Microsporum gypseumcomplex in man and animals

Abstract

Twenty-eight strains of the Microsporum gypseum complex isolated from humans and animals were studied. The perfect form was found for 25 of the isolates. Nannizzia incurvata was the species most frequently involved in human pathology, while Nannizzia gypsea was most frequently found on animal lesions. Nannizzia fulva was rarely involved pathologically and Nannizzia corniculata was not isolated during this study. It is surprising to note that this species was not found even though most of our strains (22/28) came from Africa. Reliable methods are not available for differentiating among the anamorphs, which are commonly called M. gypseum, Microsporum fulrum or Microsporum boullardii. The Sabouraud medium conventionally used for medical mycology makes almost no distinction among them. We found that the species could be easily distinguished by colonial and microscopic features when grown on Takashio medium. When strains are atypical, sexual reproduction remains the reference technique but, in most cases, Takashio medium makes it possible to avoid this long drawn-out procedure.The Microsporum gypseum complex is made up of four dermatophytic species of which three, Nannizzia incurvata, Nannizzia gypsea and Nannizzia fulva* belonging to the Gymnoascaceae family, are pathogenic for both man and animals [8]. The fourth species, Nannizz& corniculata, more recently discovered [13], is a saprophyte of the soil and apparently has not been involved pathologically.Even though perfect forms of three of the species of the complex M. gypseum were among the first to be discovered, the anamorphs are frequently confused with each other because of similarities of their morphologies on different versions of Sabouraud medium [3]. Some authors, Stockdale [8], Visset [14] and Rippon [6] have described slight differences but they are inadequate for making exact distinctions. The conidial states of both N. gypsea and N. incurvata are called M. gypseum [2]. The anamorphs of two other species, N. fulva and N. corniculata, are called M. fulvum and M. boullardii, respectively, but identifying the distinctive characteristics of the latter two, or even all four, is not easy.

A survey on the pathogenic fungi in soil samples of potted plants from Sari hospitals, Iran

“…16 The keratinophilic fungi such as M. gypseum and M. cookei isolated in this study have been reported to cause infection in human. 17,18 With the continuing increase in the number of severely immunocompromised patients, hospitals are faced with the growing problem of opportunistic fungal infections. As treatment of these infections is difficult, and the outcome often fatal, preventive measures are of major importance in the control of invasive fungal infections, therefore, full understanding of their epidemiology is crucial in the development of effective preventive strategies.…”

Correspondence

“…M. gypseum and M. fulvum are closely related organisms, and rich garden soils are their favorite habitats 3 . The M. gypseum ‐complex is implicated in cases of tinea capitis (rarely tinea favosa) and tinea corporis, and infection often results from direct contact with either soil or domestic pets; the fungus has been recovered from fur 1 , 4–6 . The prevalence rates are low when compared with other dermatophyte isolates, ranging from 0.72% to 5.2% 6–8…”

Microsporum gypseum complex in Madras, India

“…All the strains of M. gypseum were subjected to mating experiments [1]. The organisms were maintained on Takashio medium.…”

“…Microsporum gypseum is a geophilic dermatophyte widely distributed in soil throughout the world [1]. The discovery of the perfect state of this fungus in 1963 [2] revealed that M. gypseum in its teleomorphic state is a complex made up of three species.…”