Microbiological Evaluation Of Gram Negative Bacteria From Different Street Foods Responsible For Enteric Diseases

Abstract

In this present study, we analyzed the microbial quality of street vended food samples. The main purpose of this study was to find out the incidence of enteric bacteria specially Escherichia coli, Shigella, Vibrios, Klebsiella and Salmonella in different food samples. Total 30 samples were collected from the street vended shops beside the 10 universities in Dhaka city, Bangladesh. Five different agar media were used for isolation and identification of our suspected organisms from the samples. The agar media were MacConkey, TBX (Tryptone Bile X-glucuronide Agar), BGA (Brilliant Green Agar), XLD (Xylose lysine deoxycholate) and TCBS (Thiosulfate citrate-bile salts sucrose). Microbial growth was observed in different media plates. In the study, among 12 fried items, 2(17%) samples were contaminated with E.coli, again 2(17%) were contaminated with Klebsiella spp. and 1(8%) were contaminated with Vibrio spp. Among 17 spicy items 2(12%) samples were contaminated with Klebsiella spp., again 2(12%) were contaminated with Vibrio spp. among 1 baked items, only 1(100%) samples were contaminated with Klebsiella spp. No Salmonella spp. and no Shigella spp. were found from any food sample. Seven biochemical tests were performed for characterizing the organisms. We have also performed colony counting of additional six foods standards method. Among six samples, highly concentrated colonies were found in plain cake. Therefore, adequate measures and specific training should be provided for the street food venders, and should be concerned about it in the students community.