Characterization of Bacteriophages Infecting Clinical Isolates of Clostridium difficile
Characterization of Bacteriophages Infecting Clinical Isolates of Clostridium difficile
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DOI：
10.3389/fmicb.2018.01701
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发表时间：
2018-07-31
影响因子：
5.2
通讯作者：
Chankhamhaengdecha, Surang
中科院分区：
文献类型：
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作者：
Phothichaisri, Wichuda;Ounjai, Puey;Chankhamhaengdecha, Surang
艰难梭菌被认为是一种有问题的病原体，可引起严重的肠道疾病，包括抗生素相关性腹泻和伪膜性结肠炎。抗生素耐药性艰难梭菌的出现推动了对替代抗感染方式的探索。控制细菌感染的一种有前景的策略包括使用噬菌体及其基因产物。目前，对艰难梭菌活性噬菌体的了解仍然相对有限，因为细菌宿主本身难以培养，因此分离该生物体的噬菌体是一种技术要求很高的方法。为了分离和表征艰难梭菌特异性噬菌体，使用基因毒性剂丝裂霉素 C 从 12 种艰难梭菌临床分离株中诱导出温带噬菌体。成功诱导并分离出由 Phi HR24、Phi HN10、Phi HN16-1、Phi HN16-2 和 Phi HN50 组成的 5 个温带噬菌体。对一组 92 株艰难梭菌分离株进行点样测定，以筛选易感细菌宿主。结果显示，本研究中获得的所有艰难梭菌噬菌体都表现出相对较窄的宿主范围，为测试分离株的 0-6.5%。电子显微镜表征显示，所有分离的噬菌体都包含与长收缩尾相连的二十面体头部，表明它们属于肌病毒科。限制性内切酶分析表明这些噬菌体具有独特的双链DNA基因组。进一步的电子显微镜表征表明，Phi HN10 通过附着在细胞壁上而吸收到细菌表面，可能与 S 层蛋白相互作用。从这项研究中分离出的噬菌体可能会导致艰难梭菌新型治疗剂和检测策略的开发。
Clostridium difficile is recognized as a problematic pathogen, causing severe enteric diseases including antibiotic-associated diarrhea and pseudomembranous colitis. The emergence of antibiotic resistant C. difficile has driven a search for alternative anti-infection modalities. A promising strategy for controlling bacterial infection includes the use of bacteriophages and their gene products. Currently, knowledge of phages active against C. difficile is still relatively limited by the fact that the isolation of phages for this organism is a technically demanding method since bacterial host themselves are difficult to culture. To isolate and characterize phages specific to C. difficile, a genotoxic agent, mitomycin C, was used to induce temperate phages from 12 clinical isolates of C. difficile. Five temperate phages consisting of Phi HR24, Phi HN10, Phi HN16-1, Phi HN16-2, and Phi HN50 were successfully induced and isolated. Spotting assays were performed against a panel of 92 C. difficile isolates to screen for susceptible bacterial hosts. The results revealed that all the C. difficile phages obtained in this work displayed a relatively narrow host range of 0-6.5% of the tested isolates. Electron microscopic characterization revealed that all isolated phages contained an icosahedral head connected to a long contractile tail, suggesting that they belonged to the Myoviridae family. Restriction enzyme analysis indicated that these phages possess unique double-stranded DNA genome. Further electron microscopic characterization revealed that the Phi HN10 absorbed to the bacterial surface via attachment to cell wall, potentially interacting with S-layer protein. Bacteriophages isolated from this study could lead to development of novel therapeutic agents and detection strategies for C. difficile.