Title

Transposon mutagenesis of Campylobacter jejuni identifies a bipartite energy taxis system required for motility

UMMS Affiliation

Department of Molecular Genetics and Microbiology

Date

4-12-2001

Document Type

Article

Medical Subject Headings

Amino Acid Sequence; Bacterial Proteins; Campylobacter jejuni; *DNA Transposable Elements; Molecular Sequence Data; Mutagenesis; Reverse Transcriptase Polymerase Chain Reaction; Sequence Homology, Amino Acid; Transcription, Genetic

Disciplines

Microbiology | Molecular genetics

Abstract

Campylobacter jejuni constitutes the leading cause of bacterial gastroenteritis in the United States and a major cause of diarrhoea worldwide. Little is known about virulence mechanisms in this organism because of the scarcity of suitable genetic tools. We have developed an efficient system of in vitro transposon mutagenesis using a mariner-based transposon and purified mariner transposase. Through in vitro transposition of C. jejuni chromosomal DNA followed by natural transformation of the transposed DNA, large random transposon mutant libraries consisting of approximately 16 000 individual mutants were generated. The first genetic screen of C. jejuni using a transposon-generated mutant library identified 28 mutants defective for flagellar motility, one of the few known virulence determinants of this pathogen. We developed a second genetic system, which allows for the construction of defined chromosomal deletions in C. jejuni, and demonstrated the requirement of sigma28 and sigma54 for motility. In addition, we show that sigma28 is involved in the transcription of flaA and that sigma54 is required for transcription of three other flagellar genes, flaB and flgDE. We also identified two previously uncharacterized genes required for motility encoding proteins that we call CetA and CetB, which mediate energy taxis responses. Through our analysis of the Cet proteins, we propose a unique mechanism for sensing energy levels and mediating energy taxis in C. jejuni.

Rights and Permissions

Citation: Mol Microbiol. 2001 Apr;40(1):214-24.

Related Resources

Link to Article in PubMed