An Engineered R-Type Pyocin Is a Highly Specific and Sensitive Bactericidal Agent for the Food-Borne Pathogen Escherichia coli O157:H7
An Engineered R-Type Pyocin Is a Highly Specific and Sensitive Bactericidal Agent for the Food-Borne Pathogen Escherichia coli O157:H7
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DOI：
10.1128/aac.01660-08
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发表时间：
2009-07-01
影响因子：
4.9
通讯作者：
Mandrell, Robert
中科院分区：
文献类型：
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作者：
Scholl, Dean;Cooley, Mike;Mandrell, Robert
一些铜绿假单胞菌菌株产生 R 型脓毒素，这是一种高分子量噬菌体尾状蛋白复合物，对其他假单胞菌菌株具有杀菌活性。这些颗粒通过尾部纤维识别并结合细菌表面结构，尾部纤维是细菌的主要光谱决定因素。 R型脓毒素通过收缩鞘状结构并将其中空核心插入细胞膜来杀死细胞，从而导致细胞膜电位耗散。我们通过将 O157 特异性噬菌体 phi V10 的尾部刺突蛋白融合到化脓菌素尾纤维，将 R 型化脓菌素重新靶向大肠杆菌 O157:H7。 phi V10 尾刺蛋白识别并降解 O157 脂多糖。这种工程化的脓毒素被称为 AVR2-V10，具有敏感性和特异性，可杀死 100% 的多种大肠杆菌 O157: H7 分离株，但未测试其他血清型。 AVR2-V10 可以杀死牛肉表面的大肠杆菌 O157: H7，使其成为消除食品中这种病原体的候选药物。所有分离和检查的罕见 AVR2-V10 抗性突变体都失去了产生 O157 抗原的能力，预计毒力也会减弱。此外，与许多抗生素经常发生的情况一样，暴露于 AVR2-V10 并被杀死的大肠杆菌 O157:H7 不会释放志贺毒素，这表明了潜在的治疗应用。通过将短足病毒科的催化尾刺与肌病毒科成员的尾部纤维融合，可以在实验室中产生一种新型的R型脓毒素，这证明在噬菌体尾部基因中观察到的可塑性可以通过现代分子技术用于生产非天然的靶向抗菌剂。
Some strains of Pseudomonas aeruginosa produce R-type pyocins, which are high-molecular-weight phage tail-like protein complexes that have bactericidal activity against other Pseudomonas strains. These particles recognize and bind to bacterial surface structures via tail fibers, their primary spectrum determinant. R-type pyocins kill the cell by contracting a sheath-like structure and inserting their hollow core through the cell envelope, resulting in dissipation of the cellular membrane potential. We have retargeted an R-type pyocin to Escherichia coli O157:H7 by fusing a tail spike protein from an O157-specific phage, phi V10, to the pyocin tail fiber. The phi V10 tail spike protein recognizes and degrades the O157 lipopolysaccharide. This engineered pyocin, termed AVR2-V10, is sensitive and specific, killing 100% of diverse E. coli O157: H7 isolates but no other serotypes tested. AVR2-V10 can kill E. coli O157: H7 on beef surfaces, making it a candidate agent for the elimination of this pathogen from food products. All rare AVR2-V10-resistant mutants isolated and examined have lost the ability to produce the O157 antigen and are expected to have compromised virulence. In addition, E. coli O157:H7 exposed to and killed by AVR2-V10 do not release Shiga toxin, as is often the case with many antibiotics, suggesting potential therapeutic applications. The demonstration that a novel R-type pyocin can be created in the laboratory by fusing a catalytic tail spike from the family Podoviridae to a tail fiber of a member of the family Myoviridae is evidence that the plasticity observed among bacteriophage tail genes can, with modern molecular techniques, be exploited to produce nonnatural, targeted antimicrobial agents.