Incidence of Enterotoxigenic Escherichia coli in Slaughter Houses in Sagamu, Nigeria

Abstract

Enterotoxigenic Escherichia coli (ETEC) is one of the strains of E. coli responsible for E. coli-associated diarrhea outbreaks world-wide due to the consumption of contaminated foods. Cattle and their environment have been incriminated as the most important sources of pathogenic E. coli. The aim of this study was, therefore, to isolate and identify ETEC in abattoirs in Sagamu. A total of 108 swab samples were collected from different anatomical sites and faeces of selected cattle and floor of slaughter houses in Sagamu, Nigeria. The faeces were collected into a universal bottle with scoop, the tip of sterile swab stick was moistened with sterile water and was used to collect samples from the body coats (Rump and Brisket) before slaughtering, skin (Brisket and Rump) after evisceration and slaughter house floors before and after use. All the samples were homogenized into sterile peptone water and incubated at 37oC for 18-24hrs. Each sample was cultured into MacConkey and Eosin Methylene Blue agar for bacteria isolates. Colonies with typical green metallic sheen after sub culturing into EMB were further identified using BD BBL identification system. All the positive isolates were a screen for enterotoxigenic Escherichia coli genes (LT and ST) by polymerase chain reaction. A total of 50 (46.3%) Escherichia coli were recovered from the different samples. The percentage of occurrence of E. coli in faeces 7 (70%) at Kara abattoir was slightly higher than that of Agbele abattoir 6 (60%) but the difference was not statistically significant (P > 0.05). E. coli was observed to be higher in brisket area of the body coat 5 (50%) at Agbele than the rump area of the body coat 4 (40%) but E. coli in the rump area of body coat 5 (50%) was higher than the region of the brisket of body coat 3 (30%) at Kara. The rump area of the skin had the least isolation rate when compared with the brisket of the skin at the two abattoirs. Furthermore, the molecular identification of enterotoxigenic Escherichia coli virulence genes showed that none of the 50 E. coli isolated was positive for heat labile and heat stable genes.