Choosing an Animal Model Pathogen may not affect animal at all -OR￾may give different symptoms Given disease may have a number of animal models, none of which fully satisfies characteristics of disease

实验动物质量控制 ❖遗传质量控制 ❖微生物质量控制 ❖营养质量控制 ❖环境质量控制

遗传质量控制 微生物质量控制 营养质量控制 环境质量控制

General aspects – Remember definition: organisms frequently found on or within body of healthy individuals – Most are bacteria, but some are viruses, fungi, and protozoa

American Legion Convention in 1976 in Philadelphia hotel – Respiratory distress and fever – 200 affected – 34 died

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

Staphylococci Important human pathogen – Causes both relatively minor and serious diseases One of the hardiest of the non￾sporeforming bacteria – Can exist on dry surfaces for a long period – Relatively heat-resistant; temperature range

Production of Ab and Activation of Macrophages and Cytotoxic T Cells T-Dependent T-Independent