O side chain deficiency enhances sensitivity of Escherichia coli to Shiga toxin 2-converting bacteriophages
O side chain deficiency enhances sensitivity of Escherichia coli to Shiga toxin 2-converting bacteriophages
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DOI：
10.1007/s00284-006-0139-x
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发表时间：
2007-01-01
影响因子：
2.6
通讯作者：
Osawa, Ro
中科院分区：
文献类型：
--
作者：
Iguchi, Atsushi;Iyoda, Sunao;Osawa, Ro
我们研究了正常和良性大肠杆菌菌株中外膜脂多糖 (LPS) O 侧链的表达与志贺毒素 2 (Stx2) 转化噬菌体感染之间的关系。从健康受试者粪便中分离出的 19 株野生型大肠杆菌菌株中，具有低分子量 LPS 的菌株对 Stx2 噬菌体的溶解性和溶原性感染的敏感性明显高于具有高分子量 LPS 的菌株。所有溶原菌均产生感染性噬菌体颗粒和 Stx2。具有完整 O 侧链的 Stx 阴性大肠杆菌 O157:H7 菌株 ATCC43888 被发现能够抵抗 Stx2 噬菌体的裂解和重组 Stx2 噬菌体的溶原性感染，而 O 侧链表达缺陷的 rfbE 突变体很容易被噬菌体感染并产生稳定的溶原性。有证据表明，O 侧链缺陷会导致肠道菌群内产生志贺毒素大肠杆菌 (STEC) 新致病型。
We investigated the relationship between expression of the O side chain of outer membrane lipopolysaccharide (LPS) and infection by a Shiga toxin 2 (Stx2)-converting phage in normal and benign strains of Escherichia coli. Of 19 wild-type E. coli strains isolated from the feces of healthy subjects, those with low-molecular-weight LPS showed markedly higher susceptibility to lytic and lysogenic infection by Stx2 phages than those with high-molecular-weight LPS. All lysogens produced infectious phage particles and Stx2. The Stx-negative E. coli O157:H7 strain ATCC43888 with an intact O side chain was found to be resistant to lysis by an Stx2 phage and lysogenic infection by a recombinant Stx2 phage, whereas a rfbE mutant deficient in the expression of the O side chain was readily infected by the phage and yielded stable lysogens. The evidence suggests that an O side chain deficiency leads to the creation of new pathotypes of Shiga toxin-producing E. coli (STEC) within the intestinal microflora.