Biochemical Tests Flashcards
Contains lactose, glucose, sucrose and iron and forms H2S
Triple Sugar Iron
Utilization of carbohydrates by bacteria. In bacteriology, observing color changes in pH indicator as acid products are formed.
Fermentation
If glucose are fermented, butt will produce and slant will produce what?
Butt becomes yellowish and Slant becomes initially yellow.
Since glucose is in low conc., organism in aerobic conditions uses Peptone medium, slabs will become what?
Slant becomes alkaline
TSI organism that ferments lactose will have an?
A/A reaction
A/A with gas on TSI
E.coli
A/A with H2S on TSI
Citrobacter freundii
K/A with gas and H2S on TSI
Proteus mirabilis
K/K on TSI
Pseudomonas aeruginosa
TSI
pH indicator ( phenol red)
Result on CHO Fermentation Test: NLF
Edwardsiella, Morganella, Hafnia, Proteus, Providencia, Salmonella, Yersinia, Shigella, Serratia
Result on CHO Fermentation Test: LF
Enterobacter, Escherichia, Klebsiella
Result on CHO Fermentation Test: LLF
Citrobacter, Arizona
Two enzymes that must be present in the Klebsiella-Enterobacter-Hafnia-Serratia Group.
Beta-galactoside permease
Beta-galatosidase
Many of anaerobic bacteria that produces large quantities of butyric acid
Clostridium, Peptostreptococcus, Fusibacterium
Contains lactose, glucose and iron salt
Kligler’s Iron Agar
Reactions of KIA on P. Aeruginosa
K/K
Reactions of KIA on Shigella sp.
K/A
Reactions of KIA on Samonella, Citrobacter, Arizona and some Proteus
K/A with gas and H2S
Reaction of E.coli and Klebsiella-Enterobacter group
A/A
Indicators: sodium thiosulfate and ferrous sulfate
+ black color or black ppt
H2S production
+ bubble formation or splitting of the media or complete displacement of the media from the bottom of the tube
Gas Production
Glucose and lactose
Russell’s Double Agar
Structure similar to lactose that detects the enzyme from beta-galatosidase. Used to distinguish enteric bacteria (Salmonella -, Citrobacter +) and identify Pseudomonas. Similar to lactose, except glucose replaced ton ONPG
Beta-galactosidase and ONPG Test Orthonitrophenyl beta-d-galatopyaranoside
Chromophere that is released into the medium and detected by a pale yellow color.
Orthopnitrophenol
Result in Beta-galatosidase and ONPG test
+ Yellow
- no color change
SIM test:
Ability of an organism to split tryptophan to form compound indole.
+ pink to wine colored ring
INDOLE production
SIM: + blackening of agar
Sulfide
Use for initial grouping of enterobacteriaceae
IPViC
Production from tryptophan
INDOLE
Production from phenylalanine
Phenylpyruvic acid
Due to the formation of acetoin from pyruvate in glucose broth
Positive Vogues-proskauer test
Ability to utilize as a single carbon source
Citrate
Acidification of glucose broth due to formation of mixed carboxylic acids from pyruvate
Methyl red test
Ability of an organism to produce INDOLE from tryptophan
INDOLE test
Media used in INDOLE test
Tryptophan Agar
Reagent used in Indole test
Ehrlich’s reagent
Result of INDOLE test
+ pink to wine colored ring
- no color development
Screening for INDOLE production
Rapid spot INDOLE test
Reagent used in Rapid spot indole test
P-aminocinnamaldehyde
Ability of organism to produce and maintain stable end products from glucose fermentation; mixed acid glucose fermentation
Methyl red test
Indicator used in methyl red test
Methyl red
Results in Methyl red test
+ distinct red or bright color red ( E.coli)
- yellow or no color change (E.cloacae)
Butylene glycol of glucose formation; ability of an organism to produce acetoin
Vogues-Proskauer test
Media used in Vogues-Proskauer test
MRVP or Clark Lubs Broth
Reagent used in Vogues-Proskauer test
Alpha napthol and KOHn(Barritt’s method)
Results in Vogues-Proskauer test
+ pink to red color (E.cloacae)
- no color change (E.coli)
Other reagent used in vogues-Proskauer test
Apha napthol in 40% KOH creatine (Coblentz method)
Result in vogues-Proskauer test
+ red (Strep.mutans)
- yellow (strep mitis)
Key biochemical property of Salmonella, Klebsiella, Serratia, Enterobacter and Citrobacter. Ability of an organism to utilize sodium citrate as a carbon source and inorganic ammonium salts as a nitrogen source.
Citrate Utilization test
Media used in Citrate utilization test
Simmon Citrate Agar
Reagent used in Citrate Utilization test
Bromythmol Blue
Results in citrate utilization test
+ intense blue color (Klebsiella, Enterobacter, Pseudomonas)
- green color ( Escherichia and Edwardsiella)
Enzyme produced by some aerobic bacteria as part of the respiratory oxidation mechanisms.
P.aeruginosa and N.meninggitis
Oxidase test (Cytochrome oxidase/ indophenol blue)
Filter paper method of Oxidase test
Tetramethyl p-phenylalanine diamine dihydrocholride
Results in Oxidase test
+ bluish purple ( P.aeruginosa)
- E.coli
To produce enzyme urease.
Some organism hydrolyze urea rapidly releasing ammonium and CO2.
Urease test
Strong urea producer
Providencia, Proteus, Morganella
Weak urea production
Klebsiella
Urease producer
Yersinia Enterocolitica
Results of urease test
+ pink/magenta P.vulgaris and S.marcesens
- no color change
Slow urease producer
Citrobacter, Klebsiella, Enterobacter
Rapid Urease Production
Proteus and Providencia rettgeri, K.pneumonia, K.oxytoca, E.cloacae and Yersinia enterocilitica
Media used in Urease test
Christensen’s Urea Agar
pH indicator used in Urease test
Phenol red
Some organisms can deaminate phenylalanine converting it to phenylpyruvic acid
Phenylalanine Deaminase Test
Results of Phenylalanine Deaminase Test
+ dark green color after addition of ferric chloride
Media used in Phenylalanine Deaminase test
Phenylalanine Agar or Tryptohpan agar
Reagent used in Phenylalanine Deaminase test
10% Ferric Chloride
Results in Phenylalananine Deaminase Test or the reagent Alpha napthol in 40% KOH in creatine (Coblentz method)
+ green color in slant (P.vulgaris)
- E.coli
Some organisms can Decarboxylase Lysine converting it to cadaverine
Lysine Decarboxylase Test
Indicator used in Lysine Decarboxylase Test
Bromcresol blue
Medium used in Lysine Decarboxylase Test
Lysine Iron Agar or Moeller’s Agar
Result in Lysine Decarboxylase Agar
+ remains purple denoting an alkaline medium
Used to determine gram - can Decarboxylase or deaminates Lysine and form H2S
Lysine iron agar test
Media used on LIA.
Lysine Iron Agar contains Lysine, Glucose, Peptones, Ferric NH4 Citrate and Na thiosulfate
If glucose is fermented
Butt becomes acid
If Decarboxylase is not produce
Butt remains acid
If oxidative deamination of Lysine occurs
It forms burgundy color on slant in the presence of Ferric Ammonium Citrate and Flavin mononucleotide
If deamination do not occur
LIA slant remains purple
K/K on LIA reaction
- Lysine deamination
+ Lysine Decarboxylation
K/A on LIA reaction
- Lysine deamination
- Lysine Decarboxylation
R/A on LIA reaction
+ Lysine deamination
- Lysine Decarboxylation
H2S indicator on LIA reaction
Ferric ammonium citrate
Indicator on LIA reaction
Bromcresol purple
Test measures the ability of an organism to decarboxylate an amino acid to form an amine.nit requires acid in pH and anaerobic environment.
Decarboxylase test (Moeller’s method)
Indicator used in Decarboxylate Test
Bromcresol purple
Decarboxylation of the amino acids results in
Alkaline pH change
3 decarboxylate broth
Lysine, Arginine, Orthinine
Result in Decarboxylase test
+ alkaline purple color
If an enterobacteriaceae contains amino acid Decarboxylase, amines produced by Decarboxylase action cause an alkaline pH. Lysine, Arginine, Orthinine are utilized. A base broth without amino acid is included in which glucose fermentation acidifies the broth.
Amino Acid Decarboxylase
Lysine ➡️❓
Cadaverine (decarboxylase)
Orthinine ➡️❓
Putrescine (decarboxylase)
Arginine ➡️❓
Citrulline (dihydrolase)
Conversion of Arginine to Citrulline
Dihydrolase reaction
Decarboxylation of patterns are essential for the genus identification
Klebsiella, Enterobacter, Escherichia and Salmonella
Decarboxylation of patterns are essential for the species identification
Enterobacter cloacae, Enterobacter aerogenes, proteus mirabilis, shigella sonnei
Systems for H2S production
Lead acetate paper SIM tube Hektoen and SS agar XLD agar Triple Sugar-Iron Agar
H2S producing
Edwardsiella, Salmonella, Citrobacter, Proteus
Media used in H2S
TSI, LIA, SIM, HEA
Result in H2S production
Production of black color
Non motile on Motility test
Shigella and Klebsiella
Non motile on 35C and motile on 22-25C on motility test
Yersinia
Ability of organism to produce protease that hydrolyzes gelatin and liquify solid gelatin medium. Used in identification of Clostridium, Flavobacterium, Pseudomonas and Serratia.
Gelatin Liquifacation
Results in gelatin Liquifacation.
+ gel liquifies (P. Vulgaris)
- gel solidifies (E.aerogenes)
Determine the ability of an organism to reduce nitrate to nitrate by adding sulfanilic acid and alpha-napthylamine
Nitrite Reduction
Result in Nitrite reduction
+ red, water soluble azo dye (E.coli)
MUG test and result
4-methylumberriferyl-beta-D-glucoronide
+ blue fluorescence (E.coli)
- no fluorescence (P.aeruginosa)
Result in Esculin Hyrdolysis
+ black (K.pneumonia)
- yellow (S.Flexneri)
KCN Broth results
- clear
+ turbid
Mako ate Utilization Test
- green
+ blue
String Test
ID of Vibrio
Reagent of String test
0.5% sodium desoxycholate
Result on String test
+ string like
