AUTHOR=Levin Sofia , Galbraith David , Sela Noa , Erez Tal , Grozinger Christina M. , Chejanovsky Nor 

TITLE=Presence of Apis Rhabdovirus-1 in Populations of Pollinators and Their Parasites from Two Continents

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.02482

DOI=10.3389/fmicb.2017.02482

ISSN=1664-302X

ABSTRACT=<p>The viral ecology of bee communities is complex, where viruses are readily shared among co-foraging bee species. Additionally, in honey bees (<italic>Apis mellifera</italic>), many viruses are transmitted – and their impacts exacerbated – by the parasitic <italic>Varroa destructor</italic> mite. Thus far, the viruses found to be shared across bee species and transmitted by <italic>V. destructor</italic> mites are positive-sense single-stranded RNA viruses. Recently, a negative-sense RNA enveloped virus, Apis rhabdovirus-1 (ARV-1), was found in <italic>A. mellifera</italic> honey bees in Africa, Europe, and islands in the Pacific. Here, we describe the identification – using a metagenomics approach – of ARV-1 in two bee species (<italic>A. mellifera</italic> and <italic>Bombus impatiens</italic>) and in <italic>V. destructor</italic> mites from populations collected in the United States and Israel. We confirmed the presence of ARV-1 in pools of <italic>A. mellifera</italic>, <italic>B. impatiens</italic>, and <italic>V. destructor</italic> from Israeli and U.S. populations by RT-PCR and found that it can reach high titers in individual honey bees and mites (10<sup>7</sup>–10<sup>8</sup> viral genomic copies per individual). To estimate the prevalence of ARV-1 in honey bee populations, we screened 104 honey bee colonies across Israel, with 21 testing ARV-1-positive. Tagged-primer-mediated RT-PCR analysis detected the presence of the positive-sense ARV-1 RNA in <italic>A. mellifera</italic> and <italic>V. destructor</italic>, indicating that ARV-1 replicates in both hosts. This is the first report of the presence of ARV-1 in <italic>B. impatiens</italic> and of the replication of a rhabdovirus in <italic>A. mellifera</italic> and <italic>V. destructor</italic>. Our data suggest that <italic>Varroa</italic> mites could act as an ARV-1 vector; however, the presence of ARV-1 in <italic>B. impatiens</italic> (which are not parasitized by <italic>Varroa</italic>) suggests that it may not require the mite for transmission and ARV-1 may be shared among co-foraging bee species. Given that ARV-1 is found in non-Apis bee species, and because “ARV” is used for the Adelaide River virus, we propose that this virus should be called bee rhabdovirus 1 and abbreviated BRV-1. These results greatly expand our understanding of the diversity of viruses that can infect bee communities, though further analysis is required to determine how infection with this virus impacts these different hosts.</p>