ABSTRACT
Background: The family Enterobacteriaceae belongs to the order Enterobacterales, a large diverse group of Gramnegative, facultatively anaerobic bacteria that sometimes cause multidrug-resistant infections which treatment options are often challenging. They are the leading cause of nosocomial bloodstream infection (BSI) and urinary tract infections (UTI). The objective of the study was to carry out a point-prevalence survey of antimicrobial resistance and carbapenem-resistant Enterobacteriaceae (CRE) clinical isolates in two hospitals in Kuwait and Nigeria. Methodology: Clinically significant bacterial isolates of patients from Kuwait and Nigeria, identified by VITEK-2 and MALDI-TOF mass spectrometry analysis were studied. Susceptibility testing of selected antibiotics was performed using E-test and broth dilution methods. Genes encoding carbapenemase, ß-lactamases, and extended-spectrum ßlactamases (ESBLs) were detected by conventional PCR and sequencing, and whole genome sequencing (WGS) analyses. Results: Of 400 isolates from Kuwait and Nigeria, 188 (47.0%) and 218 (54.5%) were Escherichia coli and 124 (31.0%) and 116 (29.0%) Klebsiella pneumoniae, respectively. The prevalence of CRE was 14.0% in Kuwait and 8.0% in Nigeria. The resistance rates of CRE isolates against colistin and tigecycline in Kuwait were 6.6% versus 25.0%, and in Nigeria were 14.2% versus 14.2%, respectively. blaOXA-181 gene was the commonest in CRE isolates in Kuwait and blaNDM-7 in Nigeria. The commonest ESBL gene among the CRE isolates was blaCTX-M-15 in both countries. AmpC resistance genes were present in only Kuwait isolates and mediated by blaEBC, blaCIT and blaDHA. WGS analysis of 12 selected CRE isolates with carbapenem MICs>32µg/ml but no detectable genes from conventional PCR, revealed the presence of multidrug efflux pump genes such as major facilitator superfamily antibiotic efflux pump and resistance-nodulation-cell division antibiotic efflux pump groups. Conclusion: The prevalence of CRE was higher among isolates from Kuwait than Nigeria and the genes encoding resistance in CRE were different. The presence of efflux pump was a main mechanism of resistance in most of the Nigerian CRE isolates.