Plasmid-mediated quinolone resistance among extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolated from hospitalized patients, hospital environment and wastewaters in Cameroon

Extended-spectrum β-lactamase-producing Escherichia coli (ESBL-Ec) and Klebsiella pneumoniae (ESBL-Kp) are among the leading causes of hospital-acquired infections globally. Fluoroquinolone-resistant ESBL-Ec/Kp infections have limited therapeutic options. This study investigated the prevalence and antibiotic resistance patterns of ESBL-Ec/Kp isolated from hospitalized patients, hospital environments, and wastewaters in Yaoundé, Cameroon. It further characterized ESBL genes and clonal relatedness in all ESBL-Ec/Kp isolates and assessed plasmid-mediated quinolone resistance (PMQR) genes specifically in ciprofloxacin-resistant isolates. A cross-sectional study was conducted from February to June 2024 in two healthcare facilities in Yaoundé, Cameroon. Clinical, inanimate surfaces, and wastewater samples were collected. Bacteria identification was done using the API20E kit. The ESBL phenotype was detected using the double-disk synergy test and CHROMagar™ ESBL. Antimicrobial susceptibility testing was performed using the disc diffusion method. Genes conferring resistance to β-lactams and fluoroquinolones were detected using polymerase chain reaction (PCR). Clonal relatedness was assessed using enterobacterial repetitive intergenic consensus (ERIC)-PCR. The overall ESBL prevalence across all sources was 16% (103/652). This ESBL prevalence was 10% (49/495) in hospitalized patients, 27% (38/141) in the hospital environment, and 100% (16/16) in hospital wastewaters. Nearly all (99.5%) ESBL-Ec and ESBL-Kp were multidrug-resistant. The bla_CTX-M was the most prevalent β-lactamase gene, with prevalence ranging from 74% (42/57) in hospitalized patients to 85% (68/80) in wastewater ESBL-Ec/Kp isolates. The main PMQR resistance gene was aac-(6')-Ib-cr, with prevalence varying from 57% (43/75) in wastewater to 70% (23/33) in hospital environment ESBL-Ec/Kp isolates. The spread of ESBL-Kp across the three interfaces as well as within and between the two healthcare facilities was evidenced. This study reported a high magnitude of PMQR among ciprofloxacin-resistant ESBL-Ec/Kp. These results underscore the crucial need to implement real-time surveillance and monitoring antimicrobial resistance and implement antimicrobial stewardship programs to curb the spread of ESBL-Kp and ESBL-Ec in healthcare facilities in Cameroon.