碳青霉烯类耐药肺炎克雷伯菌分型数据库的初步建立与同源性分析

Establishment of carbapenem-resistant Klebsiella pneumonia typing database and homology analysis

目的 初步建立碳青霉烯类耐药肺炎克雷伯菌(CRKP)分型数据库,并分析同源性。方法 2020年1月—2021年12月收集分离CRKP 48株,进行细菌鉴定以及药敏实验,采用改良Hodge试验(MHT)筛选产碳青霉烯酶菌株、纸片法检测超广谱β-内酰胺酶(ESBL),实时荧光定量PCR法确定耐药酶基因型,多位点序列分型技术分析同源性。结果 43株CRKP对厄他培南具有抗药性;MHT实验显示,阳性37株;ESBL表型阳性13株。48株CRKP中,77.08%携带KPC基因、4.17%携带IMP基因、12.50%携带DHA基因、87.50%携带CRKP基因、75.00%携带TEM基因、50.00%携带CTX-M基因,SHV、TEM、CTX-M的优势基因型分别为blaSHV-11、blaTEM-1、blaCTX-M-14。48株CRKP分为ST1型6株,ST11型42株。结论 CRKP的基因型以KPC为主,ESBL基因型以SHV为主,同一种CRKP可携带多种耐药酶基因,耐药机制复杂。

Objective This paper aims to establish a carbapenem-resistant Klebsiella pneumoniae(CRKP) typing database and conduct homology analysis. Methods A total of 48 CRKP strains were collected from January 2020 to December 2021. Bacterial identification and drug sensitivity test were performed. Modified Hodge test(MHT) was conducted to screen carbapenemase-producing strains, paper disk method was used to detect extended-spectrum β-lactamases(ESBL), quantitative real-time PCR method was used to determine genotypes of drug-resistant enzymes, and multilocus sequence typing was used for homology analysis. Results A total of 43 CRKP strains were resistant to ertapenem. MHT observed 37 positive strains. 13 strains were positive for ESBL phenotype. Of the 48 CRKP strains, 77.08% carried KPC gene, 4.17% carried IMP gene, 12.50% carried DHA gene, 87.50% carried CRKP gene, 75.00% carried TEM gene, and 50.00% carried CTX-M gene. The dominant genotypes of SHV, TEM and CTX-M were blaSHV-11, blaTEM-1 and blaCTX-M-14. 48 CRKP strains included 6 strains of ST1 type and 42 strains of ST11 type. Conclusion KPC is the main genotype of CRKP, and SHV is the main genotype of ESBL. The same type of CRKP carries multiple drug resistance enzyme genes, and the mechanism is complicated.