Soria-Bustos Jorge, Ares Miguel A, Gómez-Aldapa Carlos A, González-Y-Merchand Jorge A, Girón Jorge A, De la Cruz Miguel A
Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico.
Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico.
Front Microbiol. 2020 Sep 24;11:560488. doi: 10.3389/fmicb.2020.560488. eCollection 2020.
has emerged as an opportunistic pathogen in healthcare-associated infections. Analysis of the genomic sequences of several strains revealed the presence of genes that code for expression of at least one type VI secretion system (T6SS). Here, we report that strain ATCC 13047 codes for two functional T6SS named T6SS-1 and T6SS-2. T6SS-1 and T6SS-2 were preferentially expressed in tryptic soy broth and tissue culture medium (DMEM), respectively. Mutants in T6SS-1-associated genes and significantly affected their ability of inter- and intra-bacterial killing indicating that T6SS-1 is required for bacterial competition. In addition, the Hcp effector protein was detected in supernatants of cultures and a functional T6SS-1 was required for the secretion of this protein. A mutant was impaired in both biofilm formation and adherence to epithelial cells, supporting the notion that these phenotypes are T6SS-2 dependent. data strongly suggest that both T6SSs are required for intestinal colonization because single and double mutants in and genes were defective in gut colonization in mice. We conclude that the two T6SSs are involved in the pathogenesis scheme of with specialized functions in the interaction with other bacteria and with host cells.
已成为医疗保健相关感染中的一种机会致病菌。对几种菌株的基因组序列分析显示存在编码至少一种VI型分泌系统（T6SS）表达的基因。在此，我们报告菌株ATCC 13047编码两种功能性T6SS，分别命名为T6SS-1和T6SS-2。T6SS-1和T6SS-2分别在胰蛋白酶大豆肉汤和组织培养基（DMEM）中优先表达。T6SS-1相关基因和的突变体显著影响其细菌间和细菌内杀伤能力，表明T6SS-1是细菌竞争所必需的。此外，在培养物的上清液中检测到Hcp效应蛋白，并且该蛋白的分泌需要功能性T6SS-1。一个突变体在生物膜形成和对上皮细胞的黏附方面均受损，支持了这些表型依赖于T6SS-2的观点。数据强烈表明，两种T6SS对于肠道定植都是必需的，因为和基因的单突变体和双突变体在小鼠肠道定植中存在缺陷。我们得出结论，两种T6SS参与了的致病机制，在与其他细菌和宿主细胞的相互作用中具有特定功能。
