Rhinosporidiosis is a chronic polypoidal infection of the nose, conjunctiva and other sites, believed to be caused by a fungus, Rhinosporidium Seeberi, with a doubtful taxonomy. Polyps contain histological round bodies and the exact mode of infection is not known. The round bodies are filled up with spherules. In tissue the organism forms spherical round bodies approaching 50-500µ in diameter that contain innumerable single-celled organisms that mature at different rates. Mature organisms are approximately 7-9µ in size and escape through a pore that develops in the wall of the round body. The round body does not exist in nature outside the host.
The organism in rhinosporidiosis was believed to be uncultivable, until we cultured it for the first time in our laboratory. We further modified the culture medium and succeeded in culturing the causative agent of the disease in CBEML (Cell Biology and Electron Microcopy Laboratory) medium. Here we present some of the peculiar conspicuous features of the organism in culture leading to symmetry patterning.
Rhinosporidiosis is a polypoidal disease of the nose and mucocutaneous tissues, the diagnosis of which is based on the presence of round bodies believed to be causative agents of the disease. Historically, the round body has been considered to be a sporangium of a fungus Rhinosporidium seeberi but without any convincing evidence. Round bodies contain numerous daughter cells, which are likely in the infective stage and are shed through a rupture in the wall of the round body. The released single-celled organisms eventually develop into round bodies on availability of suitable transformative trigger and favourable environment. Surgical excision of the polyp by electrocautery is the only effective treatment; however, recurrence may occur due to spillage of infective endospores in the surrounding mucosa during removal. There are many enigmatic features of the causative agent of this disease, which have been baffling researchers for more than a century. Here we present some rare electron microscopic and previously unreported features of the coat of the round body and single-celled organism in nasal rhinosporidiosis.