New class of precision antimicrobials redefines role of Clostridium difficile S-layer in virulence and viability.
New class of precision antimicrobials redefines role of Clostridium difficile S-layer in virulence and viability.
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DOI：
10.1126/scitranslmed.aah6813
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发表时间：
2017-09-06
影响因子：
17.1
通讯作者：
Fagan RP
中科院分区：
文献类型：
--
作者：
Kirk JA;Gebhart D;Buckley AM;Lok S;Scholl D;Douce GR;Govoni GR;Fagan RP
阿维菌素-CD是一种新型的精密杀菌剂，不会破坏常驻的肠道微生物区系，也不太可能促进抗生素耐药性的传播。这种精确的杀灭特性是由R型细菌素将噬菌体受体结合蛋白(RBPs)融合到致命的收缩支架上而产生的。我们最近描述了原型Avidocin-CD，Av-CD291.2，它可以特异性地杀死艰难梭菌027株，并防止小鼠定植。此后，我们选择了两个罕见的R20291株抗Av-CD291.2的突变体(RT027；S-层盒4型，SCLT-4)。这些突变体在SLPA基因上有明显的点突变，导致S层零表型。突变恢复到野生型后，恢复了正常的SLCT-4 S层形成和Av-CD291.2敏感性，但与其他SCLT等位基因互补后，虽然恢复了S层的形成，但不能恢复对Av-CD291.2的敏感性。利用新发现的噬菌体限制性商业惯例，我们构建了一组新的阿维菌素-CD，以SLCT依赖的方式杀灭艰难梭菌，证实S层是每个病例的受体。除了对噬菌体的吸附外，对S层缺失突变体的鉴定还揭示了SLpA在孢子形成、对溶菌酶和LL-37的抗性以及毒素产生中的重要作用。令人惊讶的是，S层零突变体被发现在仓鼠肠道中持续存在，尽管其毒力完全减弱。阿维菌素-CD对艰难梭菌感染(CDI)具有极高的特异性，在治疗和预防CDI方面具有巨大的治疗潜力。此外，耐药性的出现迫使突变株以毒力换取持续的生存能力，因此大大降低了它们潜在的临床影响。
Avidocin-CDs are a new class of precision bactericidal agents that do not damage resident gut microbiota and are unlikely to promote the spread of antibiotic resistance. The precision killing properties result from the fusion of bacteriophage receptor binding proteins (RBPs) to a lethal contractile scaffold from an R-type bacteriocin. We recently described the prototypic Avidocin-CD, Av-CD291.2, that specifically kills C. difficile ribotype 027 strains and prevents colonization of mice. We have since selected two rare Av-CD291.2 resistant mutants of strain R20291 (RT027; S-layer cassette type-4, SCLT-4). These mutants have distinct point mutations in the slpA gene that result in an S-layer null phenotype. Reversion of the mutations to wild-type restored normal SLCT-4 S-layer formation and Av-CD291.2 sensitivity; however, complementation with other SCLT alleles did not restore Av-CD291.2 sensitivity despite restoring S-layer formation. Using newly identified phage RBPs, we constructed a panel of new Avidocin-CDs that kill C. difficile isolates in an SLCT-dependent manner, confirming the S-layer as the receptor in every case. In addition to bacteriophage adsorption, characterization of the S-layer null mutant also uncovered important roles for SlpA in sporulation, resistance to lysozyme and LL-37, and toxin production. Surprisingly, the S-layer-null mutant was found to persist in the hamster gut despite its completely attenuated virulence. Avidocin-CDs have significant therapeutic potential for the treatment and prevention of C. difficile Infection (CDI) given their exquisite specificity for the pathogen. Furthermore, the emergence of resistance forces mutants to trade virulence for continued viability and, therefore, greatly reduce their potential clinical impact.
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影响因子：
6.7
作者：
Ryan A;Lynch M;Smith SM;Amu S;Nel HJ;McCoy CE;Dowling JK;Draper E;O'Reilly V;McCarthy C;O'Brien J;Ní Eidhin D;O'Connell MJ;Keogh B;Morton CO;Rogers TR;Fallon PG;O'Neill LA;Kelleher D;Loscher CE
通讯作者：
Loscher CE
影响因子：
4.8
作者：
Fagan, Robert P.;Fairweather, Neil F.
通讯作者：
Fairweather, Neil F.
基于 S 层基因序列中 slpA 可变区的艰难梭菌基因分型：血清分型的替代方法
影响因子：
9.4
作者：
Karjalainen, T;Saumier, N;Collignon, A
通讯作者：
Collignon, A
影响因子：
3.2
作者：
Plaut, Roger D.;Beaber, John W.;Sozhamannan, Shanmuga
通讯作者：
Sozhamannan, Shanmuga
影响因子：
3.1
作者：
Deakin, Laura J.;Clare, Simon;Lawley, Trevor D.
通讯作者：
Lawley, Trevor D.