Identification and Characterization of an Antibacterial Type VI Secretion System in the Carbapenem-Resistant Strain Klebsiella pneumoniae HS11286.
Identification and Characterization of an Antibacterial Type VI Secretion System in the Carbapenem-Resistant Strain Klebsiella pneumoniae HS11286.
复制标题
碳青霉烯类耐药菌株肺炎克雷伯菌 HS11286 中抗菌 VI 型分泌系统的鉴定和表征
DOI：
10.3389/fcimb.2017.00442
复制
发表时间：
2017
影响因子：
5.7
通讯作者：
Ou HY
中科院分区：
文献类型：
--
作者：
Liu L;Ye M;Li X;Li J;Deng Z;Yao YF;Ou HY
VI型分泌系统（T6SS）是一类复杂的细胞接触依赖性装置，具有抗真核或抗菌功能。肺炎克雷伯菌是最常见的细菌病原体之一，对碳青霉烯类抗生素具有耐药性。然而，人们对肺炎克雷伯菌中的抗菌 T6SS 知之甚少。通过核心成分蛋白搜索，我们在产碳青霉烯酶肺炎克雷伯菌 (CRKP) 菌株 HS11286 的染色体上发现了一个假定的 T6SS 基因簇。种内和种间竞争测定揭示了 HS11286 T6SS 的抗菌功能。磷脂酶 Tle1KP 被发现是一种由 T6SS 转移的效应蛋白。该效应基因在周质中的过度表达引起了大肠杆菌的严重生长抑制。亚抑制浓度的 β-内酰胺抗生素刺激 HS11286 T6SS 的表达和分泌，并增强 T6SS 依赖性杀伤作用。提示抗生素可能是T6SS分泌和抗菌活性的影响因素。
The type VI secretion system (T6SS) is a class of sophisticated cell contact-dependent apparatus with anti-eukaryotic or anti-bacterial function. Klebsiella pneumoniae is one of the most common bacterial pathogens with resistance to the carbapenem antibiotics. However, little is known about the antibacterial T6SS in K. pneumoniae. Using core-component protein searches, we identified a putative T6SS gene cluster on the chromosome of the carbapenemase-producing K. pneumoniae (CRKP) strain HS11286. Intraspecies and interspecies competition assays revealed an antibacterial function of the HS11286 T6SS. The phospholipase Tle1KP was found to be an effector protein that is transferred by T6SS. The overexpression of this effector gene in the periplasm caused severe growth inhibition of Escherichia coli. A sub-inhibitory concentration of β-lactam antibiotics stimulated the expression and secretion of the HS11286 T6SS and enhanced T6SS-dependent killing. It suggested that the antibiotics might be an impact factor for the T6SS secretion and antibacterial activity.