Molecular Epidemiology of Carbapenem-Resistant Klebsiella pneumoniae Infections in Southwest China
Abstract Background: We determined epidemiological characteristics and resistance mechanisms of carbapenem-resistant Klebsiella pneumoniae (CRKP) strains found in Southwest China and assessed disease burden to provide evidence-based strategies for control and treatment of CRKP infection. Methods: A total of 159 strains of CRKP were isolated from sputa, blood, urine, ascites and wound secretions from three tertiary hospitals in Southwest China between August 1st, 2018 and December 31st, 2019. The sensitivity of each strain to 12 antibiotic agents was determined by micro-broth dilution. Identification of carbapenemase genes and multi-locus sequence typing (MLST) were performed using polymerase chain reaction (PCR). The disease burdens of patients with CRKP were assessed based on invasive procedures, antibiotic use, laboratory tests and clinical outcomes. Results: Of 159 CRKP strains analyzed, 50.9% were isolated from sputum samples. The percentage of patients who underwent invasive procedures before positive cultures for CRKP were detected was 96.3%. The mortality of blood infection was highest (66.6%) among patients with CRKP infection. All strains were insensitive to carbapenems. The resistance rates to levofloxacin and amikacin were 85.5% and 81.8%, respectively. All CRKP strains produced carbapenemases, with a majority of isolates (81.1%) producing KPC-2. The MICs of strains harbouring both KPC-2 and NDM-1 were higher than those of strains with only KPC-2 or NDM-1. ST11 is the most popular clonotype found in Southwest China. Conclusions: CRKP strains in Southwest China are characterized by strong drug resistance and associated with poor clinical prognoses. It is therefore urgent to both strengthen control measures and improve prevention awareness.