Choosing an Animal Model Pathogen may not affect animal at all -ORmay give different symptoms Given disease may have a number of animal models, none of which fully satisfies characteristics of disease
General aspects – Remember definition: organisms frequently found on or within body of healthy individuals – Most are bacteria, but some are viruses, fungi, and protozoa
Microbial pathogenesis—process of causing disease Colonization—presence of microbes at site of body – Does not imply tissue damage or disease symptoms – Does imply invasion of site and multiplication
General Aspects Ecology – Found throughout the environment Very simple nutritional requirements – Not usually in normal flora unless hospitalized or immunocompromised
Diversity of species Ecology – Found worldwide in soil, water, vegetation, and microbial flora of animals and humans – Some are always associated with disease
Comparison of Meningococcus and Gonococcus Pathobiology Similarities: – Both diploccocci – Share about 80% DNA – Neither makes exotoxin; both make endotoxin – Both are relatively good colonizers