Content Section
Under a very high magnification of 12000X, this colorized scanning electron micrograph shows a large grouping of Gram-negative Salmonella bacteria.  A salmonella outbreak has sickened at least 21 people and prompted the recall of 800,000 pounds of ground beef, federal officials announced August 7, 2009. REUTERS/Janice Haney Carr/CDC/Handout  (UNITED STATES HEALTH) FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS - RTR26I3N Photo Illustration by The Daily Beast