Bat Distribution Size or Shape as Determinant of Viral Richness in African Bats

Maganga, Gaël D.; Bourgarel, Mathieu; Vallo, Peter; Dallo, Thierno D.; Ngoagouni, Carine; Drexler, Jan Felix; Drosten, Christian; Nakouné, Emmanuel R.; Leroy, Eric M.; Morand, Serge

Two methods were used to document viral richness of the studied bat species. First, we tested our bat samples for viruses. We Determinant of Viral Richness of African Bats PLOS ONE | www.plosone.org used (i) nested Reverse-Transcription polymerase chain reaction (RT-PCR) assay targeting the RNA-dependent RNA polymerase gene using generic consensus primers for the genus Coronavirus [33] ; (ii) hemi-nested RT-PCR targeting the N terminal end of the NS5 gene by using degenerate primers for the genus Flavivirus [34, 35] ; and (iii) filoviruses (Marburg virus and Ebola virus) as previously described [4, 36] (Table 3) . Then, additional virological data were drawn from literature. In published papers, the methods used to detect viruses directly were mouse inoculation, cell culture, electron microscopy and PCR; indirect methods utilised to detect markers of replication and viral infection in bats from organs, tissues or blood were direct fluorescent antibody, indirect fluorescence antibodies, radio immuno assay, rapid fluorescent focus inhibition test, fluorescent antibody test, and seroneutralization. The serological detection of arbovirus antibodies alone (particularly genus Flavivirus and Alphavirus) was not considered as evidence of a viral association because of some degree of crossreaction within the virus family, rendering it difficult to differentiate viruses. Viruses forming distinct clusters within the same genus were recorded as a unique viral species. For example, in Rousettus aegyptiacus, bat gammaherpes viruses (Bat GHV) 1, 2, 4, 5, 6 and 7 were recorded as one unique viral species and Bat GHV 3 as another viral species [37] . For Ebola virus, different viral species of this genus were considered as a single virus. For each bat species, we calculated the viral richness as the total number of different viruses described for the given bat species.