Major Genetic Determinants of Extended-Spectrum β-Lactamase (ESBL), Carbapenemase, Fosfomycin and Colistin Resistance in Escherichia Coli from Intensive Care Units

Abstract

Escherichia coli (E. coli) strains placed in predominant nosocomial bacteria in intensive care units (ICUs), resulting in severe drug-resistant infections. Non-susceptibility to β-lactams and last-line drugs such as Fosfomycin and Colistin cause limited availability of infections eradication. The objective of this study included the determination of genes encoding extended-spectrum β-lactamase (ESBL), Carbapenemase, Colistin, and Fosfomycin resistance in clinical isolates of E. coli in ICUs. A total of 200 E. coli isolates were identified from ICU settings. The CTXM-1, SHV, IMP and OXA-48 genes were detected for β-lactamases using the polymerase chain reaction (PCR) technique. The fosA3 and mcr-1 and mcr-2 genes were also detected for resistance against Fosfomycin and Colistin. The CTX-M1, SHV, IMP and OXA-48 genes were detected in 60 (30%), 56 (28%), 28 (14%) and 4 (8%) of isolates. none of the E. coli isolates had the mcr-2 and fosA3 genes. Despite the existence of resistance genes to the third-generation antibiotics and Carbapenemase s, any isolates had genes for resistance to Fosfomycin and Colistin. More studies are needed to follow the resistance genes against last-resort antibiotics.