Molecular epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae in intensive care unit of a hospital in Hunan Province from 2020 to 2021
Molecular epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae in intensive care unit of a hospital in Hunan Province from 2020 to 2021
Objective To investigate the clinical distribution,antimicrobial resistance,carbapenemase resistance genes,virulence genes,capsular serotypes and ST subtypes of carbapenem-resistant Klebsiella pneumoniae(CRKP)strains in intensive care unit of a tertiary hospital in Hunan Province for better management of CRKP infections.Methods CRKP strains were isolated from 8 intensive care units of the First People's Hospital of Chenzhou City from January 2020 to December 2021.The isolates were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and tested by VITEK Compact 2 for antimicrobial susceptibility.Carbapenemase phenotype was detected by modified carbapenem inactivation method(mCIM).The capsular serotypes were determined by wzi sequencing.Carbapenem resistance genes and virulence genes were identified by PCR and Sanger sequencing.The strains were also analyzed by multilocus sequence typing(MLST)in terms of ST subtypes.Results The 75 CRKP strains were mainly isolated from geriatric ICU(28.0％)and neurosurgery ICU(20.0％).Overall,6.7％(5/75)and 16.0％(12/75)of the CRKP strains were resistant to tigecycline and ceftazidime-avibactam,respectively.The CRKP strains(＞96.0％resistant)were highly resistant to carbapenems,cephalosporins,β-lactam/β-lactamase inhibitor combinations,and levofloxacin.PCR and sequencing analysis found blaKPC-2 gene in 61 strains(81.3％),blaNDM-1 gene in 11 strains(14.7％),blaNDM-5 gene in 1 strain(1.3％),and blaOXA-48 gene in 2 strains(2.7％).MLST revealed that ST11(54.7％,41/75),ST1883(13.3％,10/75),and ST307(6.7％,5/75)were the top three ST subtypes.All ST11 and ST1883 CRKP strains harbored blaKPC-2.KL64(38.7％,29/75)and KL47(25.3％,19/75)were the most prevalent capsular serotypes among the 75 CRKP strains.The most common virulence genes among these CRKP strains were rmpA2(48.0％,36/75),iroN(38.7％,23/75)and iucA(37.3％,15/75).Conclusions The CRKP strains isolated from the intensive care units were mainly ST11-KL64 and ST11-KL47 types.Most of the strains harbor blaKPC-2 and virulence gene,and associated with high level antimicrobial resistance.It is urgent to strengthen the monitoring of molecular epidemiological characteristics of CRKP in order to inform individualized and precision treatment of CRKP infections.
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