Occurrence and Antimicrobial Susceptibility Profile of Escherichia coli Isolates from Vended Milk in University of Abuja Community, Federal Capital Territory, Nigeria

Abstract

Purpose: This study was conducted to establish occurrence and antimicrobial susceptibility profile of Escherichia coli (E. coli) isolates from cow milk (Nono) sold within University of Abuja campuses. Methodology: Fifty (50) samples of "nono" milk were randomly collected from vendors in mini and main campus of University of Abuja from August to October 2021. All samples were analyzed using pour and surface plating methods. Presumptive E. coli isolates on Eosin methylene blue agar were characterized using preliminary and standard biochemical identification methods such as microbial plate count, Gram staining, oxidase, indole, methyl red, voges-proskauer, citrate and catalase tests. Antimicrobial susceptibility testing was conducted on positive isolates using the disc diffusion method. Findings: Out of the 50 samples of nono milk cultured, thirty (30) yielded growth for Escherichia coli which appeared as greenish metallic sheen on EMB agar plate and Gram-negative short rods on microscopic examination, representing an overall prevalence of 60%. The overall viable count of all samples was extremely high, with 8.7x10^7cfu/ml recorded as the highest colony forming unit per milliliter (CFU/ml) and 1.5×10^7cfu/ml recorded the lowest colony forming unit per milliliter (CFU/ml). All isolates were indole positive, methyl red positive, oxidase negative, citrate negative, catalase positive and voges-proskauer negative. E. coli isolates in this study were susceptible to sparfloxacin (66.7%), gentamicin (66.7%), ciprofloxacin (60%), streptomycin (60%), and tarivid (53.3%) and resistant to Septrin (73.3%), Augumentin (60%), Pefloxacin (66.7%), chloramphenicol (60%) and amoxicillin (53.3%). In conclusion, this study showed that the degree of contamination of E. coli in vended milk in the study area is higher than the maximum permissible bacteria count recommended by Codex Alimentarius standard for fermented milk products which is indicative of potential hazard to consumers. Recommendation: Public enlightenment on hygienic handling of milk during milking and especially vending by milk vendors is hereby recommended. Use of cool thermos for milk hawking is also advocated.