Phenotypic and Genotypic Characteristics of Uropathogenic Escherichia coli Isolates from Kenya

Introduction: Uropathogenic Escherichia coli (UPECs) are a significant cause of urinary tract infections (UTIs). In Kenya, UTIs are typically treated with beta-lactam antibiotics without antibiotic susceptibility testing, which could accelerate antibiotic resistance among UPEC strains. Aim: This study determined the occurrence of UPEC producing extended-spectrum beta-lactamases (ESBLs), the genes conferring resistance to beta-lactams, and the phylogenetic groups associated with ESBLs in Kenyan UPECs. Methodology: Ninety-five UPEC isolates from six Kenyan hospitals were tested for ESBL and plasmid-mediated AmpC beta-lactamase (pAmpC) production by combined disk diffusion and disk approximation tests, respectively. Real-time and conventional polymerase chain reactions (PCRs) were used to detect three ESBL and six pAmpC genes, respectively, and phylogenetic groups were assigned by a quadruplex PCR method. Results: Twenty-four percent UPEC isolates were ESBL producers with bla(CTX-M) (95.6%), bla(TEM) (95.6%), and bla(SHV) (21.7%) genes detected. Sixteen isolates had bla(CTX-M/TEM), whereas five had bla(TEM/CTX-M/SHV). A total of 5/23 ESBLs were cefoxitin resistant, but no AmpC genes were detected. The UPECs belonged predominantly to phylogenetic groups B2 (31/95; 32.6%) and D (30/95; 31.6%), while groups B2 and A had the most ESBL producers. Conclusions: beta-Lactam antibiotics have reduced utility for treating UTIs as a quarter of UPECs were ESBL producing. Single or multiple ESBL genes were present in UPECs, belonging primarily to phylogenetic groups B2 and A.

Automated summary

Uropathogenic Escherichia coli (UPECs) in Kenya have a 24% occurrence of ESBL production, with predominant genes being bla(CTX-M), bla(TEM), and bla(SHV). These UPECs primarily belong to phylogenetic groups B2 and D.