Prevalence of antibiotic resistance and molecular characterization of <i>Escherichia coli</i> from faeces of apparently healthy rams and goats in Ile-Ife, Southwest, Nigeria

Abstract

The study reports isolation and identification of Escherichia coli from the faecal samples of goats and rams in Ile- Ife, Nigeria. It also determines the antibiotic susceptibility profile, presence of plasmid DNA, resistance (bla_CTX, tetK, tetM) and virulence (Stx₁, eae) genes in the isolates. Four hundred rectal swabs were collected from goats and rams at three different locations in Ile-Ife. The susceptibility of the isolates to antibiotics was carried out by disk diffusion technique. The amplification of virulence (eae and stx1) and resistance (tetM, tetK and bla_CTX(480 bp)genes in isolates was carried out by polymerase chain reaction. One hundred and sixty-six E. coli comprising rams (96) and goats (70) were recovered. Susceptibility of isolates to antibiotics varied greatly. The highest
resistance was recorded against nitrofurantoin in E. coli from ram (97%) and goat (71%). The study revealed that Escherichia coli from rams (85.4%) and goats (87.1%) were multiple antibiotic resistant (MAR) types. The estimated molecular weight of plasmid DNA recovered from the MAR E. coli from rams and goats ranged from 9.41 to 30.84kb. Resistance genes (tetK, tetM) and virulence (Stx₁, eae) genes were not harboured by the representative E. coli profiled. The bla_CTX (480 bp) gene was detected in only three E. coli recovered from rams. The  incidence of multiple antibiotic resistance in E. coli isolated from apparently healthy goats and rams is high in the study area, hence, indiscriminate use of antibiotics in the animal husbandry sector should be discouraged.

Keywords: Escherichia coli, ram, goat, antibiotic, resistant gene, virulence factors