Phenotypic Characterization and Comparative Study on ESBL-producing E. coli of Clinical Origin

Extended-spectrum β-lactamases (ESBLs) continue to be a major challenge in clinical setups worldwide, conferring resistance to the expanded-spectrum cephalosporins. The present study focused on the prevalence of ESBL-producing E. coli clinical isolates among patients diagnosed of Wound and Urinary Tract Infections attending Federal Teaching Hospital Abakaliki. A total of one hundred and ninety two clinical isolates of E. coli was studied for their susceptibility patterns to cephalosporin antibiotics and detection of ESBL producers was carried out by double disc synergy test (DDST) and Brilliance ESBL Agar. Of the 192 isolates tested for their antibiogram, 19(9.9%), 41(21.4%), 132(68.7%); 48(25.0%) and 144(75.0%) isolates were from wound, high virginal swab, urine, male and female respectively. The isolates showed higher susceptibility to cefepime (a 4th-generation cephalosporin) with percentage susceptibility of 78.9, 85.4 and 73.5 to the isolates from wound, HVS and urine respectively. Higher resistance was recorded among the 3rd-generation cephalosporins which include Cefotaxime (63.4%), Ceftriaxone (57.9%), and Cefpodoxime (73.7%). Among the resistant isolates of E. coli, 20 isolates were phenotypically confirmed ESBL producers by the DDST and Brilliance ESBL Agar methods. Ten (10) ESBL producing E. coli was confirmed using DDST method whereas 15 ESBL producing E. coli was confirmed using the Brilliance ESBL Agar. Brilliance ESBL Agar was found to be better than DDST in the detection of ESBLs. Continuous monitoring of drug resistance and regulating the use of cephalosporin drugs in our hospitals is vital for proper infectious disease management and treatment.