A fibrinogen-binding lipoprotein contributes to the virulence of Haemophilus ducreyi in humans.
A gene expression study of Haemophilus ducreyi identified the hypothetical lipoprotein HD0192, renamed here "fibrinogen binder A" (FgbA), as being preferentially expressed in vivo. To test the role played by fgbA in virulence, an isogenic fgbA mutant (35000HPfgbA) was constructed using H. ducreyi 35000HP, and 6 volunteers were experimentally infected with 35000HP or 35000HPfgbA. The overall pustule-formation rate was 61.1% at parent sites and 22.2% at mutant sites (P = .019). Papules were significantly smaller at mutant sites than at parent sites (13.3 vs. 37.9 mm(2); P = .002) 24 h after inoculation. Thus, fgbA contributed significantly to the virulence of H. ducreyi in humans. In vitro experiments demonstrated that fgbA encodes a fibrinogen-binding protein; no other fibrinogen-binding proteins were identified in 35000HP. fgbA was conserved among clinical isolates of both class I and II H. ducreyi strains, supporting the finding that fgbA is important for H. ducreyi infection.
Bauer
Margaret E
ME
Departments of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, USA. mebauer@iupui.edu
Townsend
Carisa A
CA
Doster
Ryan S
RS
Fortney
Kate R
KR
Zwickl
Beth W
BW
Katz
Barry P
BP
Spinola
Stanley M
SM
Janowicz
Diane M
DM
D000328:Adult; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002602:Chancroid / Q000382:microbiology*; D005260:Female; D005340:Fibrinogen / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D006191:Haemophilus ducreyi / Q000235:genetics* / Q000472:pathogenicity*; D006801:Humans; D008074:Lipoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D017192:Skin Diseases, Bacterial / Q000382:microbiology; D014774:Virulence; D055815:Young Adult
D001426:Bacterial Proteins; D008074:Lipoproteins; D005340:Fibrinogen