Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 12
pubmed:dateCreated
2009-12-1
pubmed:abstractText
Analysis of the genome of Francisella tularensis has revealed few regulatory systems, and how the organism adapts to conditions in different niches is poorly understood. The stringent response is a global stress response mediated by (p)ppGpp. The enzyme RelA has been shown to be involved in generation of this signal molecule in a range of bacterial species. We investigated the effect of inactivation of the relA gene in Francisella by generating a mutant in Francisella novicida. Under amino acid starvation conditions, the relA mutant was defective for (p)ppGpp production. Characterization showed the mutant to grow similarly to the wild-type, except that it entered stationary phase later than wild-type cultures, resulting in higher cell yields. The relA mutant showed increased biofilm formation, which may be linked to the delay in entering stationary phase, which in turn would result in higher cell numbers present in the biofilm and reduced resistance to in vitro stress. The mutant was attenuated in the J774A macrophage cell line and was shown to be attenuated in the mouse model of tularaemia, but was able to induce a protective immune response. Therefore, (p)ppGpp appears to be an important intracellular signal, integral to the pathogenesis of F. novicida.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1465-2080
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
155
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4104-13
pubmed:meshHeading
pubmed-meshheading:19762448-Animals, pubmed-meshheading:19762448-Bacterial Proteins, pubmed-meshheading:19762448-Base Sequence, pubmed-meshheading:19762448-Biofilms, pubmed-meshheading:19762448-Cell Line, pubmed-meshheading:19762448-DNA, Bacterial, pubmed-meshheading:19762448-DNA Primers, pubmed-meshheading:19762448-Female, pubmed-meshheading:19762448-Francisella, pubmed-meshheading:19762448-Genes, Bacterial, pubmed-meshheading:19762448-Gram-Negative Bacterial Infections, pubmed-meshheading:19762448-Guanosine Pentaphosphate, pubmed-meshheading:19762448-Guanosine Tetraphosphate, pubmed-meshheading:19762448-Macrophages, pubmed-meshheading:19762448-Mice, pubmed-meshheading:19762448-Mice, Inbred BALB C, pubmed-meshheading:19762448-Mutation, pubmed-meshheading:19762448-Stress, Physiological, pubmed-meshheading:19762448-Transcription Factor RelA, pubmed-meshheading:19762448-Virulence
pubmed:year
2009
pubmed:articleTitle
RelA regulates virulence and intracellular survival of Francisella novicida.
pubmed:affiliation
Biomedical Sciences, Dstl Porton Down, Salisbury, Wiltshire SP4 0JQ, UK. redean@dstl.gov.uk
pubmed:publicationType
Journal Article