ABSTRACT Street vended foods are readily available source of meals for many people but the biological safety of such food is always uncertain. In developing countries, the major source of food borne illnesses is ready to eat foods that are prepared and sold at public places. The main objective of this study was to evaluate the bacteriological quality and safety of ready to eat potato (Solanum tuberosum) available in common streets of Balemi town. A prospective cross-sectional study was conducted. A total of 40 purposively samples were processed for both peel and flesh analysis by dividing each sample in to two portions and detection of total coliforms, fecal coliforms and Salmonella and Shigella were done for both peel and flesh part of potato sample using standard methods of microbiological analysis from November, 2014 to June, 2015. Biochemical and antimicrobial susceptibility test was performed for 50 sample bacteria (sample Salmonella 35 and sample 15 Shigella) isolated from both flesh and peel parts. The degree of susceptibility of these isolates were evaluated against eight different antibiotics, Cefoxitin, Chloramphenicol, Ciprofloxacin, Cotrimoxazole, Erythromycin, Gentamycin, Nalidixicacid and Tetracycline using Kirby-Bauer disk diffusion method. Gentamycin, Chloramphenicol and Ciprofloxacin antibiotics were effective to Salmonella and Cefoxitin antibiotics were effective to Shigella. Interview guide and checklist were also administered in order to get information from street vendors to trace source of contamination. The result of this study showed that, total coliform count ranged from 15 to 1100 MPN/g and 11 to 1100 MPN/g from peel and flesh potato parts respectively, Fecal coliform also ranged from 15 to 1100 and 11 to 1100MPN/g from peel and flesh respectively and Salmonella 35 (87.5%) and 15 Shigella (37.5%) from both parts of samples were isolated. Both total coliforms and fecal coliforms counts of flesh and peel samples had significant difference (P<0.05). The finding of this study indicated the poor hygiene practice of street food handlers at the study site is poor. Education and training on good food handling practice should be provided to all food handlers as a means of prevention. Keywords: Street food, Total coliform, Fecal coliform, Salmonella, Shigella, xi

A Thesis submitted to the Biology department, College of Science, Bahir Dar University in partial fulfillment of the requirement for the degree of Master of Science in Biology