M. Seibold

Taxonomic and diagnostic markers for identification of Coccidioides immitis and Coccidioides posadasii

The ribosomal Internal Transcribed Spacer (ITS) regions of the two recognized species of Coccidioides were studied using a reference set of strains that had been previously identified with species defining microsatellite polymorphisms. Unambiguous identification of the two species proved to be possible by amplifying and sequencing the ITS region. PCR-reactions are sensitive to amplification conditions requiring their careful optimization. Stable amplification and sequencing was achieved with primers ITS3 and 4, enabling species diagnosis. Alternatively, Restriction Fragment Length Polymorphism (RFLP) of the entire ITS region using an annealing temperature of 52 degrees C with the restriction enzymes BsrI and XcmI can also distinguish the species. Three strains typifying the species, Glenospora meteuropaea, G. metamericana and Geotrichum louisianoideum, were analyzed and found to be conspecific with C. posadasii. Although these species have nomenclatural priority over C. posadasii, the latter will be proposed for conservation as it has been included in the US select agent list. In addition, Coccidioides immitis is neotypified in this report. Results of antifungal susceptibility testing did not reveal differences between the two species.

Adherence of different Candida dubliniensis isolates in the presence of fluconazole.

Background The recently described yeast species Candida dubliniensis is closely related to C. albicans and has been recovered predominantly from the oral cavities of HIV-infected individuals and AIDS patients who are often receiving fluconazole as prophylactic or therapeutic treatment for oropharyngeal candidiasis. Like C. albicans, C. dubliniensis secretes aspartic poteinases which in C. albicans have been shown to be involved in adherence. Objective To explain the increasing prevalence of C. dubliniensis in AIDS patients and to investigate the virulence factors of this yeast. Methods An in vitro assay was developed to compare the adherence to epithelial cells of C. dubliniensis from HIV-patients with that of C. albicans. Results All C. albicans isolates adhered better than the 22 C. dubliniensis isolates. In the presence of fluconazole, the C. dubliniensis isolates tested showed increased adherence as compared with controls without fluconazole. In contrast, all C. albicans isolates decreased in adherence to epithelial cells in the presence of fluconazole independently of their in vitro susceptibility to this drug. Proteinase antigens are present on the surface of C. dubliniensis cells adherent to epithelial target cells. In the presence of fluconazole this proteinase antigen was more strongly expressed. Conclusion Increased adherence of C. dubliniensis strains in the presence of fluconazole could explain its high recovery rate from HIV-positive patients in recent years. The induction of proteinase secretion in the presence of fluconazole found for most of the C. dubliniensis isolates could be one of the factors involved in adherence.

Re-identification of clinical isolates of the Pseudallescheria boydii-complex involved in near-drowning

Fungal infections caused by the members of the genera Pseudallescheria and/or Scedosporium are important complications in patients after near‐drowning. As the taxonomy of Pseudallescheria and Scedosporium has been revised, clinical isolates from 11 patients, after near‐drowning, previously identified as P. boydii or S. apiospermum had to be re‐identified. S. apiospermum, now separated from P. boydii as a distinct species, was found most frequently (n = 8), while S. aurantiacum, recently described as new species and P. boydii were less common (n = 2 and n = 1, respectively). Three patients near‐drowned during the Tsunami 2004 were infected by different species of the P. boydii complex. In vitro testing resulted in lowest minimal inhibitory concentration (MICs) for voriconazole (range 0.25–2.0 μg ml−1).

Fungal infections following heart transplantation

Summary. Following heart transplantation (HTx), patients often suffer from mycoses due to the necessary immunosuppressive treatment to prevent rejection episodes. Oropharyngeal Candida infections which mostly occur after HTx under high‐dose immunosuppressive therapy can be avoided and treated successfully by prophylactic medication to be started immediately after transplantation, either by using azoles (e.g. fluconazole) or amphotericin B suspension. Contrary to this, invasive aspergillosis, beginning in the upper respiratory tract and the lung and mostly followed by hematogenous dissemination into various organs, is always a serious disease with high mortality. To avoid this infection, specimens from the respiratory tract, serum and urine should be examined mycologically prior to HTx. After HTx, apart from prophylactic avoidance of exposure to airborne fungal spores, close mycological control is mandatory to detect colonizations by aspergilli early. Timely administration of amphotericin B and 5‐flucytosine, i.e. as soon as invasive growth is suspected, enables curative treatment of the often lethal course of this disease, even under immunosuppressive therapy.

Successfully treated Candida krusei infection of the lumbar spine with combined caspofungin/posaconazole therapy

Candidal vertebral osteomyelitis represents an extremely rare invasive mycosis and can be difficult to treat due to poor drug penetration into bony tissue. We report on a case of vertebral osteomyelitis caused by Candida krusei in a patient who had neutropenia as a result of chemotherapy for acute myelogenous leukaemia. The patient received prophylactic liposomal amphotericin B during chemotherapy but became febrile and experienced severe lumbar pain. Magnetic resonance imaging revealed vertebral osteochondrosis. C. krusei was recovered from blood cultures and voriconazole monotherapy was initiated but proved unsuccessful. The patient was then started on caspofungin monotherapy, which was discontinued after Candida krusei was no longer recoverable from blood cultures. However, as lumbar pain increased and spinal biopsy confirmed the presence of Candida krusei, caspofungin therapy was resumed. Oral posaconazole was added to the regimen when the patient did not improve after 30 days of caspofungin therapy. Combined antimycotic therapy resulted in a successful outcome.

Aspergillus Findings in AIDS Patients Suffering from Cryptococcosis Aspergillus‐Befunde während des Cryptococcose‐Verlaufs bei AIDS‐Patienten

Summary: Because of the known pathoge‐nicity of Cryptococcus neoformans and of aspergilli depending on defined but different immunodeficiencies of the host, the evaluation of their simultaneous cultural detection in specimens of the respiratory tract of AIDS patients is of epidemiological, diagnostic, pathogenetic and therapeutic interest. In 10 out of 15 AIDS patients the following species of the genus Aspergillus could be isolated either once or repeatedly during the course of Cr. neoformans infections in specimens from the respiratory tract: A.fumigatus, A.flavus, A. nidulans, A. niger and A. glaucus.

Mycological-diagnostic assessment of the efficacy of amphotericin B+ flucytosine to control Cryptococcus neoformans in AIDS patients

Abstract: Optimal diagnostic data (microscopy, culture and serology) on 15 cases of Cr. neoformans infection in AIDS patients served as a basis for the preliminary subdivision of the stages of cryptococcosis: Primary (minor involvement of the lungs only) and secondary (hematogenous dissemination with involvement of various organs) stages. Cr. neoformans counts in body fluids and antigen titres in serum and CSF proved to be useful criteria to assess the stage of infection. The efficacy of the combination therapy with amphotericin B + flucytosine seems to be related to the stage of infection. From the mycological point of view, the standard combination of 0.3–0.5 mg/kg BW/d amphotericin B and 150 mg/kg BW/d flucytosine proved to be effective. Data on sensitivity of the agent to amphotericin B and flucytosine are presented in a summarized form. The subjects of duration of therapy, relapse and resistance to flucytosine are commented by means of examples. It should be the aim of an optimal therapy of cryptococcosis to diagnose this mycotic disease in its primary stage.

Cryptococcus neoformans in the Seminal Fluid of an AIDS Patient. A Contribution to the Clinical Course of Cryptococcosis: Cryptococcus neofomans im Sperma eines AIDS‐Patienten. Ein Beitrag zum Minischen Verlauf der Cryptococcose

Summary: In a 33‐year‐old HIV‐positive homosexual male suffering from unexplained headache, cryptococcosis was diagnosed in a progressive secondary stage. After treatment with the standard combination therapy of amphotericin B + flucytosine for 34 d, the patient was clinically symptom‐free and discharged, upon his own request, from the hospital. He remained under ambulatory mycological control. After an interval of 65 d during which the urine had been free from Cryptococcus neoformns (Cr.n), the fungus could not be isolated from urine but 3 × 105 CFUs/ml were found in the seminal fluid. Andrologically, teratospermia and hyposemia were present. There were no clinical signs in the genitourinary tract including the prostate. The significance of ecological niches for Cr.n. colonization of the genitourinary tract after antimycotic therapy is discussed. In such cases, in addition to cultural examination of urine for Cr.n. by the membrane filtration technique (MFT) and Staib agar, an additional cultural examination of seminal fluid is recommended. It is also proposed to pay more attention to Cr.n. in andrological examinations. Special regard should be given to a possible occurrence of Cr.a in the seminal fluid of AIDS patients. In cytology of the seminal fluid, use of the Giemsa stain is unsuitable for the purpose of Cr.n. detection. For this reason, it should be supplemented by PAS staining.

Case Reports. Disseminated cryptococcoses without cryptococcal antigen detection

During the last decade cryptococcoses were most frequently diagnosed in AIDS patients, where serologically high amounts of glucoronoxylomannan (GXM) were detectable. Disseminated cryptococcoses without cryptococcal antigen detection is unusual. Between August and October 1998 disseminated cryptococcoses were diagnosed in three patients consecutively although cryptococcal antigen was not detectable. Only one of the patients was HIV infected.

First report of a Cryptococcus magnus infection in a cat

This report describes an uncommon case of cryptococcosis in an apparently immunocompetent cat caused by Cryptococcus magnus. An amputation of the complete left foreleg and excision of the ipsilateral cervical lymph node were performed in a young-adult male Domestic Shorthair cat due to suspicion of a tumor. Granulomatous dermatitis, panniculitis, myositis, and lymphadenitis were diagnosed histologically. Intralesional, numerous round-to-ovoid yeast cells showing no capsule were detected within macrophages using special staining methods. The tissue material cultured on Sabourauds glucose agar at 26°C yielded abundant growth of yeast colonies. Morphological, physiological, and molecular analyses of the yeasts demonstrated that the fungus was C. magnus. Response to treatment with fluconazole was fast and effective, and one year after the end of the therapy no further clinical signs of infection were observed.