Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Chancroid”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
PubMedDate not supplied

Comparison of Sheffield media with standard media for the isolation of Haemophilus ducreyi.

Isolation of Haemophilus ducreyi is the only method for the definitive diagnosis of chancroid. Culture on supplemented gonococcal base (GCHgs) or on supplemented Muller-Hinton agar (MHHb) has yielded the best isolation rates. Sheffield media is an alternative to standard media. We compared the isolation rate of H. ducreyi on GCHgs and MHHb to that on the Sheffield media with and without 5% horse blood. Vancomycin (3 mg/L) was added to all media. Of the 87 specimens cultured from patients with genital ulcer disease, 57 (66%) were positive on either GCHgs or MHHb or on both. Twenty six (30%) were positive on GCHgs only, 15 (17%) on MHHb only, and 15 (17%) on both. One culture was positive on Sheffield medium with 5% horse blood; none were positive on Sheffield medium without horse blood. Stock strains showed good growth at 48 hr on GCHgs and MHHb, but no growth at 48 hr and only minimally detectable growth at 72 hr on Sheffield media with horse blood. No growth was detected on Sheffield media without horseblood. Thus optimal culture of H. ducreyi in Kenya requires two media, supplemented gonococcal base and Muller-Hinton agar. Sheffield media is not useful for the primary isolation of H. ducreyi.

Agar↗
PubMedDate not supplied

Accuracy of clinical diagnosis of genital ulcer disease.

In Africa, establishment of an accurate clinical diagnosis in cases of genital ulcer disease is difficult owing to atypical presentation of ulcerations and mixed infections. This is compounded by the frequent lack of suitable laboratory facilities. In 240 cases of genital ulcer disease among mineworkers in Carletonville, South Africa, this study endeavored to correlate the clinical diagnosis with laboratory findings. Clinical accuracy and positive and negative predictive values were determined for each type of genital ulcer disease encountered. Overall, the accuracy of clinical diagnosis was 68% for single infections, 80% for chancroid, 55% for primary syphilis, 27% for lymphogranuloma venereum (LGV), and 22% for genital herpes. Adequate laboratory facilities are indispensible for the establishment of an accurate etiologic diagnosis of genital ulcer disease and thus the institution of appropriate antimicrobial therapy.

Chancroid↗
PubMedDate not supplied

Condom use prevents genital ulcers in women working as prostitutes. Influence of human immunodeficiency virus infection.

Control of genital ulcer disease (GUD) is a proposed intervention to slow the dissemination of human immunodeficiency virus (HIV) infection. Programs for the control of sexually transmitted diseases (STD) should focus on groups of high-frequency transmitters, such as prostitutes and their clientele. This study illustrates the interaction between the prevalence of chancroid, use of barrier prophylaxis against STDs, and HIV infection in a population of female prostitutes in Nairobi. Four hundred and twenty three women were evaluated. Despite the increased use of condoms, the prevalence of genital ulcers remained constant between 1986-87 and 1987-88. Genital ulcer disease was simultaneously associated with HIV infection (adjusted odds ratio: 3.7, P less than .01) whereas it was independently and inversely associated with more consistent condom use (P less than .01). The authors conclude that genital ulcer disease can be controlled in these populations but concurrent HIV infection increases the difficulty of this intervention.

Chancroid↗
PubMedDate not supplied

Crack, sex, and STD.

Increasing rates of syphilis, gonorrhea, chancroid, and sexually transmitted human immunodeficiency virus infection appear to be related to crack cocaine use. This article critically reviews 16 epidemiologic studies that examine drug use, sexual behavior, and sexually transmitted disease (STD). Eight studies found an association between crack and STD, one study found no association between crack and STD, and seven studies found STD to be related to other drugs or methods of cocaine use. The exchange of sex for money or drugs was associated with STD in seven studies. Publications that were reviewed have numerous methodologic weaknesses: broader sampling, uninfected comparison groups, and greater specification of drug use and sexual risk behaviors are needed. Further research should compare different drugs and associated sexual behavior and STD to assess the unique risk conferred by crack. Designing effective interventions will require investigation of risk behavior determinants and barriers to health care.

Chancroid↗
PubMedDate not supplied

Transport media for Haemophilus ducreyi.

Stuart's, Amies' and four thioglycollate/hemin-based media containing, respectively, selenium dioxide and albumin (SA); selenium dioxide, L-glutamine and albumin (SGA); selenium dioxide and L-glutamine (SG); and L-glutamine and albumin (GA); were evaluated as transport media for Haemophilus ducreyi in a simulated, laboratory-based study. No transport medium was able to maintain the viability of H. ducreyi for more than 24 hours at room temperature. Amies' transport medium, however, maintained viability of H. ducreyi for up to 3 days and all the newly formulated transport media maintained viability of H. ducreyi for more than 4 days at 4 degrees C. Subsequently, swabs were taken from cases of genital ulcerations with a diagnosis of chancroid, plated directly onto selective media, and held at 4 degrees C in the two most efficient transport media (SGA and GA) for various periods of time. On direct plating, H. ducreyi was recovered from the genital ulcerations of 110 of 156 (71%) patients. The rates of recovery of H. ducreyi from transport media stored at 4 degrees C decreased with time. Although recovery was enhanced at day 4 (117/110 [106%]) using both SGA and GA, a recovery rate of 37/41 (90%) was obtained after storage in GA for 1 week.

Chancroid↗
PubMedDate not supplied

Development of a polymerase chain reaction assay for the detection of Haemophilus ducreyi.

BACKGROUND AND OBJECTIVES: Haemophilus ducreyi, the causative agent of chancroid is a fastidious organism difficult to culture and identify. Consequently, culture is an insensitive method for diagnosis. The polymerase chain reaction (PCR) offers a sensitive and specific nonculture method for the detection of bacterial pathogens. STUDY DESIGN: A polymerase chain reaction (PCR) assay was developed to detect the presence of Haemophilus ducreyi. A pair of primers was selected from sequences of an anonymous fragment of DNA cloned from H. ducreyi. The primers were tested in amplification reactions with both purified DNA and lysed organisms for their ability to detect H. ducreyi, and with DNA from a variety of different bacteria for their specificity. The utility of the primers for the detection of H. ducreyi in samples taken from genital ulcers was also tested and compared with culture. RESULTS: PCR was positive for 62% of the specimens that were culture-positive, however, PCR was also positive for 49% of the culture-negative specimens. Comparison of specimens that were dark field positive for T. pallidum and PCR-positive with those that were culture-positive for herpes simplex virus and PCR positive suggested that PCR was giving true and not random positive results. Additional studies demonstrated that the failure of PCR to detect H. ducreyi in all of the culture-positive specimens probably resulted from inhibitors of the Taq DNA polymerase that were present in the nucleic acids extracted from the clinical specimen. CONCLUSION: PCR should be a useful method for the detection of H. ducreyi in genital lesions, especially where culture sensitivity is poor. However, the presence of unidentified Taq polymerase inhibitors in some ulcers specimens require the development of improved methods for specimen handling.

Chancroid↗
PubMedDate not supplied

Trends in the acquisition of sexually transmitted diseases among HIV-positive patients at STD clinics, Miami 1988-1992.

BACKGROUND AND OBJECTIVES: To assess trends in the acquisition of new sexually transmitted diseases (STDs) among patients who test positive for human immunodeficiency virus (HIV) at STD clinics. STUDY DESIGN: Cohorts of HIV-positive and HIV-negative persons were compared using computerized records from Miami STD clinics for 1988-1992. Persons were assigned to cohorts according to their first positive or first negative HIV test results. New STDs were defined if persons had new diagnoses of gonorrhea, primary or secondary syphilis, chancroid, or lymphogranuloma venereum; were undergoing treatment as contacts for syphilis or gonorrhea; or were undergoing epidemiologic treatment for syphilis or gonorrhea. RESULTS: Of the 103,549 persons who visited the clinics, 53,467 were tested for HIV, and 5,615 had results that were positive. The percentages returning with new STDs were similar for the HIV-positive and HIV-negative cohorts, and both decreased over time. For the 1988 cohorts, 26% of those testing positive and 30% of those testing negative for HIV returned with at least one STD within 5 years. Returns with STD within 1 year decreased from 16% in 1988 to 3% in 1992. CONCLUSIONS: Returns decreased dramatically among HIV-positive cohorts; however, there were similar decreases of new STDs among HIV-negative cohorts, so the decrease may have been caused by the decreasing prevalence of bacterial STD in the community rather than by behavioral changes among HIV-positive persons.

Adult↗
PubMed2002

The etiology and management of genital ulcers in the Dominican Republic and Peru.

BACKGROUND: Clinical diagnosis of genital ulcers is difficult, and diagnostic tests are least available in settings where rates of disease are highest. The World Health Organization (WHO) has developed protocols for the syndromic management of genital ulcers in resource-poor settings. However, because risk factors, patterns and causes of disease, and antimicrobial susceptibilities differ from region to region and over time, they must be adapted to local situations. GOAL: The goal of this study was to determine etiologic factors, evaluate syndromic management, and compare polymerase chain reaction (PCR) testing with other diagnostic alternatives for genital ulcers among patients attending sexually transmitted disease clinics in the Dominican Republic and Peru. STUDY DESIGN: Eighty-one men with genital ulcers in the Dominican Republic and 63 in Peru underwent identical interviews and identical multiplex PCR (M-PCR) tests of genital lesion specimens for etiologic diagnoses. Algorithms for managing genital ulcers were developed. RESULTS: In the Dominican Republic, 5% were M-PCR-positive for, 26% for, and 43% for herpes simplex virus (HSV); in Peru, 10%, 5%, and 43%, respectively, were positive. The WHO algorithm for treating syphilis and chancroid had a sensitivity of 100%, a positive predictive value (PPV) of 24%, and an overtreatment rate of 76%. A modified algorithm for treating only those without vesicular lesions had 88% sensitivity and a 27% PPV, and the overtreatment rate was reduced to 58%. CONCLUSION: HSV caused 43% of genital ulcers in these populations. The modified algorithm had lower sensitivity but a reduced overtreatment rate. M-PCR testing was more sensitive than standard tests and more specific and sensitive than clinical diagnosis.

Adolescent↗
PubMed1998

HIV-1 DNA shedding in genital ulcers and its associated risk factors in Pune, India.

HIV infection status was determined in 302 consecutive patients with genital ulcer disease (GUD) presenting to two sexually transmitted disease (STD) clinics in Pune, India. Of the 71 (24%) individuals with HIV infection, 67 (94%) were HIV antibody-positive, and 4 (6%) were HIV antibody-negative but p24 antigen-positive at the time of presentation. HIV-1 DNA was detected in 24 (34%) specimens. The genital ulcers of all four acutely infected p24-antigenemic subjects were HIV-1 DNA-positive by polymerase chain reaction (PCR) assay, compared with 20 of 67 (30%) seropositive patients (p = .01). Presence of chancroid, GUD symptoms for > 10 days, and concurrent diagnosis of cervicitis or urethritis were significantly associated risk factors for HIV-1 DNA shedding in ulcers. Early GUD diagnosis and aggressive treatment of HIV-infected patients may significantly reduce secondary transmission of HIV to other sex partners.

Adolescent↗
PubMed2001

Prevalence of cdtABC genes encoding cytolethal distending toxin among Haemophilus ducreyi and Actinobacillus actinomycetemcomitans strains.

The aim of this study was to investigate the presence of the three cdtABC genes responsible for production of cytolethal distending toxin (CDT) in Haemophilus ducreyi and Actinobacillus actinomycetemcomitans strains. Of 100 H. ducreyi strains from the culture collection of the University of Göteborg (CCUG), 27 strains with low or intermediate cytotoxic titre (< 1 in 10(4)) and 23 of the remaining isolates with a high cytotoxic titre (> or = 1 in 10(4)) were selected. Twenty-nine strains of H. ducreyi were isolated recently from patients with chancroid and 50 A. actinomycetemcomitans strains from patients with periodontitis. The cytotoxic activity on HEp-2 cells and the presence of cdtABC genes were studied by cytotoxicity assay of bacterial sonicates and PCR with primers specific for individual cdtA, B, and C genes of H. ducreyi in bacterial DNA preparations, respectively. All strains that manifested a cytotoxic titre in sonicate > or = 1 in 100 possessed all the three cdt genes. Eighteen of the 50 strains selected from the culture collection were negative and 32 positive for cdt genes. As all strains with a high cytotoxic titre gave positive PCR results, it can be assumed that the remaining 50 strains, which have high cytotoxic titre, would have been positive as well. Thus, it can be estimated that 82% of the culture collection strains had cdtABC genes. Similarly, 24 (83%) of 29 recent H. ducreyi isolates expressed the CDT activity and displayed all cdtABC genes. Forty-three (86%) of 50 strains of the closely related A. actinomycetemcomitans, expressing a cytotoxic activity > or = 1 in 100, also possessed all three genes. Furthermore, the nucleotide sequence of the cdtABC genes was highly conserved among H. ducreyi strains from different geographic areas. These results indicate that the majority of pathogenic H. ducreyi and A. actinomycetemcomitans strains express a CDT activity encoded by all three cdtABC.

Actinobacillus Infections↗
PubMed1998

The rrs (16S)-rrl (23S) ribosomal intergenic spacer region as a target for the detection of Haemophilus ducreyi by a heminested-PCR assay.

The intergenic spacer region between the rrs and rrl ribosomal RNA genes of Haemophilus ducreyi was analysed and the DNA sequence was used for the selection of specific PCR primers. A highly sensitive and specific heminested-PCR assay for the identification of H. ducreyi was developed. The assay showed a sensitivity of 96% on genital ulcer specimens from patients with clinically diagnosed chancroid, compared with a sensitivity of 56% for culture methods. These results indicate that this PCR assay has the potential to become an accurate and easy reference method for the detection of H. ducreyi.

Base Sequence↗
PubMed1986

Isolation and identification of Haemophilus ducreyi in a clinical laboratory.

Routine procedures used to isolate Haemophilus ducreyi in a busy laboratory are reported. Identification was based on colony morphology and nutritional and biochemical properties of 120 fresh isolates of H. ducreyi. These isolates grew very well on Gonococcal Agar and Mueller-Hinton Agar incubated at 34 degrees C in candle extinction jars containing moistened filter paper. Colonies varied in size, giving a polymorphic appearance. They were smooth, dome-shaped, and buff-yellow to grey in colour, and measured 2 mm in diameter. They could be pushed intact across the agar surface. By microscopic examination of gram-stained smears the isolates were gram-negative coccobacilli arranged in short chains, clumps or whorls and occasionally in typical "rail track" arrangements. Individual bacteria showed bipolar staining. Colonies autoagglutinated in saline. All strains were catalase-negative and did not produce indole or H2S. They were oxidase- and beta-lactamase positive and required X but not V factor for growth. Now that reliable techniques have been developed and characteristics established it is possible for most clinical laboratories to isolate and identify this organism from most patients with chancroid.

Chancroid↗
PubMed1994

Emergence of Haemophilus ducreyi resistance to trimethoprim-sulfamethoxazole in Rwanda.

The in vitro susceptibilities of 112 clinical isolates of Haemophilus ducreyi to six antimicrobial agents were determined. These isolates were obtained in Kigali, Rwanda, during three studies on genital ulcer disease performed in 1986 (18 isolates), 1988 (23 isolates), and 1991 (71 isolates). All H. ducreyi isolates were susceptible to azithromycin, ceftriaxone, ciprofloxacin, and erythromycin; all isolates obtained in 1986 were also susceptible to trimethoprim and to the combination trimethoprim-sulfamethoxazole. In contrast, 39 and 9% of the isolates obtained in 1988 and 59 and 48% of the isolates obtained in 1991 were resistant to trimethoprim (MIC, > or = 4.0 mg/liter) and trimethoprim-sulfamethoxazole (MIC, < or = 4.0/76 mg/liter), respectively. These data indicate that trimethoprim-sulfamethoxazole can no longer be recommended for use in the treatment of chancroid in Rwanda, and possibly elsewhere in Africa.

Anti-Bacterial Agents↗
PubMed1984

Monoclonal antibodies reactive with all strains of Haemophilus ducreyi.

We have isolated plasma cell hybridomas which secrete monoclonal antibodies directed against Haemophilus ducreyi. Two of these monoclonal antibodies recognize all strains of H. ducreyi tested to date and are capable of detecting the presence of H. ducreyi in skin lesions produced by this pathogen in experimental animals. These monoclonal antibodies which react with apparently all strains of H. ducreyi have the potential to be developed into a rapid immunodiagnostic test for chancroid.

Animals↗
PubMed1991

Role of lipooligosaccharides in experimental dermal lesions caused by Haemophilus ducreyi.

The mouse and rabbit intradermal injection models have been used to define factors that may be important in Haemophilus ducreyi pathogenesis. We used H. ducreyi strains with diverse geographic origins and phenotypic characteristics to evaluate the experimental models. Injection of live and heat-killed bacteria caused skin abscesses in both models. Semiquantitative cultures of skin injected with live bacteria showed that H. ducreyi failed to replicate in animal tissue. These data suggested that the experimental lesions were caused by a heat-stable substance such as lipooligosaccharide (LOS). In mice, injection of H. ducreyi and Haemophilus influenzae LOS and Escherichia coli lipopolysaccharide caused mild to moderate inflammation. In rabbits, injection of H. ducreyi LOS caused intradermal abscesses that were histologically similar to those caused by live and heat-killed bacteria. H. ducreyi and Neisseria gonorrhoeae LOS caused significantly larger lesions than equivalent amounts of H. influenzae LOS and E. coli lipopolysaccharide in the rabbit model. We conclude that the intradermal injection models are not valid models to study the growth of H. ducreyi in vivo. However, these data indicate that H. ducreyi LOS may play an important role in the pathogenesis of chancroid and that the rabbit model should be useful in studying H. ducreyi LOS toxicity at the cellular level.

Animals↗
PubMed1993

Haemophilus ducreyi adheres to but does not invade cultured human foreskin cells.

Haemophilus ducreyi is the etiologic agent of the localized genital ulcer disease known as chancroid. The pathogenesis of this organism is poorly understood. The role of attachment in the disease process has not been evaluated. In this study, 125I-H. ducreyi was used to quantitatively evaluate the interaction of virulent and avirulent H. ducreyi strains with human foreskin cells. Using this in vitro model system, we demonstrated that, at 22 and 35 degrees C, the attachment of virulent H. ducreyi 35000 to human foreskin cells was significantly more marked than that of avirulent H. ducreyi A77. Although H. ducreyi penetrated between human foreskin cells, internalization was not a major component. Our competition assay data suggest that the attachment mechanism of H. ducreyi may be similar to that of Neisseria gonorrhoeae. We speculate that the attachment and microcolony formation of virulent H. ducreyi may provide a mechanism for bacterial localization and evasion of host defenses.

Bacterial Adhesion↗
PubMed1994

Haemophilus ducreyi attaches to and invades human epithelial cells in vitro.

Haemophilus ducreyi is a sexually transmitted pathogen that causes genital ulcers and inguinal adenopathy. Because chancroidal ulcers are most commonly located on the foreskins of uncircumcised males, we utilized human foreskin epithelial cells (HFECs) to investigate the initial interaction of H. ducreyi with its host. The eight different strains of H. ducreyi that were studied varied in their abilities to attach to these epithelial cells, with six strains consistently attaching to > or = 90% of HFECs and two strains attaching to < 25% of HFECs. The strains with low levels of adherence also failed to exhibit chaining in broth culture and were avirulent in the rabbit model, suggesting that virulence in this model and attachment may be linked. The most adherent strain, LA228R, was further evaluated for its ability to invade HFECs and HEp-2 cells. Scanning electron microscopy and transmission electron microscopy of HFECs after interaction with LA228R produced images consistent with attachment, ingestion into vesicles, and escape from the vesicles into the cytoplasm. In addition, the gentamicin protection assay and inhibition of invasion by cytochalasin B and D indicated that LA228R was able to invade both HFECs and HEp-2 cells. Further examination of the mechanisms involved in the adherence and invasion of H. ducreyi into epithelial cells and their correlation with virulence will provide a better understanding of the pathogenesis of the disease caused by this important pathogen.

Animals↗
PubMed1995

Inducible immunity with a pilus preparation booster vaccination in an animal model of Haemophilus ducreyi infection and disease.

Using the temperature-dependent rabbit model of Haemophilus ducreyi infection as a quantitative virulence assay, we tested the abilities of two bacterial antigen preparations to induce protection against subsequent infection and disease. Lipooligosaccharide (LOS) and a pilus preparation were purified from H. ducreyi 35000 and were used in a booster immunization procedure. The serologic response to each immunogen was monitored by enzyme immunoassay. H. ducreyi virulence was assayed by intraepithelial inoculation and subsequent measurement of disease for homologous strain 35000 or clinical isolate RO-34. LOS and the pilus preparation induced humoral responses. The kinetics of the LOS antibody response suggest a type 1 T-independent response, whereas the pilus preparation induced an anamnestic response. An inoculum of 10(5) CFU of H. ducreyi 35000 or RO-34 consistently produced ulcerative chancroidal lesions in naive rabbit controls. Immunization with LOS did not modify the virulence of H. ducreyi 35000. Immunization with the strain 35000 pilus preparation significantly reduced the severity of disease and the duration of infection and disease compared with controls, with either homologous or heterologous strain infection. The histology of lesions from pilus preparation-vaccinated rabbits compared with that of lesions from controls revealed accelerated lymphoid cell recruitment, more prominent plasma cell infiltrate, and reduction in subsequent histiocytic infiltration. We conclude that both LOS and the pilus preparation are immunogenic and that the latter induces homologous and heterologous strain protection in this animal model of infection and disease.

Animals↗