Isolation, Phenotypic Characterization and Prevalence of ESBL-Producing Escherichia Coli and Klebsiella Species from Orthopedic Wounds in National Orthopedic Hospital Enugu (NOHE), South East Nigeria

Abstract

The objective of this research work was to isolate, characterize and determine the prevalence of Extended- Spectrum β-Lactamase (ESBL)-producing E. coli and Klebsiella spp. from orthopedic wounds of patients admitted at National Orthopedic Hospital Enugu (NOHE), South East Nigeria. In this study, 171 bacterial isolates were obtained from 257 orthopedic wound swabs over a period of one year. Sixty nine (69) of the bacterial isolates were identified as E. coli while 102 were Klebsiella spp based on standard microbiological techniques. The phenotypic screening of the 171 bacterial isolates (E. coli and Klebsiella spp) for ESBL production was done by disc diffusion method using second and third generation cephalosporins. The ESBL producers were confirmed using double disc synergy test. Susceptibility of the ESBL-producing bacterial isolates to antibiotics was done on Mueller-Hinton agar by Kirby-Bauer disc diffusion methods. Exactly 59.65% and 40.35% of the identified Klebsiella spp and E. coli isolates respectively were confirmed to be ESBL producers. The bacterial isolates were highly resistant (89%-100%) to ceftazidime, amoxicillin, aztreonam, cefpirome, cefoxitin, cefotetan, and cefotaxime. However, imipenem was the most active antibiotic against the bacterial isolates as they were highly susceptible to this antibiotic (64%-71%). This study has revealed that E. coli and Klebsiella spp colonize orthopedic wounds. They were also multidrug-resistant with Multiple Antibiotic Resistance Index (MARI) values within the range of 0.20 to 0.85. The increasing prevalence of bacterial resistance to antibiotics has made susceptibility testing a crucial aspect in the treatment of serious bacterial infections. Therefore, there is need for increased surveillance of ESBL-producing organisms as they pose serious threat to successful treatment of infections and exacerbates the problem of antimicrobial resistance in the hospitals, especially in resource poor settings.