McDonald’s shares drop as Quarter Pounders tied to fatal US E. coli outbreak Financial TimesE. coli Outbreak Linked to McDonald’s Quarter Pounders CDCMcDonald’s E. Coli Outbreak: Stock Drops After CDC Ties Quarter Pounder to 1 Death Barron’sHow McDonald’s can learn from other fast-food giants in recovering from the deadly E. coli outbreak Business InsiderFry Sauce: McDonald’s E. coli outbreak hits Utah Axios