Pathogenicity of Escherichia coli O125 in commercial broiler chickens

Abstract

Commercial broiler chickens are frequently infected with Ecoli serotypes in form of collibacillosis which characterized as an initial respiratory infection (air sacculitis) followed by generalized septicemia, perihepatitis and pericarditis. The present work aimed to study the ability of E.coli O125 previuosly isolated and identified from diseased broilers suffered from pericarditis , airsacculitis and perihapatitis to induce a disease and The current study aimed to determine the pathogenicity of E. coli serogroup O125 in broiler chicks, a trial of prevention and treatment using probiotic ( Guardyazin-m) or antibiotic (Cipronate20%). The chicks were divided into seven groups including control negative, orally infected , subcutenously infected , probiotic treated group, and finally antibiotic treated group. The clinical signs, mortality, performance parameters and postmortem examination as well as the pathological changes in liver and intestine were recorded. The probiotic group gave the best results in controlling infection by E. coli O125 followed by antibiotic. In conclusion, the E. coli O125 serogroup was pathogenic to chicks when experimentally inoculated, so particular attention must be directed toward E. coli O125 as a pathogen infecting bird. Also probiotics was of great value in protection against the E. coli infection and improve the performance parameters of chicks . Its effect on feed consumption , weekly body weight gain and feed conversion rate (FCR) was determined.