Curvularia inaequalis | |
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Scientific classification
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Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Dothideomycetes |
Order: | Pleosporales |
Family: | Pleosporaceae |
Genus: | Curvularia |
Species: | C. inaequalis
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Binomial name | |
Curvularia inaequalis (Shear) Boedijn (1907)
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Synonyms | |
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Curvularia inaequalis is a plant saprobe [1] that resides in temperate and subtropical environments. [2] It is commonly found in the soils of forage grasses and grains. [3] The species has been observed in a broad distribution of countries including Turkey, France, Canada, The United States, Japan and India. [4] This species is dematiaceous and a hyphomycete. [5]
The Curvularia genus can be identified by its spiral borne phaeophragmospores, which contain both hyaline end cells and disproportionately large cells. [6] They possess conidia with differing curvature and number of septa. [6] C. inaequalis was first described in 1907 by ecologist Cornelius Lott Shear. [7] The fungus was isolated from diseased New Jersey cranberry pulp [7] and termed Helminthosporium inaequale. [6] Later, during Karl Boedijin's taxonomic organization and grouping of this genus, he recognized a similarity between them and H. inaequale. [6] He recognized a morphological similarity between its conidia and those of the lunata group within Curvularia, and so renamed it C. inaequalis. [6] Recognition of the three- septate curved conidia motivated the introduction of the now popularized name. [6]
The species' spore producing cells take on a model of sympodial growth. [6] Conidia grow through successive apices which end in a terminal prospore. [6] Growth can be affected by static magnetic fields with field flux densities. [8] Under these conditions, the number of conidia are able to increase by a minimum of 68 percent. [8]
Curvularia inaequalis is a filamentous fungus, with 3 to 12 densely packed filaments. [7] The species is mostly brown in appearance, with pale brown end cells. [2] [7] Conidia themselves, consist of 3-5 cells with thick cell walls and a larger central cell. [7] [2] The diameter of the conidia ranges from 10 to 30 micrometers and have a slight leading curvature. [9] [10] Overall the appearance of the species is described as looking "cottony" with clear branching cells. [2] [7]
The species can be difficult to identify due to its similar appearance to both C. and geniculate. [2] Instead, sequencing of nuclear rRNA internal transcribed spacer regions (ITS) can be done to achieve accurate identification. [2]
The optimal growth temperature for the species is 30°C. [7] It is able to produce a multitude of chemical products with enzymatic properties. One enzyme produced is chloroperoxidase, which can catalyze halogenation reactions. [11] Chloroperoxidase secreted from C. inaequalis contains vanadium active site. [5] The presence of the vanadium substrate vanadate is essential for the function of chloroperoxidase. [12] The compound glucose however, acts as an inhibitor for both enzyme function and production. [13] In its active form, the enzyme is able to then produce hypochlorous acid, a strong oxidizing agent. [5] It has been theorized that C. inaequalis utilizes chloroperoxidase and hypochlorous acid in combination to penetrate the host's cell wall. [5]
Other significant compounds produced include of B-galactosidase, 4-hydroxyradianthin and Curvularone A. The species is able to produce large amounts of β-galactosidase, which can hydrolyze lactose in acid whey. [9] C. inaequalis also contains 4-hydroxyradianthin and Curvularone A compounds which have been identified as potential anti-tumor agents. [14]
Curvularia inaequalis is known to cause leaf spot, also known as Leaf Blight. [10] [15] Symptoms of infection by C. inaequalis include the combination of oval shaped dark brown patches and leaf tip dieback. [10] The infection slowly spreads causes necrosis until it has covered the entirety of the leaf. [10] It results in the thinning of grass vegetation such as Zoysia-, Bent-, Bermuda- and Buffalo- grasses. [10] [15] Blighting is believed to be caused by two C. inaequalis mycotoxins, Pyrenocines A and B. [15] Pyrenocines A is the more potent of the two, stunting growth and causing necrosis in vegetation. [15] Both cause leaf tip die back in turf grass and leaf leakage of electrolytes in Bermuda grass. [15]
Curvularia inaequalis is typically a rare human pathogen. [2] There are however, recorded medical cases that mention infection by the species. One such case is of an Eosinophilic fungal rhinosinusitis in an immunocompromised male. [16] Endoscopic sinus surgery was required to remove a large polyposis. [16] C. inaequalis was found to have grown favorably in the eosinophilic mucus. [16] Oral itraconazole and other corticosteroids successfully were administered to prevent reinfection. [16] Another case of C. inaequalis causing disease includes peritonitis in an elderly patient. [2]
It is suggested that contraction of the fungus occurs due to contact with soils. [2] Furthermore, a case of recorded aerosolized C. inaequalis in one Canadian home supports airborne movement of spores as an important mode of transfer. [2] While many cases of infection due to soil contact with the genus Curvularia, connection with the specific species has not yet been confirmed. [2] Further studies are required to determine its human pathogen potential.
Curvularia inaequalis | |
---|---|
Scientific classification
![]() | |
Domain: | Eukaryota |
Kingdom: | Fungi |
Division: | Ascomycota |
Class: | Dothideomycetes |
Order: | Pleosporales |
Family: | Pleosporaceae |
Genus: | Curvularia |
Species: | C. inaequalis
|
Binomial name | |
Curvularia inaequalis (Shear) Boedijn (1907)
| |
Synonyms | |
|
Curvularia inaequalis is a plant saprobe [1] that resides in temperate and subtropical environments. [2] It is commonly found in the soils of forage grasses and grains. [3] The species has been observed in a broad distribution of countries including Turkey, France, Canada, The United States, Japan and India. [4] This species is dematiaceous and a hyphomycete. [5]
The Curvularia genus can be identified by its spiral borne phaeophragmospores, which contain both hyaline end cells and disproportionately large cells. [6] They possess conidia with differing curvature and number of septa. [6] C. inaequalis was first described in 1907 by ecologist Cornelius Lott Shear. [7] The fungus was isolated from diseased New Jersey cranberry pulp [7] and termed Helminthosporium inaequale. [6] Later, during Karl Boedijin's taxonomic organization and grouping of this genus, he recognized a similarity between them and H. inaequale. [6] He recognized a morphological similarity between its conidia and those of the lunata group within Curvularia, and so renamed it C. inaequalis. [6] Recognition of the three- septate curved conidia motivated the introduction of the now popularized name. [6]
The species' spore producing cells take on a model of sympodial growth. [6] Conidia grow through successive apices which end in a terminal prospore. [6] Growth can be affected by static magnetic fields with field flux densities. [8] Under these conditions, the number of conidia are able to increase by a minimum of 68 percent. [8]
Curvularia inaequalis is a filamentous fungus, with 3 to 12 densely packed filaments. [7] The species is mostly brown in appearance, with pale brown end cells. [2] [7] Conidia themselves, consist of 3-5 cells with thick cell walls and a larger central cell. [7] [2] The diameter of the conidia ranges from 10 to 30 micrometers and have a slight leading curvature. [9] [10] Overall the appearance of the species is described as looking "cottony" with clear branching cells. [2] [7]
The species can be difficult to identify due to its similar appearance to both C. and geniculate. [2] Instead, sequencing of nuclear rRNA internal transcribed spacer regions (ITS) can be done to achieve accurate identification. [2]
The optimal growth temperature for the species is 30°C. [7] It is able to produce a multitude of chemical products with enzymatic properties. One enzyme produced is chloroperoxidase, which can catalyze halogenation reactions. [11] Chloroperoxidase secreted from C. inaequalis contains vanadium active site. [5] The presence of the vanadium substrate vanadate is essential for the function of chloroperoxidase. [12] The compound glucose however, acts as an inhibitor for both enzyme function and production. [13] In its active form, the enzyme is able to then produce hypochlorous acid, a strong oxidizing agent. [5] It has been theorized that C. inaequalis utilizes chloroperoxidase and hypochlorous acid in combination to penetrate the host's cell wall. [5]
Other significant compounds produced include of B-galactosidase, 4-hydroxyradianthin and Curvularone A. The species is able to produce large amounts of β-galactosidase, which can hydrolyze lactose in acid whey. [9] C. inaequalis also contains 4-hydroxyradianthin and Curvularone A compounds which have been identified as potential anti-tumor agents. [14]
Curvularia inaequalis is known to cause leaf spot, also known as Leaf Blight. [10] [15] Symptoms of infection by C. inaequalis include the combination of oval shaped dark brown patches and leaf tip dieback. [10] The infection slowly spreads causes necrosis until it has covered the entirety of the leaf. [10] It results in the thinning of grass vegetation such as Zoysia-, Bent-, Bermuda- and Buffalo- grasses. [10] [15] Blighting is believed to be caused by two C. inaequalis mycotoxins, Pyrenocines A and B. [15] Pyrenocines A is the more potent of the two, stunting growth and causing necrosis in vegetation. [15] Both cause leaf tip die back in turf grass and leaf leakage of electrolytes in Bermuda grass. [15]
Curvularia inaequalis is typically a rare human pathogen. [2] There are however, recorded medical cases that mention infection by the species. One such case is of an Eosinophilic fungal rhinosinusitis in an immunocompromised male. [16] Endoscopic sinus surgery was required to remove a large polyposis. [16] C. inaequalis was found to have grown favorably in the eosinophilic mucus. [16] Oral itraconazole and other corticosteroids successfully were administered to prevent reinfection. [16] Another case of C. inaequalis causing disease includes peritonitis in an elderly patient. [2]
It is suggested that contraction of the fungus occurs due to contact with soils. [2] Furthermore, a case of recorded aerosolized C. inaequalis in one Canadian home supports airborne movement of spores as an important mode of transfer. [2] While many cases of infection due to soil contact with the genus Curvularia, connection with the specific species has not yet been confirmed. [2] Further studies are required to determine its human pathogen potential.