Uncommon Fungi and 268 Related Species Duane R. Hospenthal SHORT VIEW SUMMARY SCEDOSPORIUM APIOSPERMUM Diagnosis FUSARIUMM SPP. (PSEUDALLESCHERIA BOYDIII) SPECIES Diagnosis is made by culture recovery from the } Definition COMPLEX infected site. } Can cause disseminated infection in } Because L. prolificanss may colonize airways, Definition immunocompromised patients. sputum cultures may not reflect infection. } Infection of the lungs, bones and joints, or } Common cause of keratitis and other eye central nervous system (CNS); may be Therapy infections in contact lens wearers and disseminated. } No effective therapy. Consider voriconazole following trauma. } Also causes mycetoma (see Chapter 261). with amphotericin B. } Skin and soft tissue infection after trauma, onychomycosis; can cause mycetoma. Epidemiology DARK-WALLED FUNGI (BIPOLARIS, } Typically occurs in the immunocompromised or EXOPHIALA, EXSEROHILUM, Epidemiology following trauma. PHIALOPHORA, OCHROCONIS, } Common plant pathogens; found in soil and } CNS infection in immunocompetent persons CURVULARIA, OTHERS) organic debris. after near drowning. Have been recovered in hospital water supplies. Definition } } Organism can be found in soil and fresh water, } This infection involves fungi that have melanin Microbiology especially stagnant or polluted. in their cell walls and may appear dark walled } The most common species infecting humans Microbiology in tissue. belong to one of three species complexes: } Scedosporium apiospermum, Scedosporium } Infection is often termed Fusarium solani, Fusarium oxysporum, or boydiii (formerly Pseudallescheria boydiii), and “phaeohyphomycosis” and typically presents Fusarium fujikuroi, although the number of Scedosporium aurantiacumm are the most as localized skin and soft tissue infections, species identified as causing infection is common species infecting humans. CNS infections, or allergic sinusitis. increasing as molecular methods of } Identification is typically made by DNA } Dark-walled fungi that cause identification have supplanted morphology. sequencing. Formerly, identification was based chromoblastomycosis (see Chapter 260) and } Fusariumm produces banana- (or crescent)- on microscopic structures of organism in culture. mycetoma (see Chapter 261) are not included shaped multicellular macroconidia in culture. in the agents of phaeohyphomycosis. Diagnosis Diagnosis } Diagnosis is made by culture recovery from Epidemiology } Recovery of the fungus from culture of an infected site. } Infection is commonly acquired from minor otherwise sterile site. } Because S. apiospermumm complex species may trauma or inhalation. } One of the few molds that are commonly colonize airways, sputum cultures may not } Fungi are found in soil, organic material, recovered from blood culture. reflect infection. plants, and air. Therapy } They may be spread through contaminated Therapy } Optimum therapy is not known. products (e.g., injectable steroids). } Voriconazole is likely the most effective agent. } Recovery from neutropenia is essential in Microbiology response to therapy of disseminated infection. LOMENTOSPORA (SCEDOSPORIUM) The most common agents of Amphotericin B or voriconazole is suggested. PROLIFICANS } } phaeohyphomycosis are Alternaria, Bipolaris, TRICHOSPORONN SPP. Definition Cladophialophora, Curvularia, Exophiala, } Disseminated infection and bone and joint Exserohilum, Ochroconis, and Wangiella. Definition infections are most common. Most commonly presents as disseminated Diagnosis } } Lomentosporaa (formerly Scedosporiumm) infection. } Diagnosis is made by recovery of these prolificanss may cause onychomycosis and organisms in culture from the site of Epidemiology infections of the eye and wounds. infection. } Typically an infection of the Epidemiology } Cell walls may appear dark brown or golden immunocompromised; may be associated with } Disseminated infection commonly occurs in the on histopathology (hematoxylin and eosin). central venous catheter. severely immunocompromised. Use of a Fontana-Masson stain may allow } Fungi found colonizing the skin, } Localized infection occurs in easier identification of these fungi. gastrointestinal, respiratory, or genital tract. immunocompetent individuals after trauma. Found in soil and water. Therapy } } The organism can be found in soil and } Breakthrough infections in patients receiving } Surgical débridement of lesions or colonizing colonizing the respiratory tract, especially in echinocandins. fungi in the case of allergic fungal sinusitis. patients with cystic fibrosis. } Amphotericin B in life-threatening infections. Microbiology Microbiology } Voriconazole and itraconazole are typically } Most common pathogen is Trichosporon } Identification is made by culture. effective but prolonged therapy is needed. asahii. 3222 3223 SHORT VIEW SUMMARY—cont’d } Trichosporonn are identified by their unique Epidemiology Microbiology Cha ability to produce septate hyphae, } Limited to Southeast Asia. More common } Secondary to Emmonsiaa spp., usually p arthroconidia, and budding yeast. in rainy season, in young adult males with Emmonsia crescens. ter 268 } Appears yeastlike on initial culture. HIV infection, typically with low CD4 cell } Dimorphic fungi closely related to Blastomyces Diagnosis counts. dermatitidis. } By recovery of the organism from the blood or Microbiology Diagnosis Uncommon Fungi and Related Specie lesion biopsy. } Typical Penicillium-like structures on } Identification is limited to observation of Therapy microscopic examination of culture. typical structures on histopathology showing } Cultures produce red pigment that diffuses adiaspores, up to 500 μm in diameter, } Azole antifungal (voriconazole, itraconazole, into the agar. nondividing, and surrounded by granulomata isavuconazole, posaconazole, or fluconazole). composed of epithelioid and giant cells. Diagnosis MALASSEZIA FURFUR } Typically made from recovery of the organism Therapy Definition in blood. } Corticosteroids appear to be useful. } Catheter-related bloodstream infection. May also be recovered in culture of skin } EMERGOMYCES AFRICANUS } Also causes pityriasis versicolor (see Chapter lesions, lymph nodes, or bone marrow 266). aspirates. Definition } Serologic testing may be available in endemic } Disseminated infection most commonly Epidemiology s regions. afflicting HIV-infected persons. } Typically associated with parenteral lipid infusion. Therapy Epidemiology } Commonly reported in neonates. } Amphotericin B in life-threatening } Severely immunocompromised persons. Microbiology presentations. } Largest report from South Africa. } Itraconazole or voriconazole in initial therapy } May be difficult to grow from positive blood Microbiology (not life-threatening). cultures without lipid supplementation. } Thermally dimorphic fungus of soil. } Itraconazole secondary prophylaxis in Diagnosis HIV-infected patients. Diagnosis } Recovery of fungus from blood culture. Recovery of the dimorphic fungus from skin LACAZIA LOBOI } Therapy biopsy or blood culture. Definition } Catheter removal and discontinuation of Therapy } Chronic nodular or keloidal skin infection, parenteral lipids. } Responses to amphotericin B and triazole commonly of the ears or face. } Susceptible to most antifungals (voriconazole, antifungals have been reported. fluconazole, or amphotericin B). Epidemiology PROTOTHECAA SPP. } Limiting use of parenteral lipids. } Limited to Central and South America. Infection also found in dolphins. Definition OTHER UNCOMMON YEASTS } Localized skin or subcutaneous infection Microbiology } Definition caused by algal pathogen. } Has not been recovered in culture. } Other less common yeasts may also cause } Rare reports of disseminated or deep infection. Identified as closely related to Paracoccidioides catheter-related bloodstream infection. } brasiliensiss by molecular techniques. Epidemiology Epidemiology Likely cause infection after traumatic Diagnosis } } Typically associated with use of central venous inoculation. } Based on clinical presentation and finding catheters and immunocompromise. } Organisms colonize skin, gastrointestinal and typical structures on histopathology. respiratory tracts. Microbiology } Globose (yeast) cells end-to-end in short } Include Magnusiomyces capitatuss (formerly “strings.” Microbiology called Saprochaete capitataa and Disease is typically due to Prototheca Therapy } Blastoschizomyces capitatuss), Pichia anomala, wickerhamiii or Prototheca zopfii. } Surgical removal. Rhodotorulaa spp., and Saccharomyces cerevisiae. } Unicellular algae lack chlorophyll. AGENTS OF ADIASPIROMYCOSIS Protothecaa spp. grow on fungal culture media Diagnosis } (EMMONSIAA SPP.) with yeastlike colonial morphology. } Made by recovery of the yeast in blood culture. Microscopic appearance in tissue is diagnostic. Definition } Therapy } Disease secondary to host immune response to Diagnosis } Removal of central venous catheter. nonreplicating fungal conidia, termed } Recovery of algae in culture is diagnostic. } Antifungals based on recovered yeast. “adiaspores.” } Yeast biochemical panels commonly identify TALAROMYCES (PENICILLIUM) MARNEFFEI } Chiefly a pulmonary disease; may range from Prototheca. asymptomatic to rapidly progressing Definition Therapy respiratory failure and occasionally death. } Acute disseminated infection of persons } Surgical excision with amphotericin B or } May also present as ocular nodules. infected with human immunodeficiency virus itraconazole. (HIV) in Southeast Asia. Epidemiology PYTHIUMM SPP. } Infection