Premium
Construction and analysis of chromosomal Clostridium difficile mutants
Author(s) -
O'Connor Jennifer R.,
Lyras Dena,
Farrow Kylie A.,
Adams Vicki,
Powell David R.,
Hinds Jason,
Cheung Jackie K.,
Rood Julian I.
Publication year - 2006
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2006.05315.x
Subject(s) - biology , clostridium difficile , gene , virulence , operon , clostridium perfringens , mutant , genetics , microbiology and biotechnology , transcriptome , shuttle vector , response regulator , computational biology , vector (molecular biology) , bacteria , gene expression , recombinant dna , antibiotics
Summary Clostridium difficile is an emerging nosocomial pathogen of increasing importance and virulence but our ability to study the molecular mechanisms underlying the pathogenesis of C. difficile ‐associated disease has been limited because of a lack of tools for its genetic manipulation. We have now developed a reproducible method for the targeted insertional inactivation of chromosomal C. difficile genes. The approach relies on the observation that an Escherichia coli–Clostridium perfringens shuttle vector is unstable in C. difficile and can be used as a form of conditional lethal vector to deliver gene constructs to the chromosome. We have used this methodology to insertionally inactivate two putative response regulator genes, rgaR and rgbR , which encode proteins with similarity to the toxin gene regulator, VirR, from C. perfringens . Transcriptomic analysis demonstrated that the C. difficile RgaR protein positively regulated four genes, including a putative agrBD operon. The RgaR protein was also purified and shown to bind specifically to sites that contained two consensus VirR boxes located just upstream of the putative promoters of these genes. The development of this methodology will significantly enhance our ability to use molecular approaches to develop a greater understanding of the ability of C. difficile to cause disease.