multidrugresistant isolates

Abstract

Fast foods and street foods are a part of life of the people of Dhaka city nowadays. Through these foods, food borne diseases are also increasing in an alarming rate. This study was conducted on chicken burgers of the Gulshan area of Dhaka city as it is one of the most consumed fast foods. Total viable count (TVC), coliform and enteric pathogens count (CEC), Staphylococci count (SC), and also the presence of urinary tract infection causing pathogens, Salmonella spp., Shigella spp. were observed in this study. In the present study, it was observed that the total viable count, enteric pathogen and coliform count were very high in almost every level of restaurant foods. This might be due to the street dust, unhygienic water, unclean dishes, improper food handling etc for the street side foods. In higher-middle level and high level restaurants, this result might be due to unhygienic handling of foods, improper storage temperature and storing and uses of unhygienic and expired raw materials. Bacterial count in Nutrient Agar (NA) isolated from street level, lower-mid level, higher-mid level and high level restaurants ranged from 3.3X105 to 2.2X107 CFU/ml, 1.9X106 to 2.0X106 CFU/ml, 7.0X105 to 2.3X107 CFU/ml and 7.5X106 to 2.3X107 CFU/ml respectively. Bacterial count in MacConkey agar isolated from street level, lower-mid level, higher-mid level and high level restaurants ranged from nil to 5.48X105 CFU/ml, 9.55X105 to 1.8X106 CFU/ml, nil to 1.0X105 CFU/ml and nil CFU/ml respectively. Bacterial count in Manitol Salt Agar (MSA) of street level, lower-mid level, higher-mid level and high level restaurants ranged from nil to 1.6X106 CFU/ml, nil to 8X105 CFU/ml, nil to 4.33X105 CFU/ml and 2.1X106 to 2.2X107 CFU/ml respectively. Antimicrobial sensitivity results of the bacteria Raoultella planticola isolated from a higher midlevel restaurant showed resistance to 4 antibiotics out of 7 antibiotics and Bacillus coagulans isolated from a street level restaurant showed resistance to 3 antibiotics. This study specifically highlighted the level of microbial loads and multi-drug resistant (MDR) bacteria found in burgers. Finally, this study recommended some preventive measures, which the government and food-maker together should follow and should also maintain the standard hygienic procedure for preparing and handling foods.