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Penicillium marneffei
By: Jenee Thurston, Adam Speerstra, and Kelly Bees Alternative Name: Penicilliosis
Taxonomy
Kingdom: Fungi
Phylum: Ascomycota
Class: Euascomycetes
Order: Eurotiales
Family: Trichocomaceae
Genus: Penicillium
Species: P. marneffei
Geographic Distribution
3 BIOL 4849: Medical Mycology August 7, 2011 Widespread Specifically in Southeast Asia o Burma (Myanmar), Cambodia, Southern China, Indonesia, Laos, Malaysia, Thailand and Vietnam Cases were reported in HIV-positive patients in Australia, Europe, Japan, the UK and the U.S.. All, except one traveled to Southeast Asia. http://www.crownrms.com/rms/ office.southeast.asia.html^ Courtesy of:
Epidemiology
Affects HIV-infected & immunosuppressed patients Discovered in bamboo rats (Rhizomys & Cannomys ) Epidemiological markers and reservoirs for human infections High mortality and morbidity rates 10% of HIV patients in Hong Kong affected Soil exposure, especially during the rainy season, is a critical risk factor. Third most common opportunistic infection (after extrapulmonary tuberculosis and cryptococcosis) in HIV- positive individuals 4 BIOL 4849: Medical Mycology 8/7/ http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Rhizomyinae.html^ Courtesy of:
Life Cycle
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Thermally dimorphic
Divided into three distinct phases:
- A multicellular, filamentous (mold) vegetative form
- Asexual reproductive stage (conidiogenesis)
- A unicellular yeast- like/arthroconidial phenotype
Temperature and nutrition are key
factors to determine which
specific phase is displayed
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Young colonies are grown
on Sabouraud glucose agar
Rapid growing, flat, filamentous, and velvety, woolly, or cottony in texture Usually appear bluish gray- green Mature colony is reddish yellow, producing a pink or red-rose pigment that diffuses into the surrounding medium Courtesy of :http://cmr.asm.org/cgi/content/full/19/1/ Morphologies of P marneffei under a microscope
Pathogenesis
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Pathogen found in bamboo rat
feces, liver, lungs and spleen
Higher incidence during rainy
season
Favorable for production of fungal spores (conidia)
Airborne spores inhaled by
susceptible individuals
Unclear whether people get
the disease by eating infected
rats, or by inhaling fungi from
their feces
Courtesy of: http://medicine.med.nyu.edu/pulmonary/node/
Diagnosis and Histopathology
Biopsy of skin lesions, lymph nodes or bone marrow
The organism can also be identified on peripheral blood
smear or bone marrow aspirate
Fungi shown:
Spherical or oval in shape Basophilic intracellular or extracellular yeastlike appearance on Wright stain, often with clear central septation
Histopathologic features include granulomatous,
suppurative, or necrotizing inflammation
Polymerase chain reaction (PCR) assay is under
evaluation for rapid diagnosis of P marneffei infection
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Clinical Manifestations
9 BIOL 4849: Medical Mycology August 7, 2011 Fever 99% Anemia 78% Weight loss 76% Skin lesions 71% Lymphadenopathy 58% Hepatomegaly 51% Pulmonary disease/symptom 49% Diarrhea 31% Splenomegaly 16% Oral lesions 4%
Clinical Manifestations
Duration of symptoms before presentation is 4 weeks. Other common manifestations: Skin lesions, anemia, lymphadenopathy, and hepatomegaly with or without splenomegaly. Skin lesions are present in two thirds of cases Include papular eruptions, central umbilicated papules, acnelike lesions and folliculitis. Found on the face, trunk, and extremities. Pharyngeal and palatal lesions Subcutaneous nodules Pulmonary symptoms (cough and dyspnea) occur in about 50% of cases. 10 BIOL 4849: Medical Mycology 8/7/ http://cid.oxfordjournals.org/content/32/4/e78/F2.expansion.html^ Courtesy of:
Treatment & Prevention
11 BIOL 4849: Medical Mycology August 7, 2011 Mortality is at a 20% rate with treatment Amphotericin B with or without flucytosine, or itraconazole Ketoconazole & miconazole Newer azoles (posaconazole, ravuconazole, and voriconazole) Clinical failure rates: Fluconazole (63.8%) Amphotericin B (22.8%) Itraconazole (25%) Primary prophylaxis with itraconazole 200 mg daily can prevent the occurrence of penicilliosis among patients with AIDS
Case 1.
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Patient:
Located in India
27 - year-old male
Recently developed multiple nodules on his face
Other Symptoms:
Fever, weight loss, anorexia, and general weakness.
General examination revealed multiple molluscum
contagiosum-like papules of various sizes with
central umbilications mainly on his face, trunk, and
upper and lower limbs
