Epidemiologic, clinical, laboratory, and therapeutic features of an urban outbreak of chancroid in North America

The office approach to the sexually transmitted diseases: Part II

All physicians share a responsibility for educating the public in the expanding risks of sexually transmitted diseases, and in the vital importance of safe sexual practices. Both the public health implications of undiagnosed STDs and the adverse social consequences of an incorrect diagnosis emphasize the need to comprehensively and precisely diagnose these diseases, despite the problems encountered in obtaining material for culture. Current interest in AIDS should not obscure the facts that genital herpes continues to increase in prevalence, and that syphilis no longer is declining. The many extragenital syndromes associated with STDs, such as perihepatitis, polyarthritis, and acute septic states make it necessary to evaluate all sexual contacts.

Immunoblot analysis of antigens associated with Haemophilus ducreyi using serum from immunised rabbits

Sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblotting were used to characterise isolates of Haemophilus ducreyi. Isolates of H ducreyi were heterogeneous in protein composition, but isolates from single outbreaks appeared similar both in protein profiles and antigenic analysis. Rabbits immunised with H ducreyi responded with a vigorous humoral immune response in which multiple antigenic polypeptides were detected. The most prominent antigens had molecular masses of 67, 42, 22.5, and 20 kilodaltons.

Three day oral course of Augmentin to treat chancroid

Amoxycillin and clavulanic acid (Augmentin; Beecham Research Laboratories) was used to treat patients with bacteriologically proved chancroid in three different dose regimens. A single dose of Augmentin (amoxycillin 3 g, clavulanic acid 350 mg) was found to be ineffective. A similar dose repeated after 24 hours was equally ineffective, but a dose (amoxycillin 500 mg, clavulanic acid 250 mg) given every 8 hours for three days was found to be effective. The drug was well tolerated and no side effects were noted in any of the patients treated.

Plasmid-mediated aminoglycoside phosphotransferases in Haemophilus ducreyi

Three clinical isolates of Haemophilus ducreyi, representing at least two subtypes, were shown to be resistant to streptomycin and kanamycin. They also produced a beta-lactamase and chloramphenicol acetyltransferase and were resistant to tetracycline. In the three strains the resistance to both aminoglycoside antibiotics was encoded by a plasmid of ca. 4.7 kilobases which apparently did not carry ampicillin, chloramphenicol, or tetracycline resistance genes, as determined after transfer to Escherichia coli by transformation. Resistance to streptomycin and kanamycin was due to the presence of two aminoglycoside phosphotransferases (APH). The enzyme modifying kanamycin was a 3',5"-APH of type I [APH(3',5")-I], as inferred from its substrate profile and immunological cross-reactivity with the APH(3',5")-I encoded by the transposable element Tn903. However, the APH(3',5")-I gene in H. ducreyi did not appear to be carried by Tn903.

Haemophilus ducreyi

Haemophilus ducreyi is the etiologic agent of chancroid, an infection which is endemic in tropical and subtropical areas of the world and which is becoming more prevalent in Europe and North America. Recently, several strains have demonstrated resistance to several antimicrobials by plasmid acquisition and cell envelope alteration making control of the spread of this organism a challenge. Equally challenging is the growth of this organism in the clinical microbiology laboratory because of its in vitro fastidious nature. Currently, the therapy of choice for Haemophilus ducreyi infection is trimethoprim sulfamethoxazole or erythromycin. Plasmid enumeration and restriction endonuclease fingerprinting in addition to outer membrane protein profiles may provide a basis for subtyping which would be useful in epidemiologic studies.

Anaerobic bacteria and herpes simplex virus in genital ulceration

Of 91 patients with genital ulceration, herpes simplex virus was isolated from 52 (57%) and Haemophilus ducreyi from 12 (13%); none had syphilis. The difference in incidence of other aerobes in patients and controls was not significant. Anaerobes, predominantly Bacteroides spp, were isolated from a large proportion (77%) of men and women patients with ulcers but from few control men. The most common anaerobic species were B asaccharolyticus and B ureolyticus, with fewer isolates of the melaninogenicus/oralis group. The bacterial flora of herpetic and non-herpetic ulcers were similar, but Candida albicans was isolated significantly more often from non-herpetic ulcers. Anaerobic bacteria may contribute to the pathogenesis of genital ulcers.

Antimicrobial susceptibility and characterization of outer membrane proteins of Haemophilus ducreyi isolated in Thailand

One hundred strains of Haemophilus ducreyi isolated in Thailand from patients with chancroid were tested by the agar dilution method against 10 antimicrobial agents and typed by outer membrane protein pattern by using sodium dodecyl sulfate gel electrophoresis. All strains produced beta-lactamase and were resistant to tetracycline, kanamycin, and sulfonamides. Most had a decreased susceptibility to trimethoprim (MIC for 50% of the strains [MIC50], 0.5 micrograms/ml) and chloramphenicol (MIC50, 8 micrograms/ml). Strains were susceptible to ciprofloxacin (MIC90, 0.001 micrograms/ml), ceftriaxone (MIC50, 0.0015 micrograms/ml), erythromycin (MIC50, 0.015 micrograms/ml), rosoxacin (MIC50, 0.03 micrograms/ml), and spectinomycin (MIC50, 8 micrograms/ml). The degree of antimicrobial resistance found in Thailand is higher than that reported for H. ducreyi isolated in other regions. Five different outer membrane protein patterns were found by analyzing proteins in the range of 29 to 61 kilodaltons, but 98% of the Thai strains fell into three patterns which did not differ greatly. Outer membrane protein patterns of Thai strains were also seen in strains from other geographic areas. A new outer membrane protein type was found among nine strains isolated in Singapore.

Susceptibility of 40 Haemophilus ducreyi strains to 34 antimicrobial products

A study was performed to examine compounds that might improve the selectivity of the primary isolation medium for Haemophilus ducreyi. The susceptibility of 40 H. ducreyi strains to 34 antimicrobial agents, including 10 antibiotics, 3 quaternary ammonium compounds, 3 phenolic derivatives, 3 acridines, and 15 heavy metal compounds, was investigated by using an agar plate dilution technique. Results were compared with the susceptibilities of other gram-negative rods which may be contaminants on isolation media. The minimal inhibitory concentration range for colistin (16 to 128 micrograms/ml) indicated that this antibiotic might be of use as a selective agent. H. ducreyi was susceptible to spectinomycin (minimal inhibitory concentration range, 16 to 64 micrograms/ml), thiamphenicol (0.12 to 1 microgram/ml), chloramphenicol (0.12 to 0.5 micrograms/ml), and streptomycin (4 to 32 micrograms/ml) and moderately susceptible to kanamycin (2 to 8 micrograms/ml). For the heavy metal compounds, a high susceptibility was seen with copper(II) chloride (2 to 8 micrograms/ml, corresponding to a concentration of 0.75 to 3 micrograms of Cu2+ ions per ml), sodium selenite (1 to 4 micrograms/ml, or 0.45 to 1.83 micrograms of Se- ions per ml), and phenylmercury acetate (0.12 to 0.5 micrograms/ml). The minimal inhibitory concentrations of quaternary ammonium compounds, acridines, and phenolic derivatives were between 1 and 32 micrograms/ml, 8 and 32 micrograms/ml, and 8 and 250 micrograms/ml, respectively.

Single-dose therapy of chancroid with trimethoprim-sulfametrole

We conducted a randomized double-blind trial comparing a single dose of trimethoprim-sulfametrole (640 to 3200 mg) with five-day regimens of either trimethoprim-sulfametrole (160 to 800 mg twice daily) or trimethoprim alone (200 mg twice daily) for the treatment of men with chancroid. Of 95 patients, 78 had cultures positive for Hemophilus ducreyi. Twenty-seven, 23, and 28 patients, respectively, were assigned to the single-dose trimethoprim-sulfametrole, the five-day trimethoprim-sulfametrole, and the five-day trimethoprim treatments. The rate of ulcer and bubo resolution, the mean (+/- S.D.) healing times (10.3 +/- 5.7, 11.0 +/- 7.4, and 11.9 +/- 8.2 days, respectively), the microbiologic response, the number of treatment failures, and the number of recurrent ulcers were similar in all three treatment groups. We conclude that single-dose trimethoprim-sulfametrole is a highly effective, inexpensive therapy for chancroid in men and may prove to be an important strategy for the control of H. ducreyi infection.

Pathogenic microbial flora of genital ulcers in Sheffield with particular reference to herpes simplex virus and Haemophilus ducreyi

The pathogenic microbial flora of genital ulcers in 161 (80 men and 81 women) unselected patients was studied prospectively. In only one case was Treponema pallidum responsible whereas herpes simplex virus was considered to be the cause of 130 (80.8%) genital ulcers. H ducreyi was isolated from 46 (28.6%) patients, most commonly as a secondary pathogen in herpetic lesions. Two or more pathogens were isolated from the ulcers in 67 (41.6%) patients, and in 21 (13%) patients no pathogens were isolated. Our results indicate an urgent need for antiviral treatment to reduce the local reservoir of genital herpes, challenge traditional concepts about the prevalence of H ducreyi in Britain, and call for a reappraisal of its role in the causation of genital ulcers.

Isolation and rapid identification of Haemophilus ducreyi

During a 2-month period, 62 strains of Haemophilus ducreyi were isolated from 168 genital lesions and 2 lymph node aspirates. Of these strains, 22 were found on both chocolate agar and fetal bovine serum agar supplemented with vancomycin, 29 were found only on chocolate agar, and 9 were found only on fetal bovine serum agar. Two additional strains were isolated on sheep blood agar. All of these isolates were correctly identified with the RapID NH system (Innovative Diagnostic Systems, Inc., Decatur, Ga.) a new identification kit that has a database for Haemophilus, Neisseria, and other genera that include fastidious gram-negative bacilli.

Characteristics of Haemophilus ducreyi. A study

In a study of 13 local and four reference strains of Haemophilus ducreyi all grew well on a selective medium consisting of Bacto proteose No 3 agar (Difco), soluble starch, IsoVitalex, human blood, and vancomycin. All the strains reduced nitrate, were alkaline-phosphatase-positive, and (with one exception) used glucose, fructose, and mannose, beta-lactamase was produced by 12 local strains. Erythromycin was the the most effective antibiotic tested, followed by streptomycin, co-trimoxazole, and spectinomycin.

Characterization of ampicillin resistance plasmids from Haemophilus ducreyi

Seven strains of Haemophilus ducreyi from diverse geographic origins were analyzed for their plasmid content. All strains were multiply resistant, but only resistance to ampicillin was transferred to Escherichia coli by transformation. The H. ducreyi plasmids encoding for ampicillin resistance were 7.4, 5.7, and 3.6 megadaltons and encoded for part or all of TnA, and ampicillin transposon. The relatedness of these plasmids was examined by restriction endonuclease digestion and DNA-DNA homology with isolated DNA fragments from TnA.

Genital ulcers in Kenya. Clinical and laboratory study

Of 97 patients with genital ulcers attending a special treatment clinic in Nairobi, Kenya, 60 harboured Haemophilus ducreyi, four herpes simplex virus, and five Neisseria gonorrhoeae. Eleven patients had serological evidence of syphilis; of these one case was confirmed by darkfield microscopy. In the remaining cases no aetiological agent was identified. An enriched chocolate agar with vancomycin and serum was a useful medium for primary isolation of H ducreyi. Tetracycline was generally ineffective in the treatment of ulcers, but sulfadimidine was successful in almost 80% of cases.

Synergistic antibacterial activity of clavulanic acid and amoxicillin against beta-lactamase-producing strains of Haemophilus ducreyi

The susceptibility of 47 strains of Haemophilus ducreyi to amoxicillin, clavulanic acid, and the combination of both drugs was determined by agar dilution susceptibility testing. A synergistic antibacterial activity of the combination was found for beta-lactamase-producing strains.