Molecular Characterization of Enteroxigenicity Profiles of Enteric Bacteria Isolated from Chicken Feeds

Abstract

This study focused on molecular characterization of enterotoxigenicity profiles of enteric bacteria isolated from different brands of commercially produced chicken feeds sold in Anambra State. A total of 1,536 different chicken feed samples (starter, growers, finisher and layers) were collected from the consumers, retailers and wholesalers and screened for the presence of enteric bacteria using pour plate technique. The isolates were characterized and identified using their colony descriptions, biochemical and molecular characteristics. Presence of enterotoxins among the isolates was detected using Polymerase Chain Reaction (PCR) amplification of Ltx1 and Ltx2 genes. The result of this study revealed that Escherichia coli O157:H7 SS52 (EC), Salmonella serovar Typhimurium U288 (ST), Escherichia coli SEC470 (ES), Salmonella serovar Enteritidis YU39 (SY) and Salmonella serovar Enteritidis FM366 (SE) were isolated from the feed samples. The PCR results showed significant (P<0.05)  amplification of heat labile-1 (Ltx1) and heat labile-2(Ltx2) enterotoxin genes from EC, SE and ST of which EC showed most pronounced results. Thus, this study has shown that EC, ST, ES, EY and SE were detected from the studied chicken feed samples. The PCR results have revealed regions that contained heat labile enterotoxins, of which this region was most significant in EC.

Keywords: Enterotoxigenicity, Enteric bacteria, Chicken Feeds, Polymerase Chain Reaction.