Identification

• Acetamide utilization


  Used to check the ability of an organism to use acetamide as a sole source of carbon
• Acetamide utilization


  • Indicator: Bromothymol blue
  • (+) Blue
  • (-) Green
• Acetate utilization


  Used to determine if an organism can use acetate as the sole source of carbon
• Acetate utilization


  • (+) Blue
  • (-) Green
• Bacitracin test


  • Amount of Bacitracin: 0.04 U
  • This drug interferes in the peptidoglycan synthesis of bacteria
  • The presumptive identification of group A streptococci
• Bacitracin test


  • (+) Any zone of inhibition
  • (-) No zone
• Bile Esculin agar


  • Based on the ability of certain bacteria to hydrolyze esculin in the presence of bile
  • Conc.: 40% Bile
  • Indicator: Ferric ammonium citrate
• Bile Esculin agar


  • (+) Blackening of agar
  • (-) No blackening
• Bile Solubility test


  • Distinguishes Streptococcus pneumoniae from all other alpha-hemolytic streptococci
  • Sodium deoxycholate (2% in water) will lyse the pneumococcal cell wall
• Bile Solubility test


  • (+) Colony disintegrates
  • (-) Intact colonies
• Butyrate disk


  • Detection of the enzyme butyrate esterase
  • Rgt: Bromo-chloro-indolyl butyrate
• Butyrate disk


  • (+) Blue color
  • (-) No color change
• CAMP test


  Test based on the formation of CAMP factor that enlarges the area of hemolysis formed by the β-hemolysin elaborated from Staphylococcus aureus
• CAMP test


  • (+) Arrowhead zone of beta-hemolysis
  • (-) No enhancement of hemolysis
• Catalase test


  • Catalase mediates the breakdown of hydrogen peroxide H2O2 into oxygen and water
  • To find out if a particular bacterial isolate is able to produce catalase enzyme
• Catalase test


  • (+) Bubble formation
  • (-) No or few bubbles
• Cetrimide


  Used to isolate and identify Pseudomonas aeruginosa
• Cetrimide


  • (+) Growth
  • (-) No growth
• Citrate utilization


  • Used to determine if an organism can use citrate as the sole source of carbon
  • Indicator: Bromthymol blue
  • Medium: Simmon's citrate agar
• Citrate utilization


  • (+) Growth w/ or w/o change in color from green to blue
  • (-) No growth
• Coagulase test


  • Slide test: detects clumping factor (bound coagulase)
  • Tube test: detects free coagulase
  • Rgt: Rabbit EDTA plasma
• Coagulase test


  • Slide test: (+) Clumping, (-) No clumping
  • Tube test: (+) Clot formation, (-) No clot
• Decarboxylase test (Moeller's method)


  • Decarboxylase enzymes is capable of reacting with the carboxyl (COOH) portion of amino acids, forming alkaline-reacting amines and byproduct carbon dioxide
  • Lysine: To assist in the identification of Salmonellae (+ve) and Shigellae (-ve)
• Decarboxylase test (Moeller's method)

  • (+) Alkaline (purple color)
  • (-) Acid (yellow color)
• DNA Hydrolysis (DNase)


  • Used to determine the ability of an organism to hydrolyze DNA and utilize it as a source of carbon and energy for growth
  • Medium: DNase agar (DNA-methyl green complex)
• DNA Hydrolysis (DNase)


  • (+) Colorless around the inoculum
  • (-) Green
• Esculin Hydrolysis


  To see if the microbe can hydrolyze the compound esculin as a carbon source
• Esculin Hydrolysis


  • (+) Blackened medium and loss of fluorescence under Wood's lamp
  • (-) No blackening and no loss of fluorescence under Wood's lamp
• Fermentation Media


  • a. Peptone medium: Indicator: Andrade's indicator
  • b. Heart infusion broth: Indicator: Bromcresol purple
• Fermentation Media


  • Peptone medium: (+) Pink w/ or w/o gas formation in Durham tube, (-) Growth but no change in color
  • Heart infusion broth: (+) Yellow, (-) Growth but no change in color (purple)
• Flagella Stain (Wet-Mount technique)

  Rgt: RYU flagella stain
• Flagella Stain (Wet-Mount technique)

  • (+) Flagella: a. Peritrichous, b. Lophotrichous, c. Polar, d. Tufted
• Gelatin Hydrolysis (Gelatinase)


  Gelatin hydrolysis test is used to detect the ability of an organism to produce gelatinase (proteolytic enzyme) that liquefy gelatin
• Gelatin Hydrolysis (Gelatinase)


  • (+) Partial or total liquefaction at 4'C
  • (-) Complete solidification at 4'C
• Growth at 42'C


  To test the ability of an organism to grow at high temperature
• Growth at 42'C


  • (+) Good growth at both 35'C and 24'C
  • (-) No growth at 42'C but good growth at 35'C
• Hippurate test


  • Hippuric acid is hydrolyzed to benzoic acid and glycine by the enzymatic action of hippuricase
  • The glycine end product is detected by the addition of ninhydrin reagent
• Hippurate test


  • (+) Deep purple color
  • (-) Colorless or slightly yellow pink color
• Indole production


  Determine the ability of an organism to split amino acid tryptophan to form the compound indole by tryptophanase
• Indole production


  • Kovac's method: (+) Pink- to wine-colored ring, (-) No color change
  • Ehrlich's method: (+) Pink- to wine-colored ring, (-) No color change