Sporotrichosis is a subcutaneous mycosis especially frequent in Latin American countries with temperate and tropical climates. Due to the presence of Sporothrix schenckii fungal elements in vegetative matter, this disease is associated with different occupations such as gardening, forestry, and fieldwork (3,6,9,11,16,27). In Mexico (MX), Guatemala (GT), and Colombia (CO), it is a relevant mycosis mainly in farmers who work with a variety of vegetation in the field and individuals who manipulate fungus-contaminated material (10, 17, 21, 37). The fungus has been isolated from soil, different plants, and sphagnum moss (9,11,16,19,20), and when it is introduced into the host via trauma, the mycelial-saprophytic form changes to the yeast-parasitic form. Previous reports have demonstrated other forms of inoculation of infecting mycelia, such as mosquito bites and, probably, cat scratches, as recently demonstrated by molecular techniques in Brazil (R. S. Reis, T. M. P. Schubach, A. J. Guimarães, P. C. F. Monteiro, and R. M. Zancopé-Oliveira, Abstr. 14th Congr. Int. Soc. Hum. Anim. Mycol., abstr. 498, p. 133, 2000). Although the prevalence of this mycosis among AIDS patients is low, it is extremely serious in human immunodeficiency virus-seropositive patients and becomes disseminated, with a poor prognosis (30).Researchers from Japan and the United States have performed epidemiological studies with S. schenckii isolates from Asia, the United States, and Australia based on restriction fragment length polymorphisms. They have shown 24 different genotypes divided into two groups: group A includes isolates from the United States, and group B includes isolates from Asia and Australia (12, 13; H. Ishizaki, H., M. Aoki, J. Lin, S. Wu, and J. A. Kim, Abstr. 14th Congr. Int. Soc. Hum. Anim. Mycol., abstr. 56, p. 120, 2000). Kawasaki et al. (M. Kawasaki, R. Arenas, C. Zaitz, J. T. Yamashita, and C. Rubio, Abstr. 14th Congr. Int. Soc. Hum. Anim. Mycol., abstr. 54, p. 120, 2000) also studied by restriction fragment length polymorphism analysis isolates from Brazil, Mexico, and Spain, and again, two groups were formed: isolates from Brazil and Mexico were in group A, and those from Spain were in group B. Despite the widespread use of the random amplified polymorphic DNA (RAPD) analysis method for genotypic characterization of other pathogenic fungi (5,18,23,25,34), identical DNA patterns for clinical isolates and isolates from infecting cats were