Format

Send to

Choose Destination
Microb Pathog. 2010 Jun;48(6):214-9. doi: 10.1016/j.micpath.2010.03.005. Epub 2010 Mar 19.

The Salmonella enterica serovar Typhimurium QseB response regulator negatively regulates bacterial motility and swine colonization in the absence of the QseC sensor kinase.

Author information

1
Agroecosystems Management Research Unit, USDA, ARS, National Laboratory for Agriculture and the Environment, Ames, IA 50011, USA. brad.bearson@ars.usda.gov

Abstract

Salmonella enterica serovar Typhimurium (S. Typhimurium) responds to the catecholamine, norepinephrine by increasing bacterial growth and enhancing motility. In this study, iron with or without the siderophore, ferrioxamine E also enhanced bacterial motility. Iron-enhanced motility was growth-rate dependent, while norepinephrine-enhanced motility was growth-rate independent. The outer membrane catecholate receptors, IroN, FepA and CirA (required for norepinephrine-enhanced growth) were not required for norepinephrine-enhanced motility, nor was ExbD of the energy-transducing TonB-ExbB-ExbD ferri-siderophore uptake system. Examination of the QseBC two-component system revealed that qseB and qseBC mutants have motility phenotypes similar to wild-type S. Typhimurium, while motility of the qseC mutant was significantly decreased (P<0.01). Each mutant of the QseBC system, as well as mutants of qseE and pmrA, responded to norepinephrine with increased motility, suggesting that other genes are involved in norepinephrine-enhanced motility of S. Typhimurium. In the swine host, fecal shedding of the qseBC mutant was similar to wild-type S. Typhimurium, whereas fecal shedding of the qseC mutant was significantly decreased (P<0.01). Our data indicate that, in a qseC mutant, the QseB response regulator decreases motility and swine colonization; inactivation of the qseBC operon restores these bacterial phenotypes, classifying QseB as a negative regulator of bacterial motility and swine colonization.

PMID:
20227482
DOI:
10.1016/j.micpath.2010.03.005
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center