First detection of the Africa/Caribbean/Latin American subtype of Culex flavivirus in Asian country, Taiwan

• Published in: Comparative immunology, microbiology and infectious diseases Vol. 36; no. 4; pp. 387 - 396
• Main Authors: Chen, Yi-Ying, Lin, Jen-Wei, Fan, Yi-Chin, Tu, Wu-Chun, Chang, Gwong-Jen J., Chiou, Shyan-Song
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.07.2013
• Subjects: Allergy and Immunology; Animals; Base Sequence; cell biology; Culex; Culex - virology; Culex flavivirus; Culex mosquitoes; Flavivirus; Flavivirus - classification; Flavivirus - genetics; Flavivirus - isolation & purification; Infectious Disease; Insect-only flavivirus; Molecular Sequence Data; Phylogeny; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral - chemistry; RNA, Viral - genetics; Sequence Alignment; Sequence Analysis, DNA; Taiwan; Taiwan; USA; ASW, Caribbean Sea; Asia; Africa; Culex mosquitoes; Insect-only flavivirus; Culex flavivirus
• ISSN: 0147-9571; 1878-1667; 1878-1667
• DOI: 10.1016/j.cimid.2013.02.001

Culex flavivirus (CxFV), a member of the genus flavivirus, is a novel insect-specific flaviviruses that can be divided into two subtypes, the cytopathic Asia/U.S. and the noncytopathic Africa/Caribbean/Latin American subtypes. The CxFV circulates in several Asian countries, and here we conducted the first study investigating CxFV in Taiwan. A total of 14,016 mosquitoes were collected between 2010 and 2012 and 3.4% (6/179) of the pools were CxFV-positive. The phylogenetic analyses indicate that the Taiwan isolates are closely related to the Africa/Caribbean/Latin American subtype, but form an independent cluster. In the cytology experiments, the CxFV Taiwan isolate infected only mosquito cells and caused cell–cell fusion that might be associated with a unique glycine residue at position 117 within the envelope protein, which is shared with the cytopathic effect-causing Asia/US subtype. This study marks the first time the Africa/Caribbean/Latin American subtype of CxFV has been identified in an Asian country and grouped into a novel cluster.