Genomic characterization of disinfectant resistance genes in carbapenem-resistant Klebsiella pneumoniae isolates

Abstract The emergence and widely global spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates are of great concern. This multi-center study was conducted to investigate the antimicrobial susceptibility, the disinfectant resistance genes and genetic relationship of CRKP isolates from inpatients in Wuhan, China. Seventy-four nonduplicated CRKP clinical isolates were collected from six hospitals in Wuhan from June 2018 toMarch 2019. MICs of eighteen antibiotics were determined. Real-time PCR was used to detect the presence of disinfectant resistance genes qacEΔ1 and cepA. Pulsed-field gel electrophoresis (PFGE) were conducted for genetic relatedness of 46 CRKP isolates co-producing qacEΔ1 and cepA. Among 74 CRKP isolates, the rates of resistance to carbapenems were 93.24% to ertapenem, 90.54% to imipenem and 87.84% to meropenem, all isolates were resistant to at least one carbapenem antibiotic. Only the rate of susceptibility to tetracycline was 52.70%. 64.86% (48/74) of them were positive for qacEΔ1, 93.24% (69/74) for cepA, the cepA gene was much more prevalent than qacEΔ1, there is a significant difference (x2 = 17.00,P<0.05), qacEΔ1 and cepA were detected concomitantly in 46 isolates (62.16%),only 4.05% (3/74) had no disinfectant resistance genes. PFGE analysis clustered the 46 CRKP strains co-producing qacEΔ1 and cepA into 15 different clonal clusters (Type A to O) using 80% similarity as the cut-off, the most common clonal clusters were Type C (41.30%), Type E (13.04%), Type J (8.70%), Type I (6.52%) and Type L (6.52%). The study showed high rates of resistance to the majority antibiotics, high frequency of qacEΔ1 and cepAin CRKP isolates, PFGE results suggest polyclonal dissemination, specific clonal disseminations of CRKP either within the same hospital or between different hospitals were detected. Therefore, medical institutions should choose and use disinfectants correctly to prevent the spread of CRKP.