El Meouche Imane, Peltier Johann
Dunlop lab, Boston University, Boston, Massachussets, USA.
Laboratoire Pathogenese des Bacteries Anaerobies, Institut Pasteur, Paris, France.
Microb Cell. 2018 Aug 10;5(9):421-423. doi: 10.15698/mic2018.09.648.
, also known as , is a Gram positive, spore-forming bacterium and a leading cause of antibiotic-associated diarrhea in nosocomial environments. The key virulence factors of this pathogen are two toxins, toxin A and toxin B, released from the cells to the gut and causing colonic injury and inflammation. Although their mechanism of action is well known, the toxins A and B have no peptide signals and their secretion mechanisms involving the holin-like protein TcdE and autolysis are still under active investigation. Autolysis is primarily mediated by peptidoglycan hydrolases, an important group of enzymes that cleave covalent bonds in the cell wall peptidoglycan. Peptidoglycan hydrolases are essential for peptidoglycan remodeling but most of them also have the potential to lyse the cells under various conditions. In a recent report by Wydau-Dematteis (MBio 9(3): e00648-18), we characterized a novel peptidoglycan hydrolase Cwp19 in . Importantly, Cwp19 mediates toxins secretion in a glucose-dependent fashion suggesting a potential role in pathogenesis. Peptidoglycan hydrolases are not very well characterized in despite the important role of these enzymes in cell division and sporulation as shown in model organisms like . In addition, these enzymes can be implicated in pathogenicity as exemplified by the release of pneumococcal virulence factors.
[细菌名称]，也被称为[别名]，是一种革兰氏阳性、形成芽孢的细菌，是医院环境中抗生素相关性腹泻的主要病因。这种病原体的关键毒力因子是两种毒素，毒素A和毒素B，它们从细胞释放到肠道，导致结肠损伤和炎症。尽管它们的作用机制已为人所知，但毒素A和B没有肽信号，它们涉及类霍林蛋白TcdE和自溶作用的分泌机制仍在积极研究中。自溶主要由肽聚糖水解酶介导，肽聚糖水解酶是一组重要的酶，可切割细胞壁肽聚糖中的共价键。肽聚糖水解酶对于肽聚糖重塑至关重要，但它们中的大多数在各种条件下也具有裂解细胞的潜力。在Wydau-Dematteis最近的一份报告（《MBio》9(3): e00648-18）中，我们鉴定了[细菌名称]中的一种新型肽聚糖水解酶Cwp19。重要的是，Cwp19以葡萄糖依赖的方式介导毒素分泌，提示其在[细菌名称]致病过程中可能发挥作用。尽管肽聚糖水解酶在细胞分裂和芽孢形成中具有重要作用，如在[模式生物名称]等模式生物中所示，但在[细菌名称]中对这些酶的了解并不多。此外，这些酶可能与致病性有关，如肺炎球菌毒力因子的释放所示。
