Biochemical Tests Part 1 Flashcards
Determines an organisms ability to use acetamide as a sole source of carbon
Acetamide Utilization test
Acetamide Utilization (+) organisms produce acylamidase > deaminates acetamide > releasing ammonia
*Alkaline pH = Green to royal blue
Positive QC for Acetamide utilization test
P. aeruginosa
Negative QC for Acetamide Utilization Test
Stenotrophomonas maltophilia
Determines an organism’s ability to use acetate as a sole source of carbon
Acetate Utilization Test
Differentiates E. coli to Shigella spp.
Positive result for Acetamide utilization test
Color change from green to royal blue
*Due to change in pH (Alkaline)
Positive QC for Acetate Utilization test
E. coli
Negative QC for Acetate Utilization test
Shigella flexneri
Positive result for Acetate utilization test
Blue
*Due to change in pH (Alkaline)
Acetamide and Acetate utilization tests requires incubation at what temp and for how long?
35 deg C for up to 7 days
This test detects the presence of enzyme butyrate esterase
Butyrate Esterase Test
Positive QC for Butyrate Esterase Test
Moraxella catarrhalis
What is the old name for Moraxella catarrhalis
Branhamella catarrhalis
What is the susbtrate used for Butyrase Esterase Test
Bromo-chloro-indolyl butyrate impregnated disks
The negative QC for Butyrate Esterase test
Neisseria gonorrhoeae
Positive result for Butyrase Esterase Test
Blue within 5 minutes
Other name for Butyrate esterase test
Butyrate disk or Catarrhalis test
*Rapid test to detect Moraxella Catarrhalis
This test is used to differentiate Staphylococci and Streptococci
Catalase Test
*Staphylococci (Cat +), Streptococci (Cat -)
Reagent used for Catalase test
Hydrogen Peroxide
Positive result for Catalase test
Effervescence or Bubbling
Positive QC for Catalase Test
Staph aureus
Negative QC for Catalase Test
Streptococcus pyogenes
This test differentiates S. aureus to other Staphylococci
Coagulase test
Reagent used for Coagulase Test
Rabbit plasma w/ 0.5 mL EDTA
Slide tests and Tube tests for coagulase detects?
Slide test = Bound Coagulase
Tube test = Free Coagulase
Slide test (Screening), Tube test (Confirmatory)
Positive QC for Coagulase test
S. aureus
Negative QC for Coagulase test
S. epidermidis
What is the positive result for Coagulase test
Visible clumping/clotting of any size
This test detects an organism’s ability to produce gelatinase
Gelatinase/Gelatin Hydrolysis Test
Presumptive test for the identification of various organisms, including Staphylococcus spp., Enterobacteriaceae, and some gram-positive bacilli
Positive result for Coagulase Slide test
Clumping seen w/in 10 min
Positive result for Tube Coagulase test
Clumping/Coagulation after 4 hours
*If negative after 4 hrs, incubate overnight then recheck
Positive test for Gelatinase/Gelatin Hydrolysis test
Liquefaction of the inoculated tube at 4 deg C w/in 14 days
Positive QC for Gelatinase test
Serratia liquifaciens
Negative QC for Gelatinase test
Enterobacter aerogenes
A test for the enzyme hippuricase/Hippurate hydrolase
Hippurate
*Test medium must only contain hippurate: Ninhydrin reagent might react with any free amino acid present in growth media or broths
What are the end products for Hippurate test
Glycine & Benzoic Acid
Positive QC for Hippurate Test
Group B Strep: Strep agalactiae
Negative QC for Hippurate test
Strep. pyogenes
This is a presumptive test for gram positive, catalase negative cocci
Leucine aminopeptidase test
What is the substrate used for LAP test
Leucine-beta-naphthylamide
Reagent for LAP test
Cinnamaldehyde
Product of LAP test
Beta-naphthylamine
Positive QC for LAP test
Streptococcus/Enterococcus
Positive result for LAP test
Red color w/in 1 min after addition of cinnamaldehyde
Negative result for LAP test
No color change or Slight yellow
Negative QC for LAP test
Leuconostoc spp.
Rapid test wich detects gram positive, catalase positive cocci (Staph and Micrococcus)
Microdase test
*aka Modified oxidase test
Detects the enzyme Oxidase
In the presence of atmospheric oxygen: OXIDASE ENZYME reacts with OXIDASE REAGENT and CYTOCHROME C = Indophenol (Colored compound)
Positive result for Microdase test
Blue to purple color
Reagent of Microdase test: Disk impregnated with Tetramethyl-Para-Phenylenediamine dihydrochloride + Dimethyl Sulfoxide
Positive QC of Microdase test
Micrococcus
*MICROdase for MICROcoccus
Negative QC for Microdase test
Staphylococcus
Detects B-Glucoronidase
MUG test
*aka 4-Methylumbelliferyl-b-d-Glucuronide (MUG) Test - Impregnated disk
-Also used as presumptive identification of Enterobacteriaceae and verotoxin producing E. coli (0157-H7 is neg)
Positive result for MUG
Electric blue fluorescence under UV light
Positive QC for MUG test
E. coli except (0157-H7)
Negative QC for MUG test
Pseudomonas aeruginosa
Determines the presence of bacterial enzyme cytochrome oxidase activity in microorganisms
For the identification of oxidase-negative Enterobacteriaceae, differentiating them from other gram-negative bacilli
Oxidase Test
Reagent for Oxidase Test
Tetramethyl-para-phenylenediamine dihydrochlodride
Positive result for Oxidase test
Purple
*Development of Dark purple color within 10 sec
Positive QC for Oxidase Test
Neisseria gonorrhoeae
Negative QC for Oxidase Test
Escherichia coli
Detects the presence of the enzyme l-pyrrolidonyl arylamidase
Presumptive identification of group A streptococci (Streptococcus pyogenes) and Enterococci
PYR test
*l-Pyrrolidonyl ArylAmidAse (Pyr) Test
Enzyme detected in PYR test
Pyrollidonyl arylamidase/PYRase
Reagent for PYR test
N-N dimethylaminocinnamaldehyde
Positive result for PYR test
Bright red color w/in 5 min after addition of the reagent
Positive QC for PYR test
Streptococcus pyogenes (Group A)
Enterococcus faecalis
Negative QC for PYR test
Streptococcus mitis
Differentiates Group D enterococci and Group D non-enterococci
Bile Esculin Test
-Gram (+) organisms inhibited by Bile Salts
-Organisms capable of growth in the presence of 4% bile and able to hydrolyze esculin to esculetin will demonstrate growth
What is the H2S indicator for Bile Esculin Test
Ferric Ammonium Citrate
*All H2S indicator = FAC except TSI = FAS (Ferric Ammonium Sulfide)
Positive result for Bile Esculin Test
Blackening of Agar
Positive QC for Bile Esculin Test
Group D Enterococci
Negative QC for Bile Esculin Test
Streptococcus mitis
Primarily used to isolate and purify Pseudomonas aeruginosa from contaminated specimens
Cetrimide Agar
Cetrimide is toxic to many bacteria except for P. aeruginosa
Positive result for Cetrimide Agar Test
Growth (Color change: Yellow-green to Blue-green colonies)
Positive QC for Cetrimide Agar
Pseudomonas Aeruginosa
Negative QC for Cetrimide Agar
E. coli
Determines the ability of an organism to grow in high salt concentration
Primarily used to differentiate Enterococci from Non-Enterococci
Salt Tolerance Test
-Enterococci are resistant to high salt concentration
-Heart infusion broth w/ ____ salt conc. is used as a test medium
Concentration of salt used in Salt Tolerance Test
6.5% NaCl
*MSA is 7.5% NaCl
What is the indicator used for Salt Tolerance Test
Bromcrescol Purple
Positive result for Salt Tolerance Test
Visible turbidity (Color change from pink to yellow)
Negative Result for Salt Tolerance Test
No turbidity (Pink = No color change)
Positive QC for Salt Tolerance Test
Group D enterococcus
Negative QC for Salt Tolerance Test
Group D non-enterococcus
Presumptive identification and differentiation of beta-hemolytic group A streptococci from other beta-hemolytic streptococci
Also used to distinguish staphylococci species from micrococci
Bacitracin Test
Other name for Bacitracin
Taxo A
*bAcitracin = taxo A, oPtochin = taxo P
What is the concentration of Bacitracin to be used
0.04 U of Bacitracin
Positive result for Bacitracin Test
Any zone of inhibition
After incubation in 35 deg C for 18-24 hours
Positive QC for Bacitracin Test
Streptococcus pyogenes
*Group A Streptococci
Negative QC for Bacitracin Test
S. agalactiae
Differentiates Streptoccus pneumoniae from other alpha hemolytic streptococci
Bile Solubility Test
*Bile (ex. sodium deoxycholate) rapidly lyses pneumococcal colonies (Lysis depends on presence of amidase)
What is the concentration of bile to be used in Bile Solubility test when the organism is plated
10% Sodium Deoxycholate
What is the concentration of bile to be used in Bile Solubility test when the organism is in a tube
2% Sodium deoxycholate
Positive result for Bile solubility test
Dissolution of Colonies
*After incubation at 35 deg C for 30 min
Positive and Negative QC for Bile solubility Test
Positive QC: Streptococcus pneumoniae
Negatie QC: E. faecalis
S. pneumoniae (+), Other alpha hemolytic organisms (-)
Test to determine the effect of Taxo P to the growth of a particular organism
Can be used to differentiate S. pneumoniae to other alpha hemolytic strep
Optochin Test
Cultures are incubated at 35 de C for 24 hrs at 5% CO2
Positive result for Optochin Test
Zone of inhibition >14mm
ZOI of <14 mm is questionable
Positive and Negative QC for Optochin Test
Positive QC: Streptococcus peumoniae
Negative QC: Streptococcus mitis
Optochin lyses pneumococci (positive test), but alpha-streptococci are resistant (negative test)
Used to determine whether a gram negative rod utilized glucose and lactose or sucrose fermentatively and forms hydrogen sulfide
Triple Sugar Iron Test
Sugars used in Triple Sugar Iron Test
Include concentration of each
Lactose (10 parts) = 1%
Sucrose (10 parts) = 1%
Glucose (1 part) = 0.1%
pH indicator for TSI
Phenol Red
*TX MU C Aling Dionesia Pacquiao (TSI, XLD, MSA, Cystine Trypticase Agar, Urease, Acidemetry, Dermatophyte Test Medium = Phenol Red)
H2S Indicator for TSI
Ferrous Ammonium Sulfate
*All media with H2S Indicator = FAC (Ferric Ammonium Citrate) except TSI = FAS
Results and interpretation of TSI
Yellow = Acidic
Red = Alkaline
Black = H2S +
Breaks on medium = Gas production
Pag phenol red ang indicator same results
*TSI should be read within 24 hrs (Fermentation products are oxidized and slant reverts back to alkaline state = False neg)
How to inoculate TSI media
Stab then Streak
E. coli, Klebsiella, Enterobacter presentation on TSI medium
A/A, Gas (+), H2S (-)
Presentation of Shigella on TSI
K/A, Gas (-), H2S (-)
*Shigellla non-lactose fermenter (Sugars Can Kill My PaPa Ed)
*H2S (SPACE)
Presentation of Salmonella Arizonae, Citrobacter, Edwardsiella, Proteus on TSI
K/A, Gas(+), H2S (+)
*H2S + (SPACE)
*Non Lactose Fermenter (Sugars Can Kill My PaPa Ed)
*Late Lactose Fermenter (Yana Eats Half Sugar Cookies)
Presentation of Pseudomonas aeruginosa
K/K, Gas (-), H2S (-)
*Pseudomonas CANNOT ferment GLUCOSE
Used to determine if a gram negative rod decarboxylates or deaminates lysine and forms hydrogen sulfide
Lysine Iron Agar
*LIA composition: Lysine, Peptones, Small amount of Glucose
pH Indicator of Lysine Iron Agar
Bromcrescol Purple
Results: Acidic (Yellow), Alkaline (Purple)
H2S Indicator of Lysine Iron Agar
Ferric Ammonium Citrate
*All media H2S Indicator = FAC except TSI = FAS
Lysine decarboxylase product
Cadaverine
Inoculation of organisms in LIA
Stab, Streak, Stab
Sulfur Source of LIA
Sodium Thiosulfate
