Capnodiales » Piedraiaceae » Piedraia

Piedraia hortae

Piedraia hortae Fonseca & Leão, Memórias do Instituto Oswaldo Cruz, Supplemento 4 (Suppl.): 124 (1928).

 Index Fungorum number: IF 267365; Facesoffungi number: FoF 06140, Fig. 1

 Description: see Hyde et al. (2013).

Material examined: see Hyde et al. (2013).

Fig. 1 Piedraia hortae. a Ascostroma with numerous locules (redrawn from Fig. 12 in von Arx 1963) b Asci. c Ascospores (redrawn from Shoemaker and Egger 1982). Scale bars: a = 50 μm, b, c = 10 μm.

 

Importance and distribution

Piedraia species are dermatophytes which cause fungal infection known as ‘black piedra’. Piedraia infects hair on the scalp, beard and pubic hairs (Figueras et al. 1997). The natural habitat of Piedraia is hair, which is composed primarily of keratin (Savill 1952). Based on previous studies, it has been demonstrated that Piedraia can use keratin as its sole nutrient source (Jones 1976). Piedraia comprises two species. Piedraia hortae isolated from hair of a dead person in South America (Brazil) and P. quintanilhae is found from hair of Cape genet (Genetta tigrina; Viverridae) in Central Africa (Angola).

 

Industrial relevance and applications

Piedraia are cultivated for cosmetic use. The nodules of black Piedraia are considered attractive and are used to darken the hair especially of albino people in some tribes (Moyer and Keeler 1964).

 

Quarantine significance

Piedraia is pathogenic to human and cause fungal infection of the hair shafts. The disease is also known as Trichomycosis nodosa (Sharma et al. 2022).

 

Biochemical importance of the genus, chemical diversity or applications

Piedraia forms a variety of crystals in cultures in which high concentration of calcium ions were detected. This explains the hard and crusty nature of the fungus (Jones 1976).

 

References

Hyde, K.D., Jones, E.B.G., Liu, JK., Ariyawansa, H., … Zhang M. (2013). Families of Dothideomycetes. Fungal Diversity, 63, 1–313.

von Arx, J.A. (1963). Die Gattungen der Myriangiales. Persoonia, 2(4), 421–475.

Shoemaker, R.A. & Egger, K.N. (1982). Endoxylina allantospora. Fungi Canadiensis, 227.

Figueras, M. J., Guarro, J., & Zaror, L. (1997). Ultrastructural aspects of hair digestion in black piedra infection. Journal of medical and veterinary mycology: bi-monthly publication of the International Society for Human and Animal Mycology, 35 (1), 1–6.

Savill, Agnes F. (1952). The hair and scalp: a clinical study with a chapter on hirsuties. 4th Ed. Williams and Wilkins. Baltimore.

Jones, J.T. (1976). Growth and morphology of Piedraia hortae (Brumpt) Fonseca and Arêa Leão: the causal agent of Black Piedra.

Moyer, D. G., & Keeler, C. (1964). Note on culture of black piedra for cosmetic reasons. Archives of dermatology, 89, 436.

Sharma, P., Nassereddin, A., & Sonthalia, S. (2022). Black Piedra. [Updated 2022 Feb 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Available at: https://www.ncbi.nlm.nih.gov/books/NBK545178/

 

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