Isolation of a novel species of flavivirus and a new strain of Culex flavivirus (Flaviviridae) from a natural mosquito population in Uganda.
The genus Flavivirus, which contains approximately 70 single-stranded, positive-sense RNA viruses, represents a unique model for studying the evolution of vector-borne disease, as it includes viruses that are mosquito-borne, tick-borne or have no known vector. Both theoretical work and field studies suggest the existence of a large number of undiscovered flaviviruses. Recently, the first isolation of cell fusing agent virus (CFAV) was reported from a natural mosquito population in Puerto Rico, and sequences related to CFAV have been discovered in mosquitoes from Thailand. CFAV had previously been isolated from a mosquito cell line in 1975 and represented the only known 'insect-only' flavivirus, appearing to replicate in insect cells alone. A second member of the 'insect-only' group, Kamiti River virus (KRV), was isolated from Kenyan mosquitoes in 2003. A third tentative member of the 'insect-only' group, Culex flavivirus (CxFV), was first isolated in 2007 from Japan and further strains have subsequently been reported from the Americas. We report the discovery, isolation and characterization of two novel 'insect-only' flaviviruses from Entebbe, Uganda: a novel lineage tentatively designated Nakiwogo virus (NAKV) and a new strain of CxFV. The individual mosquitoes from which these strains were isolated, identified retrospectively by using a reference molecular phylogeny generated using voucher specimens from the region, were Mansonia africana nigerrima and Culex quinquefasciatus, respectively. This represents the first isolation, to our knowledge, of a novel insect-only flavivirus from a Mansonia species and the first isolation of a strain of CxFV from Africa.
Cook
Shelley
S
Natural History Museum, Cromwell Road, London SW7 5BD, UK.
Moureau
Gregory
G
Unité des Virus Emergents UMR190 'Emergence des Pathologies Virales', Université de la Méditerranée et Institut de Recherche pour le Développement, Marseille, France.
Harbach
Ralph E
RE
Natural History Museum, Cromwell Road, London SW7 5BD, UK.
Mukwaya
Louis
L
Mosquito Research Programme, Uganda Virus Research Institute, PO Box 49, Entebbe, Uganda.
Goodger
Kim
K
Natural History Museum, Cromwell Road, London SW7 5BD, UK.
Ssenfuka
Fred
F
Mosquito Research Programme, Uganda Virus Research Institute, PO Box 49, Entebbe, Uganda.
Gould
Ernest
E
Centre for Ecology and Hydrology Oxford, Mansfield Road, Oxford OX1 3SR, UK.|Unité des Virus Emergents UMR190 'Emergence des Pathologies Virales', Université de la Méditerranée et Institut de Recherche pour le Développement, Marseille, France.
Holmes
Edward C
EC
Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA.
de Lamballerie
Xavier
X
Unité des Virus Emergents UMR190 'Emergence des Pathologies Virales', Université de la Méditerranée et Institut de Recherche pour le Développement, Marseille, France.
D000818:Animals; D016000:Cluster Analysis; D003465:Culex / Q000821:virology*; D005416:Flavivirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D005838:Genotype; D019660:Malvaceae / Q000821:virology*; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics*; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014454:Uganda; D014771:Virion / Q000648:ultrastructure
D012367:RNA, Viral