culture media

Question 1

TSB

Answer 1

-nutritional: grow everything
-CSF shunt & ground tissue

Question 2

TSA

Answer 2

-nutritional: grow everything
-white or clear organisms
-water culture

Question 3

LIM broth (todd hewitt w/ cna)

Answer 3

-enriched, selective
-enhances growth of group B strep
-inhibit growth of gram neg bacilli

Question 4

Blood agar

Answer 4

-enriched
-grow everything
-grey, white, clear or yellow colonies
-alpha hemolysis = green
-beta hemolysis = clear
-gamma hemolysis = no clearing

Question 5

SSA

Answer 5

-enriched, selective
-isolation of group A strep
-grey, white, yellow or clear colonies
-alpha hemolysis = green
-beta hemolysis = clear
-gamma hemolysis = no clearing

Question 6

CNA

Answer 6

-enriched, selective
-isolation of gram pos bacteria
-inhibition of gram neg bacteria
-grey, white, yellow or clear colonies
-alpha hemolysis = green
-beta hemolysis = clear
-gamma hemolysis = no clearing

Question 7

chocolate agar & slant (sendouts)

Answer 7

-enriched
-wide variety of organisms grow
-growth of fastidious organisms (haemophilus/neisseria)
-tan, grey, white, clear or yellow colonies
-contain factor V & X that allow the fastidious organisms to grow

Question 8

MTM

Answer 8

-enriched, selective
-isolate neisseria gonorrhoeae
-tan/grey colonies
-antibiotics in the agar inhibit GPC, GNB & proteus
-will grow yeast

Question 9

MAC

Answer 9

-differential, selective
-isolate & differentiate gram neg bacilli
-low concentration of bile salts to inhibit GPC
-pink/clear colonies
-lactose fermenter = pink
-nonlactose fermenter = clear

Question 10

MAC with sorbitol

Answer 10

-differential, selective
-differenciate E. coli 0157 : H7 from other gram neg bacilli
-pink/clear
-E. coli 0157 : H7 clear or sorbitol, pink on MAC

Question 11

hekton agar (HE)

Answer 11

-differential, selective
-differentiate salmonella & shigella from other gram neg bacilli (normal flora)
-clear, black, yellow, orange, pink colonies
-salmonella = black colonies
-shigella, aeromonas, pleasimonas, E. coli 0157:H7 = clear colonies

Question 12

salmonella shigella agar (SS)

Answer 12

-differential, selective
-differentiate salmonella & shigella from other gram neg bacilli
-clear, black, yellow, orange, pink (normal flora)
-salmonella = black colonies
-shigella, aeromonas, pleasimonas, E. coli 0157:H7 = clear colonies

Question 13

GN broth

Answer 13

-enriched, selective
-enhance growth of entero-hemorrahgic E. coli & S. dysenteriae type 1 (looks for shiga toxin)
-cloudy broth
-inhibit gram pos and some gram neg bacteria
-incubated for 16-24 hrs in non-CO2

Question 14

Burkholderia cepacia agar (Burk)

Answer 14

-differential, selective
-isolate burkholderia cepacia in CF patients
-pink (fuchsia)
-inhibits some gram neg bacilli that are not burkholderia cepacia

Question 15

mueller-hinton agar

Answer 15

-base media for manual susceptibility
-E test & kirby-bauer
-generally clear/white colonies
-agar depth is always 4mm deep & pH is checked to ensure accurate sensitivities

Question 16

mueller-hinton agar with 5% sheep blood

Answer 16

-enriched for manual susceptibility
-E test and kirby-bauer testing for strep and some nutrient dependent organisms
-beta, alpha, gamma hemolysis
-agar depth is always 4mm deep & pH is checked to ensure accurate sensitivities

Question 17

vancomycin screen agar

Answer 17

-selective
-used to screen for vanco resistant enterococcus in urine
-full MIC with urine growth, gram stain for pos before setting
-white colonies
-0.5 mcfarland suspension of enterococcus species is made. 10uL is deposited onto the afar and incubated for 24 hrs in non-CO2

Question 18

MAC with ciprofloxacin

Answer 18

-differential, selective
-screening medium for ciprofloxacin resistant gram neg bacilli in transrectal prostate specimens
-pink or clear colonies
-any gram neg bacilli that grows is presumptively resistant to fluroquinolones

Question 19

mycobiotic slant (mycosel)

Answer 19

-selective
-recovery of dimorphic fungi & dermatophytes from species potentially contaminated with bacteria and saprophytic fungi
-white but variable colors
-inhibits saprophytic fungi, nocardia, gram pos & neg bacteria

Question 20

SABHI agar slant

Answer 20

-selective
-most fungi/bacteria grow. recovery of pathogenic fungi
-generally white but color varies

Question 21

inhibitory mold agar

Answer 21

-selective
-cultivation of pathogenic fungi
-selective recovery of pathogenic yeasts & mold from sources contaminated with bacteria
-generally white but color varies
-inhibit growth of gram pos & neg bacteria

Question 22

potato dextrose agar

Answer 22

-non selective
-growth of yeasts and molds
-generally white but color varies
-isolate yeast/mold for ID

Question 23

lowenstein-jensen slant

Answer 23

-selective
-isolation of TB
-M. TB = buff, cauliflower-like dry colonies
-other mycobacteria = bright orange or yellow/creamy
-enhances growth of mycobacterium sp. and inhibits bacteria
-incubates for 6 weeks

Question 24

chromagar yeast

Answer 24

-differential, selective
-selective & differential medium for isolation of fungi
-green = C. albicans
-bluish green = C. tropicalis
-light rose = C. krusei
-other yeasts may appear white
-used for subbing
-isolate yeast from bacteria but not for presumptive ID. to develop color, must incubate 48hrs in non-CO2 & out of direct light

Question 25

MRSA spectra agar

Answer 25

-differential, selective
-ID of MRSA from nasal swab
-MRSA = denim blue
-incubate 24 hrs in non-CO2
-usually an add on after pt receives tx to see if it worked & all pts <2 yrs