PowerPoint Presentation - Slide 1, Lecture notes of Mycology

Download PowerPoint Presentation - Slide 1 and more Lecture notes Mycology in PDF only on Docsity! 8/7/2011 1 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 August 7, 2011 BIOL 4849: Medical Mycology 3  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. Courtesy of: http://www.crownrms.com/rms/ office.southeast.asia.html 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 8/7/2011 BIOL 4849: Medical Mycology 4 Courtesy of: http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Rhizomyinae.html Life Cycle 8/7/2011 BIOL 4849: Medical Mycology 5  Thermally dimorphic  Divided into three distinct phases: 1. A multicellular, filamentous (mold) vegetative form 2. Asexual reproductive stage (conidiogenesis) 3. A unicellular yeast- like/arthroconidial phenotype  Temperature and nutrition are key factors to determine which specific phase is displayed 8/7/2011 BIOL 4849: Medical Mycology 6  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/19/1/95 Morphologies of P marneffei under a microscope 8/7/2011 2 Pathogenesis 8/7/2011 BIOL 4849: Medical Mycology 7  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/673 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 8/7/2011 BIOL 4849: Medical Mycology 8 Clinical Manifestations August 7, 2011 BIOL 4849: Medical Mycology 9  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. 8/7/2011 BIOL 4849: Medical Mycology 10 Courtesy of: http://cid.oxfordjournals.org/content/32/4/e78/F2.expansion.html Treatment & Prevention August 7, 2011 BIOL 4849: Medical Mycology 11  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. August 7, 2011 BIOL 4849: Medical Mycology 12  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