Pérez-Varela María, Corral Jordi, Vallejo Juan Andrés, Rumbo-Feal Soraya, Bou Germán, Aranda Jesús, Barbé Jordi
Departament de Genètica i Microbiologia, Facultat de Biociències, Universitat Autònoma de Barcelona, Barcelona, Spain.
Servizo de Microbioloxía-INIBIC, Complexo Hospitalario Universitario A Coruña (CHUAC), A Coruña, Spain.
Infect Immun. 2017 Jul 19;85(8). doi: 10.1128/IAI.00327-17. Print 2017 Aug.
is a major cause of antibiotic-resistant nosocomial infections worldwide. In this study, several rifampin-resistant spontaneous mutants obtained from the ATCC 17978 strain that differed in their point mutations in the gene, encoding the β-subunit of the RNA polymerase, were isolated. All the mutants harboring amino acid substitutions in position 522 or 540 of the RpoB protein were impaired in surface-associated motility and had attenuated virulence in the fertility model of The transcriptional profile of these mutants included six downregulated genes encoding proteins homologous to transporters and metabolic enzymes widespread among clinical isolates. The construction of knockout mutants in each of the six downregulated genes revealed a significant reduction in the surface-associated motility and virulence of four of them in the ATCC 17978 strain, as well as in the virulent clinical isolate MAR002. Taken together, our results provide strong evidence of the connection between motility and virulence in this multiresistant nosocomial pathogen.
是全球范围内耐抗生素医院感染的主要原因。在本研究中，从ATCC 17978菌株中分离出了几种耐利福平的自发突变体，它们在编码RNA聚合酶β亚基的基因中的点突变有所不同。所有在RpoB蛋白第522位或540位存在氨基酸替换的突变体，其表面相关运动能力受损，并且在生育模型中的毒力减弱。这些突变体的转录谱包括六个下调基因，这些基因编码的蛋白质与临床分离株中广泛存在的转运蛋白和代谢酶同源。在六个下调基因中构建基因敲除突变体后发现，其中四个基因敲除突变体在ATCC 17978菌株以及强毒临床分离株MAR002中的表面相关运动能力和毒力均显著降低。综上所述，我们的结果有力地证明了这种多重耐药医院病原体中运动能力与毒力之间的联系。
