Host Defense Against Foodborne Pathogens

Abstract

Interaction of pathogenic microbes with a host leads to two consequences: disease or recovery. Microbial dominance results in the disease while successful host response averts the full-blown infection. Immune system plays a key role in either of these outcomes. The ability of the human body to protect against the microbial infections is continuously evolving because of continued exposure to different elements. Ironically, microbes are also evolving in the same fashion so that they can adapt themselves in the host. Human body has a rich source of nutrients that supports the growth of both pathogens and commensal microbes. Though the pathogens are the primary disease producing organism, the commensal organisms can also cause disease only under a favorable environment. In most situations, immune system restricts the infection and the spread of disease; however, breach in the immune response or overt reaction to the pathogen presence results in the onset of symptoms. Therefore, to understand the disease process one has to understand the host immune system and the defense mechanism. The host immune system can be compared as ``impenetrable fort'' impervious to attack and is guarded by soldiers as immune cells, armed with deadly weapons like cytokines, complement proteins and antibodies to stay at an ``alert'' position to combat sudden or deliberate attack by unsuspected enemies as pathogens. Immune responses are of two types; innate and adaptive.