bacteria 5,6 Flashcards

1
Q

when does microbial contamination occur

A

during manufacturing process and products escape quality assurance checks

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2
Q

what are the impacts of microbial contamination

A

medicine unfit for use, potential litigation, financial loss, limits supply to patients, health hazards, infections, endoxins

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3
Q

what medicine components/pharmaceutical ingredients are at risk of microbial attacks

A

active drugs- metabolised to less potent/chemically inactive forms

non/anionic surfactants- alkyl/alkylbenzene sulphonates are readily metabolised

organic polymers (thickening agents)- microbial depolymerisation

humectants- readily metabolised in low amounts

fats/oils- attacked when dispersed in aqueous formulations

sweeteners/flavourings/colouring agents- substrates for bacteria, high conc are resistant to degradation

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4
Q

how to resist microbial contamination

A

use preservatives

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5
Q

what are visible signs of contamination

A

unpleasant smell, sour taste, appearance change, texture/viscosity changes, sedimentation, production of bubbles, cracking, change in efficacy

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6
Q

what causes viscosity and textures to change when a medicine component is contaminated

A

metabolism of thickening agents or sugar polymerisation

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7
Q

what are preservatives used for

A

resist microbial contamination

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8
Q

factors that affect/cause microbial contamination of a pharmaceutical product

A

type/size of inoculum, nutritional factors, moisture content (greater solute conc=lower water activity), redox potential, storage temp, pH, packaging design protection of microorganisms in pharmaceutical products

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9
Q

list some non-antibiotic antimicrobials available

A

antiseptics, disinfectants, preservatives, creams/ointments, disinfectant sprays, biocides, alcohol based gel scrubs

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10
Q

describe how the non-antibiotic antimicrobial, antiseptics, work

A

destruction/inhibition of microorganisms on living tissue, against sepsis, prevents systemic infection, non toxic to host, ex vivo use (wounds, mouth)

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11
Q

what is ex vivo

A

outside living body

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12
Q

what is sepsis

A

body doesnt respond properly to an infection

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13
Q

describe how the non-antibiotic antimicrobial, disinfectants, work

A

removes microorganisms from inanimate objects/surfaces, kills/reduce numbers to a level that is acceptable for defined purpose, most are too toxic to use on body tissue

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14
Q

describe how the non-antibiotic antimicrobial, preservatives, work

A

added to pharmaceutical,cosmetics,foods to prevent microbial contamination, non toxic, lower activity level than antiseptics and disinfectants

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15
Q

what trait must a preservative have to be considered efficient

A

effective against two bacterias, a yeast and a mould

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16
Q

a chemical exhibits antimicrobial activity if…

A

it interacts and enters a host cell

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17
Q

how do non-antibiotic antimicrobials initially interact with the cell wall/membrane

A

electrostatic or hydrophobic interactions

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18
Q

how do non-antibiotic antimicrobials enter a cell

A

porin channels or diffusion

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19
Q

what affects the efficacy of a biocide

A

affinity for structural/molecular components

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20
Q

what is the rate of non-antibiotic antimicrobials activity affected by

A

temperature, concentration pH, solubility, type/form of microorganisms present

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21
Q

how do biocides work/exhibit antimicrobial activity

A

structural damage to cell wall/membrane or interactions with cellular components

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22
Q

why is resistance to biocides not often seen

A

biocides are short lasting

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23
Q

which type of bacteria is more resistant to biocides

A

gram-negative

24
Q

list the 5 methods of sterilisation

A

moist heat (steam), dry heat, ionising radiation, gas, filtration

25
Q

describe how moist heat (steam) is used for sterilising, what it is used to sterilise and its lethal effects

A

used for: culture media, medical implements (tools), aq injections, ophthalmic preparations

lethal effects: denaturation of enzymes or destruction of cell

steams at 121-134c for 20 minutes on phase boundary with water in an autoclave

2 types of steams: wet steam (boiled within autoclave) and dry steam
(boiled externally and supplied under pressure)

26
Q

what is an autoclave

A

pressure vessel

27
Q

why is dry steam preferred over wet steam in moist heat sterilisation

A

wet steam soaks the load preventing steam penetration

28
Q

describe how dry heat is used for sterilising, what it is used to sterilise and what is its lethal effects due to

A

used for: medical implements, glassware, non aqueous thermo stable liquids, powders

lethal effects due to oxidative processes, less effective than moist sterilisation

involves higher temps, 160-180 up to 2 hours, effective destruction of bacterial endotoxins produced by gram negative bacteria

works by conduction, heat absorbed by exterior surface then pass inward to the next layer until entire object reaches proper temp to achieve sterilisation

29
Q

describe how ionising radiation is used for sterilising, what it is used to sterilise and what its lethal effects are due to

A

used on: dry products, finish and packaging components, medical implements, medical implants

lethal effects due to microbial DNA damage, leads to cell death as consequence of ionisation and free radical production or excitation from uv

uses accelerated electrons/gamma rays/UV light, exposure to 25 kGy for effective kill

bacterial resistance to irradiation depends of effectiveness of their repair mechanism, UV is less effective as it has lower energy so less DNA damage

30
Q

what is UV ionising radiation sterilisation useful for

A

water sterilisation

31
Q

describe how gas is used for sterilising, what it is used to sterilise and what its lethal effects are due to

A

used for: reusable medical implements, pharmaceutical components (glassware, plastics, syringes), medical equipment

lethal effects due to alkylation of sulfhydryl, amino, hydroxyl and carboxyl groups on proteins and nucleic acids

uses chemically reactive gases that are toxic to the operator (eg. formaldehyde, hydrogen peroxide, ethylene oxide)

lethality non uniform with increasing conc, temp, humidity

32
Q

describe how filtration is used for sterilising, what it is used to sterilise

A

used for: most pharmaceutical solutions and suspensions, biological products (depends on size), air

involves passing substance through a filter (0.22um) under pressure, removes bacteria instead of destroying, particles entrapped within mesh

33
Q

what does the efficiency of filtration sterilisation depend on

A

adsorption, material entrapped, charge effects, mesh structure, depth, initial bioburden

34
Q

what is bioburden

A

number of contaminated microorganisms in a material before sterilisation procedure is carried out

35
Q

what is quality assurance

A

arrangements put in place to ensure final product is at quality required for its purpose

36
Q

what does good quality mean

A

fit for its therapeutic purpose, safe for adminsitration

37
Q

what is good manufacturing practise (GMP)

A

part of quality assurance that ensures the product is consistently manufactured

-includes control of ingredients, plant construction, process validation, production, cleaning

38
Q

what is quality control

A

part of quality assurance that conducts test at each stage of manufacture, products not released until they pass the test

39
Q

what is in process control

A

any test on product during manufacture

-ensures manufacturing equipment/environment is checked before and after use
-test/controls must be documented to confirm pass criteria has been met

40
Q

what is quality risk management and what happens when a deviation occurs

A

systemic process for identification, assessment and control of risks to quality of pharmaceutical products across product lifestyle

when deviation occurs, quality management system initiates tests to determine cause and identify corrective actions and risks asses and confirms effectiveness of change

41
Q

what is HACCP and its steps

A

hazard analysis of critical control points= risk assessment tool for evaluating steps of a manufacturing process and in response to a deviation

-analyses/identifies potential hazards, determines critical control points (CCP) to control hazard and limit control of CCP, establish in house control methods to contain CCP hazards and corrective measures to correct CCP, confirm HACCP regime is functioning and then documentation of above

42
Q

name 5 main sources of contamination during pharmaceutical manufacturing process

A

raw materials- can carry natural bioburden

equipment- used in processing/holding/transferring/packaging, generation of dust and aerosols, improper cleaning

personnel- person to person contact, poor hygiene, natural flora

atmosphere- source of dust and particles including microorganisms and spores

packaging- some dont appropriately exclude microbial contaminants during storage

43
Q

ways to control microbial contamination

A

environmental hygiene- disinfect areas, no stagnant water or any water, clean air, educate workers

quality of starting materials- correctly stored, free from bacteria and endotoxins, raw materials stored correctly to prevent contamination, quality checks

process design- user defined requirements, installation and monitoring of equipment, fully defined/evaluated/validated manufacturing process

quality control and documentation- environmental monitoring in process and out of hours, personnel training, documentation of raw materials/packaging materials/intermediate products required for each batch (traceability), room classifications qualified prior to use

packaging/storage- keeps contents in and contaminants out, clean, suitable for purpose, store at appropriate temperature

44
Q

what does sterile mean

A

free of viable microorganisms

-product must undergo sterilisation process to ensure minimum level or sterility assurance

45
Q

what are sterile products

A

medicines that are administered directly to blood stream or body tissue
-sterile avoids possibilities of microbial degradation or infection

46
Q

what is sterility assurance limit (SAL)

A

numerical value that predicts the probability that microorganisms has survived sterilisation process

-acceptable probability for a pharmaceutical product post sterilisation is 10^-6

47
Q

what is the aim of sterility testing

A

attempts to reveal presence or absence of viable microorganisms in a sample, only small portion of batch is tested (40-60 out of >100,000), must be conducted in a suitable environment and be validated

48
Q

if product is manufactured aseptically what is the only available analytical method

A

sterility testing, show regulatory authorities the sterility status of it

49
Q

describe sterility test environment

A

strictly controlled as aseptic processing environment, isolator technology, hydrogen peroxide gassing, environmental monitoring, ISO class 5/GMP grade A

50
Q

list pharmacopeial requirements for sterility testing

A

-for products that cant be filtered and medical devices, use membrane filtration or direct inoculation (?)
-media used FTM and TSB
-incubate samples for 14 days at 2 different temperatures to allow microbial growth of bacteria/fungi/yeast

51
Q

what is FTM and TSB

A

FTM=fluid thioglycollate medium
TSB=tryptic soy broth

52
Q

describe the observations/interpretations of results of sterility test

A

-samples comply or dont (its either a yay or a nay)
-turbidity/growth indicates noncompliance
-test complies if no evidence of microbial growth is found

53
Q

4 reasons sterility tests can be invalid

A
  1. data of microbiological monitoring of sterility testing facility shows a fault
  2. review of testing procedure reveals fault
  3. microbial growth found in negative control
  4. after determination of identity of microorganisms isolated from test, growth of species ascribed unequivocally to faults with respect to materials/techniques used when conducting sterility test (?)
54
Q

limitations of sterility test

A

-can only recognise microorganisms able to grow under conditions of the test
-sample size restricted, only provides gross estimate of state of sterility of product
-sample size set arbitrarily so doesnt provide statistically significant population to estimate sterility
-results cant be used independently to determine sterility of a batch

55
Q

what does the susceptibility of microorganisms to biocides depend on

A

the microorganism and stage of life cycle

56
Q

what is bioburden

A

number of contaminated microorganisms in a material before sterilisation procedure is carried out