| Harposporium anguillulae | |
|---|---|
 | |
| Scientific classification | |
| Kingdom: | |
| Division: | |
| Subdivision: | |
| Class: | |
| Order: | |
| Family: | |
| Genus: | |
| Species: | H. anguillulae |
| Binomial name | |
| Harposporium anguillulae Lohde emend. Zopf, (1888) | |
Harposporium anguillulae is a member of the genus Harposporium. [1] It is an endoparasitic nematophagous fungus that attacks nematodes and eelworms [2] and is isolated commonly from field and agricultural soils as well as used as an experimental organism in the laboratory. [3] [4]
Harposporium anguillulae was described in the late 1800s as a parasite of nematodes. [1] [2] It has since been commonly reported in the literature. [5] This fungus also traps eelworms. [1] Harposporium anguillulae is one of 26 species in the genus Harposporium in the division Ascomycota. [3] [5] It is a pathogen of eelworms and nematodes, [5] notable for its distinct sickle-shaped conidia that grow in pierce out through the host body. [6] This genus Harposporium was treated initially in the Clavicipitaceae [7] and is thought to be closely related to members of the genus, Tolypocladium . [5] Both genera occur on nematodes and eelworms but rarely insects. [7] [8] The two genera can be differentiated morphologically, as members of the genus Tolypocladium produce more complex conidiophores with narrower conidiogenous cells. [5]
The invasive apparatus of this species consists of non-adhesive, crescent-shaped conidia that are ingested by hosts and lodge in the esophagus or gut. [2] [3] The sickle shape of the conidia is also contributes to the ability of the fungus to pierce through the host cuticle. [1] [2] In the laboratory, cultures of the fungus can be cultivated on agar containing yeast hydrolysate or glucose, though growth is much slower on glucose. [1] [2] The fungus grows rapidly on water-agar and produces chlamydospores, implying an oligotrophic physiology. [2]
Nematophagous fungi occur in a variety of habitats including leaves entering the decomposition phase, soil samples that contain decomposed leaves or in soil samples from agricultural land and they can also be found in pasture land. [4] The latter possibly relates to the tendency of this species to occur in dung of cow [4] and sheep [2] where its nematode hosts are abundant. [4] The fungus is commonly found in tropical [4] and warm climates. [2] It is more commonly encountered in the spring and fall. [9] The fungus has been isolated from include Brazil, [2] China, [4] Florida, [10] New Zealand, [8] and eastern Canada. [11] The fungus tends to be more commonly reported from climate regions subject to monsoons and does not appear to survive cold weather well, [4] though the predilection of this species for warm damp climates may relate more to the distributions of its hosts. [2] [6]
The fungus is known primarily as a parasite of nematodes and eelworms. [1] During its life cycle, conidia of the fungus are ingested by eelworms or nematodes and lodge in the pharnyx or gut. [1] Once inside the host, the conidia germinate and begin to colonize the host digestive tract. [1] [2] [3] During the initial phases of this process, the host remains alive, [1] but as the fungus spreads from the gut to the surrounding tissues in the latter stages of infection and the death of the host soon follows. [1] Conidial production occurs on nematode cadavers by the eruption of conidiophores and conidia through the host cuticle. [1] [2] [6]
This fungus has been investigated as a biocontrol agent of agriculturally important nematodes, most notably those responsible for gastrointestinal infection of grazing animals. [4] These parasitic infections are commonly treated with anthelmintic agents including benimidazole, levamisole and invermectin. [4] However, increasing levels of anthelmintic resistance have been observed, driving the search for new treatment and prevention options. [4] Larvae of animal-pathogenic nematodes are found in soil. [4] The prospect of treating contaminated soils with nematode pathogenic fungi such as H. anguillulae has shown potential to reduce nematode populations. [9] However, the fungus does not persist in soil following the elimination of nematode populations, potentially limiting its use as a sustainable biocontrol agent. [2]
An entomopathogenic fungus is a fungus that can kill or seriously disable insects.
Tolypocladium inflatum is an ascomycete fungus originally isolated from a Norwegian soil sample that, under certain conditions, produces the immunosuppressant drug ciclosporin. In its sexual stage (teleomorph) it is a parasite on scarab beetles. It forms a small, compound ascocarp that arises from the cadaver of its host beetle. In its asexual stage (anamorph) it is a white mold that grows on soil. It is much more commonly found in its asexual stage and this is the stage that was originally given the name Tolypocladium inflatum.
Trichoderma is a genus of fungi in the family Hypocreaceae that is present in all soils, where they are the most prevalent culturable fungi. Many species in this genus can be characterized as opportunistic avirulent plant symbionts. This refers to the ability of several Trichoderma species to form mutualistic endophytic relationships with several plant species. The genomes of several Trichoderma specieshave been sequenced and are publicly available from the JGI.
Hyphomycetes are a form classification of fungi, part of what has often been referred to as fungi imperfecti, Deuteromycota, or anamorphic fungi. Hyphomycetes lack closed fruit bodies, and are often referred to as moulds. Most hyphomycetes are now assigned to the Ascomycota, on the basis of genetic connections made by life-cycle studies or by phylogenetic analysis of DNA sequences; many remain unassigned phylogenetically.
Cochliobolus lunatus is a fungal plant pathogen that can cause disease in humans and other animals. The anamorph of this fungus is known as Curvularia lunata, while C. lunatus denotes the teleomorph or sexual stage. They are, however, the same biological entity. C. lunatus is the most commonly reported species in clinical cases of reported Cochliobolus infection.
Setosphaeria rostrata is a heat tolerant fungus with an asexual reproductive form (anamorph) known as Exserohilum rostratum. This fungus is a common plant pathogen, causing leaf spots as well as crown rot and root rot in grasses. It is also found in soils and on textiles in subtropical and tropical regions. Exserohilum rostratum is one of the 35 Exserohilum species implicated uncommonly as opportunistic pathogens of humans where it is an etiologic agent of sinusitis, keratitis, skin lesions and an often fatal meningoencephalitis. Infections caused by this species are most often seen in regions with hot climates like Israel, India and the southern USA.
Acrophialophora fusispora is a poorly studied ascomycete fungus found in soil, air and various plants. A. fusispora is morphologically similar to the genera Paecilomyces and Masonia, but differ in the presence of pigmented conidiophores, verticillate phialides, and frequent sympodial proliferation. Moreover, A. fusispora is distinguished by its pigmented spindle-shaped conidia, covered with spiral bands. The fungus is naturally found in soils of tropical to temperate regions. The fungus has been identified as a plant and animal pathogen, and has recently been recognized as an emerging opportunistic human pathogen. A. fusispora infection in human is rare and has few documented clinical cases, but due to the rarity of the fungus and potential misidentification, the infections may be underdiagnosed. Clinical cases of A. fusispora include cases of keratitis, pulmonary colonization and infection, and cerebral infections. The fungus also has two documented cases of infection in dogs.
Nematophagous fungi are carnivorous fungi specialized in trapping and digesting nematodes. Around 160 species are known. Species exist that live inside the nematodes from the beginning and others that catch them, mostly with glue traps or in rings, some of which constrict on contact. Some species possess both types of traps. Another technique is to stun the nematodes using toxins, a method employed by Coprinus comatus, Stropharia rugosoannulata, and the family Pleurotaceae. The habit of feeding on nematodes has arisen many times among fungi, as is demonstrated by the fact that nematophagous species are found in all major fungal groups. Nematophagous fungi can be useful in controlling those nematodes that eat crops. Purpureocillium, for example, can be used as a bio-nematicide.
The Orbiliaceae are a family of saprobic sac fungi in the order Orbiliales. The family, first described by John Axel Nannfeldt in 1932, contains 288 species in 12 genera. Members of this family have a widespread distribution, but are more prevalent in temperate regions. Some species in the Orbiliaceae are carnivorous fungi, and have evolved a number of specialized mechanisms to trap nematodes.
Mycetophagites is an extinct fungal genus of mycoparasitic in the order Hypocreales. A monotypic genus, it contains the single species Mycetophagites atrebora.
Purpureocillium lilacinum is a species of filamentous fungus in the family Ophiocordycipitaceae. It has been isolated from a wide range of habitats, including cultivated and uncultivated soils, forests, grassland, deserts, estuarine sediments and sewage sludge, and insects. It has also been found in nematode eggs, and occasionally from females of root-knot and cyst nematodes. In addition, it has frequently been detected in the rhizosphere of many crops. The species can grow at a wide range of temperatures – from 8 to 38 °C for a few isolates, with optimal growth in the range 26 to 30 °C. It also has a wide pH tolerance and can grow on a variety of substrates. P. lilacinum has shown promising results for use as a biocontrol agent to control the growth of destructive root-knot nematodes.
Charles Drechsler was an American mycologist with 45 years of research with the United States Department of Agriculture. He spent considerable time working with cereal fungal diseases, and the genus Drechslera was named after him. Drechsler also worked extensively on oomycete fungi and their interactions with vegetable plants. Drechsler was recognized as a leading authority on helminthosporia, oomycetes, and other parasitic fungi.
Geomyces pannorum is a yellow-brown filamentous fungus of the phylum Ascomycota commonly found in cold soil environments including the permafrost of the Northern hemisphere. A ubiquitous soil fungus, it is the most common species of the genus Geomyces; which also includes G. vinaceus and G. asperulatus. Geomyces pannorum has been identified as an agent of disfigurement of pigments used in the 15,000-year-old paintings on the walls of the Lascaux caves of France. Strains of Geomyces have been recovered from the Alaskan Fox Permafrost Tunnel and radiocarbon dated to between 14,000 and 30,000 years old.
Arthrobotrys oligospora was discovered in Europe in 1850 by Georg Fresenius. A. oligospora is the model organism for interactions between fungi and nematodes. It is the most common nematode-capturing fungus, and most widespread nematode-trapping fungus in nature. It was the first species of fungi documented to actively capture nematodes.
Dactylellina haptotyla is a common soil-living fungus that develops structures to capture nematodes as nutrient source. In the presence of nematodes, spores can germinate into sticky knobs or non-constricting loops. The fungus traps nematodes with sticky knobs and non-constricting loops, then breakdown the cuticle, and penetrates the body of nematodes to obtain nutrients. For its predatory nature, Dactylellina haptotyla is also considered as nematode-trapping fungus or carnivorous fungus.
Arthrobotrys dactyloides is a species of fungus in the family Orbiliaceae. It is nematophagous, forming loops of hypha to trap nematodes, on which it then feeds.
Oidiodendron cereale is a species of ascomycetes fungi in the order Helotiales. This fungus is found globally in temperate climates where average summer temperatures are below 25 °C, but there have been scattered reports from tropical and subtropical environments. It is predominantly found in soil, but little is known regarding their ecological roles in nature. However, an enzymatic study from Agriculture Canada showed that O. cereale can break down a variety of plant, fungal, and animal based substrates found in soil, which may have beneficial effects for plants. On rare occasions, this fungus is found on human skin and hair. There has been one reported case of O. cereale infection in 1969, causing Neurodermitis Nuchae.
Stylopage is a polytypic genus of predacious fungus in the order Zoopagales, within the subphylum Zoopagomycotina. All known species of Stylopage subsist on various species of amoebae or nematodes by trapping their prey, typically using an adhesive substance that coats their vegetative hyphae, and absorbing nutrients through the projection of a haustorium. 17 extant Stylopage species have been described thus far.
Meristacrum is a fungal genus in the monotypic family Meristacraceae, of the order Entomophthorales. They are parasites of soil invertebrates, they typically infect nematodes, and tardigrades.
Arthrobotrys musiformis is a species of nematode catching fungi, genus Arthrobotrys. This, like other Arthrobotrys species, captures and feeds on nematodes. It is widespread, with its initial discovery being in Norfolk, Virginia. This species demonstrates promising anti-helminth potential, and is hypothesized to reduce the number of parasitic nematodes in plants and livestock as either a biocontrol or through isolating metabolites.