rifamycin An antibiotic which inhibits RNA synthesis in sensitive strains of Escherichia coli by binding to a subunit of the bacterial RNA polymerase. Does not inhibit eukaryotic cell RNA poly-merases, although 3-oxime derivatives with some inhibitory action against mammalian RNA polymerases have been described (rifamycins AF/05 and AF/013). Rifamycin will prevent focus formation by Rous sarcoma virus (Vaheri and Hanafusa, 1971) and inhibits maturation of Poxviridae (Pennington et al, 1970).
Pennington TH et al (1970) J Gen Virol 9, 225 Vaheri A and Hanafusa H (1971) Cancer Res 31, 2032
Rift Valley fever virus (RVFV) A species in the genus Phlebovirus. Member of the Rift Valley fever complex in the sandfly fever serogroup. Found in central and southern Africa. Causes abortion and many deaths in pregnant and newborn sheep, goats and cattle. Lambs develop fever, vomiting, mucopurulent nasal discharge and bloody diarrhea. Cattle are less seriously affected. Herdsmen and slaughtermen often become infected and develop a biphasic illness which is usually mild, although retinal damage may occur. Buffalo, camels and antelopes may be naturally infected and die. Infection is mosquito-borne, but contact infection probably also occurs. Large mosquito-borne epizootics occurred in 1977-78 in Egypt, in 1987-88 in East Africa. Absent for a decade, it returned to Egypt in 1993. Then in 1999 a large outbreak began in the Kingdom of Saudi Arabia and Yemen, the first outbreak ever recorded outside the African continent, with more than a thousand human cases and more than 150 deaths by the end of 2000. Control is by protection from mosquitoes and by vaccination of livestock with formalin-ized or attenuated vaccines. Mice die of hepatitis when infected experimentally. Guinea pigs, ferrets and young dogs can also be infected, but birds are resistant. Virus replicates in cultures of chick, rat, mouse and human cells, and on the CAM, causing thickening. The virus hemagglutinates day-old chick cells at pH 6.5 and 25°C.
Arthur R et al (1993) Lancet 342, 1149
RIID 3229 virus A strain of Oliveros virus in the genus Arenavirus.
Riley virus Synonym for Lactate dehydroge-nase-elevating virus.
Was this article helpful?