一种新型转座子Tn介导产超广谱β-内酰胺酶菌株中变异体的转移
A Novel Transposon, Tn, Mediated Transfer of Variant in ESBL-Producing .
作者信息
Wang Xiaoming, Zhai Weishuai, Wang Shaolin, Shen Zhangqi, Wang Yang, Zhang Qidi
机构信息
MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, People's Republic of China.
Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Veterinary Medicine, China Agriculture University, Beijing, People's Republic of China.
出版信息
Infect Drug Resist. 2020 Mar 25;13:893-899. doi: 10.2147/IDR.S239865. eCollection 2020.
PURPOSE
The aim of this study was to determine the prevalence and transmission mechanism of in spp. isolated from chicken cloaca.
MATERIALS AND METHODS
w55 was isolated from chicken in 2008. PCR assay was used to detect genes and putative circular intermediate. Susceptibility testing was identified by the microdilution method. WGS was performed to obtain the whole sequence. S1-PFGE and DNA southern hybridization were used to study the location of .
RESULTS
PCR-based analysis indicated that 1 out of 55 spp. isolates was -positive. Whole-genome sequencing revealed that the strain w55 belonged to novel sequence type ST514 and had two adjacent chromosomally located variants, and -like. The and -like genes showed 93.67% and 82.84% nucleotide sequence identity, respectively, to original from w55 also exhibited resistance to extended-spectrum β-lactams and was positive for , and this is the first time to report in . Genetic environment analysis revealed that the segment of -like- was flanked by five insertion sequence elements originated from species, and the structure of IS-IS-IS-like--IS was designated as a novel transposon Tn, in which an 8405-bp circular intermediate carrying two variants can be looped out.
CONCLUSION
This result suggested the variant genes could be disseminated between various species via transposon-mediated transmission.
目的
本研究旨在确定从鸡泄殖腔分离出的沙门氏菌属中某菌的流行情况及传播机制。
材料与方法
w55于2008年从鸡中分离得到。采用聚合酶链反应（PCR）检测某基因及假定的环状中间体。通过微量稀释法进行药敏试验。进行全基因组测序以获得完整序列。采用S1-脉冲场凝胶电泳（S1-PFGE）和DNA Southern杂交研究某菌的定位。
结果
基于PCR的分析表明，55株沙门氏菌属分离株中有1株对某菌呈阳性。全基因组测序显示，菌株w55属于新的序列型ST514，有两个相邻的位于染色体上的某菌变体，即某菌1和类某菌2。某菌1和类某菌2基因与原始基因的核苷酸序列同一性分别为93.67%和82.84%。w55对超广谱β-内酰胺类药物也表现出耐药性，并且某菌检测呈阳性，这是首次在某菌中报道某菌。遗传环境分析表明，类某菌2片段两侧有5个源自某物种的插入序列元件，IS-IS-IS-类某菌2-IS的结构被指定为一种新的转座子Tn，其中一个携带两个某菌变体的8405碱基对环状中间体可以环出。
结论
该结果表明某菌变体基因可通过转座子介导的传播在各种沙门氏菌物种之间传播。
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