Isolation, identification and molecular characterization of pathogenic organisms obtained from meat samples (cooked, semicooked and raw) of different areas of Dhaka city

Abstract

Meat is the main source of protein now a days all over the world. From the people living under boarder line of poverty to high maintenance society, beef, mutton and chicken are taken as important source of proteins. Although beef and mutton are the most desirable ones; because of the availability and low price chicken is consumed even more than the rest. Due to improper handling and poor hygiene at the time of preparing the food, meat related foods are extremely unhealthy in Bangladesh. In this study 43 samples were taken from different areas of Dhaka city, the results supported the mentioned concern. Most of the meat samples were cheap and on the list of regular intake of students studying in these areas. Some of the samples showed almost 80- 90% contamination with Escherichia coli that is a coliform bacterium and found in human excreta mostly. Most of the samples were cooked and processed; nonetheless they did not lack any less of organisms or contaminations. Chicken samples were collected in three states, which were cooked, semi-cooked and raw. Some of the cooked and most consumed samples showed presence of 6-7 organisms. The organisms identified so far are Escherichia coli, Enterobacteor aerogens, Salmonella spp, Staphylococcus spp, Pseudomonas and others. The purpose of this study is to make the authorities regulating food safety aware of such contamination and take necessary steps to avoid this sort of disorientation towards food related business. In our research biochemical tests such as streaking on EMB and MacConkey agar, MRVP, TSI etc. were done, in addition morphological characteristics of the single colonies of isolated microorganisms were also examined and interpreted. DNA from samples positive for E. coli were isolated and by gel electrophoresis their bands were examined where most of them gave positive bands for STEC, meaning positive for pathogenic E. coli strains.