ArticleInfection and immunity2004
Expression of the LspA1 and LspA2 proteins by Haemophilus ducreyi is required for virulence in human volunteers.
Article in Infection and immunity, 2004. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 36 papers.
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Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
36 citing papers in PubMed, 47 citations in OpenAlex.
- A Class IInfection and immunity · 2019Trial
- Molecular pathogenesis ofMicrobiology and molecular biology reviews : MMBR · 2025Review
- AInfection and immunity · 2024Article
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- Interactions of the Skin PathogenFrontiers in immunology · 2020Review
- Article
- Secreted Effectors Encoded within and outside of the Francisella Pathogenicity Island Promote Intramacrophage Growth.Cell host & microbe · 2016Article
- Host Polymorphisms in TLR9 and IL10 Are Associated With the Outcomes of Experimental Haemophilus ducreyi Infection in Human Volunteers.The Journal of infectious diseases · 2016Article
- Outer membrane protein P4 is not required for virulence in the human challenge model of Haemophilus ducreyi infection.BMC microbiology · 2014Article
- Article
- Haemophilus ducreyi Hfq contributes to virulence gene regulation as cells enter stationary phase.mBio · 2014Article
- The Haemophilus ducreyi Fis protein is involved in controlling expression of the lspB-lspA2 operon and other virulence factors.Infection and immunity · 2013Article
- Haemophilus ducreyi-induced interleukin-10 promotes a mixed M1 and M2 activation program in human macrophages.Infection and immunity · 2012Article
- Permeases of the sap transporter are required for cathelicidin resistance and virulence of Haemophilus ducreyi in humans.The Journal of infectious diseases · 2012Article
- Sialylation of lipooligosaccharides is dispensable for the virulence of Haemophilus ducreyi in humans.Infection and immunity · 2012Article
- Expression of the Flp proteins by Haemophilus ducreyi is necessary for virulence in human volunteers.BMC microbiology · 2011Article
- A Haemophilus ducreyi CpxR deletion mutant is virulent in human volunteers.The Journal of infectious diseases · 2011Article
- Deletion of mtrC in Haemophilus ducreyi increases sensitivity to human antimicrobial peptides and activates the CpxRA regulon.Infection and immunity · 2011Article
- Characterization of the CpxRA regulon in Haemophilus ducreyi.Infection and immunity · 2010Article
- Activation of the CpxRA system by deletion of cpxA impairs the ability of Haemophilus ducreyi to infect humans.Infection and immunity · 2010Article
Corrections and comments
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Authors and funding
7 authors at 2 institutions in 2 countries.
Funding
Abstract
Haemophilus ducreyi colocalizes with polymorphonuclear leukocytes and macrophages and evades phagocytosis during experimental infection of human volunteers. H. ducreyi contains two genes, lspA1 and lspA2, which encode predicted proteins of 456 and 543 kDa, respectively. Compared to its wild-type parent, an lspA1 lspA2 double mutant does not inhibit phagocytosis by macrophage and myelocytic cell lines in vitro and is attenuated in an experimental rabbit model of chancroid. To test whether expression of LspA1 and LspA2 was necessary for virulence in humans, six volunteers were experimentally infected. Each volunteer was inoculated with three doses (ranging from 85 to 112 CFU) of the parent (35000HP) in one arm and three doses (ranging from 60 to 822 CFU) of the mutant (35000HP Omega 12) in the other arm. The papule formation rates were 88% (95% confidence interval [95% CI], 76.8 to 99.9%) at 18 parent sites and 72% (95% CI, 44.4 to 99.9%) at 18 mutant sites (P = 0.19). However, papules were significantly smaller at mutant sites (mean size, 24.8 mm(2)) than at parent sites (mean size, 39.1 mm(2)) 24 h after inoculation (P = 0.0002). The pustule formation rates were 44% (95% CI, 5.8 to 77.6%) at parent sites and 0% (95% CI, 0 to 39.4%) at mutant sites (P = 0.009). With the caveat that biosafety regulations preclude testing of a complemented mutant in human subjects, these results indicate that expression of LspA1 and LspA2 facilitates the ability of H. ducreyi to initiate disease and to progress to pustule formation in humans.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.