Phenotypic Determination and Antimicrobial Resistance Profile of Extended Spectrum Beta-lactamases in Escherichia coli and Klebsiella pneumoniae in Accra, Ghana

Abstract

Extended-spectrum beta-lactamases (ESBLs) are plasmid-mediated beta lactamases commonly found in the Enterobacteriaceae that are capable of hydrolysing ?-lactams except carbapenems and cephamycins. ESBLs confer resistance to several non-ß-lactam antibiotics. ESBL-producing organisms appear susceptible to cephalosporins in vitro using conventional breakpoints but ineffective in vivo. This work sought to determine the occurrence of ESBL in E. coli and K. pneumoniae and their antibiotic resistance profile. Four hundred K. pneumoniae and E. coli non-duplicate isolates were collected at the Central Laboratory of Korle Bu Teaching Hospital and Advent Clinical Laboratories. They were definitively identified and their minimum inhibition concentration and antibiotic sensitivity testing for 17 antibiotics were determined using Vitek 2 Compact System (bioMérieux, Marcy I’Etoile, France).  The isolates were confirmed as ESBL-producing strains using the Combination Disk Synergy Method. The results indicated that 202 (50.5%) of the bacterial isolates were ESBL-producing phenotypes with high resistant to gentamicin, ciprofloxacin, tetracycline and trimethoprim/sulfamethoxazole indicating 82.2%, 79.7%, 70.8% and 97% resistant rates respectively. imipenem and amikacin were the antibiotics of choice with 99% and 94.1% susceptibility rates (MIC₉₀ of ?1µg/ml and 4µg/ml respectively). It is imperative to routinely detect ESBL-phenotypes in health facilities, implement appropriate antibiotic administration policy and infection control measures in the hospitals.  

Keywords: Extended Spectrum Beta-lactamase, Antimicrobial Resistance, ?-lactams, K. pneumoniae, E. coli