Prevalence of Foodborne Pathogens and Spoilage Microorganisms and Their Drug Resistant Status in Different Street Foods of Dhaka city

Abstract

The street foods play an important socio-economic role in meeting food and nutritional requirements of city consumers at affordable prices. This study was designed to evaluate the detailed microbial status including foodborne pathogen and spoilage bacteria and their drug sensitivity status in different street foods of Dhaka city. For this assessment, 39 street foods samples of 13 kinds were collected from Motijheel area, the busiest part of the Dhaka city area. These samples were analyzed for foodborne pathogens including, Salmonella spp., Escherichia coli O157, O111, O26 and other E. coli, other coliforms, Cronobacter sakazakii, Yersinia spp., Listeria spp., Staphylococcus spp., and spoilage microorganisms including Enterococcus spp., Pseudomonas spp., Bacillus spp., and lactic acid fermenting bacteria (LAB). The average natural aerobic bacterial population varied from 3.0 ± 0.04 log CFU/g to 8.8 ± 0.02 log CFU/g and the average coliform count varied from 2.0 ± 0.01 log CFU/g to 7.5 ± 0.02 log CFU/g. In addition, Salmonella spp. and Escherichia coli (O157, O111, O26) were identified in 2 street food samples, other E. coli were found in 5 samples, coliform bacteria was found in 28 samples and Enterococcus spp. in 10 samples, out of 39 food sample analyzed. Moreover, Listeria spp.

were detected in 15 samples, Yersinia spp. in 10 samples, Enterobacter sakazakii in 8 samples, and Staphylo- coccus spp. in all 39 samples. Among the spoilage organisms, Bacillus spp. were identified in 12 food samples,

Pseudomonas spp. in 15 food samples and lactic acid fermenting bacteria (LAB) in 24 samples, out of the 39 samples tested. The isolated pathogens were then checked for antibiotic sensitivity and the results revealed that all the Salmonella spp. exhibited multi drug resistance (at least 7 antibiotics), all Escherichia coli O157, O111, O26 and other E. coli were multi drug resistant (at least 6 antibiotics), Enterobacter sakazakii (at least 6 drugs) and the similar results were found for all the coliform (at least 5 antibiotics), Listeria spp., Pseudomonas spp. and lactic acid fermenting bacteria (LAB). In addition, Staphylococcus spp., Bacillus spp., isolates were resistant to most of the antibiotics and some isolates were resistant to all the antibiotics tested. Enterococcus spp. was found to be sensitive to vancomycin. These study result demonstrated that foods sold in the street of Dhaka City constitutes a potential microbial hazard to human health.