IC5 Flashcards
what are pyrogens
substances that induce fever when injected into mammals
what are the types of pyrogens
1) LPS from gram -ve bacteria
2) microbial substances: basically the microorganisms
3) non microbial: rubber, microscopic plastic, metal compound in elastomer
types of animal based pyrogen test - rabbit pyrogen test (RPT) - general
- measure rise in rabbit temp after IV injection of tested product
- qualitative
types of animal based pyrogen test - rabbit pyrogen test (RPT) - disadvantages
1) low sensitivity
2) development of pyrogen tolerance after repeated injection
3) stress from rabbit when performing assay
4) POOR RABBITS
types of animal based pyrogen test - bacterial endotoxin test (BET) or limulus amoebocyte lysate (LAL) test
- horseshoe crab
- high sensitivity (quantification)
- can’t test for non endotoxin pyrogens
types of in vitro pyrogen test - monocyte activation test (MAT) - how it works
IF PYROGEN PRESENT:
monocyte activated -> produce inflamamtory molecule & cytokines for febrile reaction -> detect cytokines using ELISA for specific antibodies & enzymatic colour reaction
types of in vitro pyrogen test - recombinant factor C (rFC)
- factor C react w endotoxin + marker = quantifiable, fluorescent end product
- similar to BET/LAL but no horseshoe crab blood
types of culture media used for sterility testing
1) fluid thioglycolate medium (FTM)
- anaerobic & some aerobic bacteria
2) soybean casein digest medium (SCDM)
- fungi & aerobic bacteria
3) sabouraud dextrose agar (SDA)
- yeast
how many days are samples incubated for in culture medium and why so long
14 days, not every bacteria grow at the same rate
types of sterility testing methods - j list down all
1) membrane filtration
2) direct inoculation
3) direct transfer
4) product flush
membrane filtration sterility testing - process
passed through 0.45 micrometer membrane in filtration canister & culture medium added for incubation
membrane filtration sterility testing - sensitivity
HIGH
- whole sample passed through single filter
membrane filtration sterility testing - advantages
can wash away components that cause turbidity/inhibit growth (abx, preservative)
membrane filtration sterility testing - most probable number (MPN)
estimate viable numbers of bacteria in sample by inoculating broth in 10-fold dilutions based on principle of extinction dilution
direct inoculation sterility testing - process
small vol of sample removed aseptically from sample -> inoculated directly into suitable vol of growth medium -> incubation
direct inoculation sterility testing - sensitivity
LOW
- only small vol inoculated into culture medium
direct inoculation sterility testing - disadvnatages
if sample cloudy/turbid after inoculation: tough to detect turbidity from microbial growth at end of incubation period
direct inoculation sterility testing - testing sterility of antimicrobial product
need to neutralise first so microorganism can growth
direct transfer sterility testing - what is it used for
medical device