CEPAVE   05420
CENTRO DE ESTUDIOS PARASITOLOGICOS Y DE VECTORES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Discovery of an Encephalitozoon sp. (Fungi: Microsporidia) in the lubber grasshopper Romalea microptera (Orthoptera: Romaleidae).
Autor/es:
LANGE, C.E., L.F. SOLTER, M.D. BAKER, S. JOHNY, D.W. WHITMAN, A. CALI.
Lugar:
Wuhan, China.
Reunión:
Congreso; XXXIX Annual Meeting of the Society for Invertebrate Pathology; 2006
Institución organizadora:
Society for Invertebrate Pathology (SIP).
Resumen:
We isolated an unusual microsporidium from wild lubber grasshoppers, Romalea microptera, collected from Weeks Island, Louisiana, USA. We initially observed that the development of the isolate in the grasshopper host was not characteristic of other common microsporidia infecting terrestrial insects, including those found infecting grasshoppers. Large vesicles containing multiple developmental forms in different stages occurred in the midgut and gastric caecae cells.  Transmission electron microscopy revealed that presporulation stages developed in association with the vesicle and dissociated from the membrane as they matured.  The sporont plasma membrane was studded with electron dense exudates that persisted until the resulting sporont was fully developed. The vesicles were remarkably varied, with no specific number of spores; some contained more than 60 spores and other developmental forms.  Fresh uninucleate mature spores measure approximately 4 x 2 µm, and the spores average eight polar filament coils. The development is nearly identical to that of Encephalitozoon cuniculi but mature spores are significantly larger and the number of polar filament coils differs.   The small subunit ribosomal DNA sequence places this microsporidium near Encephalitozoon hellem and well within the Encephalitozoon clade.  With the exception of an Encephalitozoon cuniculi infection reported in mites that were fed on infected rabbits, no other arthropod microsporidia have been found to be congeneric with Encephalitozoon species. Our finding suggests the possibility of undiscovered invertebrate hosts for Encephalitozoon spp. that could serve as reservoirs for vertebrate pathogens.  This novel invertebrate host-parasite system may offer some advantages over vertebrate-Encephalitozoon interactions for testing therapeutic systems.