Phenotypic and genotypic characterization of clinical plasmid-mediated quinolone resistance (PMQR) and extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales in two healthcare facilities in Douala, Cameroon.

Abstract

Background: The emergence and escalation of antibiotic resistance in community and hospital settings remain a major public health concern worldwide. The co-occurrence of fluoroquinolone resistance in extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E), which are responsible for life-threatening infectious diseases, poses a critical threat, leading to increase therapeutic costs, prolonged hospital stays, and higher mortality rates, particularly in low- and middle-income countries (LMICs) like Cameroon. Given the lack of data regarding the co-occurrence of plasmid-mediated quinolone resistance (PMQR) among ESBL-E responsible for infectious diseases in Cameroon, this study aims at determining the prevalence, phenotypic and genotypic characterization of PMQR among ESBL-Enterobacterales isolated from clinical samples in two healthcare facilities in Douala, Cameroon.

Material and methods: Out of 1,139 non-repetitive clinical samples collected from patients, a total of 140 Enterobacterales were identified from February to May 2024. Identification was done using API20E. ESBL screening was performed using the double-disk synergy test and Chromogenic ESBL Agar. Antimicrobial susceptibility testing was done using a Kirby Bauer Disc Diffusion method. Conventional and multiplex PCR were done for the detection of PMQR and ESBL genes.

Results: Of the different clinical samples collected, Enterobacterales were most isolated from urine (57.1%), endocervical swabs (12.9%), wounds (12.9%), and blood (9.3%). Out of 140 non-duplicate Enterobacterales, the predominant species were Escherichia coli (60/140; 42.9%) and Klebsiella pneumoniae (50/140; 35.7%). The prevalence of ESBL-producing Enterobacterales (ESBL-E) was 64%. Among all ESBL-E, 81.1% and 94.4% were fluoroquinolone and multi-drug resistant (MDR) respectively. The bla_CTX‑M (65.6%), bla_TEM (55.6%), and aac(6')-Ib (47.8%) were the most frequent resistance genes detected.

Conclusion: This study reveals a high prevalence of PMQR among ESBL-producing Enterobacterales in two healthcare facilities in Douala, Cameroon. It also showed that hospitalized patients were more infected than outpatients, suggesting the need to reinforce infection prevention and control measures (IPC). The high prevalence of resistance genes observed among these strains underlines the excessive antibiotic use, highlighting the urgent need for rigorous surveillance systems and the implementation of antimicrobial stewardship (AMS) in these healthcare facilities. An integrated, proactive, and real-time genomic surveillance of AMR is crucial to curb the dissemination of these bacterial AMR in hospital and community settings.