Bacteria (IMAGE) Penn State Caption The virus SW1 is carried by cells so that related bacteria may recognize other SW1 carriers and kill bacteria that do not have the virus, giving bacteria with SW1 a competitive advantage when foraging for food. Credit Sooyeon Song and Missy Hazen/Penn State Usage Restrictions Non commercial use only License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.