Isolation of a new strain of the flavivirus cell fusing agent virus in a natural mosquito population from Puerto Rico.
The genus Flavivirus contains approximately 70 single-stranded, positive-sense RNA viruses that are mosquito-borne, tick-borne or have no known vector. Two discoveries support previous suggestions of the existence of a large number of unsampled flaviviruses: (i) a new flavivirus, Kamiti River virus, was recently isolated from Kenyan mosquitoes, and (ii) sequences with high similarity to those of flaviviruses have been found integrated into the genome of Aedes mosquitoes, suggesting a past infection with a virus (or viruses) that has yet to be discovered. These sequences were related most closely to a flavivirus that infects insects alone, cell fusing agent virus (CFAV). CFAV was originally isolated in the laboratory from an Aedes aegypti cell line. To date, this virus had not been found in the wild. In the present study, over 40 isolates of a novel strain of CFAV were discovered from mature mosquitoes sampled from the wild in Puerto Rico. The viral strain was present in a range of mosquito species, including Aedes aegypti, Aedes albopictus and Culex sp., from numerous locations across the island and, importantly, in mosquitoes of both sexes, suggesting vertical transmission. Here, results from viral screening, and cell culture and molecular identification of the infected mosquitoes are presented. Experimental-infection tests were also conducted by using the original CFAV strain and a highly efficient reverse-transcription mechanism has been documented, in which initiation of copying occurs at the 3' terminus of either the genomic RNA or the intermediate of replication, potentially elucidating the mechanism by which flaviviral sequences may have integrated into mosquito genomes.
Cook
Shelley
S
Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
Bennett
Shannon N
SN
Asia-Pacific Institute of Tropical Medicine and Infectious Diseases, University of Hawaii at Manoa, 3675 Kilauea Avenue, Honolulu, HI 96816, USA.
Holmes
Edward C
EC
Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA.
De Chesse
Reine
R
Unité des Virus Emergents, Faculté de Médecine de Marseille, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France.
Moureau
Gregory
G
Unité des Virus Emergents, Faculté de Médecine de Marseille, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France.
de Lamballerie
Xavier
X
Unité des Virus Emergents, Faculté de Médecine de Marseille, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France.
D000330:Aedes / Q000821:virology*; D000818:Animals; D002478:Cells, Cultured; D003465:Culex / Q000821:virology*; D017931:DNA Primers; D004279:DNA, Viral / Q000032:analysis / Q000302:isolation & purification; D005260:Female; D005416:Flavivirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011647:Puerto Rico; D014776:Virus Cultivation
D017931:DNA Primers; D004279:DNA, Viral