Clinical Characteristic Analysis Of High-Virulence Carbapenem-Resistant Klebsiella Pneumoniae In A Hospital In Inner Mongolia

Objective: Carbapenem-resistant Klebsiella pneumoniae(CRKP)is an independent risk factor for hospital-acquired infections and poses a serious threat to the health of hospitalized patients.This study aims to determine the molecular typology,drug resistance/sensitivity,and distribution of resistance and virulence genes of CRKP in hospital-acquired infections,and explore the molecular characteristics of drug resistance and virulence of CRKP.Methods: This study collected 80 CRKP strains isolated from inpatients at the First Affiliated Hospital of Inner Mongolia Medical University between August 2019 and December 2022.Multiple locus sequence typing(MLST)was used for molecular typing,and goe BURST software was used for population structure and evolutionary pattern analysis.The CRKP genome was compared with antimicrobial resistance gene databases and virulence factor databases to explore the distribution of resistance genes and virulence factors in the CRKP genome,and to compare the differences in resistance genes and virulence genes carried by strains of different molecular types.Results: The 80 strains of CRKP were divided into five different ST types,including 68 strains of ST11,accounting for 85.00%,5 strains each of ST15 and ST323,accounting for 6.25% each,as well as 1 strain each of ST1049 and ST1869.ST11 and ST1869 belong to the ST258 clone group,ST323 and ST485 belong to the same clone group,while ST15 and ST1049 belong to the same clone group.80 strains of CRKP showed high resistance to most tested antibiotics,including 100% resistance to ampicillin,levofloxacin,and ciprofloxacin.The resistance of ST11 type to cefepime,tobramycin,and amikacin was higher than that of non ST11 type,with a statistically significant difference(P<0.05).There was no statistically significant difference in resistance to other antibiotics between the two types(P>0.05).The analysis of resistance genes in the genome sequencing results of the 80 strains of CRKP revealed a total of 29 resistance genes,including 10 β-lactam resistance genes,7 aminoglycoside resistance genes,5quinolone resistance genes,2 sulfonamide resistance genes,2 phosphomycin resistance genes,1 erythromycin resistance gene,1 tetracycline resistance gene,and 1chloramphenicol resistance gene.There was a statistically significant difference(P<0.05)in the carriage rate of the five resistance genes between ST11 and non-ST11 strains.The genome sequencing results of the 80 strains of CRKP showed that a total of 35 virulence genes were screened,which could be classified into three categories: 9adhesion genes(25.71%),25 iron acquisition genes(71.43%),and 1 invasion gene(2.86%).There was no statistically significant difference(P>0.05)in the detection rate of virulence genes between ST11 and non-ST11 strains.Conclusion: This study identified multiple resistance genes and virulence factors,and found clear dominant microbial populations that were primarily associated with hospital-acquired infections.ST11 Klebsiella pneumoniae was the main type,consistent with the most common type in China.The identified microbial populations in this study may serve as targets for the clinical prevention and treatment of severe bacterial infections.