Arthroderma benhamiae

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Classification

Domain: Eukaryota ; Phylum: Fungi ; Class Dikayrya ; Order: ascomycota ; family: Arthroderma

Species

Genus species

Arthroderma benhamiae

NCBI: [1]

Description and Significance

Arthroderma benhamiae is a dermatophyte fungus morph that belongs to the Trichophyton mentagrophytes species. The guinea pig is considered it's natural host as it is primarily carried by guinea pigs and small rodents with the highest infection rate. The fungus is characterized by inflammatory skin lesions that are raised and erythematous and crusty. This organism is important to study as dermatophytoses are the most common fungal infections and their primary carriers are commonly kept as household pets. This can increase the infection rates in humans who are handling these pets in close contact. The treatment for a mild infection can include topical treatment, but can be more extensive in some cases where oral antifungals are necessary.

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?

The genomes of these dermatophytes are extremely small ranging from 22.5 to 24 Mb and are highly collinear. A. benhamiae genome yields 7,405 protein-encoding genes. The genomes in these dermatophytes have been found to be rich with genes encoding secreted proteases where as genes encoding enzymes for sugar metabolism were not present at all. Those genes are particularly important for plant cell wall breakdown which isn't important in our fungus since it primarily infects animal and human skin.

Cell Structure, Metabolism and Life Cycle

Interesting features of cell structure; how it gains energy; what important molecules it produces.

Arthroderma Benhamiae has been studied to use certain biosyntheses of pigments for growth and metabolism. Based on some evidence collected, they connected the pigments to playing an active role in respiration, specifically in the electron transport chain. According to a series of pigment extraction, purification and characterization methods, they found that nitrogen containing amino acid pigments supported growth. They also found that growth was inhibited on the sulfur containing amino acids.

Nitrogen acquisition from the host is imperative for this pathogenic fungus to survive, grow and persist. The dermophytes have a high degree of metabolic flexibility. In the absence of their preferred nitrogen source, they will use amino acids or cetain proteins. To that point, it has been studied that extracellular proteases aid in metabolism of the fungal pathogenic dermophytes like our organism. Acting as a key virulence attribute to the fungus to break down the keratin containing tissues. Their genomes show enrichment of these protease genes which are expressed typically only when in growth on keratin in vitro. This is expected as when they are infecting a host, those specialized genes are up regulated to assist in the degradation of the keratin.

Ecology and Pathogenesis

Habitat; symbiosis; biogeochemical significance; contributions to environment.

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

References

1. GHANI HM. Physiological, Chemical, And Genetic Study Of Pigment Production By Arthroderma Benhamiae. [Order No. 7309154]. The University of Oklahoma; 1972.

2. Ene IV, Brunke S, Brown AJ, Hube B. Metabolism in fungal pathogenesis. Cold Spring Harb Perspect Med. 2014;4(12):a019695. Published 2014 Sep 4. doi:10.1101/cshperspect.a019695

3. Tran VD, De Coi N, Feuermann M, et al. RNA Sequencing-Based Genome Reannotation of the Dermatophyte Arthroderma benhamiae and Characterization of Its Secretome and Whole Gene Expression Profile during Infection. mSystems. 2016;1(4):e00036-16. Published 2016 Aug 2. doi:10.1128/mSystems.00036-16

4. Martín-Peñaranda T, Lera Imbuluzqueta JM, Alkorta Gurrutxaga M. Arthroderma benhamiae en pacientes con cobayas. An Pediatr (Barc). 2019;90:51–52.

Author

Page authored by Kathleen Bessette, _____, _____, & _____, students of Prof. Bradley Tolar at UNC Wilmington.