Montes-Bravo Nicolás, Romero-Rodríguez Alba, García-Yunge José, Medina César, Pizarro-Guajardo Marjorie, Paredes-Sabja Daniel
ANID-Millennium Science Initiative Program-Millennium Nucleus in the Biology of the Intestinal Microbiota, Santiago 8320000, Chile.
Department of Molecular Biology and Biotechnology, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México 34955, Mexico.
Microorganisms. 2022 Sep 27;10(10):1918. doi: 10.3390/microorganisms10101918.
is Gram-positive spore-former bacterium and the leading cause of nosocomial antibiotic-associated diarrhea. During disease, forms metabolically dormant spores that persist in the host and contribute to recurrence of the disease. The outermost surface of spores, termed the exosporium, plays an essential role in interactions with host surfaces and the immune system. The main exosporium proteins identified to date include three orthologues of the BclA family of collagen-like proteins, and three cysteine-rich proteins. However, how the underlying spore coat influences exosporium assembly remains unclear. In this work, we explore the contribution of spore coat proteins and , and the spore surface protein, CDIF630_02480, to the exosporium ultrastructure, formation of the polar appendage and the surface accessibility of exosporium proteins. Transmission electron micrographs of spores of insertional inactivation mutants demonstrate that while contributes to the formation of thick-exosporium spores, and CDIF630_02480 contribute to maintain proper thickness of the spore coat and exosporium layers, respectively. The effect of the absence of , and CDIF630_02480 on the surface accessibility of the exosporium proteins CdeA, CdeC, CdeM, BclA2 and BclA3 to antibodies was affected by the presence of the spore appendage, suggesting that different mechanisms of assembly of the exosporium layer might be implicated in each spore phenotype. Collectively, this work contributes to our understanding of the associations between spore coat and exosporium proteins, and how these associations affect the assembly of the spore outer layers. These results have implications for the development of anti-infecting agents targeting spores.
是革兰氏阳性芽孢形成菌，也是医院获得性抗生素相关性腹泻的主要病因。在疾病发生过程中，会形成代谢休眠的孢子，这些孢子在宿主体内持续存在并导致疾病复发。孢子的最外层表面称为芽孢衣，在与宿主表面和免疫系统的相互作用中起着至关重要的作用。迄今为止鉴定出的主要芽孢衣蛋白包括胶原蛋白样蛋白BclA家族的三个直系同源物和三种富含半胱氨酸的蛋白。然而，潜在的芽孢外壳如何影响芽孢衣组装仍不清楚。在这项工作中，我们探究了芽孢外壳蛋白和以及孢子表面蛋白CDIF630_02480对芽孢衣超微结构、极性附属物形成以及芽孢衣蛋白表面可及性的贡献。插入失活突变体孢子的透射电子显微镜图像表明，虽然有助于形成厚芽孢衣孢子，但和CDIF630_分别有助于维持芽孢外壳和芽孢衣层的适当厚度。芽孢附属物的存在会影响缺失、和CDIF630_02480对芽孢衣蛋白CdeA、CdeC、CdeM、BclA2和BclA3与抗体表面可及性的影响，这表明芽孢衣层的不同组装机制可能与每种孢子表型有关。总的来说，这项工作有助于我们理解芽孢外壳蛋白与芽孢衣蛋白之间的关联，以及这些关联如何影响孢子外层的组装。这些结果对开发针对孢子的抗感染药物具有重要意义。
