IAI FigSearch
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Fortney, K. R.
Right arrow Articles by Spinola, S. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Fortney, K. R.
Right arrow Articles by Spinola, S. M.

Infection and Immunity, November 2000, p. 6441-6448, Vol. 68, No. 11
0019-9567/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Expression of Peptidoglycan-Associated Lipoprotein Is Required for Virulence in the Human Model of Haemophilus ducreyi Infection

Kate R. Fortney,1 Royden S. Young,1 Margaret E. Bauer,1 Barry P. Katz,1 Antoinette F. Hood,1,2 Robert S. Munson Jr.,3,4 and Stanley M. Spinola1,5,6,*

Departments of Medicine,1 Microbiology and Immunology,5 Pathology and Laboratory Medicine,6 and Dermatology,2 Indiana University School of Medicine, Indianapolis, Indiana 46202-5124, and Children's Research Institute3 and Departments of Pediatrics and Medical Microbiology and Immunology,4 Ohio State University, Columbus, Ohio 43205-2696

Received 19 June 2000/Returned for modification 2 August 2000/Accepted 18 August 2000

Haemophilus ducreyi expresses a peptidoglycan-associated lipoprotein (PAL) that exhibits extensive homology to Haemophilus influenzae protein 6. We constructed an isogenic PAL mutant (35000HP-SMS4) by the use of a suicide vector that contains lacZ as a counterselectable marker. H. ducreyi 35000HP-SMS4 and its parent, 35000HP, had similar growth rates in broth and similar lipooligosaccharide profiles. 35000HP-SMS4 formed smaller, more transparent colonies than 35000HP and, unlike its parent, was hypersensitive to antibiotics. Complementation of the mutant in trans restored the parental phenotypes. To test whether expression of PAL is required for virulence, nine human volunteers were experimentally infected. Each subject was inoculated with two doses (41 to 89 CFU) of live 35000HP and one dose of heat-killed bacteria on one arm and with three doses (ranging from 28 to 800 CFU) of live 35000HP-SMS4 on the other arm. Papules developed at similar rates at sites inoculated with the mutant or parent but were significantly smaller at mutant-inoculated sites than at parent-inoculated sites. The pustule formation rate was 72% (95% confidence interval [CI], 46.5 to 90.3%) at 18 parent sites and 11% (95% CI, 2.4 to 29.2%) at 27 mutant sites (P < 0.0001). The rates of recovery of H. ducreyi from surface cultures were 8% (n = 130; 95% CI, 4.3 to 14.6%) for parent-inoculated sites and 0% (n = 120; 95% CI, 0.0 to 2.5%) for mutant-inoculated sites (P < 0.001). H. ducreyi was recovered from six of seven biopsied parent-inoculated sites and from one of three biopsied mutant-inoculated sites. Confocal microscopy confirmed that the bacteria present in a mutant inoculation site pustule lacked a PAL-specific epitope. Although biosafety regulations precluded our testing the complemented mutant in humans, these results suggest that expression of PAL facilitates the ability of H. ducreyi to progress to the pustular stage of disease.

* Corresponding author. Mailing address: 435 Emerson Hall, Indiana University, 545 Barnhill Dr., Indianapolis, IN 46202-5124. Phone: (317) 274-1427. Fax: (317) 274-1587. E-mail: sspinola{at}iupui.edu.

Infection and Immunity, November 2000, p. 6441-6448, Vol. 68, No. 11
0019-9567/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2000 by the American Society for Microbiology. All rights reserved.