title: Use of signature-tagged mutagenesis to identify virulence determinants in Haemophilus ducreyi responsible for ulcer formation.
abstract: Elucidating the molecular mechanisms responsible for chancroid, a genital ulcer disease caused by Haemophilus ducreyi, has been hampered in part by the relative genetic intractability of the organism. A whole genome screen using signature-tagged mutagenesis in the temperature-dependent rabbit model (TDRM) of H. ducreyi infection uncovered 26 mutants with a presumptive attenuated phenotype. Insertions in two previously recognized virulence determinants, hgbA and lspA1, validated this genome scanning technique. Database interrogation allowed assignment of 24 mutants to several functional classes, including transport, metabolism, DNA repair, stress response and gene regulation. The attenuated virulence for a 3 strain with a mutation in hicB was confirmed by individual infection in the TDRM. The results from this preliminary study indicate that this high throughput strategy will further the understanding of the pathogenesis of H. ducreyi infection.
authors.affiliation: Department of Biochemistry Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada.
authors.forename: Angela
authors.initials: A
authors.lastname: Yeung
authors.forename: D William
authors.initials: DW
authors.lastname: Cameron
authors.forename: Marc
authors.initials: M
authors.lastname: Desjardins
authors.forename: B Craig
authors.initials: BC
authors.lastname: Lee
mesh_terms: D000818:Animals; D002602:Chancroid / Q000382:microbiology* / Q000473:pathology*; D004195:Disease Models, Animal; D006191:Haemophilus ducreyi / Q000235:genetics* / Q000472:pathogenicity*; D008297:Male; D016254:Mutagenesis, Insertional; D011817:Rabbits; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D037521:Virulence Factors