Sekse C, Solheim H, Urdahl A M, Wasteson Y
Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Oslo, Norway.
J Appl Microbiol. 2008 Oct;105(4):1114-20. doi: 10.1111/j.1365-2672.2008.03845.x. Epub 2008 May 20.
To determine whether a Shiga toxin 2 (Stx2)-encoding phage from Escherichia coli O157:H7 could be transmitted to commensal E. coli in a ruminant host without adding a specific recipient strain.
Sheep were inoculated with an E. coli O157:H7 strain containing an Stx2-encoding bacteriophage (Phi3538) in which a chloramphenicol-resistant gene, cat, is inserted into stx(2). A total of 149 faecal samples were sampled and analysed for detection and quantification of E. coli O157:H7 and presumptive transductants. Phage Phi3538 (Deltastx(2)::cat) was demonstrated to be transduced to an ovine E. coli O175:H16 at one occasion.
The study demonstrates an in vivo transduction in sheep from an E. coli O157:H7 strain to an ovine E. coli O175:H16. A functional Stx2-encoding phage was incorporated into the host's DNA.
This is the first in vivo stx phage transduction study reported in which a recipient strain was not fed to the test animals. We suggest that the access to susceptible hosts is one main limiting factor for transduction to occur in the intestine.
确定来自大肠杆菌O157:H7的一种编码志贺毒素2（Stx2）的噬菌体在不添加特定受体菌株的情况下是否能在反刍动物宿主体内传递给共生大肠杆菌。
给绵羊接种一株含有编码Stx2的噬菌体（Phi3538）的大肠杆菌O157:H7菌株，其中氯霉素抗性基因cat插入stx(2)中。共采集149份粪便样本，分析检测和定量大肠杆菌O157:H7及推定的转导子。噬菌体Phi3538（Deltastx(2)::cat）有一次被证明转导至绵羊的大肠杆菌O175:H16。
该研究证明了在绵羊体内从大肠杆菌O157:H7菌株到绵羊大肠杆菌O175:H16的体内转导。一个功能性的编码Stx2的噬菌体被整合到宿主的DNA中。
这是首次报道的体内stx噬菌体转导研究，其中未给试验动物投喂受体菌株。我们认为，易感染宿主的存在是肠道内发生转导的一个主要限制因素。
