Further studies on RpoS in enterobacteria: identification of rpoS in Enterobacter cloacae and Kluyvera cryocrescens

Citation
E. Martinez-garcia et al., Further studies on RpoS in enterobacteria: identification of rpoS in Enterobacter cloacae and Kluyvera cryocrescens, ARCH MICROB, 175(6), 2001, pp. 395-404
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
ARCHIVES OF MICROBIOLOGY
ISSN journal
0302-8933 → ACNP
Volume
175
Issue
6
Year of publication
2001
Pages
395 - 404
Database
ISI
SICI code
0302-8933(200106)175:6<395:FSORIE>2.0.ZU;2-3
Abstract
RpoS, the alternative sigma factor sigma (s), is important for bacterial su rvival under extreme conditions. Many enterobacteria are opportunistic huma n pathogens and their ability to survive in a changing environment could be an essential step for their virulence. To determine the presence of this g ene in enteric bacteria, an Escherichia coli rpoS probe was constructed and used to detect the presence of this gene in different species. A gene homo logous to rpoS was found in Citrobacter amalonaticus, Enterobacter cloacae, Klebsiella planticola, Kluyvera cryocrescens, Serratia rubidaea, Shigella sonnei, and Yersinia ruckeri. Providencia stuartii and Proteus vulgaris wer e the only tested enterobacteria that did not show any signal with the E. c oli rpoS probe or that did not lead to amplification of an rpoS fragment us ing specific primers. The rpoS gene from E. cloacae and from K. cryocrescen s was cloned and sequenced and a mutant allele was constructed in E. cloaca e. Survival rates under different harsh conditions were followed in order t o determine the effect of rpoS inactivation in exponential- and stationary- phase cells of both strains. E. cloacae rpoS mutants were more sensitive to extreme pH, high osmolarity, and high temperature than the wild-type.