Isolation and Identification of Bacillus Cereus and Escherichia coli from Food Sample Sold Within, Kaduna Town

Abstract

This study was carried out to isolate and identify Bacillus cereus and Escherichia coli. Bacillus cereus and Escherichia coli were isolated and identified from food samples sold from local food vendors within Kaduna town, Nigeria. This was done using conventional standard method. The molecular characteristics were confirmed by the Polymerase Chain Reaction (PCR) technique. The results of the microscopic characteristics of the isolates revealed that B. cereus is a Gram positive, rod shaped bacterium. The colony of the bacteria appeared rough with dried pink background surrounded by egg yolk precipitate on MYP medium while E. coli appeared Gram negative rod shaped under the microscope. And its colony on plate appeared flat with green metallic sheen on Eosin Methylene Blue (EMB) agar. The biochemical identification showed that B. cereus is positive to haemolysis, catalase, citrate, Vouges Proskauer, motility and spore tests. While E. coli is positive to catalase, indole, methyl red and motility tests and showed a green sheen characteristics on Eosin Methylene blue agar. The PCR showed band at 204bp amplicons of 16S rDNA primer targeting bacterial DNA templates V3 hyper-variable region for B. cereus and E. coli respectively. The amplified DNA was sequenced and BLAST and accession number of KY962911.1 and KY009556.1 were obtained for B. cereus and E. coli respectively