A New Species of Leptosphaeria, an Etiologic Agent of Mycetoma

Abstract

The recent discovery of Leptosphaeria senegalensis Segretain, Baylet, Darasse & Camain (5) as a causal agent of mycetoma in Senegal and Mauritania was the first report of a human pathogen in the genus Leptosphaeria, species of which are commonly found on plant materials. The morphology of the pathogen and the disease it causes were described by Baylet et al. (1), in a comprehensive study involving eight cases of mycetoma from those two African regions. El-Ani and Gordon (3) were the first to describe and illustrate the ascospore gelatinous sheath that, in water or in aqueous solutions, swells into a turbinate structure bearing a basal satellite (Fig. 13). Further investigation of this organism was prompted by a report (4) of a new strain isolated by Segretain and his co-workers in Paris from a Mauritanian patient. Although this strain produced 8-celled asco? spores, Segretain did not consider it a new species because in certain strains of L. senegalensis, the spores of which are typically 4-septate, he "sometimes observed ascospores with 6 and even 7 or 8 cells." Our observations indicate that the isolate, 559, that produces 8-celled asco? spores is a species distinct from L. senegalensis. The new species is described and contrasted with L. senegalensis below.