Penicillium marneffei: Difference between revisions

From MicrobeWiki, the student-edited microbiology resource
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Describe the appearance, habitat, etc. of the organism, and why it is important enough to have its genome sequenced.  Describe how and where it was isolated.
Describe the appearance, habitat, etc. of the organism, and why it is important enough to have its genome sequenced.  Describe how and where it was isolated.
Include a picture or two (with sources) if you can find them.
Include a picture or two (with sources) if you can find them.
Penicillium marneffei is a unicellular organism with round to oval celled fungus, 4 to 8 m in diameter [1, 4].  These cells can actually divide by cross wall formation within macrophages, or form extracellular elongated cells.  The special feature of Penicillium marneffei compared to other penicillia is its thermal dimorphism.  This capability to grow as a mycelium at 25C and as a yeast at 37C is the organism’s main virulence factor. [1] 
The history and mode of transmission of the organism remains unclear.  The natural habitat of the fungus and its exact route of transmission have not been described [9].  Soil exposure, often during the rainy season, has been suggested to be a serious risk factor.  Also, many isolates from bamboo rats and humans were shown to share identical multi-locus genotypes.  These data show that either transmission of P. marneffei can occur from rodents to humans or rodents and humans are coinfected from common environmental sources.  The main route of infection is thought to be through inhalation of conidia into the lungs, where it can then disseminate via a hematogenous route to other body locations, especially the liver. [1]
Penicillium marneffei is a rising pathogenic fungus that can cause a fatal systemic mycosis in patients infected with human immunodeficiency virus (HIV).  P. marneffei infection is endemic in tropical Asia, especially Thailand, northeastern India, China, Hong Kong, Vietnam, and Taiwan.  It was first isolated from the hepatic lesions of a bamboo rat (Rhizomys sinensis) that had been maintained in captivity for experimental infections at the Pasteur Institute of Indochina, Dalat, South Vietnam, in 1956.  The fungus was named Penicillium marneffei, in honor of Hubert Merneffe, who was the director of the Pasteur Institute of Indochina [1].  After discovery of the infection in wild rodents, two cases of human infections were reported.  The first case was laboratory acquired.  The second, the first known natural human infection, was reported in 1973 [10].  The mortality rate of patients with P. marneffei infection has been extremely high. [1]


==Genome structure==
==Genome structure==

Revision as of 03:47, 28 August 2007

A Microbial Biorealm page on the genus Penicillium marneffei

Classification

Higher order taxa

Domain: Fungi

Phylum: Ascomycota

Class: Eurotiomycetes

Order: Eurotiales

family: Trichocomaceae

genus: Penicillium

species: marneffei

Species

NCBI: Taxonomy

Penicillium marneffei

Description and significance

Describe the appearance, habitat, etc. of the organism, and why it is important enough to have its genome sequenced. Describe how and where it was isolated. Include a picture or two (with sources) if you can find them.

Penicillium marneffei is a unicellular organism with round to oval celled fungus, 4 to 8 m in diameter [1, 4]. These cells can actually divide by cross wall formation within macrophages, or form extracellular elongated cells. The special feature of Penicillium marneffei compared to other penicillia is its thermal dimorphism. This capability to grow as a mycelium at 25C and as a yeast at 37C is the organism’s main virulence factor. [1] The history and mode of transmission of the organism remains unclear. The natural habitat of the fungus and its exact route of transmission have not been described [9]. Soil exposure, often during the rainy season, has been suggested to be a serious risk factor. Also, many isolates from bamboo rats and humans were shown to share identical multi-locus genotypes. These data show that either transmission of P. marneffei can occur from rodents to humans or rodents and humans are coinfected from common environmental sources. The main route of infection is thought to be through inhalation of conidia into the lungs, where it can then disseminate via a hematogenous route to other body locations, especially the liver. [1] Penicillium marneffei is a rising pathogenic fungus that can cause a fatal systemic mycosis in patients infected with human immunodeficiency virus (HIV). P. marneffei infection is endemic in tropical Asia, especially Thailand, northeastern India, China, Hong Kong, Vietnam, and Taiwan. It was first isolated from the hepatic lesions of a bamboo rat (Rhizomys sinensis) that had been maintained in captivity for experimental infections at the Pasteur Institute of Indochina, Dalat, South Vietnam, in 1956. The fungus was named Penicillium marneffei, in honor of Hubert Merneffe, who was the director of the Pasteur Institute of Indochina [1]. After discovery of the infection in wild rodents, two cases of human infections were reported. The first case was laboratory acquired. The second, the first known natural human infection, was reported in 1973 [10]. The mortality rate of patients with P. marneffei infection has been extremely high. [1]

Genome structure

Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? Does it have any plasmids? Are they important to the organism's lifestyle?

Cell structure and metabolism

Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.

Ecology

Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.

Pathology

How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

Application to Biotechnology

Does this organism produce any useful compounds or enzymes? What are they and how are they used?

Current Research

Enter summaries of the most recent research here--at least three required

References

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.

Edited by student of Rachel Larsen