Sequential Pathogenicity Study of SOR+ and SOR- Escherichia coli Isolated from Roasted Meat

Abstract

The roles of E. coli in cases of diseases has been established and reported to have a substantial degree of morbidity and mortality among children and adults. This study was carried out to investigate the sequential pathogenicity of sorbitol positive (SOR⁺) and sorbitol negative (SOR^-) Escherichia coli isolated from roasted meat in Uli Community. A total of 10 roasted meat samples were randomly collected from four different points in Uli Community and screened for the presence of SOR⁺ and SOR^-E. coli using the pour plate technique. The isolates obtained were characterized and identified using their colonial descriptions, morphological and biochemical characteristics. The pathogenic potentials of the isolates on chicks were investigated by challenging the chicks orally using 0.5 ml of the inoculum (10⁸cells/ml). All chicks were kept under complete observation for 2 weeks for pathological signs and symptoms, mortalities and gross morphological lesions of the internal organs. The SOR⁺E. coli; T₁ (21. 78%), T₂ (18. 18%), T₃ (26. 73%) and SOR^-E. coli R₁ (19. 80%), R₂ (12. 87%) were seen in the studied samples, and R₁ was mostly seen in the samples collected from the school front area. There were a significant (P<0.05) increase in organ weights, obvious pathological signs and lesions on the internal organs of the infected chicks, and these were seen most in SOR^-E. coli. There were significant (P<0.05) viable plate counts of the isolates from the harvested organs, of which the counts of SOR^-E. coli were recorded most. No count was recorded from non-infected chicks. It was observed that T₃ was the most predominant from the studied samples when compared to T₁, T₃, R₁ and R_2. The test isolates showed reasonable pathogenic features among chicks and SOR^-E. coli, mostly R₁ proved to be most pathogenic among the tested isolates.