碳青霉烯类耐药肺炎克雷伯菌毒力基因型及分子流行病学研究

Study on the virulence genes and molecular epidemiology of carbapenem-resistant Klebsiella pneumoniae

目的分析本院碳青霉烯耐药肺炎克雷伯菌(CRKP)的耐药情况及毒力基因型及分子流行病学情况,为临床CRKP的抗感染治疗提供依据。方法收集并鉴定滁州市第一人民医院2020年1-11月临床分离的非重复CRKP 28株。采用全自动微生物鉴定药敏分析仪VITEK-2 compact进行鉴定和药敏试验,使用全基因组测序技术(WGS)检测常见的毒力基因,采用多位点序列分型(MLST)和核心基因组多位点序列分型(cgMLST)对序列进行分析,并构建最小生成树(MST)。结果28株CRKP对碳青霉烯类抗生素的耐药率为100.00%。WGS结果显示,CRKP主要毒力基因包括Ⅰ型菌毛[fimD(100.00%)]、Ⅲ型菌毛[mrkC(100.00%)]、耶尔森菌素[fyuA(89.29%)、irp1(75.00%)、irp2(75.00%)、ybtP(89.29%)、ybtQ(75.00%)]、大肠杆菌菌毛ECP[ecpD(92.86%)、ecpC(100.00%)]、肠杆菌素[fepA(100.00%)]、Pul[pulD(100.00%)]、SCI-I T6SS[ECABU_c31030(78.57%)、APECO1_3711(75.00%)、ECS88_3097(71.43%)]。MLST分型显示,共有6个ST型,其中ST15型(20株,71.43%)为主要流行型,另有ST11型(4株,14.29%),ST110(1株,3.57%),ST306(1株,3.57%),ST447(1株,3.57%),ST5328(1株,3.57%)。cg MLST分型和MST结果显示,CC1簇(16株,57.14%)为院内流行簇,另有CC2簇(3株,10.71%)和CC3簇(3株,10.71%)。结论CRKP对碳青霉烯类抗生素的耐药率较高,同时携带大量的毒力基因,院内以ST15型为主要流行型,同时CC1簇在院内有小范围的播散。

Objective To investigate the resistance epidemiological characteristics and virulence genes of carbapenem-resistant Klebsiella pneumonia(CRKP),in order to provide the basis for the clinical treatment of CRKP.Methods A total of 28 clinical strains of CRKP were collected from January to November in 2020 in the Chuzhou First People's Hospital.The identificition and antibiotic susceptibility test of these clinical strains were carried out with the automatic VITEK-2 compact system.The virulence genes were detected by the whole genome sequencing(WGS)technology.Multilocus sequence typing(MLST)and the core genenome multilocus sequence typing(cgMLST)were used to analyze the sequence and construct the minimum spanning tree(MST).Results The resistance rate of 28 strains of Klebsiella pneumoniae to carbapenems was 100.00%.The WGS data showed that most virulence genes were observed in the CRKP strains,including type 1 fimbriae[fimD(100.00%)],type 3 fimbriae(biofilm formation)[mrkC(100.00%)],yersiniabactin[fyuA(89.29%),irp1(75.00%),irp2(75.00%),ybtP(89.29%),ybtQ(75.00%)],Escherichia coli common pilus(ECP)[ecpD(92.86%),ecpC(100.00%)],Enterobactin[fepA(100.00%)],Pul[pulD(100.00%)]and SCI-I T6SS[ECABU_c31030(78.57%),APECO1_3711(75.00%),ECS88_3097(71.43%)].MLST results showed that there were 6 ST types in total.ST15 type(20 strains,71.43%)was the main prevalent type,and other types were ST11(4 strains,14.29%),ST110(1 strain,3.57%),ST306(1 strain,3.57%),ST447(1 strain,3.57%)and ST5328(1 strain,3.57%).The cgMLST typing and the MST results showed that the CC1 cluster(16 strains,57.14%)was endemic,and the other clusters were CC2(3 strains,10.71%)and CC3(3 strains,10.71%).Conclusions The isolated CRKP showed a high level of resistance to commonly used antibacterial drugs,which was carried a lot of virulence genes.ST15 type was the main epidemic strain and CC1 cluster had a small spread in the hospital.