Temperature-Regulated IncX3 Plasmid Characteristics and the Role of Plasmid-Encoded H-NS in Thermoregulation.
Temperature-Regulated IncX3 Plasmid Characteristics and the Role of Plasmid-Encoded H-NS in Thermoregulation.
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DOI：
10.3389/fmicb.2021.765492
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发表时间：
2021
影响因子：
5.2
通讯作者：
Chao Z
中科院分区：
文献类型：
--
作者：
Baomo L;Lili S;Moran RA;van Schaik W;Chao Z
碳青霉烯耐药肠杆菌科（CRE）是世界范围内严重的公共卫生问题。在全球范围内，incx3型质粒已成为携带金属β-内酰胺酶基因blaNDM的主要载体。虽然携带blandm的IncX3质粒已经在不同环境的不同宿主中被发现，但它们的转移和持久性在不同条件下是否会发生变化，以及影响这种变化的因素是什么尚不清楚。通过观察不同温度对大肠杆菌中IncX3质粒结合率、稳定性和对宿主适合度的影响，我们证明温度是质粒表型的重要决定因素。转染频率最高的IncX3质粒pGZIncX3在37°C时最稳定，适应度成本较低。pGZIncX3性质的温度调节变化涉及一种温度调节质粒编码的h - ns样蛋白，该蛋白在30°C和42°C时产生较高水平，并抑制参与偶联的IV型分泌系统基因的表达。这些发现表明，携带blandm的IncX3质粒适合于在哺乳动物宿主中定植的肠杆菌携带，这可以解释这些质粒在人类相关物种中，特别是在医院环境中迅速传播的原因。
Carbapenem-resistant Enterobacteriaceae (CRE) are a critical public health problem worldwide. Globally, IncX3-type plasmids have emerged as the predominant vehicles carrying the metallo-β-lactamase gene blaNDM. Although blaNDM-bearing IncX3 plasmids have been found in various hosts from diverse environments, whether their transfer and persistence properties vary under different conditions and what factors influence any variation is unknown. By observing the effects of different temperatures on IncX3 plasmid conjugation rates, stability, and effects on host fitness in Escherichia coli, we demonstrate that temperature is an important determinant of plasmid phenotypes. The IncX3 plasmid pGZIncX3 transferred at highest frequencies, was most stable and imposed lower fitness costs at 37°C. Temperature-regulated variation in pGZIncX3 properties involved a thermoregulated plasmid-encoded H-NS-like protein, which was produced at higher levels at 30°C and 42°C and inhibited the expression of type IV secretion system genes involved in conjugation. These findings suggest that blaNDM-bearing IncX3 plasmids are adapted to carriage by enterobacteria that colonize mammalian hosts and could explain the rapid dissemination of these plasmids among human-associated species, particularly in hospital settings.