Lecture 6 Hygiene Flashcards
Microbiological status of lab animals (types, 4)
- Germ Free animals (GF):
- Gnotobiotic animal
- Specified Pathogen Free animal
- Conventional animal
Why is hygiene important?
- To prevent diseases/illnesses/mortality of lab animals = animal welfare
- To protect the influence on experimental research
- To prevent Zoonosis (where a pathogen is transferred from animal-human)
- Quality of biological products
Germ free animal
completely free from germs. Housing in isolators, extremely sensitive to infections. Obtained via rederivation. Pregnant (GF/SPF) animal –> hysteractomy right before partus –> take out pups under sterile conditions –> transferred to an aseptic isolator via a trap/filter systems –> raised by hand/foster mother (also germ-free).
Gnotobiotic animal
Complete microbiota composition is known, because you add them to a GF animal.
Specified pathogen free animal
.You don’t say what they have, you say what they dont have. So it’s free of specified MicroOrganisms.
o No complete isolation or barriers
o All animals have ‘normal’ biota
Conventional animals
Are not obtained via an commercial breeder.
o Microbiological status (pathogen and non-pathogen) is completely unknown
o Isolation period necessary
“burn out”
- Viral infections
- No introduction of new animals for 6 weeks
- No breeding
- If all animals will be infected, some sort of passive, protective immunity will develop and infection will be silenced
“stamping out”
All animals will be taken out of the population
Different barriers/housing
- Animal ventilated cabinets
- Individual ventilated cages: barrier around each individual cage.
- Filter-top-cage: ventilation is worse.
- Isolators: completely isolated from outside. Hepa filter, and “waterslot” for everything that goes in
Pressure + protection
Under pressure (protection staff)
Overpressure (protection animals)
Barrier between different animal facilities
SPF – GF – conventional – DM II – DM III
