A New Insect-Specific Flavivirus from Northern Australia Suppresses Replication of West Nile Virus and Murray Valley Encephalitis Virus in Co-infected Mosquito Cells

• DOI: 10.1371/journal.pone.0056534
• Publication Date: 2013-02-27T22:53:07Z
• Authors: Jody Hobson-Peters; Alice Wei Yee Yam; Jennifer Wei Fei Lu; Yin Xiang Setoh; Fiona J. May; Nina Kurucz; Susan Walsh; Natalie A. Prow; Steven S. Davis; Richard Weir; Lorna Melville; Neville Hunt; Richard I. Webb; Bradley J. Blitvich; Peter Whelan; Roy A. Hall
• Keywords: Flavivirus

Recent reports of a novel group flaviviruses that replicate only in mosquitoes and appear to spread through insect populations via vertical transmission have emerged from around the globe. To date, there is no information on presence or prevalence these insect-specific (ISFs) Australian mosquito species. assess whether such viruses occur locally, we used reverse transcription-polymerase chain reaction (RT-PCR) flavivirus universal primers are specific NS5 gene detect pools collected Northern Territory. Of 94 mosquitoes, 13 were RT-PCR positive, these, 6 isolates obtained by inoculation cell culture. Sequence analysis revealed genetically phylogenetically similar ISFs reported other parts world. The entire coding region one isolate (designated 56) was sequenced shown approximately 63.7% nucleotide identity 66.6% amino acid with its closest known relative (Nakiwogo virus) indicating prototype ISF represents new All Coquillettidia xanthogaster mosquitoes. virus tentatively named Palm Creek (PCV) after place isolation. We also demonstrated prior infection cultured cells PCV suppressed subsequent replication medically significant West Nile Murray Valley encephalitis 10–43 fold (1 1.63 log) at 48 hr post-infection, suggesting superinfection exclusion can between vertebrate-infecting despite their high level genetic diversity. generated several monoclonal antibodies (mAbs) NS1 protein PCV, represent first ISF-specific mAbs date.