DOES Louisiana hot sauce, a principal ingredient in the spicy New Orleans cocktail sauce commonly served with raw shellfish, kill certain bacteria found in raw oysters? The answer is yes, at least in the laboratory, researchers said in a preliminary report at a national scientific meeting on microbes and antibiotics yesterday. Principal ingredients of the traditional New Orleans cocktail sauce were found to kill a rare but sometimes fatal bacteria called Vibrio vulnificus. Dr. Sanders said that he saw his first case of V. vulnificus infection 10 years ago and that his interest in studying the sauces arose from lectures...