Microbiology Flashcards
What is the general media for bacteria
TSA (Trypticase soy agar)
TSA is a growth media for the culturing of moderately to non fastidious bacteria. It is a general-purpose, non-selective media providing enough nutrients to allow for a wide variety of microorganisms to grow.
What is the media for yeasts and moulds
SDA (Sabouraud Dextrose Agar)
SDA is a selective medium primarily used for skin yeasts and moulds. The acidic pH of this medium (pH about 5.0) inhibits the growth of bacteria but permits the growth of yeasts and most filamentous fungi.
What is the media for water bacteria?
R2A (Reasoner’s 2A agar)
R2A agar is a culture medium[1] developed to study bacteria which normally inhabit potable water.[2] These bacteria tend to be slow-growing species and would quickly be suppressed by faster-growing species on a richer culture medium
What is the media for E. coli?
MacConkey
What is the media for P. aeruginosa
Cetrimide
What are the media for sterility test
Fluid Thioglycollate Medium (FTM) and
Soyabean Casein Digest Medium (SCDM).
What is FTM used for and at what temp incubated?
anaerobic and aerobic bacteria - store at 30-35 °C
What is SCDM used for and at what temp incubated?
fungi and aerobic– store at 20-25 °C
What is the sample size used for a sterility test?
Number of samples changes dependent on batch size and product type.
For normal parenteral batches >500 then 20 containers or 2% whichever is less
What are the two methods available for sterility test?
Test methods = Membrane Filtration Method and Direct Inoculation
What do you need to do when developing the sterility test for a product
Need to demonstrate no anti-microbial action of the product on the sterility test. Inoculate with less than 100cfu, do the test and leave for 14 days to see turbidity.
What do you need to do to each batch of medium for sterility test
1) Demonstrate it’s sterile
2) Demonstrate it grows bacteria and yeast and moulds
3) Staph, Bacillus, pseudomonus, Clostridium sporogenes (anaerobic), candida and aspergillus
What are used to positively show sterility media grows bugs?
Staphylococcus , Bacillus, pseudomonus, Clostridium sporogenes (anaerobic), candica and aspergillus
SBPACC
What are methods to sanitise a purified water system?
Ozone
Heat
Chemical – peracetic acid and hydrogen peroxide
How would you PQ a purified water system?
3 stage approach –
1 – system not in use
2 – system in use at risk
3 – system in full use
What’s involved in stage 1 ‘system not in use’ when PQ-ing PW system?
- All user points and return sampled every day for 4-6 weeks.
- Sampling regime should include monitoring of feed water source, between each of the pre-treatment stages, pre- and post RO membrane, post final purification stage and storage tank
- Samples analysed for TOC, conductivity, endotoxin and micro
- Results obtained should establish alert and action levels for phase 2
What’s involved in stage 2 ‘system in use at risk’ when PQ-ing PW system?
- Elevated testing should be performed including monitoring of generation system, storage vessels, user points and any concern points identified at phase 1
- Should also monitor before and after micro reduction systems like UV lamps
- Samples should be taken as intended by production
- Samples analysed for TOC, conductivity, endotoxin and micro
- SOPs finalised
Interim report issued to say can be used for routine production
What’s involved in stage ‘ system in full use’ when PQ-ing PW system?
- Intended to say system ok over long usage, typical 12 months to allow for seasonal variation
- All user points monitored on a pre-defined schedule
- Trends monitored
VSR issued
What are organisms used for showing growth media is OK
Staphylococcus aureus,
Pseudomonas aeruginosa,
Bacillus subtilis,
Candida albicans,
Aspergillus
Use in the appropriate media
Examples of GPCs?
Staphylococcus aureus
streptococcus
Examples of GPRs?
Bacillus subtilis
Clostridia Spore formers
Geobacillus stearothermophilus
Examples of GNRs?
Pseudomonas aeruginosa
E.Coli,
Salmonella
Campilobacter
Examples of GNCs?
Neisseria gonorrhoeae,
Neisseria meningitidis
What is the specification for PW?
100 cfu / ml
<0.25 eu/ml endotoxin (dialysis)
0.2 ppm nitrates
500 ppb TOC
<4.3 μS/cm @ 20°C
0.1ppm heavy metal (don’t need test if conductivity <1.1 μS/cm @ 20°C)
10 ppb Al (dialysis)
What is the specification for WFI?
10 cfu / ml
<0.25 eu/ml (dialysis)
0.2 ppm nitrates
500 ppb TOC
<1.1 μS/cm @ 20°C
0.1ppm heavy metal
10 ppb Al (dialysis)
What are some common pharmaceutical preservatives?
Benzalkonium Chloride – nasal sprays / eye drops / topicals
Parabens – creams, ointments, lotions – good against bacteria and moulds
Benzyl Alcohol – injectables and topical formulations
Sorbic Acid and its salts – effective against fungi
Thimerosal – mercury containing compound used in some vaccines and ophthalmic formulations.
What is the test to demonstrate that media grows bugs called?
Growth promotion test
Or
Fertility Test
Why is Bacillus used for sterility testing?
It is both aerobic and anaerobic (aerobic by preference)
Why does the anti-microbial action test use <100 CFU
Otherwise the sample would be overdiluted with the growth medium from the inoculation sample. The bacteria would grow in that, reducing the sensitivity of the test and therefore giving false positives.
This is called carryover
How long is the Growth promotion test for FTM and SDCM incubated for and how long is a sterility test incubated for
FTM = 3 days
SDCM = 5 days
Sterility test = 14 days
When would you use a direct inoculation method for a sterility test?
When you can’t do it by membrane filtration e.g. creams or some suspensions (Cabo like paint and needs to grow, sample, grow sample, sample, grow sample until there’s sufficient clarity to see turbidity from bacteria if growth present)
How do you prepare catgut and sutures for sterility test?
3 strands approx. 30 cm long
