宿主特异性差异对大肠杆菌 O104:H4 肠道定植中 ESBL IncI1 质粒作用的影响。
Host-specific differences in the contribution of an ESBL IncI1 plasmid to intestinal colonization by Escherichia coli O104:H4.
机构信息
Department of Bacteriology, Animal and Plant Health Agency, Weybridge, UK.
School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK.
出版信息
J Antimicrob Chemother. 2018 Jun 1;73(6):1579-1585. doi: 10.1093/jac/dky037.
OBJECTIVES
To assess stability and contribution of a large ESBL-encoding IncI1 plasmid to intestinal colonization by Escherichia coli O104:H4 in two different mammalian hosts.
METHODS
Specific-pathogen-free 3-4-day-old New Zealand White rabbits and conventionally reared 6-week-old weaned lambs were orally infected with WT E. coli O104:H4 or the ESBL-plasmid-cured derivative, and the recovery of bacteria in intestinal homogenates and faeces monitored over time.
RESULTS
Carriage of the ESBL plasmid had differing impacts on E. coli O104:H4 colonization of the two experimental hosts. The plasmid-cured strain was recovered at significantly higher levels than WT during late-stage colonization of rabbits, but at lower levels than WT in sheep. Regardless of the animal host, the ESBL plasmid was stably maintained in virtually all in vivo passaged bacteria that were examined.
CONCLUSIONS
These findings suggest that carriage of ESBL plasmids has distinct effects on the host bacterium depending upon the animal species it encounters and demonstrates that, as for E. coli O157:H7, ruminants could represent a potential transmission reservoir.
目的
评估携带大量 ESBL 基因的 IncI1 质粒对大肠杆菌 O104:H4 在两种不同哺乳动物宿主体内肠道定殖的稳定性和贡献。
方法
采用无特定病原体的 3-4 日龄新西兰白兔和常规饲养的 6 周龄断奶羔羊进行口服感染，用 WT 大肠杆菌 O104:H4 或 ESBL 质粒消除衍生株感染，监测肠道匀浆和粪便中细菌的恢复情况。
结果
ESBL 质粒的携带对两种实验宿主大肠杆菌 O104:H4 的定殖有不同的影响。在兔的晚期定殖过程中，与 WT 相比，质粒消除株的回收水平显著更高，但在绵羊中则低于 WT。无论动物宿主如何，在几乎所有体内传代的细菌中都稳定地维持了 ESBL 质粒。
结论
这些发现表明，ESBL 质粒的携带对宿主细菌的影响因所遇到的动物物种而异，并表明，与大肠杆菌 O157:H7 一样，反刍动物可能代表潜在的传播储主。
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