WASHINGTON, April 4 (Xinhua) -- A team of researchers in the United States and Uganda has identified a novel coronavirus in a bat from Uganda that is similar to the one causing Middle East Respiratory Syndrome (MERS) in people, providing further support to the theory that such viruses originate in bats.
However, lab experiments with the virus, named PREDICT/PDF-2180, indicated that in its current state it is unlikely to pose a threat to humans, according to the study published Tuesday in mBio, an online open-access journal of the American Society for Microbiology.
For the study, researchers from the University of California, Davis and the non-profit organization Gorilla Doctors sequenced the genome of the PDF-2180 virus found in a rectal swab taken from a bat trapped in February 2013 in southwestern Uganda.
Overall, the virus was 87 percent identical to the deadly MERS virus and 91 percent identical to NeoCoV, another coronavirus found in a bat from South Africa.
However, part of the spike gene, the segment of the virus responsible for invading cells, was only 46 percent identical to the one belonging to the MERS virus.
Next, to test the ability of the virus to spread to humans, researchers at the University of North Carolina constructed an infectious MERS clone expressing the PDF-2180 spike protein.
Viruses derived from the clone could reproduce themselves but could not enter cells expressing DPP4, the receptor normally used by MERS, or establish new infections either in cells derived from monkeys or in human airway cells from healthy lung donors.
"In its current form, evolution notwithstanding, this virus is probably not going to be a threat to human health," said lead study author Simon Anthony, an assistant professor of epidemiology at the Columbia University.
The discovery of the virus adds to the growing number of coronaviruses identified in bats, Anthony said, including coronaviruses in South Africa, Mexico, Thailand, the Netherlands, Italy and China.
"Collectively, these examples demonstrate that the MERS-related coronaviruses are highly associated with bats and are geographically widespread," Anthony said.
MERS, first reported in Saudi Arabia in 2012, is an illness marked by severe acute respiratory disease with symptoms of fever, cough and shortness of breath. About four of every 10 patients with the condition have died, according to the U.S. Centers for Disease Control and Prevention.