Trichosporon beigelii, an emerging pathogen resistant to amphotericin B

413

396

The mortality associated with invasive fungal infections remains high with that involving rare yeast pathogens other than Candida being no exception. This is in part due to the severe underlying conditions typically predisposing patients to these healthcare-related infections (most often severe neutropenia in patients with haematological malignancies), and in part due to the often challenging intrinsic susceptibility pattern of the pathogens that potentially leads to delayed appropriate antifungal treatment. A panel of experts of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Fungal Infection Study Group (EFISG) and the European Confederation of Medical Mycology (ECMM) undertook a data review and compiled guidelines for the diagnostic tests and procedures for detection and management of rare invasive yeast infections. The rare yeast pathogens were defined and limited to the following genera/species: Cryptococcus adeliensis, Cryptococcus albidus, Cryptococcus curvatus, Cryptococcus flavescens, Cryptococcus laurentii and Cryptococcus uniguttulatus (often published under the name Filobasidium uniguttulatum), Malassezia furfur, Malassezia globosa, Malassezia pachydermatis and Malassezia restricta, Pseudozyma spp., Rhodotorula glutinis, Rhodotorula minuta and Rhodotorula mucilaginosa, Sporobolomyces spp., Trichosporon asahii, Trichosporon asteroides, Trichosporon dermatis, Trichosporon inkin, Trichosporon jirovecii, Trichosporon loubieri, Trichosporon mucoides and Trichosporon mycotoxinivorans and ascomycetous ones: Geotrichum candidum, Kodamaea ohmeri, Saccharomyces cerevisiae (incl. S. boulardii) and Saprochaete capitatae (Magnusiomyces (Blastoschizomyces) capitatus formerly named Trichosporon capitatum or Geotrichum (Dipodascus) capitatum) and Saprochaete clavata. Recommendations about the microbiological investigation and detection of invasive infection were made and current knowledge on the most appropriate antifungal and supportive treatment was reviewed. In addition, remarks about antifungal susceptibility testing were made.

Section: Susceptibility Testing and Treatmentmentioning

confidence: 99%

ESCMID and ECMM joint clinical guidelines for the diagnosis and management of rare invasive yeast infections

Arendrup

Boekhout

Akova

et al. 2014

413

396

“…Treatment relies on rapid diagnosis and differentiation of Trichosporon from the more common Candida spp. Although amphotericin B has been found to be inhibitory to Trichosporon in vitro, it has poor fungicidal activity with breakthrough infections seen in febrile neutropenic patients on high-dose empiric treatment with amphotericin B [147]. In a persistently neutropenic rabbit model of disseminated trichosporonosis, treatment with amphotericin B deoxycholate (1 mg ⁄ kg per day) and a lipid formulation of amphotericin B at 5 mg ⁄ kg per day was unable to clear tissues in comparison with saline-treated controls [140].…”

Section: Uncommon Yeast Pathogensmentioning

confidence: 99%

Infections due to emerging and uncommon medically important fungal pathogens

Walsh

Groll

Hiemenz

et al. 2004

516

405

The emergence of less common but medically important fungal pathogens contributes to the rate of morbidity and mortality, especially in the increasingly expanding population of immunocompromised patients. These pathogens include septate filamentous fungi (e.g., Fusarium spp., Scedosporium spp., Trichoderma spp.), nonseptate Zygomycetes, the endemic dimorphic pathogen Penicillium marneffei, and non-Cryptococcus, non-Candida pathogenic yeast (e.g., Trichosporon spp.). The medical community is thus called upon to acquire an understanding of the microbiology, epidemiology and pathogenesis of these previously uncommon pathogens in order to become familiar with the options for prevention and treatment.

“…Not uncommonly, acute trichosporonosis presents with a cascade of rapidly evolving skin lesions in a neutropenic patient who is receiving empirical amphotericin B for refractory fever. Laboratory investigations of these organisms have demonstrated that they may be inhibited but not killed by safely achievable levels of amphotericin B [166].…”

Section: Trichosporon Speciesmentioning

confidence: 99%

Uncommon opportunistic fungi: new nosocomial threats

Groll

Walsh

2001

273

175

During the past two decades opportunistic fungal infections have emerged as important causes of morbidity and mortality in patients with severe underlying illnesses and compromised host defenses. While Aspergillus and Candida spp. collectively account for the majority of these infections, recent epidemiological trends indicate a shift towards infections by Aspergillus spp., nonalbicans Candida spp., as well as previously uncommon opportunistic fungi. Apart from an expanding number of different Zygomycetes, previously uncommon hyaline filamentous fungi (such as Fusarium species, Acremonium species, Paecilomyces species, Pseudallescheria boydii, and Scedosporium prolificans), dematiaceous filamentous fungi (such as Bipolaris species, Cladophialophora bantiana, Dactylaria gallopava, Exophiala species, and Alternaria species) and yeast-like pathogens (such as Trichosporon species, Blastoschizomyces capitatus, Malassezia species, Rhodotorula rubra and others) are increasingly encountered as causing life threatening invasive infections that are often refractory to conventional therapies. On the basis of past and current trends, the spectrum of fungal pathogens will continue to evolve in the settings of an expanding population of immunocompromised hosts, selective antifungal pressures, and shifting conditions in hospitals and the environment. An expanded and refined drug arsenal, further elucidation of pathogenesis and resistance mechanisms, establishment of in vitro/in vivo correlations, incorporation of pharmacodynamics, combination- and immunotherapies offer hope for substantial progress in prevention and treatment.