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The cloning and characterization of a Bordetella pertussis gene encoding a putative hemolysin.

Bordetella pertussis, the etiologic agent of whooping cough or pertussis, produces a multitude of virulence factors including a hemolysin. Virulent phase B. pertussis isolates are hemolytic, whereas avirulent isolates are not. Other investigations concerning B. pertussis adenylate cyclase toxin indicate it has hemolytic activity and is a member of the bacterial RTX toxin family. In an attempt to further characterize hemolysis by B. pertussis, a new B. pertussis gene was isolated which conferred a hemolytic phenotype on non-hemolytic E. coli. DNA sequencing of the putative B. pertussis hemolysin gene revealed it encoded a 27 kDa protein similar to HlyX, an FNR-like transcriptional regulator from Actinobacillus pleuropneumonia, which also confers hemolysis upon E. coli. No similarity to bacterial cytolysins was found. The B. pertussis transcriptional regulator-like gene and its encoded protein were named btr and BTR, respectively. BJB1, a BTR deficient B. pertussis strain was constructed. The btr::kan mutation was shown to have no effect on the production, or phenotypic modulation, of hemolysis by B. pertussis. BTR production was not regulated by the BvgA-S two component sensor-regulator. An FNR deficient E. coli, JRG1728 (Δfnr), was transformed with a btr recombinant plasmid pHLY1A. The B. pertussis btr gene complemented the FNR deficient E. coli to grow anaerobically on a non-fermentable carbon source. This suggested that BTR may function as a B. pertussis transcriptional regulator which responds to anoxic conditions.

Identiferoai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/185908
Date January 1992
CreatorsBannan, Jason David.
ContributorsFriedman, Richard, Ryan, Kenneth, Adam, Rodney D., Joens, Lynn, Komm, Barry, Bernstein, Harris
PublisherThe University of Arizona.
Source SetsUniversity of Arizona
LanguageEnglish
Detected LanguageEnglish
Typetext, Dissertation-Reproduction (electronic)
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.

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