Occurrence and Antibiogram of Escherichia Coli O157:H7 in Locally Fermented Milk (Nono) Sold Under Market Conditions in Nasarawa State,

Abstract: Escherichia coli O157:H7 is a newly emerging pathogen frequently associated with the consumption of food of bovine origin. Severe and life threatening human diseases caused by E. coli O157:H7 strains have been reported throughout the world. This present study evaluated the occurrence of E. coli O157:H7 in locally-fermented milk (nono) sold under market conditions in Nasarawa State, Nigeria and the patterns of their antibiotic susceptibility. A total of 420 nono samples were purchased across Nasarawa State. The samples were bacteriologically analyzed in the laboratory for the presence of E. coli O157:H7 by means of cultural techniques (enrichment on modified tryptone soy broth and selective plating on Cefixime-Tellurite Sorbitol Mac-Conkey Agar), biochemical (Microbact 12E) and serological assays. Oxoid diagnostic kit; latex (R30959601) was used to confirm E. coli O157:H7 respectively. Confirmed isolates were further subjected to antimicrobial susceptibility test using the Agar disc diffusion technique. The results of the study showed that out of 420 nono samples examined, 19 (4.5%) were contaminated with E. coli O157:H7. Among samples examined, the highest occurrence rate (5.7%) was recorded in samples obtained from Akwanga, Wamba and Doma Local Government Areas while Lafia and Keffi had the least occurrence rate (2.9%). With respect to the senatorial zones, Nasarawa North had the highest occurrence rate of 5.7 % while the Southern zone had the least (3.6%). There was no significant difference (P>0.05) in the occurrence of E. coli O157:H7 isolated from nono samples with respect to the various Local Government Areas. Antibiotics susceptibility profile showed tha