Microbiology and potential virulence of Sporothrix cyanescens, a fungus rarely isolated from blood and skin

Abstract

Sporothrix cyanescens has been recovered from blood and a finger lesion at several medical centers in the United States. The morphology and physiology of these and three additional isolates were studied. S. cyanescens was distinguished from S. schenckii and S. fungorum by white to lavender colonial pigmentation and from S. schenckii also by the formation of secondary conidia. All isolates of S. cyanescens grew well at 37°C, were cycloheximide susceptible, strongly urease positive, and benomyl resistant, failed to hydrolyze starch, and were inhibited by sodium chloride in vitro at a concentration of ≥12%. Study of S. cyanescens in a murine model by using intravenous inoculation failed to demonstrate an invasive pathogenic potential. The validity of the transfer of S. cyanescens to the new genus Cerinosterus Moore is discussed.