PCR-Dipstick-Oriented Surveillance and Characterization of - and Carbapenemase-Carrying in a Thai Hospital.

Colistin is used as an alternative therapeutic for carbapenemase-producing (CPE) infections which are spreading at a very high rate due to the transfer of carbapenemase genes through mobile genetic elements. Due to the emergence of , the plasmid-mediated colistin resistance gene, -positive (MCRPEn) pose a high risk for the transfer of -carrying plasmid to CPE, leading to a situation with no treatment alternatives for infections caused by possessing both and carbapenemase genes. Here, we report the application of PCR-dipstick-oriented surveillance strategy to control MCRPEn and CPE by conducting the PCR-dipstick technique for the detection of MCRPEn and CPE in a tertiary care hospital in Thailand and comparing its efficacy with conventional surveillance method. Our surveillance results showed a high MCRPEn (5.9%) and CPE (8.7%) carriage rate among the 219 rectal swab specimens examined. Three different CPE clones were determined by pulsed-field gel electrophoresis (PFGE) whereas only two MCRPEn isolates were found to be closely related as shown by single nucleotide polymorphism-based phylogenetic analysis. Whole genome sequencing (WGS) and plasmid analysis showed that MCRPEn carried in two plasmids types-IncX4 and IncI2 with ~99% identity to the previously reported -carrying plasmids. The identification of both MCRPEn and CPE in the same specimen indicates the plausibility of plasmid-mediated transfer of genes leading to the emergence of colistin- and carbapenem-resistant . The rapidity (<2 h) and robust sensitivity (100%)/specificity (~99%) of PCR-dipstick show that this specimen-direct screening method could aid in implementing infection control measures at the earliest to control the dissemination of MCRPEn and CPE.