Though viruses are the most abundant life form on Earth, our knowledge of the viral universe is limited to a tiny fraction of the viruses that likely exist. In a paper published in the online journal mBio, researchers from the University of Pittsburgh, Washington University in St. Louis, and the University of Barcelona found that raw sewage is home to thousands of novel, undiscovered viruses, some of which could relate to human health.
There are roughly 1.8 million species of organisms on our planet, and each one is host to untold numbers of unique viruses, but only about 3,000 have been identified to date. To explore this diversity and to better characterize the unknown viruses, James Pipas…Roger Hendrix and…Michael Grabe…are developing new techniques to look for novel viruses in unique places around the world…The team searched for the genetic signatures of viruses present in raw sewage from North America, Europe, and Africa…
“What was surprising was that the vast majority of viruses we found were viruses that had not been detected or described before,” says Hendrix.
The viruses that were already known included human pathogens like Human papillomavirus and norovirus, which causes diarrhea. Also present were several viruses belonging to those familiar denizens of sewers everywhere: rodents and cockroaches. Bacteria are also present in sewage, so it was not surprising that the viruses that prey on bacteria dominated the known genetic signatures. Finally, a large number of the known viruses found in raw sewage came from plants, probably owing to the fact that humans eat plants, and plant viruses outnumber other types of viruses in human stool…
The main application of this new technology, says Hendrix, will be to discover new viruses and to study gene exchange among viruses. “The big question we’re interested in is, ‘Where do emerging viruses come from?’” he says. The team’s hypothesis is that new viruses emerge, in large part, through gene exchange. But before research on gene exchange can begin in earnest, large numbers of viruses must be studied, the researchers say.
“First you have to see the forest before you can pick out a particular tree to work on,” says Pipas. “If gene exchange is occurring among viruses, then we want to know where those genes are coming from, and if we only know about a small percentage of the viruses that exist, then we’re missing most of the forest.”
Great. Just what we need to know. Now, all those sci-fi movies about mutated creatures rising up from the sewers to eat all of us become a bit more real.
I know, I know. I have a strange sense of humor.
What impresses me the most – once again – is how little we know of this world we live on and within. This is just the kind of basic research the know-nothings in Congress and assorted flat-earthers resent and joke about. Their cognizance of the material world is shallow in direct proportion to the amount of time they spend whining about their self-ordained superstitious reasons for the ills that befall humankind.