Análise morfológica e termotolerância de isolados clínicos e do ambiente de Sporothrix schenckii do sul do Brasil Morphological pattern and thermotolerance of clinical and from environment isolates of Sporothrix schenckii from the south of Brazil

Sporothrix schenckii is the etiological agent of the sporotrichosis in animals and humans being this mycosis of great importance in public health. Due to clinical, epidemiological and molecular differences described in other studies, this study evaluated phenotypic and thermotolerance characteristics of 36 S. schenckii isolates from clinical cases of feline, canine and human sporotrichosis, four environmental isolates and two reference strains. Forty-two S. schenckii isolates from five towns of the south region of the Rio Grande do Sul, Brazil were utilized to phenotypic analyses, thermotolerance and conversion to the yeast phase. Cultured isolates on lactrimel agar, Sabouraud dextrose agar added chloramphenicol and potato dextrose agar at 25 and 35 o C showed differences in the colonies morphology and growth time (p=0,026) among reference strains and, clinical and environmental isolates. In the thermotolerance evaluation 26.2 % isolates were capable of growth at 41 o C. All isolates presented conversion to the yeast phase. Microscopic morphologies study showed statistical differences (p<0,01) among clinical isolates of felines and other species in relation to sessile pigmented and sympodial conidia. Our results demonstrated morphological differences among S. schenckii clinical and environmental isolates of a same region and an great probability of development of clinical forms disseminated and systemic by sporotrichosis feline isolates due to thermotolerance.