Fascinoma Rounds
Penicillium marneffei
October 26th, 2005
Sharmistha Mishra,
Vanessa Allen,
And with great thanks to Subash Mohan
Case #1: Penicillium marneffei
• What are the clinical risk factors for acquiring
disseminated penicillium marneffei?
• What are the laboratory features of this organism
(courtesy of Subash Mohan)?
• What precautions should be taken in the
laboratory environment?
Clinical Case
• 32 M originally from Vietnam, no known PMH
• Moved to Canada 16 years ago
• Travel to Vietnam every year,
– last trip in January/ February 2005
• Illness since March/April 2005
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Cough, SOB and 18 lb weight loss
went to family MD and to a local hospital treated for CAP with azithromycin
V/Q scan negative
CT scan consistent with CAP
• Also had two month history of non-pruritic papular rash on face
which he attributed to lobster allergy
Case continued
• Sept 22nd
– Presented with SOB, fever, and bilateral chest infiltrates
– Started on Ceftraixone and azithromycin for CAP
• Laboratory values
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Hgb 95 (MCV 75), Leuk 4.4 (0.3 lymphs), platelets 233
Electrolyes and creatinine normal
AST 113, ALT 109, ALP 100, bili 5
LDH 514
Case #3
• Bronchoscopy Sept 23rd
– Positive for H. influenza
– PCP
– And ….Penicillium marneffei
– Blood cultures from Sept 22nd became positive for
Penicillium marneffei
– Subsequent HIV+ , CD4 32
Discovery
• 1956  bamboo rats in Vietnam
• First human case = accidental innoculation in the
lab (1959) from a needle
• Then 1973  in pt with Hodgkin’s disease
• 1985 – pt with HIV in tropical medicine course
 suspicion of inhalation of spores!
• 1988 onwards  rising # of cases in HIV+ pts
from endemic areas
Epidemiology
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Bamboo rat & association unclear
Soil exposure felt to be a risk factor
Inhalation, ingestion, skin puncture - postulated
Geographical distribution
– Thailand, Myanmar (Burma), Vietnam, Cambodia, Malaysia, northeastern
India, Hong Kong, Taiwan, and southern China
– Imported disease from patients from these endemic regions
Clinical Risk Factors
• More commonly seen in immunocompromised (also
occurs in immunocompetent individuals)
– 29 cases diagnosed 1959-1988 prior to HIV
– Now  80% have HIV
• CD4 < 70 cells/mm3
– Among HIV + pts in N. Thailand
• 1. TB
• 2. Cryptococcal meningitis
• 3. Penicillium marneffei
– Other risk factors are lymphoproliferative disorders,
bronchiectasis and tuberculosis, autoimmune diseases
and corticosteroid therapy
Supparatpinyo K, et al.. Lancet. 1994;344:110-113.
Clinical Features
• Localized disease
• Disseminated disease
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Fever (99%)
Anemia (78%),
Pronounced weight loss (76%)
Generalized lymphadenopathy (58%)
Hepatomegaly (51%).
Skin lesions, most commonly papules with central
necrotic umbilication (71%)
– Pneumonia (CXR abnormalities)
Penicillium marneffei
Penicillium marneffei is a dimorphic fungus of RES
Grows as mycelium at RT and yeast at 370C
Usually attacks immunocompromised hosts
P. marneffei can also attack immunocompetent hosts
Reservoir – bamboo rat in south east Asia
Laboratory safety precautions similar to Coccidioides
Direct microscopy frequent confusion with Histoplasma
Penicillium marneffei
Direct Microscopy
Specimen: BAL
(E1232193)
Stain: Fungi-Fluor x400
Structure:
• small, round, oval cells
• non-budding cells
Compare with yeast.
Rule out histoplasma.
Differentiation difficult.
Penicillium marneffei
Direct Microscopy
Specimen: BAL
(E1232193)
Stain: Gram stain x1000
Structure:
• few oval cells
• non-budding
• mimic yeast
Observe septum
Penicillium marneffei
Direct Microscopy
Specimen: BAL
(E1232193)
Stain: KOH x400
Structure:
• cluster of cells
• poorly differentiated
• appear non-budding
Rule out yeast
Interpretation difficult
Penicillium marneffei
Direct Microscopy
Specimen: Blood
Stain: Gram stain x1000
(E1221874)
Structure:
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septate hyphae
right angle branching
fragmenting
Arthroconidia
Appear converted
Observe branched pattern
Not dichotomous
Penicillium marneffei
Direct Microscopy
Specimen: Sputum
Stain: GMS x1000
(E1222049)
Structure:
• cluster of small, round, oval
cells
• non-budding
• bisected cells
Septum rules out yeast
Suspect P. marneffei
A second type yeast not P. marneffei
Penicillium marneffei
Direct Microscopy
Specimen: Sputum
Stain: GMS x1000
(E1222049)
Structure:
• bisected cells
• no budding seen
• no septate hyphae
• no pseudohyphae
Go ahead and call it
P. marneffei
non-budding bisected cells
Penicillium marneffei
Macroscopic Morphology
Medium: IMA
Morphology:
• rapid growth
• mycelial phase
• red pigment
• suspect P. marneffei
Not all red pigment
producing Penicillium species
are Penicillium marneffei
Penicillium marneffei
Microscopic morphology
Stain: Lactophenol x400
Structures:
• phialides
• metulae
• bi- or univerticiallate
• brush type
• ID: Penicillium sp.
Compare with Paecilomyces
Penicillium marneffei
Conversion to Yeast Phase
Medium: Blood agar
Incubation: 370C
• glabrous & matted
• no mycelium
• yeasty consistency
• pigmentation lost
Conversion phase at higher
temperature is essential for
confirmation
DNA probe not available
Penicillium marneffei
Confirming conversion
Wet Preparation: BA 370C
Magnification: x1000
Structures:
• arthroconidia
• multiplies by fission
• bisected cells
Compare with yeast and
pseudohyphae
Treatment
• Sensitive to Itraconazole, Ketoconazole and
Ampho B
• Failure rates in a study of 86 HIV-infected patients
were as follows: amphotericin B , 8 of 35 patients
(22.8%); itraconazole , 3 of 12 (25%); and
fluconazole , 7 of 11 (63.6%)
• Current recommendation
– Amphotericin B, 0.6 mg/kg/day for 2 weeks, followed
by itraconazole, 400 mg/day orally in two divided doses
for the next 10 weeks
– 97.3% effective in 74 HIV + individuals
Sirisanthana T, Clin Infect Dis. 1998;26:1107-1110.
Lab Safety and Penicillium marneffei
• No formal guidelines
• Inhalation and direct inoculation are possible
mechanisms of transmission in lab.