VMC 221: Veterinary Immunology and Serology (1+1)

General Barriers in innate immunity

GENERAL BARRIERS OF INNATE IMMUNITY

• General barrier is the non-susceptibility of an individual against a particular disease.
• Examples: Genetic factors, physiologic factors, nutritional factors etc.
• Genetic factors
  • Species specificity - Rinderpest is a disease of animals (cattle, sheep and goats) but not for human beings. FMD virus does not infect horses and dogs.
  • Genetically resistant groups - For example, African blacks are more susceptible to tuberculosis in America. White coloured (B₁ line) broiler chickens are more susceptible to Hydro pericardium syndrome disease etc.
• Physiologic factors 
  • Cold blooded animals are not susceptible to tetanus toxins.
  • Body temperature at 42 ^o c (birds) does not allow many organisms to grow even Fever is beneficial to the body.
  • Age: Very young and old age groups are susceptible to infection with many organisms.