Viruses make home in raw sewage
Viruses lurk in the most mysterious spaces with our planet playing host to a copious lot; 3,000 viruses have been identified to date. But researchers have been unsuccessful in shedding light on size and characteristics of the viral universe and the diversity of the viral genome. With all eyes on determining the diversity and characteristics of viruses, a team of scientists in Spain and the United States has developed new techniques to identify new viruses in unique places across the globe. The results of the study are published in the journal mBio. Failing to improve our knowledge about the viral universe makes it harder for researchers to determine the origin of emerging pathogens and gene exchange among viruses. Scientists at the University of Barcelona in Spain, and the University of Pittsburgh and Washington University in St Louis in the United States say never-before-seen viruses have found a niche in raw sewage, with the potential to impact human health. Investigating the genetic signatures of these viruses in raw sewage from Europe, North America and Africa, the team detected signatures from 234 known viruses that represent 26 families of viruses. According to the researchers, raw sewage contains the widest range of viruses ever known. 'We wanted to examine environments where viral concentrations and diversity are relatively high,' the authors write in the paper. 'In this regard, we hypothesise that the highest concentrations of viruses will be found where there is a high density of host species and that viral diversity will correspond to the biodiversity of host species.' Roger Hendrix from the Department of Biological Sciences at the University of Pittsburgh says: 'What was surprising was that the vast majority of viruses we found were viruses that had not been detected or described before.' The viruses already known to researchers include human pathogens like Human papillomavirus and norovirus, which causes diarrhoea. Other viruses belonging to those familiar 'denizens' of sewers everywhere include rodents and cockroaches. Raw sewage is also home to bacteria, where viruses that feed on these bacteria dominated the known genetic signatures. The team also points out that many 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. Commenting on the research, Professor Hendrix says: 'The big question we're interested in is, 'Where do emerging viruses come from?'.' Based on their theory, gene exchange is what triggers the emergence of new viruses. However, large numbers must be investigated in order to perform more research on gene exchange. 'First you have to see the forest before you can pick out a particular tree to work on,' says James Pipas, also from the Department of Biological Sciences at the University of Pittsburgh and senior author of the study. '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.'For more information, please visit:University of Barcelona:http://www.ub.edu/web/ub/en/University of Pittsburgh:http://www.pitt.edu/mBio:http://mbio.asm.org/
Countries
Spain, United States