Riding the Virus

Viruses that infect bacteria, or phages, inject their DNA into bacterial hosts and use them to create more and more phages until the hosts die. But bacteria, which have evolved to resist many antibiotics, have also learned to use the phages to their own advantage and become "superbugs," says Not Exactly Rocket Science's Ed Yong. By adding the viruses' DNA to their own genome, these bacteria have become able to withstand harsh environments and immune to any drugs that might previously have killed them. In order to find out exactly how this virus DNA was affecting the bacteria, Texas A&M University's Xiaoxue Wang — whose study appears in Nature Communications — snipped it out of an E. coli culture and found that without this extra DNA, the bacteria lived and grew but was unable to deal with "difficult conditions," Yong says. "They became up to 400 times more sensitive to antibiotics. They succumbed more readily to extremely salty or acidic conditions. And they were almost completely unable to form biofilms." This could lead to finding new ways to prevent bacteria from becoming resistant to drugs, Yong adds.