Oxford University Clinical Research Unitgrid.412433.3, Wellcome Africa Asia Programme, Ha Noi, Vietnam.
Department of Medical Microbiology and Radboudumc Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, the Netherlands.
Microbiol Spectr. 2022 Feb 23;10(1):e0135621. doi: 10.1128/spectrum.01356-21. Epub 2022 Feb 9.
Colistin is widely used in agriculture and aquaculture as prophylaxis, particularly in Asia. Recently, and other mobilizable genes conferring colistin resistance have spread globally in community and hospital populations. Characterizing mobile genetic elements and host genetic background is important to understand the transmission of this resistance mechanism. We conducted whole-genome sequencing of 94 -positive Escherichia coli isolates (Mcr1-Ec isolates) from human and animal feces, food, and water in a community cohort (N = 87) and from clinical specimens from a referral hospital (N = 7) in northern Vietnam. was plasmid-borne in 71 and chromosomally carried in 25 (2 isolates contain one copy on chromosome and one copy on a plasmid) of 94 E. coli isolates from the community and hospital settings. All seven clinical isolates carried on plasmids. Replicon types of -carrying plasmids included IncI2, IncP, IncX4, and IncFIA single replicons and combinations of IncHI2, IncN, and IncX1 multireplicons. Alignment of a long-read sequence of an IncI2 plasmid from animal feces with short-read sequences of IncI2 plasmids from a healthy human, water, and hospitalized patients showed highly similar structures (query cover from 90% to 98%, overall identity of >81%). We detected the potential existence of multireplicon plasmids harboring regardless of sample setting, confirming 10/71 with long-read sequencing. An intact/conserved transposon sequence or its genetic context variants were found in 6/25 Mcr1-Ec isolates with chromosomally carried . The dissemination of is facilitated by a high diversity of plasmid replicon types and a high prevalence of the chromosomal transposon. The article presented advances our understanding of genetic elements carrying in Escherichia coli in both community and hospital settings. We provide evidence to suggest that diverse plasmid types, including multireplicon plasmids, have facilitated the successful transmission of in different reservoirs. The widespread use of colistin in agriculture, where a high diversity of bacteria are exposed, has allowed the selection and evolution of various transmission mechanisms that will make it a challenge to get rid of. Colocalization of and other antibiotic resistance genes (ARGs) on multireplicon plasmids adds another layer of complexity to the rapid dissemination of genes among community and hospital bacterial populations and to the slow pandemic of antimicrobial resistance (AMR) in general.
黏菌素被广泛用于农业和水产养殖作为预防药物，特别是在亚洲。最近，和其他可移动基因赋予粘菌素耐药性已在社区和医院人群中在全球范围内传播。描述移动遗传元件和宿主遗传背景对于了解这种耐药机制的传播非常重要。我们对来自越南北部社区队列（N=87）的人和动物粪便、食物和水中的 94 株 -阳性大肠杆菌分离株（Mcr1-Ec 分离株）和来自转诊医院的临床标本（N=7）进行了全基因组测序。在社区和医院环境中，71 株大肠杆菌分离株的质粒上携带 ，25 株大肠杆菌分离株的染色体上携带 （2 株分离株的染色体上携带一个拷贝，质粒上携带一个拷贝）。7 株临床分离株均携带质粒上的 。携带 的质粒的复制子类型包括 IncI2、IncP、IncX4 和 IncFIA 单复制子以及 IncHI2、IncN 和 IncX1 多复制子的组合。对来自动物粪便的 IncI2 质粒的长读序列与来自健康人类、水和住院患者的 IncI2 质粒的短读序列进行比对，显示出高度相似的结构（查询覆盖率为 90%至 98%，总相似度大于 81%）。无论样本设置如何，我们都检测到了携带多复制子质粒的潜在存在，通过长读测序确认了 10/71 株。在 25 株染色体上携带 的 Mcr1-Ec 分离株中，发现了 转座子的完整/保守序列或其遗传结构变体。在 6/25 株带有染色体 的 Mcr1-Ec 分离株中发现了带有 转座子的高多样性和多复制子质粒的存在促进了 的传播。该文章增进了我们对社区和医院环境中携带 的大肠杆菌中遗传元件的理解。我们提供的证据表明，各种质粒类型，包括多复制子质粒，促进了不同储层中 的成功传播。在农业中广泛使用粘菌素，使各种细菌暴露其中，从而选择和进化了各种传播机制，这将使其难以消除。 和其他抗生素耐药基因 (ARGs) 在多复制子质粒上的共定位增加了 基因在社区和医院细菌群体中快速传播的复杂性，以及一般抗微生物药物耐药性 (AMR) 的缓慢流行。
