Yuan Yi, Li Ying, Wang Guangxi, Li Chengwen, Xiang Li, She Junping, Yang Yan, Zhong Fangcai, Zhang Luhua
Department of Clinical Laboratory, The First People's Hospital of Neijiang, Sichuan, People's Republic of China.
Department of Immunology, School of Basic Medical Sciences, Southwest Medical University, Luzhou, Sichuan, People's Republic of China.
Infect Drug Resist. 2019 Sep 19;12:2979-2985. doi: 10.2147/IDR.S217168. eCollection 2019.
Colistin acts as the last line of defense against severe infections caused by carbapenem-resistant . Infections caused by extensively drug-resistant isolates coproducing MCR and carbapenemases have posed a serious public health concern.
In this study, we reported the first clinical colistin and carbapenem-resistant isolate SCNJ07 coharboring and from a patient with bloodstream infection in China.
Bacterial antimicrobial susceptibility testing was performed using the broth microdilution method. Conjugation assay was carried out to investigate the transferability of and . Whole-genome sequencing of strain SCNJ07 was performed using an Illumina HiSeq system and the genetic characteristics of the - and -harboring plasmids were analyzed.
Conjugation assays revealed that both and genes could successfully transfer their resistance phenotype to strain J53. Whole genome sequencing showed that SCNJ07 possessed an FIB36:FIIY4 type self-transmissible plasmid bearing , which possessed high similarity to previously reported pRJF866 in China. was located on a ~28-kb self-transmissible plasmid pMCR-SCNJ07 with both IncHI2 and IncR replicons. Two copies of intact IS903 that bracketed a ~8-kb region containing the gene were identified in pMCR-SCNJ07. BLASTn analysis revealed that a number of -positive plasmids have been around for a while among worldwide.
This study reveals the likelihood of a wide dissemination of this newly identified colistin resistance gene among . Further surveillance is urgently needed to understand the prevalence and dissemination of , thereby facilitating establishment of measures to control its spread.
黏菌素是对抗碳青霉烯耐药菌引起的严重感染的最后一道防线。由同时产生MCR和碳青霉烯酶的广泛耐药菌株引起的感染已成为严重的公共卫生问题。
在本研究中，我们报道了中国首例从一名血流感染患者中分离出的同时对黏菌素和碳青霉烯耐药的菌株SCNJ07，该菌株同时携带 和 。
采用肉汤微量稀释法进行细菌药敏试验。进行接合试验以研究 和 的可转移性。使用Illumina HiSeq系统对菌株SCNJ07进行全基因组测序，并分析携带 和 的质粒的遗传特征。
接合试验表明， 和 基因均可成功将其耐药表型转移至J53菌株。全基因组测序显示，SCNJ07拥有一个携带 的FIB36:FIIY4型自我传递质粒，该质粒与中国先前报道的pRJF866具有高度相似性。 位于一个约28 kb的同时具有IncHI2和IncR复制子的自我传递质粒pMCR-SCNJ07上。在pMCR-SCNJ07中鉴定出两个完整的IS903拷贝，它们包围着一个包含 基因的约8 kb区域。BLASTn分析显示，许多携带 的质粒在全球 中已经存在了一段时间。
本研究揭示了这种新鉴定的黏菌素耐药基因 在 中广泛传播的可能性。迫切需要进一步监测以了解 的流行和传播情况，从而促进制定控制其传播的措施。
