Researchers have identified dozens of DNA and RNA viruses in seasonal and migratory species in Switzerland, including a MERS-CoV-linked coronavirus behind Middle Eastern respiratory syndrome.
For an article published in PLOS One Wednesday, a team from the University of Zurich and the Swiss Bat Foundation performed DNA sequencing and RNA sequencing on stool, stool, or organ tissue samples from about 7,000 bats that covering 18 species found at sites in Switzerland over several years. Comparing the sequences in these samples to those of the available databases, they traced representatives from more than three dozen viral families – a set containing viruses in 16 viral families linked to infections in other vertebrate species.
In particular, the team noted, metagenomic sequencing on stool samples collected in one of the bat colonies of Vespertilio murinus considered led to an almost complete genome sequence for a coronavirus that was most closely related to MERS-CoV. . Even so, it remains to be seen whether this virus can spread to other species, as well as the possible consequences of such an infection.
“It will be interesting to study the zoonotic potential of this betacoronavirus to beat and monitor the colony where it has been detected over time because this will allow [us] to assess the accumulation of mutations in the VOC genome in a host natural reservoir, ”co-senior and co-correspondent author Jakub Kubacki, a researcher at the University of Zurich’s Institute of Virology, and his colleagues wrote.
Using common metagenomic DNA sequencing and RNA-seq, the researchers looked for recognizable viral sequences in fresh samples of feces or organ tissue collected from healthy, sick or dead bats in colonies across Switzerland from 2015 to 2020. The bats considered come from 14 species native to Switzerland and four migratory species.
With these sequences, the team took a look at the viruses found in Swiss bats in general, as well as the virus characteristics that differed between bats from different sites, species, sample types, and so on. While most vertebrate-related viral sequences come from the Circoviridae family, for example, the tested bats also carried viruses from the Genomoviridae, Coronaviridae, and Adenoviridae families, with viral families previously reported in insects, plants, or fungi.
In an email, Kubacki called next-generation sequencing, or NGS, “ideal for studying the so-called virus, the totality of viruses present in a specific environment,” and said that the University of Zurich “is the first laboratory of Swiss veterinary diagnostics to offer NGS for diagnostic purposes, in particular for unknown causes of disease, herd screening, and to monitor or detect new viruses in environmental samples. “
“Metagenomic analysis of ground stool samples from bat colonies represents an ideal non-invasive high-flow method to monitor the complexity of viral genome diversity,” he and his co-authors reasoned. “It also allows us to detect viruses with zoonotic potential and to assess the potential risk for their transmission to other species including humans.”
The team’s analysis revealed sequences corresponding to 39 viral families, including coronavirus, adenovirus, hepevirus, rotavirus and parvovirus. The collection included sequences that were aligned with 16 viral families previously found in other vertebrate hosts, highlighting the zoonotic potential of viruses carried by bats.
“Human interaction with wildlife is one of the main contributors to zoonotic spillover and this impact needs to be re-evaluated,” the authors wrote, noting that the “first assessment of the Swiss bat virus” forms a platform for future in-depth studies to investigate changes in virus prevalence, virus biology, virus-host interaction and virus emergence. “
This story first appeared in our sister publication, GenomeWeb.