Prevalence of extended spectrum β-Lactamase genes among Klebsiella pneumoniae and Escherichia coli clinical isolates

Abstract

Extended spectrum β-lactamases (ESBLs) of Escherichia coli and Klebsiella pneumoniae became a major problem in the whole world. This work aimed to study the prevalence of ESBLs genes (blaTEM, blaSHV and blaCTX-M) in E. coli and K. pneumoniae clinical isolates that recovered from Al Kasr AL-Ainy hospital, Cairo, Egypt, during the period between 2016 and 2018. One hundred sixty-eight clinical isolates were screened for ESBLs production by the phenotypic tests double disc synergy test (DDST) and combination disc test (CDT). Out of 168 isolates, 113 (67.26%) were phenotypically positive ESBLs. Determination of MICs values confirmed that all ESBLs producing isolates (113) were >512 µg/ml for cefotaxime (CTX) while 128 to ≥ 512 µg/ml for ceftazidime (CAZ). Screening the isolates for selected ESBLs genes (blaCTX-M, blaSHV and blaTEM) showed that the only 108 (95.92%) isolates were found to have one or more ESBLs genes with percentage of prevalence for blaCTX-M, blaSHV and blaTEM, 91.7%, 82.4% and 78.7%, respectively. The co-existence of blaTEM, blaSHV and blaCTX-M genes were found in 72.34% and 47.54 of K. pneumoniae and E. coli, respectively. Nucleotide sequences of selected ESBLs genes were carried out and submitted to GenBank under the accession numbers MN096660, MN96661, MN096662, MN096663, MN096664 and MN096665 for blaTEM (K.p.1 and E.c. 2), blaCTX-M (K.p.38 and E.c. 60) and blaSHV (K.p.46 and E.c. 40), respectively. SDS-PAGE of total proteins showed bands > 34 KD in all isolates, which may play role in carbapenem sensitivity.