Rift Valley fever virus detection in susceptible hosts with special emphasis in insects.

Rift Valley fever phlebovirus (RVFV, Phenuiviridae) is an emerging arbovirus that can cause potentially fatal disease in many host species including ruminants and humans. Thus, tools to detect this pathogen within tissue samples from routine diagnostic investigations or for research purposes are of major interest. This study compares the immunohistological usefulness of several mono- and polyclonal antibodies against RVFV epitopes in tissue samples derived from natural hosts of epidemiologic importance (sheep), potentially virus transmitting insect species (Culex quinquefasciatus, Aedes aegypti) as well as scientific infection models (mouse, Drosophila melanogaster, C6/36 cell pellet). While the nucleoprotein was the epitope most prominently detected in mammal and mosquito tissue samples, fruit fly tissues showed expression of glycoproteins only. Antibodies against non-structural proteins exhibited single cell reactions in salivary glands of mosquitoes and the C6/36 cell pellet. However, as single antibodies exhibited a cross reactivity of varying degree in non-infected specimens, a careful interpretation of positive reactions and consideration of adequate controls remains of critical importance. The results suggest that primary antibodies directed against viral nucleoproteins and glycoproteins can facilitate RVFV detection in mammals and insects, respectively, and therefore will allow RVFV detection for diagnostic and research purposes.

Entamoeba ranarum Infection in a Ball Python (Python regius).

The pathogenic Entamoeba species in snakes is widely regarded to be Entamoeba invadens, which can cause severe amoebiasis with up to 100% mortality. In this case report, we describe a ball python (Python regius) that died after short-term weight loss. Necropsy revealed severe necrotizing colitis with large numbers of intralesional Entamoeba trophozoites. Molecular genetic analysis identified these trophozoites as Entamoeba ranarum, a parasite more usually found in amphibians. Furthermore, the extended history revealed that toads (Rhinella marina) had been housed together with the python. This report illustrates the danger of protozoal cross-infections in exotic animals as well as the importance of molecular genetic tools in Entamoeba diagnosis.