Slippery Salmonella (IMAGE) DOE/Pacific Northwest National Laboratory Caption PNNL scientists have identified a protein in Salmonella bacteria that enables it to infect immune cells called macrophages. Seen here: Salmonella, isolated from infected macrophrages. (Mildly color-enhanced. Photo credit: Pacific Northwest National Laboratory.) Credit Pacific Northwest National Laboratory Usage Restrictions None 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.