Qu M, Huang Y, Tian Y, Zhang X, Jia L, Lyu B, Wang Q Y
Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Research Center for Preventive Medicine, Beijing Center for Disease Prevention and Control, Beijing 100013, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2021 Jul 10;42(7):1252-1259. doi: 10.3760/cma.j.cn112338-20201206-01382.
To investigate the epidemiological, drug resistance and molecular characteristics of (.) Kentucky strains isolated from diarrheal patients in Beijing. The drug susceptibility of 22 Kentucky strains isolated in Beijing during 2010-2020 was tested by using the micro broth dilution method. The multilocus sequence typing (MLST), drug resistance genes and genomic island (SGI) identifications of the strains were performed by whole-genome sequencing (WGS).The pulsed field gel electrophoresis (PFGE) was performed to analyze the molecular epidemiological characteristics of the isolates. The 22 strains were highly resistant to 8-22 kinds of antibiotics, especially to ciprofloxacin, cephalosporins and azithromycin, ., showing a super high level of multidrug resistance and 21 strains were positive for extended-spetrum beta-lactamase (ESBL). The WGS analysis revealed that all the isolates belonged to ST198, carrying SGI1-K. The drug resistance genes , and were identified in all strains and Quinolone resistance-determining regions (QRDRs) showed 2 mutations in (S83F, D87 N) and 3 mutations in the gene (T57S, S80I, T255S). The resistance genes associated with -lactam antibiotics (, , , , , , ), resistance genes associated with aminoglycosides [, , , , , -, -, -,] as well as , , and had significant differences in the strains of different years, which were highly consistent with the drug-resistant phenotype. Furthermore, phylogenetic analysis showed that the similarity of the 22 strains was more than 85%, and the strains were highly homologous to CIP-resistant ST198-X1 circulating in the world. In the process of spread, the drug resistance and PFGE spectrums had changed, two clusters had formed. The Kentucky strains isolated in Beijing shared high homology with the multidrug-resistant strain ST198-X1-SGI-1K isolated in the world, which has maintained a low level of spread since 2016, causing sporadic infections and clusters of diarrhea, and has serious resistances to fluoroquinolones, ESBLs and azithromycin. The surveillance for multidrug-resistant Kentucky should be strengthened.
为调查从北京腹泻患者中分离出的肯塔基菌株的流行病学、耐药性及分子特征。采用微量肉汤稀释法检测2010 - 2020年在北京分离出的22株肯塔基菌株的药敏性。通过全基因组测序（WGS）对菌株进行多位点序列分型（MLST）、耐药基因及基因组岛（SGI）鉴定。采用脉冲场凝胶电泳（PFGE）分析分离株的分子流行病学特征。这22株菌株对8 - 22种抗生素高度耐药，尤其对环丙沙星、头孢菌素和阿奇霉素，即表现出超高水平的多重耐药性，且21株产超广谱β-内酰胺酶（ESBL）呈阳性。WGS分析显示所有分离株均属于ST198，携带SGI1-K。在所有菌株中均鉴定出耐药基因、和，喹诺酮耐药决定区（QRDRs）在基因中显示2个突变（S83F、D87N），在基因中显示3个突变（T57S、S80I、T255S）。与β-内酰胺类抗生素相关的耐药基因（、、、、、、）、与氨基糖苷类相关的耐药基因[、、、、、-、-、-]以及、、和在不同年份的菌株中存在显著差异，这与耐药表型高度一致。此外，系统发育分析表明这22株菌株的相似度超过85%，且与全球流行的耐环丙沙星ST198-X1高度同源。在传播过程中，耐药性和PFGE图谱发生了变化，形成了两个簇。在北京分离出的肯塔基菌株与全球分离出的多重耐药菌株ST198-X1-SGI-1K高度同源，自2016年以来其传播水平较低，引起散发性感染和腹泻聚集性发病，且对氟喹诺酮类、ESBLs和阿奇霉素具有严重耐药性。应加强对多重耐药肯塔基菌株的监测。
