Extended-spectrum beta-lactamases in clinical isolates of Escherichia coli and Klebsiella pneumoniae recovered from patients at the Tamale Teaching Hospital, Ghana.

Abstract

Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae are pathogens of significant public health interest for which new antibiotics are urgently needed. To determine the prevalence of ESBLs in E. coli and K. pneumoniae isolates from patients attending the Tamale Teaching Hospital (TTH) in Ghana. The study was a cross-sectional study involving convenience sampling of E. coli and K. pneumoniae isolates from consenting patients' clinical specimens, between April and June 2015. Antimicrobial susceptibility test was performed, and ESBL-producer phenotypes were further screened for BlaTEM, BlaSHV, and BlaCTX-M genes. Patients' clinical data were additionally collected using a structured questionnaire. Of the 150 non-duplicate E. coli and K. pneumoniae isolates identified, 140 were confirmed as E. coli (84%, n = 117) and K. pneumoniae (16%, n = 23). Of these, sixty-two (44%) [E. coli (84%; n = 52); K. pneumoniae (16%; n = 10)] phenotypically expressed ESBLs. The proportion of ESBL-producing isolates was higher in adults (15-65 years) than in neonates (< 28 days) (p = 0.14). Most of the isolates showed a high percentage resistance to ampicillin (96%) and tetracycline (89%), but a relatively lower resistance to amikacin (36%). No isolate was resistant to meropenem. More ESBL producers were multidrug resistant compared to non-ESBL-producers [23% (14/62) versus 18% (14/78); p = 0.573]. Overall, 74% (n = 46) of the ESBL genotypes expressed BlaCTX-M-1 genes, followed by 63% (n = 39) BlaTEM, and 16% (n = 10) BlaSHV. The study showed a high prevalence of ESBL-positive E. coli and K. pneumoniae, mostly CTX-M-1 producers at TTH. Routine laboratory ESBL screening is warranted to inform patient management.