ch14 pt7

Koch’s Postulates

1. same pathogen must be present in every case of the disease

2. pathogen must be isolated from diseased host & grown in pure culture

3. pathogen from pure culture must cause the disease when it’s inoculated into healthy, susceptible laboratory animal

4. pathogen must be isolated from inoculated animal and must be shown to be the original organism

pathway of Koch’s Postulates

1. microorganisms are isolated from a diseased or dead animal

2. the microorganisms are grown in pure culture

2b. microorganisms are identified

3. microorganisms are inoculated into a healthy laboratory animal

4. disease is reproduced in a laboratory animal

5a. the microorganisms are isolated from this animal and grown in pure culture

5b. microorganisms are identified

Koch’s Postulates exceptions

1. some pathogens can cause several disease conditions

2. some pathogens cause disease only in humans (could not be tested with lab animal)

3. some microbes have never been cultured

BSL-1

no special precautions; basic teaching labs, e. coli

BSL-2

lab coat, gloves, eye protection; P. aeruginosa

BSL-3

biosafety cabinets to prevent airborne transmission; M. tuberculosis

BSL-4

sealed, negative pressure, hot zone, exhaust air is filtered twice through HEPA filters; Ebola

Centers for Disease Control & Prevention CDC

collects and analyzes epidemiological information in US, publishes Morbidity and Mortality Weekly Report (MMWR)

morbidity

incidence of a specific notifiable disease

mortality

deaths from notifiable diseases

notifiable infections diseases

physicians required to report occurrence