Specimen collection - media Flashcards
(36 cards)
Urine cultures media used and info
- CLED (cysteine lactose electrolyte deficient agar) cysteine allows for growht of coliforms, electrolyte deficiency prevents swarming of proteus and lactose fermentation helps in identification. Incubated at 35-37 for 24 hours.
Other plates used include MacConkey without salt, chromogenic agar
Other more precious samples are also cultured on 1 MacConkey plate incubated in air, on 1 blood agar also in air and another blood agar anaerobically.
Stool sample media
- Deoxycholate Lactose Sucrose agar for salmonella and shigella
- Salmonella chromogenic agar
- Selenite broth for salmonella
- Preston broth for Campylobacter
- Campylobacter slective agar (microaerophilic incubation at 43 degrees)
- Sorbitol MacConkey agar for E.coli 0157.
To check for cholera : Alakline peptone water APW and TCBS (thiosulfate citrate bile salts sucrose agar). Yellow colonies on TCBS
what transport medium can stool samples be given in
Cary Blair’s transport medium
When shoudl stool samples NOT be given in transport medium
When testing for GIT parasites
CSF storage if it cannot be processed immediately
incubated at 37 degrees
Culture media for CSF
blood agar, chocolate agar (for neisseria and H. influenzae), MacConkey and CTA agar base
CSF in bacterial meningitis
- turbid
- not sterile, bacteria idetnfied from gram stain and culture
- 50-20,000 polymoprhs
- markedly raised protein
- reduced or absent glucose
CSF in viral meningitis
- clear or slightly turbid
- 10-500 lymphocytes
- viruses rarely isolated, normally isolated from stools if enterovirsues or by serology for mumps
- protein is normal or slighlty riased
- glucose is normal
CSF in tuberculous meningitis
- clear or slightly turbid
- 10-500 lymphocytes
- Mycobacterium tuberculosis with ZN stain and growth on Lowenstein Jensen medium
- protein is moderately raised
- gluocse is normally reduced
Processing of CSF
- centrifuge
- remove supernatant (can be used to carry out rapid antigen screen)
- deposit is inoculated on BA, CBA, MacConkey. Incubated for 24 hours in 507% CO2
- slides are prepared for GS, ZN and MB
- subculturing carried out on CTA ( cysteine tryptic agar) which acts as an enrichment medium.
What bacteria are tested for in rapid antigen screen for CSF
- streptococcus pneumonia
- strep agalactiae
- haemophilus influenzae type b
- neisseria meningitidis A,B,C,Y, W135
- E coli K1
what crytococcus species are tested for in crytpococcus anitgen rapid test for CSF
cryptococcus neoformans and c. gattii
Culture media for sputum samples
- blood agar (anaerobic) for Staph aureus and streps
- Bacitracin choco agar (5-7% CO2) Haemophilus influenzae and Moraxella catarrhalis
- MacConkey (in air ) for enterobacterales, pseudomonas etc
For cystic fibrosis: Burkholderia cepacia selective agar
For MRSA: oxacillin resistance screening agar
Sabouraud for mycology, candida
Culture media for wound cultures
blood agar (1 anaerobic and 1 5-7% CO2), media for anaerobes, MacConkey
Cooked meat medium for anaerobes (Clostridium)
Oxacillin resistance screening agar for MRSA
Sabouraud for yeatss
Commonly isolated pathogens of sputum
Staph aureus
Strep pneumonia
Strp pyogenes
enterobacterles
acinetobacter
pseudomonas
H influenzae
Burkholderia cepacia in cystic fibrosis
Commonly isoltaed pathogens of wound cultures
anaerobes (actinomyces, becteroides, clostridium)
staph aureus
strep pyogenes
enterobacterales(klebsiella,serratia, E,coli)
pseudomonas
acinetobacter
Culture media for aspirates
- blood agar 5-7% CO2
- blood agar anaerobic
- MacConkey agar for Enterobacterales
- cooked meat medium
- Castaneda broth; tryptone soya broth and colombia agar base
ORSA and sabouraud for MRSA and yeasts
Throat swab cultures
blood agar (anaerobic) for lancefield groups A,C and G
- Bacitracin chocolate agar for h. influenzae type b
- ORSA for MRSA
- Sabouraud for yeasts in diabetic and immunocompromised people
- TMSA (Thayer martin modified medium) for gonorrrhoeae
commonly isolated pathogens in throat swabs
- group a streps (pyogenes)
group C group G streps - H influenzae
- Neisseria gonorrhae (STI)
Culture media for genital tract samples
high vaginal swabs - blood agar at 5-7% CO2, sabouraud agar.
Urethral swabs and cervical swabs - blood agar, sabouraud and thayer martin modified medium for gonorrhoea
- Trichomonas vaginalis selective medium
- blood agar (anaerobic) for anaerobes
- MacConkey for enterobacterales and pseudomonads
- Haemophilus ducreyi selective agar for chancroids
- ## listeria selective agar for listeriosis
bacterial vaginosis signs symptoms and more
- heavy discharge, thin, white to grey in colour
- foul odour after intercourse
- amine odour present
- increase in pH
- presence of clue cells, few lactobacilli and wbc
lactobacillosis
- pruritis (itching)
- vulvar dysuria
- variable discharge which is thick white and curdy
- possible slightly higher pH
- many lactobacilli in chains
cytolytic vaginosis
- pruritis (itching)
- dyspareunia (painful intercourse)
- vulvar dysuria
- increase in luteal phase of menstrual cycle
- discharge; thick or thin, white, creamy or curdy
- few wbc
- large number of lactobacilli
- desquamated epithelial cells
selective culture media for Gardnerella vaginalis
Human Blood polysorbate 80 - polysorbate 80 enhances the diffusion of beta haemolysis
- Colistin - Oxalinic Acid Blood agar (COBA
