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PubMed1999

Prevalence of, antibody response to, and immunity induced by Haemophilus ducreyi hemolysin.

Haemophilus ducreyi, the etiologic agent of chancroid, a genital ulcer disease, produces a cell-associated hemolysin whose role in virulence is not well defined. Hemolysin is encoded by two genes, hhdA and hhdB, which, based on their homology to Serratia marcescens shlA and shlB genes, are believed to encode the hemolysin structural protein and a protein required for secretion and modification of this protein, respectively. In this study, we determined the prevalence and expression of the hemolysin genes in 90 H. ducreyi isolates obtained from diverse geographic locations from 1952 to 1996 and found that all strains contained DNA homologous to the hhdB and hhdA genes. In addition, all strains expressed a hemolytic activity. We also determined that hemolysin is expressed in vivo and is immunogenic, as indicated by the induction of antibodies to hemolysin in both the primate and rabbit disease models as well as in human patients with naturally acquired chancroid. Wild-type strain 35000 and isogenic hemolysin-negative mutants showed no difference in lesion development in the temperature-dependent rabbit model. However, immunization of rabbits with the purified hemolysin protein reduced the recovery of wild-type H. ducreyi, but not hemolysin-negative mutants, from lesions. Our study indicates that hemolysin is a possible candidate for vaccine development due to its immunogenicity, expression in vitro and in vivo by most, if not all, strains, and the effect of immunization on reducing the recovery of viable H. ducreyi in experimental disease in rabbits.

Animals↗
PubMed1999

Target cell range of Haemophilus ducreyi hemolysin and its involvement in invasion of human epithelial cells.

Haemophilus ducreyi, the causative agent of chancroid, produces a hemolysin, whose role in virulence is not well defined. To assess the possible role of hemolysin in pathogenesis, we evaluated its target cell range by using wild-type H. ducreyi 35000, nonhemolytic mutants with the hemolysin structural gene deleted, and isogenic strains expressing different amounts of hemolytic activity. The cytotoxicity of the various cell types was assessed by quantitating the release of lactate dehydrogenase into culture supernatants as a measure of cell lysis. In these experiments, human foreskin fibroblasts, human foreskin epithelial cells, and, to a lesser extent, HEp-2 cells were lysed by H. ducreyi hemolysin. Hemolysin also lysed human blood mononuclear cells and immune system cell lines including U937 macrophage-like cells, T lymphocytes, and B lymphocytes. In contrast, human polymorphonuclear leukocytes were not sensitive to hemolysin under the conditions tested. We also analyzed the effect of hemolysin on invasion of human epithelial cells and found that H. ducreyi strains expressing cloned hemolysin genes showed a 10-fold increase in invasion compared to the control strain. These data support the hypothesis that the H. ducreyi hemolysin is important in the pathogenesis of chancroid and may contribute to ulcer formation, invasion of epithelial cells, and evasion of the immune response.

Cell Line↗
PubMed2000

Development of a serological test for Haemophilus ducreyi for seroprevalence studies.

We developed a new enzyme immunoassay (rpEIA) for use in determining the seroprevalence of chancroid. Three highly conserved outer membrane proteins from Haemophilus ducreyi strain 35000 were cloned, overexpressed, and purified from Escherichia coli for use as antigens in the rpEIA. Serum specimens from patients with and without chancroid were assayed to determine optimum sensitivity and specificity and to establish cutoff values. On the basis of these data, rpEIA was found to be both sensitive and specific when used to test a variety of serum specimens from patients with genital ulcers and urethritis and from healthy blood donors.

Antibodies, Bacterial↗
PubMed1978

Comparison of specimen collection and laboratory techniques for isolation of Haemophilus ducreyi.

Sixteen patients with clinical chancroid were studied prospectively; different culture media and sampling techniques from genital lesions were evaluated. Technique A was aspiration of a saline wash from the ulcer which was pooled and inoculated into rabbit blood, rabbit blood + vancomycin (5 microgram/ml), and semisolid chocolate agar + vancomycin (3 microgram/ml). Each primary culture medium was subcultured to chocolate agar with 1% IsoVitaleX (CA), CA with vancomycin (3 microgram/ml) plus polymyxin (7.5 microgram/ml; CA + vp). Technique B was the use of a cotton swab, plated directly on CA, CA + v, and CA + vp. Nine strains of Haemophilus ducreyi were obtained. Technique A yielded seven strains, whereas technique B yielded eight strains; with each technique, five strains were isolated only after use of selective antibiotic media. CA + v medium yielded the largest number of isolates. Direct inoculation by swab to CA + v from chancroidal ulcers is effective as an isolation technique for growth of H. ducreyi.

Bacteriological Techniques↗
PubMed1989

Biology of Haemophilus ducreyi.

The etiological agent of the sexually transmitted genital ulcer disease chancroid was first described in 1889 by Auguste Ducrey following repeated autoinoculation of purulent ulcer material from a series of patients. The organism was isolated on artificial media a decade later but has remained difficult to isolate consistently, resulting in controversy over its characteristics and role as the causative agent of chancroid. Because of its fastidious growth requirements, including unknown components in blood, the organism was included in the original description of the genus Haemophilus. Requirement for exogenous hemin and limited phenotypic characteristics, including structural and antigenic properties, suggested that Haemophilus ducreyi was a valid member of the genus Haemophilus. Recent studies of respiratory quinones, deoxyribonucleic acid hybridization, and competition for homologous transformation of the type species, H. influenzae, suggest that H. ducreyi is unrelated to any of the present species of the family Pasteurellaceae, which includes members of the genera Haemophilus, Actinobacillus, and Pasteurella. This review summarizes the early studies with H. ducreyi and our current knowledge of the microbiology of this important human pathogen.

Chancroid↗
PubMed1994

Genital ulcer disease: accuracy of clinical diagnosis and strategies to improve control in Durban, South Africa.

OBJECTIVE: To investigate the accuracy of clinical diagnosis in genital ulcer disease (GUD); to devise management strategies for improving the control of GUD and thereby limit the spread of HIV-1 infection. DESIGN: Clinical and microbiological assessment of GUD in men and women. The index of suspicion, diagnostic accuracy, diagnostic efficiency and positive and negative predictive values of a clinical diagnosis were investigated. SETTING: City Health Sexually Transmitted Diseases Clinic, King Edward VIII Hospital, Durban, South Africa. PARTICIPANTS: 100 men and 100 women with genital ulcers. RESULTS: The accuracy of a clinical diagnosis was, in men: lymphogranuloma venereum (LGV) 66%, donovanosis 63%, chancroid 42%, genital herpes 39%, primary syphilis 32%, mixed infections 8%, and in women; secondary syphilis 94%, donovanosis 83%, genital herpes 60%, primary syphilis 58%, chancroid 57%, LGV 40%, mixed infections 14%. Overall, diagnostic efficiency was greater in women than in men. When compared with other causes of GUD, donovanosis ulcers bled to the touch and were larger and not usually associated with inguinal lymphadenopathy. In women, extensive vulval condylomata lata were readily differentiated from all other causes of GUD. CONCLUSION: A clinical diagnosis in genital ulceration was less accurate in men than in women. The diagnostic accuracies for donovanosis and secondary syphilis were relatively high but for most other conditions were low. Differences between clinical and laboratory diagnostic accuracies may reflect similarities between the clinical appearances of the various causes of GUD, the presence of mixed infections, atypical ulceration due to longstanding disease, and insensitive laboratory tests. In this community all large ulcers should be treated empirically for syphilis and donovanosis. Uncircumcised men with GUD are an important HIV core or "superspreader" group locally, and prevention strategies should include counselling and health education in the light of the inaccuracy of clinical diagnosis found in this study. The development of rapid accurate tests for GUD is urgently required.

Chancroid↗
PubMed2003

Increasing relative prevalence of HSV-2 infection among men with genital ulcers from a mining community in South Africa.

OBJECTIVES: To determine the aetiology of genital ulcer disease (GUD) and its association with HIV infection in the mining community of Carletonville, South Africa, from two cross sectional surveys of consecutive men presenting with genital lesions during October 1993 to January 1994 and July to November 1998. METHODS: A multiplex polymerase chain reaction (M-PCR) assay combined with amplicon detection was used to identify DNA specific sequences of Treponema pallidum, herpes simplex virus (HSV), and Haemophilus ducreyi. A real time PCR assay was used to differentiate between HSV-1 and HSV-2. RESULTS: M-PCR detected T pallidum, HSV, and H ducreyi in 10.3%, 17.2%, and 69.4% of 232 GUD patients during 1993-4 and in 12.4%, 36.0%, and 50.5% of 186 GUD patients in 1998. The proportion of patients with more than one agent increased significantly from 7.3% (17/232) in 1993-4 to 16.7% (31/186) in 1998 (p <0.01). HSV-2 was detected in a higher proportion of ulcer specimens from HIV infected patients than in specimens from HIV uninfected patients during both time periods (1993-4: 26.2% v 6.7%, p <0.001; 1998: 42.1% v 29.6%, p >0.09). CONCLUSIONS: Based on two cross sectional surveys, 4 years apart, chancroid remained the leading cause of GUD in men who presented at the STD clinic with genital ulcers in the mining community of Carletonville, South Africa. The relative prevalence of primary syphilis has remained low. However, HSV-2 has emerged as a more significant cause of GUD and the proportion of GUD patients infected with more than one agent also increased significantly. HSV-2 DNA was detected in a significantly higher proportion of ulcer specimens from HIV positive patients than from HIV negative patients. No association was found between HIV infection status and the relative prevalence of chancroid or syphilis.

Adult↗
PubMed1997

Immunohistochemical investigations of genital ulcers caused by Haemophilus ducreyi.

To gain information on the specific composition of the inflammatory infiltrate of genital ulcers caused by Haemophilus ducreyi, biopsies of 6 genital ulcers which were diagnosed as chancroid on clinical and microbiological grounds were subjected to immunohistochemical investigations after conventional haematoxylineosin staining. A variety of antibodies reactive against B- and T-cells, plasma cells and granulocytes were used with each tissue sections. The lymphocytic infiltrate of chancroid ulcers consisted of both B- and T-lymphocytes and showed a cluster-like formation. B-lymphocytes were preferentially localized perivascularly in the middle layer, T-lymphocytes mainly in the deep layer of the inflamed oedematous tissue. Results stress the importance of both B- and T-cell mediated immune responses in Haemophilus ducreyi infection.

Antibodies, Bacterial↗
PubMed1998

Genital ulcers in a primary health clinic in Rwanda: impact of HIV infection on diagnosis and ulcer healing (1986-1992).

During 1986-88 and 1990-92, 1025 (97%) out of 1057 genital ulcer patients in Kigali, Rwanda, were tested for HIV antibodies and for infection with Treponema pallidum, Haemophilus ducreyi and herpes simplex virus. Overall, 57% of men and 80% of women had antibodies to HIV-1. The most frequent laboratory diagnoses were chancroid (27%), syphilis (19%) and genital herpes (19%) among men and syphilis (35%), genital herpes (23%) and chancroid (20%) among women. HIV-1 seroprevalence increased sharply over time among men but not among women. The clinical presentation of ulcers as well as laboratory diagnoses were similar in the HIV-1 seropositive and seronegative groups. The relative frequency of all laboratory diagnoses remained unchanged over time. HIV-1 seropositivity had no impact on ulcer healing. Advanced immunodeficiency was diagnosed among 12% of the HIV-1 seropositive patients and was significantly associated with increasing age and genital herpes.

AIDS-Related Opportunistic Infections↗
PubMed1981

Molecular epidemiology of Haemophilus ducreyi infections.

Haemophilus ducreyi was isolated with an enriched chocolate agar containing vancomycin from seven patients with clinical evidence of chancroid. Four cases were imported from outside the United States; the other three cases were acquired in the United States from one of the imported cases. All strains of H. ducreyi contained ampicillin-resistance plasmids with molecular weights of 7.3, 5.7, or 3.6 megadaltons. Plasmid molecular weights were identical for isolates from the epidemiologically linked cases and differed according to the geographic origins of the strains. Findings of this study confirm that H. ducreyi is sexually transmitted and suggest that clinical chancroid develops frequently after acquisition of H. ducreyi.

Adult↗
PubMed1999

Drug treatment of common STDs: part I. Herpes, syphilis, urethritis, chlamydia and gonorrhea.

In 1998, the Centers for Disease Control and Prevention released guidelines for the treatment of sexually transmitted diseases. Several treatment advances have been made since the previous guidelines were published. Part I of this two-part article describes current recommendations for the treatment of genital ulcer diseases, urethritis and cervicitis. Treatment advances include effective single-dose regimens for many sexually transmitted diseases and improved therapies for herpes infections. Two single-dose regimens, 1 g of oral azithromycin and 250 mg of intramuscular ceftriaxone, are effective for the treatment of chancroid. A three-day course of 500 mg of oral ciprofloxacin twice daily may be used to treat chancroid in patients who are not pregnant. Parenteral penicillin continues to be the drug of choice for treatment of all stages of syphilis. Three antiviral medications have been shown to provide clinical benefit in the treatment of genital herpes: acyclovir, valacyclovir and famciclovir. Valacyclovir and famciclovir are not yet recommended for use during pregnancy. Azithromycin in a single oral 1-g dose is now a recommended regimen for the treatment of nongonococcal urethritis.

Anti-Infective Agents↗
PubMed1990

Drug resistance of Haemophilus ducreyi.

Chancroid, the disease caused by H. ducreyi is one of the common sexually transmitted diseases (STD) in Thailand and other tropical countries. In Thailand, the diagnosis of chancroid is still based on clinical appearance which may be confused with other STD manifested by genital ulcers. In recent years the increasing resistance strains of H. ducreyi to these antimicrobial agents has been reported so that cultivation and antimicrobial susceptibility tests of this organism have become more important. This study showed that MBV is the best medium for isolation with a success rate of 48%. All strains tested from isolates of this study were resistant to ampicillin, due to production of beta-lactamase. Approximately 99% of the strains were resistant to tetracycline 92% of strains were resistant to sulfamethoxazole and 32% were resistant to trimethoprim. All isolates were susceptible to chloramphenicol, ceftriaxone, erythromycin and the fluorinated quinolones ciprofloxacin, norfloxacin, ofloxacin and pefloxacin. Beta-lactamase enzymes produced by 37 strains of H. ducreyi were determined for their isoelectric point (pI). All had pI of 5.4, indicative of plasmid-mediated beta-lactamase type TEM-1.

Chancroid↗
PubMed1989

Clinical efficacy of antimicrobial therapy in Haemophilus ducreyi infections.

Ulcerative genital disease in the United States is commonly due to herpes simplex or syphilis. Until recently, chancroid, an infection caused by the gram-negative streptobacillus Haemophilus ducreyi, was infrequently diagnosed. Continuing immigration, however, has reintroduced the disease into this country, and urban outbreaks have been associated with contact with infected prostitutes. Extensive resistance has made previous antimicrobial agents ineffective. Evaluations of multiple antibiotics and varied dosing schedules have been undertaken in an effort to circumvent this resistance. Clinicians treating patients with genital ulcerations must be aware of this disease and its geographically variable antibiotic sensitivities. Recent evidence demonstrating an association between seropositivity for the human immunodeficiency virus and ulcerative genital disease places additional importance on the timely diagnosis and appropriate treatment of chancroidal ulcers.

Anti-Bacterial Agents↗
PubMed1989

[Morphologic variants of genital ulcer caused by Haemophilus ducreyi].

The typical clinical picture, common variants and frequent complications of chancroid are presented in cases proven by culture. In general, the conventional view of the clinical spectrum of chancroid is substantiated. Certain types such as "chancre mou volant," however, could not be found in the present material. Their existence or association with Haemophilus ducreyi remains speculative.

Adult↗
PubMedDate not supplied

Urethral infection with Haemophilus ducreyi in men.

Carriage of Haemophilus ducreyi has not been adequately investigated in men, and its role in urethritis is unknown. In this study 456 men with H. ducreyi-culture positive genital ulcers were investigated. Among these men, 16 (3.5%) had urethritis. H. ducreyi was isolated from the urethra of nine men (1.9%). Of 57 men who had chancroid but not urethritis, none had H. ducreyi isolated from the urethra. Of 106 patients presenting with only acute urethritis, H. ducreyi was found in one. We conclude that H. ducreyi is responsible for acute urethritis in men, but that it rarely, if ever, can be cultured from the urethra of men with chancroid who do not have symptomatic urethritis.

Adolescent↗
PubMed1983

Isolation of Haemophilus ducreyi from genital ulcerations in white men in Johannesburg.

An analysis of sexually acquired genital ulcerations in 31 White patients who were examined microbiologically in Johannesburg showed Haemophilus ducreyi to be the causative agent in 23 (74%), whereas syphilis was the confirmed diagnosis in only 6 (19%). All the H. ducreyi isolates produced beta-lactamase. Previously, chancroid was considered to be an infrequent cause of genital ulceration in this population group. Unlike those with syphilitic ulceration, patients with chancroid usually do not respond to penicillin. The improved isolation procedures for H. ducreyi now enable the laboratory to confirm most cases.

Chancroid↗
PubMed1983

[The autoinoculation test. False-positive reactions caused by herpes simplex virus].

The autoinoculation test has been used as a diagnostic procedure in patients with chancroid-suspected genital ulcerations. In four of 13 patients with a positive autoinoculation test, herpes simplex virus type 2 was isolated from the primary lesions. In two of the cases this virus was also isolated from the inoculation site, and one patient developed a recurrent herpetic eruption here. Two patients were proven to have chancroid. Three of the remaining seven patients developed recurrent herpes genitalis later. It is concluded that the autoinoculation test should be avoided as a diagnostic procedure because of lack of specificity and risk of inducing recurrent herpes simplex at the site of inoculation.

Chancroid↗
PubMed1994

[Importance of culture media choice in the isolation of Haemophilus ducreyi. Experience in Senegal].

Genital ulcerations typify one of the major reasons clients seek STD consultation in developing countries. The usual etiologies are syphilis, chancroid and herpes. The ideal diagnostic approach is to undertake complete laboratory examination that are rarely possible in structure destitute of laboratory analysis possibilities which is the case for most of the STD transmission agents. Chancroid is caused by Haemophilus ducreyi, a short Gram negative bacteria. The bacteriological diagnosis is based on direct examination, isolation and identification of the bacteria. The nutritive exigence of the bacteria required 3 medium of isolation (PPLO base Pasteur), GC base (GIBCO) and Muller Hinton base (Becton & Dickinson, with "chocolate" agar) have been tested from the chancre samples of 108 male patients who had a median age of 31 years. Direct exams were positive in 66 cases (61%) and culture exams positive in 53 cases (49%). The Muller Hinton base with "chocolate" agar produced the best results and seems to be the medium of choice for isolated strains in Senegal. The culture mediums currently used in Europe are apparently inappropriate for the germ culture in Senegal. We have also observed that all the isolated strains were producers of beta-lactamase. Antibiotic treatment before the sample swab is taken seems to have an inhibiting effect on the culture. Direct examination with a sensibility of 94.3% and a specificity of 70.9% remains sufficient in routine presumptive diagnosis in endemic areas.

Adult↗