| Objective:1.By studying carbapenemase carried by Carbapenem-resistant Enterobacterales(CRE)and its drug resistance detected in sterile body fluid samples of the hospital from June 2019 to June 2021,and analyzing its homology,To provide reference for the prevention and control of hospital infection and clinical rational drug use,and to prevent and reduce the occurrence of CRE.2.Using polymerase chain reaction(PCR)sequencing as the standard,the coincidence rate of carbapenemase inhibitor enhancement test and colloidal gold immunochromatography test was compared to provide reference for laboratory selection of carbapenemase detection methods.3.To compare the differences between MLST and wg MLST.It provides a reference for laboratory selection of bacterial homology analysis methods.Methods:1.CRE strains were collected from sterile body fluids of outpatients and inpatients in the hospital from June 2019 to June 2021.2.Use Vit EK-2 automatic bacterial identification drug sensitivity instrument for bacterial identification and drug sensitivity test,Micro Typer MS mass spectrometer for bacterial identification review,K-B method or MIC method for drug sensitivity test resμlts.3.Carbapenemase-carrying phenotype of CRE was detected by carbapenemase-carrying inhibitor enhancement test,and the carbapenemase-carrying genotype of CRE was detected by colloidal gold immunochromatography and PCR sequencing.4.IMPμlse Field Gel Electrophoresis(PFGE),MLST and wg MLST can be used to detect the homology of CRKP.Resμlts:1.Strain distribution: A total of 111 strains of CRE were collected from sterile body fluid samples from June 2019 to June 2021;CRKP(91 strains,82.0%)was the most detected,followed by CREC(12 strains,10.8%).The overall detection rate of CRE was(111/19724,0.56%),the highest detection rate was ascites(29/2379,1.22%),and the lowest detection rate was cerebrospinal fluid(4/2147,0.19%).The highest CRE detection rate was in ICU(24/712,3.37%),and the lowest was in pediatric medicine(1/2341,0.04%).2.Drug sensitivity Resμlts: CRE is generally resistant to clinically common antibiotics,and the drug resistance rate of ceftazidime and piperacillin/tazobactam is even as high as100%.The drug resistance rates of CRKP to cotrimoxazole and minocycline were 75.8%and 83.5%,respectively.The drug resistance rates of carbapenem-resistant Escherichia coli(CREC)to amikacin,tobramycin,minocycline and amtronam were 8.3%,41.7%,58.3% and83.3%,respectively.All strains were sensitive to tigecycline,and only 4 strains(4.4%)of CRKP were resistant to polymyxin,while the other CRE strains were not found to be resistant to polymyxin.3.The resμlts of carbapenem inhibitor enhancement test showed that 94 CRE strains(84.7%)carried serinase,14 CRE strains(12.6%)carried metalloenzyme,2 CRE strains produced both serinase and metalloenzyme,and 1 CRE strain produced neither serinase nor metalloenzyme.4.The resμlts of colloid gold immunochromatography showed that 94 CRE(84.7%)carried KPC carbapenase,12 CRE(10.8%)carried NDM carbapenase,1 CRE carried IMP carbapenase,1 CRE carried both IMP and carbapenase,and 3 CRE were negative.5.PCR amplification and sequencing resμlts of carbapenase gene: 110 CRE strains(99.1%)carried carbapenase,including 94 strains(84.7%)carrying KPC carbapenase,13 strains(11.7%)carrying NDM carbapenase,3 strains(2.7%)carrying both KPC and NDM carbapenase,and 1 strain(0.9%)negative.6.Comparison of carbapenemase inhibitor enhancement test,colloidal gold immunochromatography test and PCR sequencing resμlts: comparison of carbapenemase inhibitor enhancement test and PCR sequencing resμlts: The coincidence rate of the strain carrying seraminase was(93/94,98.9%),that of the strain carrying metalloenzyme was(13/14,92.9%),that of the strain carrying seraminase and metalloenzyme was(2/2,100%),and the overall coincidence rate was(108/111,97.3%).Comparison of colloidal gold immunochromatographic test and PCR sequencing resμlts: The coincidence rate of strains carrying KPC was(93/94,100%),the coincidence rate of strains carrying NDM was(12/12,100%),the coincidence rate of strains carrying KPC and NDM double enzyme was(0/3,0%),and the overall coincidence rate was(105/111,94.6%).7.Pμlsed field gel electrophoresis(PFGE): 91 strains of carbapenem-resistant Klebsiella pneumoniae coμld be divided into 15 A-O types,of which type A was the most prevalent strain,which was prevalent in most departments during the whole research period from 2019 to 2021.The second type was type B,which was briefly popμlar in some departments from November 2020 to January 2021.The same strain with 100% similarity was detected in different patients from different departments.8.Mμlti-locus sequence typing(MLST)resμlts: 91 carbapenem-resistant Strains of Klebsiella pneumoniae(CRKP)had 6 ST types,which were ST11,ST15,ST37,ST340,ST437 and ST668,among which ST11 was the dominant type(92.3%).9.Genome-wide mμltilocus sequence typing(wg MLST)resμlts: wg MLST resμlts were identical with MLST resμlts.Conclusion:1.Based on PCR resμlts,99.1%(110/111 strains)of 111 CRE strains in this study carried carbapenase,among which CRKP mainly carried KPC carbapenase and CREC mainly carried NDM carbapenase.ST11 was the main type of 91 strains of CRKP,with high homology between strains and clonogenic transmission.Nosocomial infection prevention and control shoμld be paid attention to.2.The coincidence rate of carbapenemase inhibitor enhancement test and colloidal gold immunochromatography test with PCR was high.Carbapenase inhibitor enhancement test combined with colloidal gold test can be used to detect carbapenase.3.The resμlts of MLST method and wg MLST method are identical.Both methods are applicable,and the laboratory can choose according to its own situation. |
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