2.2.2 Biochemical test (Gram positive, Catalase Negative) Flashcards
A test that is use to differentiate Staph and micrococcus but can also used to differentiate S. pyogenes
Bacitracin
In bacitracin, who is susceptible? (Gram pos, Cat neg)
S. pyogenes
In bacitracin, who is Resistant? (Gram pos, Cat neg)
Other strept. except pyogenes
Positive indicator for Bacitracin?
10mm zone of inhibition
A test that is use to differentiate Beta hemolytic streptococcal
Sulfamethoxazole-Trimethoprim (SXT)
What is the Susceptible in SXT?
Non “beta” hemolytic Streptococcaceae
What is the Resistant for SXT?
S. pyogenes
S. agalactiae
S. dysagalactiae subsp. equisimilis
How many grams for SXT?
1.25ug
Test for the ability of the organism to hydrolyze the substrate L-pyrrolidonyl-β-napththylamide (PYR).
Pyrrolidonyl aminopeptidase / Pyrrolidonyl-beta-naphthylamide
What bacteria is positive in PYR?
Group A
Group D Enterococcus
What bacteria is Negative in PYR?
The rest
Group D non enterococcus
Positive indicator for PYR?
5 mins Bright red (pink to cherry red)
A test used for the presumptive identification of group B streptococci (S.
agalactiae), Clostridium, Listeria
CAMP (Christie-Atkins-Munch-Peterson)
Test for synergistic hemolysis between group B Streptococcus and βhemolytic Staph. aureus
CAMP (Christie-Atkins-Munch-Peterson)
In CAMP, what bacteria is swabbed vertically?
Staphylococcus aureus
In CAMP, what bacteria is swabbed horizontally?
Group B strept
Listeria monocytogenes
What is the positive indicator for CAMP?
Arrowhead
In CAMP, what is being detected in Group B Strept?
CAMP factor
In CAMP, if Clostridium is being identified, what bacteria is vertical?
S. agalactiae
What is the positive indicator for Clostridium in CAMP?
Reversed arrowhead / Bowtie
What is the positive indicator for L. monocytogenes in CAMP?
Black arrowhead
It is test for hippuricase enzyme of Group B Streptococci
Hippurate hydrolysis
IT hydrolyzes sodium hippurate to sodium citrate and Ninhydrin
Hippuricase enzyme
What are the reagents of Hippurate hydrolysis?
Sodium hippurate and ninhydrine
What is the positive indicator for Hippurate hydrolysis
Deep blue color
What microorganisms is positive in hippurate hydrolysis?
S. agalactiae
Detects for the ability of the bacteria to hydrolyze Leucine-β-naphthylamide
LAP (Leucine aminopeptidase)
What is the reagent for LAP?
Cinnamaldehyde
What organisms is positive in LAP test?
All viridans
(S. pneumoniae and
S. pyogenes,
Enterococcus,
Pediococcus) - ppt
What is the positive indicator for LAP?
Red color in 1 min
Detects the action of β-D-glucuronidase
B-D-aminopeptidase
where can β-D-glucuronidase be found in what bacteria?
Large colony forming Beta hemolytic group C and G
What is the positive for B-D-aminopeptidase?
G, C group
What is the Negative for B-D-aminopeptidase?
Group F (Strep. anginosus)
Detects for the ability of the bacteria to grow in the presence of 40% bile and
hydrolyze esculin
Bile Esculin (Bile esculin hydrolysis)
What are the reagents for bile esculin?
40% bile
Ferric NH4 (ammonium)
What is the positive indicator for Bile esculin?
Black
What is positive for Bile esculin?
ALL Group D
Test the ability of the organism to grow in 6.5% NaCl
Salt tolerance test
Differentiates Group D strep
Salt tolerance test
What is the positive indicator for Salt tolerance test?
Turbidity and color change (After 18-24 hours)
What is positive in Salt tolerance test?
Group D enterococcus
What is Negative in Salt tolerance test?
Group D non-enterococcus
Known as Taxo P (Ethylhydrocupreine hydrochloride) that differentiates S. pneumoniae from alpha hemolytic
Optochin Susceptibility
how many grams of Ethylhydrocupreine hydrochloride in optochin susceptibility test?
5ug
What is the Susceptible indicator for optochin susceptibility?
14 or 16 mm zone of inhibition
What is the Resistant indicator for optochin susceptibility?
<14 or 16 mm zone of inhibition
What is organisms is susceptible in Optochin sus?
S. pneumoniae
Confirmation test in determining the alpha hemolytic
Differentiates S. pneumoniae and viridans
Bile solubility test
2 methods of bile solubility test
BAP
Broth
What reagent is used in bile solubility?
Sodium deoxycholate
How man Percent in BAP for sodium deoxycholate?
10%
How man Percent in Broth for sodium deoxycholate?
2%
What is the positive indicator for BAP in Bile solubility?
Clear and lyse colony
What is the negative indicator for BAP in Bile solubility?
Intact colony
What is the positive indicator for broth in Bile solubility?
Clear
What is the Negative indicator for broth in Bile solubility?
turbid
What is soluble in Bile solubility?
S. pneumoniae
What is insoluble in Bile solubility?
Viridans
What are the Test for Group A?
Bacitracin
PYR
What are the Test for Group B?
CAMP
Hippurate hydrolysis
What are the Test for Viridans and S. pneumoniae?
Optochin susceptibility
Bile solubility
What are the Test for Group D?
PYR
Bile esculin
Salt tolerance (6.5%)
What are the Test for Streptococcal like organisms?
LAP