Tropicoporus tropicalis
Species of fungus
From Wikipedia, the free encyclopedia
Tropicoporus tropicalis is a mushroom of the family Hymenochaetaceae.[2] Tropicoporus tropicalis is a wood-decaying basidiomycetes that rarely causes disease in animals and human, and is commonly found in humid climate such as Brazil.[3][4][5][6][7] In its natural environment, the fungus is associated with white rot woody angiosperms, and has its annual fruiting body on tree trunks and branches.[4] Tropicoporus tropicalis has two kinds of hyphae (a dimitic hyphal system), generative and skeletal, that lack clamp connections.[3][4][8][9]
| External image | |
|---|---|
 Fig. A – D on page 17 of Lima et al. (2022)'s paper on MNHN's website. |
| Tropicoporus tropicalis | |
|---|---|
Scientific classification  | |
| Kingdom: | Fungi |
| Division: | Basidiomycota |
| Class: | Agaricomycetes |
| Order: | Hymenochaetales |
| Family: | Hymenochaetaceae |
| Genus: | Tropicoporus |
| Species: | T. tropicalis |
| Binomial name | |
| Tropicoporus tropicalis (M.J. Larsen & Lombard) L.W. Zhou & Y.C. Dai (2015) | |
| Synonyms[1] | |
| |
Taxonomy
Poria rickii is a species described by Giacomo Bresadola in 1920.[10] Alix David and Mario Rajchenberg renamed it Phellinus rickii in 1985.[11]
However, there already is a pre-existing name Phellinus rickii Teixeira 1950. To avoid confusion, Larsen and Lombard (1988) gave David and Rajchenberg's P. rickii a new name Phellinus tropicalis.[9]
Wagner and Fischer (2002) showed that Phellinus tropicalis belong in Inonotus sensu stricto after phylogenetic analysis of the fungus's rDNA nuclear LSU sequence, and renamed it Inonotus tropicalis.[12]
In Zhou et al. (2015), Inonotus sensu lato (equivalent to Inonotus sensu stricto in Wagner and Fischer 2002) contains at least three clades (A, B, and C). Clade A is Inonotus sensu stricto, and clade B and C together form the Inonotus linteus complex. Clade B and C each was given names Tropicoporus and Sanghuangporus. The fungus, belonging to clade B, is renamed Tropicoporus tropicalis in the same time.[2]
Description
Tropicoporus tropicalis is a fungus with the growth characteristics of being appressed, short-downy, homogeneous, adherent, even margins, indistinct, and odourless.[9] It is also woolly and yellowish-orange colonies,[3] with annual fruiting bodies and dimitic hyphal system,[12] which refers to the appearance of two kinds of hyphae: generative (2.5 – 4 ɥm in diameter, thin-walled, simple-septate, and pale yellowish brown), and skeletal (3.5 – 4.5 ɥm in diameter, thick-walled, infrequently simple-septate, and dull yellowish brown).[4][8][9] Moreover, the fungus lacks setal hyphae and clamp connections in its hyphae, which is either thin or thick walled.[3][8] However, it has numerous reddish brown Hymenial setae that has a maximum length of 25 ɥm,[8][13] and has dull brown pores that becomes whiter near the margin.[9][13] The Basidiocarp of Tropicoporus tropicalis is annual, resupinate, and hyaline.[2][8] The abundant fungal spores are coloured yellowish to ochraceous, and shaped ovoid to broadly ellipsoid and smooth when mature.[13] Both the spores (7 - 9 per mm) and the basidiospores are small, with basidiospores having more than 3.5 um wide when it is ellipsoid, and are less than 3.5 um wide when it is sub-globose.[2][8]
Physiology
The fungus grows:
- Moderately rapid in MEA (Malt Extract Agar)[9]
- In 0.05% cycloheximide[3]
The mat diameter of the fungus depends on temperature, but the optimal growth temperature is around 36 °C, and the maximum temperature without growth (not killed) is 44 °C.[9] Even though all parts of the fungus could be darkened by 2% KOH, only the hyphae can be stained by phloxine, a reddish dye.[9] Furthermore, Tropicoporus tropicalis is also found to be highly resistant to caspofungin and posaconazole, two different anti-fungal compounds.[3]
Ecology and habitat
Tropicoporus tropicalis is a poroid wood-decaying basidiomycete[4][5] that is usually associated with white rot woody angiosperms,[3] grow on deciduous wood,[6] and have fruiting body on infected tree trunks and branches.[4] It is mainly found in the tropical zone[2] and humid climate,[6] such as Brazil; but is present in Mississippi, Florida, Georgia, Jamaica, Guadeloupe, Costa Rica, Colombia, East Africa, and Malaya, Johore, and Mawaii Malaysia.[7]
As a pathogen
Tropicoporus tropicalis rarely causes diseases in animals and human.[3] However, it is an opportunistic pathogen that has the potential to induce allergic and invasive diseases in mammals.[3]
Animal
The fungus has been recorded to cause fungal pericardial effusion and myocarditis in a French bulldog, that was under immunosuppressive therapy (species was non-pigmented, and has indication of a hyalohyphomycosis infection);[5] and induced a granulomatous mediastinal mass in an immunocompromised Irish Wolfhound dog.[14]
Human
The first association of an invasive infection on human occurred on a patient with chronic granulomatous disease.[7][15] In addition, two similar chronic granulomatous disease cases of I. tropicalis infection were later found in immunodeficient children and adults that had caused osteomyelitis.[6]
In 2021, the first case of Tropicoporus tropicalis infection on a immunocompetent human was reported.[16]