A virus that lives in the ocean has been shown to infect human eye cells, according to a new study from researchers in China. The pathogen, known as SIO1, is a type of bacteriophage a virus that normally attacks bacteria, not people. But laboratory tests revealed it can enter human corneal cells and replicate inside them.
How a marine virus ended up in a petri dish
The discovery came from a team at the Ocean University of China and the Chinese Academy of Sciences. They were studying viruses in coastal waters when they decided to test whether SIO1 could interact with human tissue. The virus was isolated from seawater collected off the coast of Qingdao, a port city in eastern China. When the researchers exposed cultured human corneal epithelial cells to SIO1, the virus successfully attached to the cells and began making copies of itself.
Why local scientists and doctors took notice
Qingdao is a major fishing and tourism hub where people regularly come into contact with seawater. The finding raised concerns among local health officials because eye infections are common among fishermen, swimmers, and seafood workers in the region. Until now, those infections were usually blamed on bacteria or common viruses. The study suggests that marine bacteriophages could be an overlooked cause of conjunctivitis and other eye problems in coastal communities.
What the experiment actually showed
The researchers used high-powered microscopes to watch the virus bind to the surface of human corneal cells. Once inside, SIO1 hijacked the cell's machinery to produce more viral particles. The infection did not kill the cells quickly, which means a person could carry the virus without obvious symptoms for some time. The study was published in the peer-reviewed journal Microbiology Spectrum.
This is the first time a marine bacteriophage has been shown to infect human cells. The finding does not mean SIO1 causes widespread disease, but it opens a new line of inquiry for virologists studying how pathogens move between species and environments.
