Comments on recent human infections caused by ascomycetes

Medical Mycology 1998, 36, 349 Accepted 1 May 1998 Correspondence Comments on recent human infections caused by ascomycetes Sir, Over the last few years the number of infections caused by ascomycetes which develop fruiting bodies in routine culture media has increased notably. The presence of ascomata in the cultures is a very important tool in the recognition of the fungus, at least at the genus level. However, these fungi are still rare infectious agents and they are not usually included in the medical mycological books, so their identification can cause problems for mycologists who are not aware of them. This can lead to misidentification, creating confusion among the readers of the published cases. We have found two clear examples of this fact in a search of the recent literature. A case of chromoblastomycosis from India has been attributed to the new genus Ascosubramania [1], which has two anamorphic states, Sagrahamala and Fonsecaea-like. On simple observation of the figures we note that the presumptive new fungus really belongs to Microascus. The illustrated ascomata, asci and ascospores of this fungus are typical of those of the species of that genus [2]. The genus Microascus develops dark brown ascomata with a cylindrical, often long, beak, asci obovate, barrel-shaped or spherical and ascospores reniform, heart-shaped or angular in lateral view, dextrinoid when young and straw-coloured when mature. Three species of Microascus have been reported as pathogenic in humans. They are M. cirrosus, M. cinereus and M. manginii [3–5]. According to the data reported by Rajendram [1] this fungus seems identical to M. cirrosus. This species has been implicated in cases of onychomycoses and in cattle abortion [3] and more recently in a disseminated infection in a paediatric bone transplant recipient [4]. In addition, Fig. 2c of Rajendram’s article, which illustrates the Sagrahamala anamorph, appears to show the typical conidiogenous cells of Scopulariopsis an anamorph of Microascus. The second case refers to a fungal pneumonia in a leukaemic patient, published by Yeghen et al. [6]. The causative agent was identified as Chaetomium globosum. This species is characterized by limoniform ascospores, measuring 9–12×8–10×6–8 lm and flexuous, undulate or coiled hairs in the upper part of its ascomata [7]. However, Fig. 2 of the same article shows ascospores narrowly ellipsoid or fusiform, slightly flattened on one side with the length more than double that of the width. These ascospores are typical of other species of the genus. It is also worth mentioning that the characteristic hairs of Chaetomium globosum are not observed in the figure. Without knowing more details it is impossible to ascertain the name of the species, but it cannot be C. globosum. J. Guarro Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili, C/Sant Llorenç 21, 43201 Reus, Spain References 1 Rajendran C. Ascosubramania gen. nov., and its Fonsecaea-like anamorph causing chromoblastomycosis in India. J Med Vet Mycol 1997; 35: 335–9. 2 von Arx AJ, Figueras MJ, Guarro J. Sordariaceous ascomycetes without ascospore ejaculation. Beih. Nov Hedw 1988; 94: 1–104. 3 Guarro J, de Hoog GS, Figueras MJ, Gené J. Rare opportunistic fungi: ascomycetes producing fruit bodies in culture. In: de Hoog GS, Guarro J, eds. Atlas of Clinical Fungi. Baarn: Centraalbureau voor Schimmelcultures, 1995: 275–303. 4 Krisher KK, Holdridge NB, Mustafa MM, Rinaldi MG, McGough DA. Disseminated Microascus cirrosus infection in pediatric bone marrow transplant recipient. J Clin Microbiol 1995; 33: 735–7. 5 Marques AR, Kwon-Chung KJ, Holland SM, Turner ML, Gallin JI. Suppurative cutaneous granulomata caused by Microascus cinereus in a patient with chronic granulomatous disease. Clin Infect Dis 1995; 20: 110–4. 6 Yeghen T, Fenelon L, Campbell CK, et al. Chaetomium pneumonia in patient with acute myeloid leukaemia. J Clin Pathol 1995; 49: 184–6. 7 von Arx JA, Guarro J, Figueras MJ. The ascomycete genus Chaetomium. Beih. Nov Hedw 1986; 84: 1–162. See the following page for a response to this Correspondence.  1998 ISHAM  (...truncated)