Seroprevalence Of Enterohaemorrhagic Shigatoxin-Producing Escherichia Coli 0157:H7 Isolates From Abattoir Effluents In Zango – Zaria, Nigeria

Abstract

The occurrence of verotoxin-producing Escherichia Coli 0157:H7 (VTEC 0157:H7) in abattoir effluent samples from Zango, Zaria was investigated. A total of 210 samples were obtained from 2002 to 2006. The samples were enriched at the point of collection using Modified Tryptone Soya Broth supplemented with Novobiocin and incubated at 37oC for 24 hours. The enriched samples were plated on Eosin-Methylene Blue (EMB) agar and incubated at 37oC for 24 hours. Colonies showing a greenish metallic sheen on EMB agar were biochemically screened and those that were E. Coli were stored on nutrient agar (NA) slants at 4oC. The selected colonies were later plated on Cefixime Sorbitol – MacConkey (CR-SMAC) agar and incubated at 37oC for 24 hours. Colourless colonies on CR-SMAC agar were tested for verotoxin production by reverse passive latex agglutination using VTEC-RPLA Escheriachia coli verotoxin detection kit. Isolates that produced verotoxin 1(Stx1) and/or verotoxin 2(Stx2) were finally tested serologically using Remel Wellcolex E. coli 0157:H7 Kit. E. coli 0157:H7 was detected in one sample (1/210) or 0.5%. Abattoir effluents are a risk factor to man for E. coli 0157:H7 infection and the pathogen is present in our food animals. Vegetables and fruits from abattoirs should be washed thoroughly with fresh water and/or disinfected using vinegar before consumption since it was observed that such effluents are often used for agricultural purposes on farms near the abattoirs.

Keywords: Enterohaemorrhagic, Escherichia Coli0157:H7, Shigatoxin

Nigerian Veterinary Journal Vol. 27 (3) 2006 pp. 73-79