Electron Micrograph (IMAGE) American Society for Microbiology Caption Pseudo-colored electron micrograph of Serratia marcescens bacteria (red) on a human corneal cell in vitro. The yellow arrow indicates a large surface bleb induced by a toxin produced by the bacteria. The white bar indicates 10 microns. Credit Robert Shanks 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.