Résumé
Despite the threat of antimicrobial resistance (AMR) worldwide, limited studies describe the situation in human infections in Cambodia. Our study aims to evaluate the current state of AMR and describe the resistance mechanisms of the main Enterobacterales responsible for various infections in Cambodia.
Between January and April 2020, 222 clinical Enterobacterales isolates were collected from routine diagnostics at the Medical Biology Laboratory of the Institut Pasteur du Cambodge, Phnom Penh. Antimicrobial susceptibility testing and resistance phenotype analysis were performed. Beta-lactamase genes blaCTX-M, blaSHV, blaTEM and blaOXA-1 were screened in isolates resistant to third generation cephalosporin (3 GC). Carbapenem-resistant isolates were tested for carbapenemase production using a rapid immunochromatographic assay and confirmed by gene detection. Isolates harboring blaCTX-M and carbapenemase genes were further characterized by sequencing.
Overall, 39.2 % of isolates were resistant to at least one 3 GC, with 30.2 % confirmed as extended-spectrum beta-lactamase (ESBL) producers. The corresponding ESBL genes pertain to the KLUB/CTX-M-1 and KLUY/CTX-M-9 classes. Carbapenemase genes blaNDM and blaOXA–48 were detected in 4.1 % of isolates. Notably, 6.5 % of ESBL-producing Escherichia coli and Klebsiella pneumoniae also exhibited colistin resistance.
The prevalence and molecular characterization of 3 GC-resistant and ESBL-producing Enterobacterales in our study is consistent with recent reports. Our findings further confirm the high rate of carbapenemase producing Enterobacterales (NDM and OXA-48), including in community-acquired infections. Additionally, we report notable colistin resistance among ESBL producing E. coli and K. pneumoniae isolates. These results highlight the urgent need for AMR strengthened surveillance and antimicrobial stewardship programs in Cambodia.
•High rate of 3 GC and carbapenem resistant Enterobacterales in Cambodia.•KLUB/CTX-M-1 class predominates among CTX-M-type β-lactamases.•BlaNDM and blaOXA-48 are the main circulating carbapenemase genes.•High prevalence of colistin resistance in ESBL producing E. coli and K. pneumoniae.•Frequent co-occurrence of multiple beta-lactamase genes.