RESUMEN
The rapid emergence of carbapenemase-producing gram-negative bacteria (CPGNB) is a global threat due to the high mortality of infection and limited treatment options. Although there have been many reports of CPGNB isolated from Southeast Asian countries, to date there has been no genetic analysis of CPGNB isolated from Cambodia. Sequence-based molecular epidemiological analysis enables a better understanding of the genotypic characteristics and epidemiological significance of antimicrobial-resistant (AMR) bacteria in each country, and allows countries to enact measures related to AMR issues. In this study, we performed on-site genomic epidemiological analysis of CPGNB isolated in Cambodia using a portable laboratory equipment called Bento Lab, which combines a PCR thermal cycler, microcentrifuge, gel electrophoresis apparatus, and LED transilluminator, along with the MinION nanopore sequencer. PCR targeting of major carbapenemase genes using Bento Lab revealed that two Escherichia coli isolates and one Acinetobacter baumannii isolate harbored carbapenemase genes: bla NDM, bla OXA-48, and bla OXA-23, respectively. The results of phenotypic diagnostic tests for CPGNB, such as the carbapenem inactivation method and double-disk diffusion test using a specific inhibitor of metallo-ß-lactamases, were consistent with their AMR genotypes. Whole-genome sequencing analysis using MinION revealed that bla NDM-5 gene was carried on a 93.9-kb plasmid with IncFIA/IncFIB/IncFII/IncQ1 replicons, and bla OXA-181 gene was carried on a 51.5-kb plasmid with the IncX3 replicon in E. coli isolates. bla OXA-23 was encoded in two locations on the chromosome of A. baumannii. Plasmids carrying bla NDM-5 or bla OXA-181 in E. coli were highly structurally identical to plasmids prevalent in Enterobacterales in China and other countries, suggesting that they disseminated from a common evolutionary origin. Our findings demonstrate the potential impact of portable laboratory equipment on AMR bacteria research in hospitals and research centers with limited research facilities, and provide the first glimpse into the genomic epidemiology of CPGNB in Cambodia.
RESUMEN
OBJECTIVES: Following the launch of the Global Antimicrobial Resistance Surveillance System (GLASS), antimicrobial resistance (AMR) rates in many countries remain poorly described. This review provides an overview of published AMR data from Cambodia in the context of recently initiated national human and food-animal surveillance. METHODS: PubMed and the Cochrane Database of Systematic Reviews were searched for articles published from 2000 to 2018, which reported antimicrobial susceptibility testing (AST) data for GLASS specific organisms isolated from Cambodia. Articles were screened using strict inclusion/exclusion criteria. AST data was extracted, with medians and ranges of resistance rates calculated for specific bug-drug combinations. RESULTS: Twenty-four papers were included for final analysis, with 20 describing isolates from human populations. Escherichia coli was the most commonly described organism, with median resistance rates from human isolates of 92.8% (n=6 articles), 46.4% (n=4), 55.4% (n=8), and 46.4% (n=5) to ampicillin, 3rd generation cephalosporins, fluoroquinolones, and gentamicin respectively. CONCLUSIONS: Whilst resistance rates are high for several GLASS organisms, there were insufficient data to draw robust conclusions about the AMR situation in Cambodia. The recently implemented national AMR surveillance systems will begin to address this data gap.