Scientists have identified 234 known viruses, besides harmful bacteria and insects in sewage flushed out in three cities of Pittsburgh, Pennsylvania, United States, Barcelona in Spain and Addis Ababa in Ethiopia.
The finding reverses the widely-held belief that only bacteria and germs were present in sewage and it may revolutionize the way we keep ourselves clean.
While 17 viruses found were harmful to humans, plant, insect, and algal viruses as well as bacteriophages were also present. These viruses represented 26 taxonomic families and included viruses with single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), positive-sense ssRNA [ssRNA), and dsRNA genomes.
About 3,000 different viruses are recognized, but metagenomic studies suggest that these viruses are a small fraction of the viruses that exist in nature, said the scientists who studied the raw sewerage samples.
New viruses that could be placed in specific taxonomy represented 51 different families, making untreated waste water the most diverse viral metagenome. “We have explored viral diversity by deep sequencing nucleic acids obtained from virion populations enriched from raw sewage,” said researchers.
Researchers from the Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Microbiology, Faculty of Biology, University of Barcelona, Barcelona, Spain; and Departments of Molecular Microbiology and of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA have studied the waste water from the three continents and their findings revealed that the viral universe is far more vast and diverse than previously suspected.