Antimicrobial Resistance Profile and Detection of Extended Spectrum and Amp C β-Lactamase Resistance Genes in Escherichia coli Isolated from Diarrheic Children in Lafia, Nasarawa State, Nigeria

Aims: This study evaluated the presence of extended spectrum β-lactamase (ESBL) and AmpC β-lactamase resistance genes in E. coli from stool of diarrheic children in some hospitals in Lafia metropolis, Nigeria.

Methodology: A total of 70 stool samples of children were obtained from Dalhatu Araf Specialist Hospital, Lafia, M & D Hospital, Olivet Medical Centre and Sandaji Medical Centre, Lafia. Escherichia coli were isolated and identified using standard microbiological methods. Antimicrobial susceptibility of the isolates was tested using Clinical and Laboratory Standards Institute (CLSI) method. The phenotypic detection of ESBL and AmpC β-lactamase production in some antibiotic resistant isolates were carried out using disc method. The molecular detections of ESBL and AmpC resistance genes were carried out using Polymerase Chain reaction (PCR) method.

Results: Of the 70 samples, the occurrence of E. coli was 100%. The isolates were highly resistant to ampicillin (97.14%), ciprofloxacin (90.00%), sulfamethoxazole/trimethoprim (84.29%), streptomycin (78.57%), amoxicillin/clavulanic acid (70.00%); moderate to gentamicin (38.57%), ceftazidime (37.14%) and cefotaxime (30.00%); and less resistant to cefoxitin (15.71%) and imipenem (8.57%). Twenty-one (30.00%) isolates were jointly resistant to both cefotaxime and ceftazidine. Of this number, 66.67% (14/21) were phenotypically confirmed ESBL producers; and the occurrences of ESBL resistance genes were: 7.14% (SHV), 42.86% (CTX-M) and 50.00% (TEM). Out of 11isolates resistant to cefoxitin, 4(36.36%) were phenotypically confirmed as AmpC β-lactamase producers; and the occurrence of AmpC genes were: 50.00% (CIT), 25.00% (FOX) and 25.00% (MOX).

Conclusion: The isolates were least resistant to imipenem and cefoxitin and highly resistant to ampicillin, ciprofloxacin and sulfamethoxazole/trimethoprim. TEM and CTX-M ESBL genes were more frequent than SHV. CIT AmpC gene was more frequent than FOX and MOX.