INFECTIONS CAUSED BY THE OOMYCETOUS PATHOGEN PYTHIUM-INSIDIOSUM

Pythiosis insidiosi is a disease of animals and humans in the tropical , subtropical and temperate areas of the world. It is caused by Pythiu m insidiosum an organism in the Kingdom Chromista, Phylum Pseudofungi, Class Oomycetes, Family Pythiaceae. The first observations of this di sease took place during the last century in equines afflicted with cut aneous granulomas. Pythium insidiosum was first isolated by Haan and H oogkamer, but they failed to identify it as their cultures were steril e. Several years later Bridges and Emmons isolated a similar organism from equine granulomas in Texas. They proposed the term Hyphomyces des truens, an illegitimate designation based on the disease name ''hyphom ycosis destruens equi'' coined by early workers. Austwick and Copland in 1974 successfully stimulated the production of zoospores that were similar to those produced by members of the genus Pythium, in a filame ntous microorganism they had isolated from horses with swamp cancer in New Guinea. More recently, de Cock et al. proposed the name P, insidi osum to include all strains isolated from all cases of pythiosis insid iosi. The disease has been reported in such animals as: cats, cattle, dogs, horses, captive polar bears, and in humans. This review deals wi th pythiosis insidiosi most important aspects including the biology an d life cycle of P. insidiosum, as well as the epidemiology, clinical s igns, pathology, diagnosis (animal inoculation, mycology and serology) , and treatment of this disease once known as an exotic illness of tro pical countries.