Profiling and antibiotic resistance of some human intestinal isolates

Abstract

The cases of antibiotic resistance in Enterobacteriaceae are of great global concern. This study aimed at contributing towards the fight against antibiotic resistance and ameliorate the management/treatment of Enterobacteriaceae-linked diseases. Ten (10) rectal swab samples were collected from five (5) male and five (5) females and two isolates were identified from the samples collected. The isolates were identified through colonial, morphological and biochemical tests carried out following standard procedures. Isolates were investigated for their antibiotic resistance profile, Multiple Antibiotic Resistance indices (MARi), pathogenicity and their resistance genes were identified through molecular means using plasmid amplification and primers. Primers used include. ermB, BlaTem, qnrB genes Result obtained showed the isolates to be Escherichia coli and Klebsiella oxytoca. E. coli showed Alpha (α) heamolysis, while Klebsiella oxytoca showed gamma (γ) heamolysis . E. coli was resistant to 75% of the antibiotics used, Klebsiella oxytoca was sensitive to 42% of all the antibiotics. All the test organisms were resistant to all classes of Cephalosporins. The plasmid profiling revealed that all isolates have low molecular weight plasmids. The molecular fingerprinting of the isolates using gene primers viz -a viz ermB, BlaTem, qnrB genes showed E. coli to have resistance genes for macrolides (ermB gene) while none of the isolates had resistance factor against quinolones (qnrB gene). This study showed a high carriage of Enterobacteriaceae having phenotypic resistance with corresponding plasmid-borne resistance genes. The need to understand how bacteria adapt to the antibiotic environment will lead to new therapeutic strategies for antibiotic-resistant infections. Interventions measures to minimize the abundance of antibiotic-resistant commensals and opportunistic pathogens may include faecal microbiota transplantation and the use of live biotherapeutics.