Scientist at Work (IMAGE) Washington University in St. Louis Caption Arjes examines a tame lab strain of the bacteria Staphylococcus aureus on blood agar plates. Credit Petra Levin Usage Restrictions please credit 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.