TY - JOUR
T1 - Mutations in the β-subunit of the RNA polymerase impair the surface-associated motility and virulence of Acinetobacter baumannii
AU - Pérez-Varela, María
AU - Corral, Jordi
AU - Vallejo, Juan Andrés
AU - Rumbo-Feal, Soraya
AU - Bou, Germán
AU - Aranda, Jesús
AU - Barbé, Jordi
PY - 2017/8/1
Y1 - 2017/8/1
N2 - © 2017 American Society for Microbiology. Acinetobacter baumannii is a major cause of antibiotic-resistant nosocomial infections worldwide. In this study, several rifampin-resistant spontaneous mutants obtained from the A. baumannii ATCC 17978 strain that differed in their point mutations in the rpoB 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 Caenorhabditis elegans. The transcriptional profile of these mutants included six downregulated genes encoding proteins homologous to transporters and metabolic enzymes widespread among A. baumannii 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 A. baumannii 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.
AB - © 2017 American Society for Microbiology. Acinetobacter baumannii is a major cause of antibiotic-resistant nosocomial infections worldwide. In this study, several rifampin-resistant spontaneous mutants obtained from the A. baumannii ATCC 17978 strain that differed in their point mutations in the rpoB 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 Caenorhabditis elegans. The transcriptional profile of these mutants included six downregulated genes encoding proteins homologous to transporters and metabolic enzymes widespread among A. baumannii 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 A. baumannii 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.
KW - Acinetobacter baumannii
KW - Rifampin resistance
KW - RpoB
KW - Surface-associated motility
U2 - 10.1128/IAI.00327-17
DO - 10.1128/IAI.00327-17
M3 - Article
VL - 85
JO - Infection and Immunity
JF - Infection and Immunity
SN - 0019-9567
IS - 8
M1 - e00327-17
ER -