ABSTRACT
Food products contain many human pathogens. The alimentary tract is an impassable barrier for a lot of them, which prevents them from penetrating the whole body. Examples include infections of the upper respiratory tract, especially purulent tonsillitis caused by staphylococci or streptococci, which turn tonsils into bacteria cultures. The bacteria use swallowed saliva to reach the alimentary tract, but they cannot survive there and make the infection develop. Some of them can cross the physiological and morphological barrier and in›ltrate other organs, where the infection develops, but with no visible symptoms from the alimentary tract; these include Salmonella typhi, bovine Mycobacterium tuberculosis (M. bovis), Francisella tularensis, Yersinia pseudotuberculosis, and Brucella bacteria.
