College of Veterinary Medicine, Yangzhou University, Yangzhou, China.
Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.
J Basic Microbiol. 2018 Nov;58(11):938-946. doi: 10.1002/jobm.201800156. Epub 2018 Sep 3.
Type VI secretion system (T6SS) is a secretory system found in Gram-negative bacteria. One of the main structures for T6SS is Hcp (hemolysin co-regulation protein) pipeline. To investigate the role of Hcp major sub-unit genes hcp and hcp , we deleted hcp and hcp genes for constructing the in-frame gene deletion mutants. The properties of biofilm formation and the adhesion to chicken embryo fibroblasts cells (DF1 cells) were reduced in the hcp mutant. The knockout of hcp and hcp genes reduced the ability of the avian pathogenic Escherichia coli (APEC) strain CE129 to infect developing chicken embryos. The expression of quorum sensing (QS)-associated genes luxS, lsrR, and pfs were down-regulated in the hcp mutant, and the expression of type 1 fimbriae gene fimA and the adhesion-related genes fimC and papC were decreased in the hcp mutant, as well as the expression of anti-serum survival factor genes ompA and iss were inhibited in both hcp and hcp mutants. These results described above from this study help to further elaborate the role of HCP in APEC.
VI 型分泌系统（T6SS）是革兰氏阴性菌中发现的一种分泌系统。T6SS 的主要结构之一是 Hcp（溶菌素共调节蛋白）管道。为了研究 Hcp 主要亚基基因 hcp 和 hcp 的作用，我们删除了 hcp 和 hcp 基因，构建了基因缺失突变体。在 hcp 突变体中，生物膜形成和黏附鸡胚成纤维细胞（DF1 细胞）的特性降低。hcp 和 hcp 基因的敲除降低了禽致病性大肠杆菌（APEC）菌株 CE129 感染发育中的鸡胚的能力。在 hcp 突变体中，群体感应（QS）相关基因 luxS、lsrR 和 pfs 的表达下调，而 type 1 菌毛基因 fimA 以及黏附相关基因 fimC 和 papC 的表达在 hcp 突变体中降低，同时 hcp 和 hcp 突变体中抗血清存活因子基因 ompA 和 iss 的表达也受到抑制。本研究中的这些结果有助于进一步阐述 HCP 在 APEC 中的作用。
