To Study The Risk Factors,Molecular Epidemiology And Drug Resistance Genes Of Carbapenem-resistant Klebsiella Pneumoniae In Intensive Care Unit

Objective:To study the risk factors of carbapenem-resistant Klebsiella pneumoniae(CRKP)infection in intensive care unit,Through drug sensitivity evaluation and gene detection of clinically isolated drug-resistant strains,the drug resistance of CRKP in intensive care unit,drug resistance genes carried by strains and dominant clones were analyzed,In-depth understanding of the drug resistance characteristics,molecular epidemiology of CRKP and the nosocomial transmission potential of drug-resistant strains.So as to take corresponding measures to reduce the infection rate of CRKP,help to develop a reasonable anti-infection program,and reduce the mortality of infected patients.Methods:1.A total of 150 patients infected with Klebsiella pneumoniae in the intensive care unit of Jining First People’s Hospital from January 2020 to December 2021 were retrospectively collected.According to the resistance to carbapenem drugs,they were divided into CRKP group(59 cases)and CSKP group(91 cases).The clinical data of the two groups were collected,including gender,age,underlying diseases,antibiotic use,invasive procedures,length of hospital stay,and hormone use.The independent risk factors for CRKP infection were analyzed by univariate chi-square test and multivariate Logistic regression;2.The drug sensitivity of drug-resistant strains isolated from patients in CRKP group was tested in vitro by VITEK-2 automatic microbial analysis system to evaluate the resistance of CRKP strains to common antibiotics;3.Polymerase chain reaction(PCR)was used to detect the common drug resistance genes(KPC-2,NDM-1,IMP,VIM,OXA-48)of CRKP strains.The positive PCR products were sequenced.GeneBank database comparison was used to determine the drug resistance genes carried by the resistant strains;4.Seven pairs of housekeeping genes(gapA,rpoB,infB,mdh,pgi,phoE,tonB)of CRKP strains were amplified by PCR,and the homology of isolated strains was analyzed by multilocus sequence typing(MLST).Results:1.Multi variate Logistic regression analysis showed that hypoprot einemia,endotracheal intubation/incision,central venous catheterizati on,and total length of hospital stay≥30 days were independent ris k factors for CRKP infection(P<0.05).2.The in vitro drug susceptibility test showed that CRKP strain s were highly sensitive to ceftazidime-avibactam,tigecycline,amikac in,and polymyxin(the resistance rates were 6.7%,30.5%,33.8%,a nd 22.0%,respectively),but 100%resistant to ciprofloxacin,ceftriax one,ceftazidime,cefepime,and cefoperazone sulbactam.3.Three resistance genes were detected in 3.59 CRKP strains,of which blaKPC-2(n=48,81.3%)was the main carbapenemase resistance gene detected,followed by blaNDM-1(n=4,6.7%)and blaIMP(n=1,1.6%).4.The main genotype of the 59 CRKP strains is ST11,accounting for 79.6%(47 strains).Conclusion:KPC-2 is the drug resistance gene with the highest positive detection rate,and ST11 is the most common clone type.There are many risk factors affecting the occurrence of CRKP infection in patients in intensive care unit.Therefore,early identification of high-risk patients,development of effective prevention and control measures and reasonable anti-infection regimens are very important to reduce the infection rate of CRKP in patients.