Almost 2 million cartons of eggs across the United States have been pulled off shelves because of the threat of a salmonella outbreak. The recall, announced Friday by California-based manufacturer August Egg Co., affects dozen-egg packages distributed to retail chains in at least nine states: California, Washington, Nevada, Arizona, Wyoming, New Mexico, Nebraska, Indiana and Illinois. Salmonella, a group of bacteria, is one of the most common causes of food poisoning in the United States.