Linked Life Data

21262551

Source:http://linkedlifedata.com/resource/pubmed/id/21262551

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2011-2-21
pubmed:abstractText
The ability of Listeria monocytogenes to tolerate high levels of bile stress is critical to its successful infection and colonization in the human gastrointestinal tract. L. monocytogenes encodes bile salt hydrolase by a bsh gene which plays a significant role in hydrolyzing high concentrations of bile salt when L. monocytogenes grows under hypoxemic condition. As the bsh promoter contains consensus SigB and PrfA binding sites, we investigated the role of SigB (?(B)) and PrfA in L. monocytogenes tolerance against bile stress by comparing the survival of isogenic deletion mutants of L. monocytogenes EGD(?sigB), EGD(?prfA) and EGD(?prfA?sigB) with their parent strain EGD at high levels of bile salt. Our results show that the sigB deletion significantly reduced the MICs of bile salt for EGD(?sigB) and EGD(?prfA?sigB) (2.6% and 2.2% vs 3.5% in wild type strain EGD), while the growth rates of these two sigB deletion mutants (EGD(?sigB) and EGD(?prfA?sigB)) were affected the most in the presence of 3% bile salt. Pre-exposure to alkali (pH 9.0) and osmotic (0.3M NaCl) stresses for a short period of time (30 min) resulted in improved growth of L. monocytogenes as well as its prfA-sigB isogenic mutants even under sublethal concentrations of bile salt, while pre-exposure to acid pH (pH 4.5) failed to provide cross-protection against subsequent bile stress. Furthermore, the sigB gene had more remarkable influence than that of prfA on bsh expression, as much lower levels of bsh transcription were observed in EGD(?sigB) and EGD(?prfA?sigB). Meanwhile, bsh expression in the deletion mutants did not respond to elevated levels of bile salt. These data indicate that ?(B) might play a crucial role in Listeria survival under bile salt environment in the gastrointestinal tract before its successful colonization, invasion and intracellular propagation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1879-3460
pubmed:author
pubmed:copyrightInfo
Copyright © 2010 Elsevier B.V. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
31
pubmed:volume
145
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
238-43
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
SigB plays a major role in Listeria monocytogenes tolerance to bile stress.
pubmed:affiliation
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Science, Central China Normal University, Wuhan, PR China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't