Spread and Contamination Flashcards
ways microbes can spread
air (aerosols), blood, secretions, direct contact (mucous membranes, hands), insects
procedures that can produce aerosols
using a blender
opening cups or tubes (particularly those with a wet lid)
using a vortexer
centrifuging open tubes (especially over-filled ones)
splashes from a culture
pipetting
sonication
freeze-drying
pouring off or transferring
exposure
Exposed to microorganisms means that there is no physical separation between the microorganism and you.
contamination
to come in contact with microorganism after exposure
infection
The entry of a microorganism into the body of a living being, the host, and the replication of the microorganism in the host
Sterilization
Completely destroy microbes incl. spores. Quality standard: probability of one surviving microorganism is 1 in 1,000,000.
Disinfection
Destroy/remove/restrict growth of microorganisms. No quality standard.
Sterilisation ex.
autoclaving (process using high-pressure saturated steam at 121ºC)
hot air, 180ºC
incineration
filtration through filter with 0.2 µm pores (not used for viruses)
ethylene oxide gas
formaldehyde, glutaraldehyde solutions
gamma radiation
Disinfection ex.
chlorine solutions (Staphylex)
70% ethanol
2% SDS
iodine
hot water / steam / boiling
formaldehyde gas
hydrogen peroxide gas / vapour
Autoclaving steam temp.
120 C
Autoclave: sterilize clean material
20 minutes at 121ºC
Autoclave: sterilise bio waste (no spores)
at least 30 minutes at 121ºC
Autoclave: bio waste w/ spore forming bacteria
depends on validation results
Shelf life of chlorine solution
2 weeks
Ethanol is less effective against viruses…
…w/o a viral envelope.
Physical containment: first layer
Container (vial/bottle)
Close/seal properly
Physical containment: second layer
Containment cabinet.
Class II safety cabinet blocks microorganisms - prevents contamination of lab by sample and vice versa.
outer layer (physical containment)
laboratory
bio. containment example
lentivirus (class 3 virus)
vector systems (buy) -> viruses that cannot multiply further once they are in the target cell.
class 1
Microorganism that does not cause disease in humans, animals or plants.
class 2
Microorganism that can cause disease in humans and is unlikely to spread among the population, for which an effective prophylactic, treatment or preventive measure is available.
class 3
Microorganism that can cause serious disease in humans and is likely to spread among the population, for which an effective prophylactic, treatment or preventive measure is available.
Class 4
Microorganism that can cause very serious disease in humans and is likely to spread among the population, for which no effective prophylactic, treatment or preventive measure is available.
statutory requirements for working with genetically modified microorganisms in laboratories are set out in
Ministerial Regulation on GMO (Regeling GGO).
statutory requirements for wild type microorganisms are in
Occupational Health and Safety information magazine 9 (AI 9, ARBO)
Institutes working with animal by-productes must have approval for this from the
Food and Consumer Product Safety Authority (NVWA, Nederlandse Voedsel en Waren Autoriteit).
Storing animal products: register per container unit…
Description of material
Quantity of material
Date of receiving in the laboratory
Place of origin of the material
Name and address of carrier
or (last 2) CCD no. for byproducts from RUG lab
keep documentation abt animal byproducts until
2yrs after byproducts destroyed
