From Friend to Foe: How Benign Bacteria Evolve To Virulent Pathogens (image) PLOS Share Print E-Mail Caption Macrophage (in red) infected with fluorescent labelled E. coli (in yellow or blue). Bacteria can evolve rapidly to adapt to environmental change. When the "environment" is the immune response of an infected host, this evolution can turn harmless bacteria into life-threatening pathogens. A study published on December 12 in PLOS Pathogens provides insight into how this happens. Credit Gordo lab, Instituto Gulbenkian de Ciência Usage Restrictions None Share Print E-Mail 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.