IOSR Journal of Biotechnology and Biochemistry (IOSR-JBB) ISSN: 2455-264X, Volume 5, Issue 6 (Nov. – Dec. 2019), PP 50-53 www.iosrjournals.org DOI: 10.9790/264X-0506015053 www.iosrjournals.org 50 | Page Isolation and Characterization of Escherichia coli in Street Fast Foods in Rural Areas Preeti Dwivedi 1 and Sumit Kumar 2 Research Scholar, Bhagwant University, Ajmer, Rajastha 1 Associate Professor, Bhagwant University, Ajmer, Rajastha 2 Abstract: Isolation and characterization of E. coli in fast foods concerns due to their presence indicates fecal contamination of the food. To identify, characterize and RFLP pattern analysis of E. coli isolated from vended fast foods in rural areas of Delhi-NCR. Genomic DNA was used to perform RFLP pattern analysis. Eighteen out of 24 (75%) analyzed samples of fast foods had E. coli contamination. The highest number of E. coli was isolated from chicken biryani and golgappa (83.33 %) and burger and vegetables ready to eat fast food (66.66 %) samples were also significantly E. coli positive. RFLP profiling of E. coli isolates was observed. Keywords: Vended fast foods, Escherichia coli, Genomic DNA, RFLP profiling --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 11-11-2019 Date of Acceptance: 27-11-2019 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction Food safety is an essential component of public health, linking health to different food production and agriculture sectors 1 . Most common bacterial pathogen is Escherichia coli which is capable of causing intestinal disease. Some E. coli are nontoxic and are found naturally in the intestine of humans 2 . Escherichia coli strain O157 is a part of enterohemorrhagic Escherichia coli and has been identified as the cause of numerous outbreaks by causing, hemorrhagic colitis, hemolytic uremic syndrome, diarrhea 3 . In developing countries street food and junk food plays an important role 4 . Food sector has experienced important growth during the earlier period because of social and economic changes in developing countries. They give food to large number of people daily with an extensive range of ready-to-eat foods and sometimes prepared these foods in the public places or streets, reasonably low-priced and easily offered 5 . Safe water for food and human consumption is important, but there is a limited supply. Developing countries has water shortages during summer season in many colonies and depends on other sources of water including boreholes and water tankers. Microbiological assessment of drinking water and food is important to reduce exposure to cause intestinal disease 6 . A food borne pathogen E. coli O157:H7 was first recognized in America 7 after an occurrence of hemorrhagic colitis following the ingestion of undercooked hamburgers at a fast-food restaurant chain 8 . The present research work in rural areas represents the data of E. coli in fast food products. Mostly microorganism present in different types of food items is non-toxic 9 . So it is very important to identify the toxic pathogen in order to build up an appropriate test to detect pathogen. Culturing technique is a conventional method to identify food born pathogen by plating to isolate pure culture. Genomic DNA isolation technique can arrange within pool culture of bacteria. Food borne pathogen along with dissimilar bacterial species can detect by RFLP technique. The main objective of this work was to find out the presence of E. coli in many street fast food or ready to eat food samples in rural areas in Delhi-NCR. II. Materials and Methods Sample collection: Approximately 100 g of each 24 samples of street fast food of 4 categories (6 samples of chicken biryani, 6 samples of burger, 6 samples golgappa and 6 samples of vegetables) were collected between July 2018 and August 2018 from different places in rural areas of Delhi-NCR. All samples were tested within 24 h of collection. Ten grams of each food sample was mixed with one eighth strength Ringers Solution. The sample was homogenized with an electric hand blender at 5000 rpm for 10-12 minutes (10 -1 dilution), followed by serial dilutions up to 10 -6 dilution. Isolation and test of E. coli: The most probable number (MPN) method was used for determining E. coli counts 10,11 . Fermentation tubes (10 ml) of lauryl tryptose broth medium were poured with different concentration. The tubes were inoculated with 5 ml, 1 ml with 5 ml, and 1 ml and 0.1 ml amount of sample and incubated at 37°C for 24 h. All tubes under experiment producing gas after 24 h of incubation, was further tested for conformation. In this analysis, dilutions of the each sample were made using peptone water. 1ml of each sample was pipetted into one sterile test-tube containing 9 ml of peptone water, making 1:10 dilution, second