Scientists totally not funded by the Umbrella Corporation have created the first "semi-synthetic" micro-organism. The microbe contains an extra base pair of synthetic chemicals in its DNA, ominously designated as X and Y — but thankfully no Z (which, if implemented, will obviously begin coding zombie proteins). The Independent reports:

The semi-synthetic microbe, a genetically modified E. coli bacterium, has been endowed with an extra artificial piece of DNA with an expanded genetic alphabet – instead of the usual four "letters" of the alphabet its DNA molecule has six.

This may seem kinda scary, you know, creating a biological entity with a genetic code never before seen on the planet entity humanity has no evolutionary defense against that will undoubtedly escape the lab and turn everyone's hometown into Raccoon City. But rest assured, there is absolutely nothing to worry about:

The researchers emphasised that there is little danger of the new life-forms living outside the confines of the laboratory, as they are not able to replicate with their synthetic DNA strand unless they are continuously fed the X and Y bases – synthetic chemicals called "d5SICS" and "dNaM", that do not exist in nature.

Plus as long as we have Milla Jovovich as our first line of defense we should be OK.