Huang Jinzhu, Zhao Jinxin, Yi Miao, Yuan Yaling, Xia Peiwen, Yang Bingxue, Liao Jiajia, Dang Zijun, Xia Yun
Department of Laboratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People's Republic of China.
Infect Drug Resist. 2023 Sep 5;16:5855-5868. doi: 10.2147/IDR.S426148. eCollection 2023.
This research aims to profile ten novel strains of carbapenem-resistant (CRE) co-carrying and .
Clinical CRE strains, along with corresponding medical records, were gathered. To ascertain the susceptibility of the strains to antibiotics, antimicrobial susceptibility tests were conducted. To validate the transferability and cost of fitness of plasmids, conjugation experiments and growth curves were employed. For determining the similarity between different strains, ERIC-PCR was utilised. Meanwhile, whole genome sequencing (WGS) was performed to characterise the features of plasmids and their evolutionary characteristics.
During the course of this research, ten clinical CRE strains co-carrying and were gathered. It was discovered that five out of these ten strains exhibited resistance to tigecycline. A closer examination of the mechanisms underlying tigecycline resistance revealed that 11, , and existed concurrently within a single strain (CF10). This strain, with a minimum inhibitory concentration (MIC) of 32 mg/L to tigecycline, was obtained from a sepsis patient. Furthermore, an investigation of genome evolution implied that CF10 belonged to a novel ST type 696, which lacked analogous strains. Aligning plasmids exposed that similar plasmids all had less than 70% coverage when compared to pCF10-tmexCD1, pCF10-KPC, and pCF10-NDM. It was also found that 11, , and were transferred by 5393, 5, and 6296, respectively.
This research presents the first report of coexistence of 11, , and in a carbapenem and tigecycline-resistant strain, CF10.
Tigecycline is considered a "last resort" antibiotic for treating CRE infections. The ongoing evolution of resistance mechanisms to both carbapenem and tigecycline presents an alarming situation. Moreover, the repeated reporting of both these resistance mechanisms within a single strain poses a significant risk to public health. The research revealed that the genes 11, , and , which cause carbapenem and tigecycline-resistance in the same strain, were located on mobile elements, suggesting a potential for horizontal transmission to other Gram-negative bacteria. The emergence of such a multi-resistant strain within hospitals should raise significant concern due to the scarcity of effective antimicrobial treatments for these "superbugs".
本研究旨在剖析十株新型耐碳青霉烯类肠杆菌（CRE）共携带[相关基因]的情况。
收集临床CRE菌株及相应病历。为确定菌株对抗生素的敏感性，进行了药敏试验。为验证质粒的可转移性和适合度成本，采用了接合试验和生长曲线。为确定不同菌株间的相似性，运用了ERIC-PCR。同时，进行全基因组测序（WGS）以表征质粒特征及其进化特性。
在本研究过程中，收集到十株共携带[相关基因]的临床CRE菌株。发现这十株菌株中有五株对替加环素耐药。对替加环素耐药机制的深入研究表明，11、[相关基因]和[相关基因]同时存在于一株单一的CRE菌株（CF10）中。该菌株对替加环素的最低抑菌浓度（MIC）为32mg/L，来自一名败血症患者。此外，基因组进化研究表明CF10属于一种新型ST型696，缺乏类似菌株。比对质粒发现，与pCF10-tmexCD1、pCF10-KPC和pCF10-NDM相比，相似质粒的覆盖率均低于70%。还发现11、[相关基因]和[相关基因]分别由5393、5和6296进行转移。
本研究首次报道了11、[相关基因]和[相关基因]在一株耐碳青霉烯类和耐替加环素的CRE菌株CF10中共存。
替加环素被认为是治疗CRE感染的“最后一道防线”抗生素。对碳青霉烯类和替加环素耐药机制的不断演变令人担忧。此外，在单一菌株中反复出现这两种耐药机制对公众健康构成重大风险。研究表明，在同一菌株中导致碳青霉烯类和替加环素耐药的基因11、[相关基因]和[相关基因]位于移动元件上，提示可能水平传播至其他革兰氏阴性菌。鉴于医院中出现这种多重耐药菌株，由于对这些“超级细菌”缺乏有效的抗菌治疗方法，应引起高度关注。
