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Stanley M Spinola - One of the best experts on this subject based on the ideXlab platform.
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Permeases of the Sap Transporter Are Required for Cathelicidin Resistance and Virulence of Haemophilus ducreyi in Humans
2016Co-Authors: Stanley M Spinola, Margaret E. BauerAbstract:Background. Haemophilus ducreyi encounters several classes of antimicrobial peptides (APs) in vivo and uti-lizes the sensitive-to-antimicrobial-peptides (Sap) transporter as one mechanism of AP resistance. A mutant lacking the periplasmic solute–binding component, SapA, was somewhat more sensitive to the cathelicidin LL-37 than the parent strain and was partially attenuated for virulence. The partial attenuation led us to question whether the transporter is fully abrogated in the sapA mutant. Methods. We generated a nonpolar sapBC mutant, which lacks both inner membrane permeases of the Sap transporter, and tested the mutant for virulence in human volunteers. In vitro, we compared LL-37 resistance phenotypes of the sapBC and sapA mutants. Results. Unlike the sapA mutant, the sapBC mutant was fully attenuated for virulence in human volunteers. In vitro, the sapBC mutant exhibited significantly greater sensitivity than the sapA mutant to killing by LL-37. Similar to the sapA mutant, the sapBC mutant did not affect H. ducreyi’s resistance to human defensins. Conclusions. Compared with the sapA mutant, the sapBC mutant exhibited greater attenuation in vivo, which directly correlated with increased sensitivity to LL-37 in vitro. These results strongly suggest that the SapBC channel retains activity when SapA is removed. Haemophilus ducreyi is the causative agent of chan
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draft whole genome sequence of Haemophilus ducreyi strain auspng1 isolated from a cutaneous ulcer of a child from papua new guinea
Genome Announcements, 2016Co-Authors: Dharanesh Gangaiah, Sally A. Roberts, Georgi K Marinov, Jenny Robson, Stanley M SpinolaAbstract:ABSTRACT Haemophilus ducreyi has recently emerged as a leading cause of cutaneous ulcers in the yaws-endemic areas of Papua New Guinea and other South Pacific islands. Here, we report the draft genome sequence of the H. ducreyi strain AUSPNG1, isolated from a cutaneous ulcer of a child from Papua New Guinea.
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Differences in Host Susceptibility to Disease Progression in the Human Challenge Model of Haemophilus ducreyi Infection
Infection and Immunity, 2003Co-Authors: Stanley M Spinola, Kate R Fortney, Carisa A. Townsend, Tricia L. Humphreys, Cliffton T.h. Bong, Andrew L. Faber, Stacy L. Bennett, Beth Zwickl, Steven D. Billings, Margaret E. BauerAbstract:With human volunteers inoculated at two sites with Haemophilus ducreyi, outcomes for a subject were not independent. In a reinfection trial, 2 of 11 previous pustule formers and 6 of 10 previous resolvers resolved all sites of infection. There was no correlation between serum bactericidal or phagocytic activity and outcome in the trial. These data indicate that different hosts are differentially susceptible to disease progression versus resolution in the model.
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Haemophilus ducreyi: clinical disease and pathogenesis.
Current Opinion in Infectious Diseases, 2002Co-Authors: Jaffar A. Al-tawfiq, Stanley M SpinolaAbstract:Haemophilus ducreyi causes the sexually transmitted disease chancroid, which facilitates the transmission of HIV infection. This review focuses on recent advances in the epidemiology, diagnosis, treatment and pathogenesis of this disease.
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Immunopathogenesis of Haemophilus ducreyi Infection (Chancroid)
Infection and Immunity, 2002Co-Authors: Stanley M Spinola, Margaret E. Bauer, Robert S. MunsonAbstract:Haemophilus ducreyi causes chancroid, a genital ulcer disease (GUD) that is common in many developing countries ([13][1], [14][2], [26][3], [68][4], [80][5], [103][6]). UNAIDS and the World Health Organization estimate that the annual global incidence of chancroid is approximately 6 million cases ([
David A Lewis - One of the best experts on this subject based on the ideXlab platform.
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Haemophilus ducreyi from sexually transmitted infection to skin ulcer pathogen
Current Opinion in Infectious Diseases, 2016Co-Authors: David A Lewis, Oriol MitjaAbstract:Purpose of reviewThis article provides an overview of the biology, epidemiology, clinical features, diagnostic tests, and treatment of Haemophilus ducreyi infection, with special reference to the decline of chancroid and the recent emergence of H. ducreyi as a pathogen responsible for chronic limb u
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epidemiology clinical features diagnosis and treatment of Haemophilus ducreyi a disappearing pathogen
Expert Review of Anti-infective Therapy, 2014Co-Authors: David A LewisAbstract:Chancroid, caused by Haemophilus ducreyi, has declined in importance as a sexually transmitted pathogen in most countries where it was previously endemic. The global prevalence of chancroid is unknown as most countries lack the required laboratory diagnostic capacity and surveillance systems to determine this. H. ducreyi has recently emerged as a cause of chronic skin ulceration in some South Pacific islands. Although no antimicrobial susceptibility data for H. ducreyi have been published for two decades, it is still assumed that the infection will respond successfully to treatment with recommended cephalosporin, macrolide or fluoroquinolone-based regimens. HIV-1-infected patients require careful follow-up due to reports of treatment failure with single dose regimens. Buboes may need additional treatment with either aspiration or excision and drainage.
Patricia A. Totten - One of the best experts on this subject based on the ideXlab platform.
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Haemophilus ducreyi is susceptible to protegrin
Antimicrobial Agents and Chemotherapy, 1998Co-Authors: Kate R Fortney, Robert I Lehrer, Patricia A. Totten, Stanley M SpinolaAbstract:Protegrins, potent antimicrobial peptides found in porcine leukocytes, have activity against the sexually transmitted pathogens Neisseria gonorrhoeae , Chlamydia trachomatis , and human immunodeficiency virus type 1. We tested synthetic protegrin 1 (PG-1) for activity against nine isolates of Haemophilus ducreyi , the etiologic agent of chancroid. The test organisms included CIP 542 (the type strain), 35000HP (a human-passaged variant of 35000), 35000HP-RSM2 (an isogenicd- glycero -d- manno -heptosyltransferase mutant of 35000HP), and six clinical isolates. The isolates were epidemiologically unrelated, represented three Hin dIII ribotypes, and had varying antimicrobial resistance patterns. In bactericidal assays, five isolates were rapidly killed by synthetic PG-1. In radial diffusion assays, all nine isolates were exquisitely sensitive to PG-1. These data highlight the potential of protegrins for development as topical agents to prevent many sexually transmitted diseases, including chancroid.
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Haemophilus ducreyi hemolysin acts as a contact cytotoxin and damages human foreskin fibroblasts in cell culture.
Infection and immunity, 1996Co-Authors: Michelle Alfa, Pat Degagne, Patricia A. TottenAbstract:Haemophilus ducreyi, which causes the sexually transmitted disease chancroid, produces several factors that damage human cells. We used isogenic mutants of H. ducreyi 35000 to demonstrate that the hemolytic activity and the cytotoxic effect of H. ducreyi on human foreskin fibroblasts are due to the same toxin.
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Clear broth and plate media for culture of Haemophilus ducreyi.
Journal of Clinical Microbiology, 1994Co-Authors: Patricia A. Totten, W E StammAbstract:Using catalase as a source of heme, we have developed both clear plate and broth media for the growth of Haemophilus ducreyi, the causative agent of chancroid. In the broth medium, the growth phase of the organism can be monitored and the organisms achieve a cell density of > 10(8) CFU/ml. Images
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Haemophilus ducreyi Detection by PCR
Sexually Transmitted Diseases, 1Co-Authors: Patricia A. Totten, Jane Kuypers, Stephen A. MorseAbstract:Genital ulcers are typically caused by one of three organisms, Haemophilus ducreyi, Treponema pallidum, or herpes simplex virus, which cause chancroid, syphilis, and genital herpes, respectively. Although traditionally these diseases have been differentiated by their clinical presentation, there is considerable overlap in their clinical manifestations (1).
Margaret E. Bauer - One of the best experts on this subject based on the ideXlab platform.
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Permeases of the Sap Transporter Are Required for Cathelicidin Resistance and Virulence of Haemophilus ducreyi in Humans
2016Co-Authors: Stanley M Spinola, Margaret E. BauerAbstract:Background. Haemophilus ducreyi encounters several classes of antimicrobial peptides (APs) in vivo and uti-lizes the sensitive-to-antimicrobial-peptides (Sap) transporter as one mechanism of AP resistance. A mutant lacking the periplasmic solute–binding component, SapA, was somewhat more sensitive to the cathelicidin LL-37 than the parent strain and was partially attenuated for virulence. The partial attenuation led us to question whether the transporter is fully abrogated in the sapA mutant. Methods. We generated a nonpolar sapBC mutant, which lacks both inner membrane permeases of the Sap transporter, and tested the mutant for virulence in human volunteers. In vitro, we compared LL-37 resistance phenotypes of the sapBC and sapA mutants. Results. Unlike the sapA mutant, the sapBC mutant was fully attenuated for virulence in human volunteers. In vitro, the sapBC mutant exhibited significantly greater sensitivity than the sapA mutant to killing by LL-37. Similar to the sapA mutant, the sapBC mutant did not affect H. ducreyi’s resistance to human defensins. Conclusions. Compared with the sapA mutant, the sapBC mutant exhibited greater attenuation in vivo, which directly correlated with increased sensitivity to LL-37 in vitro. These results strongly suggest that the SapBC channel retains activity when SapA is removed. Haemophilus ducreyi is the causative agent of chan
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Host-pathogen interplay of Haemophilus ducreyi.
Current Opinion in Infectious Diseases, 2010Co-Authors: Diane M. Janowicz, Margaret E. BauerAbstract:Purpose of review Haemophilus ducreyi, the causative agent of the sexually transmitted infection chancroid, is primarily a pathogen of human skin. During infection, H. ducreyi thrives extracellularly in a milieu of professional phagocytes and other antibacterial components of the innate and adaptive immune responses. This review summarizes our understanding of the interplay between this pathogen and its host that leads to development and persistence of disease.
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Haemophilus ducreyi Is Resistant to Human Antimicrobial Peptides
Antimicrobial Agents and Chemotherapy, 2007Co-Authors: Kristy L. B. Mount, Carisa A. Townsend, Margaret E. BauerAbstract:We examined the susceptibility of Haemophilus ducreyi to antimicrobial peptides likely to be encountered in vivo during human infection. H. ducreyi was significantly more resistant than Escherichia coli to the bactericidal effects of all peptides tested. Class I and II H. ducreyi strains exhibited similar levels of resistance to antimicrobial peptides.
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Differences in Host Susceptibility to Disease Progression in the Human Challenge Model of Haemophilus ducreyi Infection
Infection and Immunity, 2003Co-Authors: Stanley M Spinola, Kate R Fortney, Carisa A. Townsend, Tricia L. Humphreys, Cliffton T.h. Bong, Andrew L. Faber, Stacy L. Bennett, Beth Zwickl, Steven D. Billings, Margaret E. BauerAbstract:With human volunteers inoculated at two sites with Haemophilus ducreyi, outcomes for a subject were not independent. In a reinfection trial, 2 of 11 previous pustule formers and 6 of 10 previous resolvers resolved all sites of infection. There was no correlation between serum bactericidal or phagocytic activity and outcome in the trial. These data indicate that different hosts are differentially susceptible to disease progression versus resolution in the model.
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Immunopathogenesis of Haemophilus ducreyi Infection (Chancroid)
Infection and Immunity, 2002Co-Authors: Stanley M Spinola, Margaret E. Bauer, Robert S. MunsonAbstract:Haemophilus ducreyi causes chancroid, a genital ulcer disease (GUD) that is common in many developing countries ([13][1], [14][2], [26][3], [68][4], [80][5], [103][6]). UNAIDS and the World Health Organization estimate that the annual global incidence of chancroid is approximately 6 million cases ([
Oriol Mitja - One of the best experts on this subject based on the ideXlab platform.
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Haemophilus ducreyi from sexually transmitted infection to skin ulcer pathogen
Current Opinion in Infectious Diseases, 2016Co-Authors: David A Lewis, Oriol MitjaAbstract:Purpose of reviewThis article provides an overview of the biology, epidemiology, clinical features, diagnostic tests, and treatment of Haemophilus ducreyi infection, with special reference to the decline of chancroid and the recent emergence of H. ducreyi as a pathogen responsible for chronic limb u
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Epidemiology of Haemophilus ducreyi Infections.
Emerging Infectious Diseases, 2016Co-Authors: Camila González-beiras, Cheng Y. Chen, Michael Marks, Sally Roberts, Oriol MitjaAbstract:The global epidemiology of Haemophilus ducreyi infections is poorly documented because of difficulties in confirming microbiological diagnoses. We evaluated published data on the proportion of genital and nongenital skin ulcers caused by H. ducreyi before and after introduction of syndromic management for genital ulcer disease (GUD). Before 2000, the proportion of GUD caused by H. ducreyi ranged from 0.0% to 69.0% (35 studies in 25 countries). After 2000, the proportion ranged from 0.0% to 15.0% (14 studies in 13 countries). In contrast, H. ducreyi has been recently identified as a causative agent of skin ulcers in children in the tropical regions; proportions ranged from 9.0% to 60.0% (6 studies in 4 countries). We conclude that, although there has been a sustained reduction in the proportion of GUD caused by H. ducreyi, this bacterium is increasingly recognized as a major cause of nongenital cutaneous ulcers.
