IC5 Flashcards

1
Q

what are pyrogens

A

substances that induce fever when injected into mammals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the types of pyrogens

A

1) LPS from gram -ve bacteria
2) microbial substances: basically the microorganisms
3) non microbial: rubber, microscopic plastic, metal compound in elastomer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

types of animal based pyrogen test - rabbit pyrogen test (RPT) - general

A
  • measure rise in rabbit temp after IV injection of tested product
  • qualitative
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

types of animal based pyrogen test - rabbit pyrogen test (RPT) - disadvantages

A

1) low sensitivity
2) development of pyrogen tolerance after repeated injection
3) stress from rabbit when performing assay
4) POOR RABBITS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

types of animal based pyrogen test - bacterial endotoxin test (BET) or limulus amoebocyte lysate (LAL) test

A
  • horseshoe crab
  • high sensitivity (quantification)
  • can’t test for non endotoxin pyrogens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

types of in vitro pyrogen test - monocyte activation test (MAT) - how it works

A

IF PYROGEN PRESENT:
monocyte activated -> produce inflamamtory molecule & cytokines for febrile reaction -> detect cytokines using ELISA for specific antibodies & enzymatic colour reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

types of in vitro pyrogen test - recombinant factor C (rFC)

A
  • factor C react w endotoxin + marker = quantifiable, fluorescent end product
  • similar to BET/LAL but no horseshoe crab blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

types of culture media used for sterility testing

A

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 well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how many days are samples incubated for in culture medium and why so long

A

14 days, not every bacteria grow at the same rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

types of sterility testing methods - j list down all

A

1) membrane filtration
2) direct inoculation
3) direct transfer
4) product flush

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

membrane filtration sterility testing - process

A

passed through 0.45 micrometer membrane in filtration canister & culture medium added for incubation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

membrane filtration sterility testing - sensitivity

A

HIGH
- whole sample passed through single filter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

membrane filtration sterility testing - advantages

A

can wash away components that cause turbidity/inhibit growth (abx, preservative)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

membrane filtration sterility testing - most probable number (MPN)

A

estimate viable numbers of bacteria in sample by inoculating broth in 10-fold dilutions based on principle of extinction dilution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

direct inoculation sterility testing - process

A

small vol of sample removed aseptically from sample -> inoculated directly into suitable vol of growth medium -> incubation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

direct inoculation sterility testing - sensitivity

A

LOW
- only small vol inoculated into culture medium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

direct inoculation sterility testing - disadvnatages

A

if sample cloudy/turbid after inoculation: tough to detect turbidity from microbial growth at end of incubation period

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

direct inoculation sterility testing - testing sterility of antimicrobial product

A

need to neutralise first so microorganism can growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

direct transfer sterility testing - what is it used for

A

medical device

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

direct transfer sterility testing - how does it work

A

device in direct contact w test media during incubation -> microorganism in/on device grow & proliferate

21
Q

product flush sterility testing - what is it used for

A

medical devices w hollow tubes where fluid pathway is labelled as sterile

22
Q

product flush sterility testing - how does it work

A

product lumen flushed w rinsing fluid -> elute membrane filtered -> placed in suitable media for incubation

23
Q

what are the disadvantages of sterility testing methods

A

1) lengthy process
2) sample size problems
3) costly

24
Q

list of all the sterilisation methods

A

1) moist heat
2) dry heat
3) chemical

  • ethylene oxide
  • peracetic acid
  • gas plasma

4) gamma radiation
5) ozone

25
Q

moist heat sterilisation - process

A

expose each item to direct steam contact at required temperature & pressure for specified time

26
Q

moist heat sterilisation - MOA

A

destroy microorganism by irreversible coagulation & denaturation of enzymes & structural proteins

27
Q

moist heat sterilisation - parameters

A

1) steam
2) pressure (for high temp)
3) high temperature (121 - 132 deg celc)

28
Q

moist heat sterilisation - D-value

A
  • time to reduce surviving population by 90% or 1logD
  • used for direct comparison of microorganism heat resistance.,…dfdsfsdf
29
Q

moist heat sterilisation - F-concept

A
  • equivalent time that monitored object is exposed to desired temperature
  • basically from turning on the machine to when object reach sterilisation temperature
30
Q

dry heat sterilisation - what is it used on

A

1) materials damaged by moist heat
2) materials impenetrable to moist heat (powder, petroleum, sharp instrument)

31
Q

dry heat sterilisation - advantages

A

1) easier to operate & maintain
2) slow rate of heat penetration

32
Q

dry heat sterilisation - types

A

1) static-air type
- slower in heating (longer time to reach sterilising temp)
- less uniform in temperature control throughout chamber

2) forced-air type
- circulate heated air throughout chamber = rapid transfer of energy from air to instrument

33
Q

dry heat sterilisation - parameters

A

> 220 deg celc

34
Q

chemical sterilisation - ethylene oxide (ETO) - how it works

A

alkylating agent, attack protein, nucleic acid, other compounds

35
Q

chemical sterilisation - ethylene oxide (ETO) - advantages

A
  • works on several materials
  • well tolerated
  • residue eliminated w proper aeration
36
Q

chemical sterilisation - ethylene oxide (ETO) - limitations

A
  • flammable & explosive
  • lots of side effects
  • carcinogenic
37
Q

chemical sterilisation - paracetic acid - how it works

A

highly biocidal oxidiser that still works in organic soil

38
Q

chemical sterilisation - paracetic acid - uses

A

endoscopic tube

39
Q

chemical sterilisation - paracetic acid - parameters for inactivation of different types of microorganism dfjskdjfkasj IDK IF IMPT

A

1) gram pos, gram -ve, fungi, yeast
- < 5 mins at < 100ppm

2) presence of organic matter
- 200-500 ppm

3) virus
12-2250 ppm

4) bacterial spore
15s-30s, 500-10k ppm

40
Q

chemical sterilisation - gas plasma - production

A

deep vacuum -> radio freq/microwave energy -> excite gas molecules -> produce charged particles (free radicals) within plasma field -> interact w essential cell component -> disurpt microorganism metabolism

41
Q

chemical sterilisation - gas plasma - parameters

A

1) deep vacuum
2) 37-44 deg celc
3) 75 mins

42
Q

chemical sterilisation - gas plasma - MOA

A

h2o2 inactivate broad range of microorganism from surfaces as well

43
Q

chemical sterilisation - gas plasma - advantages

A
  • by products non toxic (X need aeration)
  • sterilised material handled safety
44
Q

gamma radiation - parameters

A

MAN I REALLY DK IF THIS IS IMPORTANT DJHFAKJSD

  • cobalt 60, cesium 137, electron accelerator
  • low temperature
45
Q

gamma radiation - general

A

1) low penetration, high dose rate
2) used for medical product & packaging material

46
Q

gamma radiation - limitations

A

deleterious effect on patient care equipment
- induced oxidation in polyethylene
- delamination/cracking in polyethylene knee bearings

47
Q

ozone - production

A

O2 oxidised -> 2 monoatomic molecules (O) -> collide w O2 -> ozone (O3)

48
Q

advantages of ozone

A
  • powerful oxidant that destroy microorganism
  • compatible w wide range of materials
49
Q

disadvantages of ozone

A

highly unstable