Lesson 8

Question 1

– Biochemical testing
– Staining characteristics, microscopic morphology
– Colony (Morphology, Odor, Pigmentation)
– Resistance or Susceptibility to Antimicrobial agents
– Nutritional requirements, metabolic capabilities, environmental requirements

Answer 1

Phenotypic Characteristics

Question 2

– Molecular Diagnosis: Nucleic Acids
– Molecular Diagnosis: Proteomics

Answer 2

Genotypic Characteristics

Question 3

– Reagent: Hydrogen Peroxide
– Product: Effervescence (Production of
bubbles)
– DO NOT USE ORGANISMS FROM BAP
– Positive: Staphylococcus, Micrococcus,
Listeria monocytogenes, Corynebacterium
– Negative: Streptococcus

Answer 3

Catalase Test

Question 4

– Enzyme: Cytochrome Oxidase
– Reagent: 1% Tetramethyl-pphenylenediamine dihydrochloride
– Positive Reaction: Purple Color
– False Positive: Iron wires (Use Platinum or Wood)
– Positive: Enterobacteriaceae,
Stenotrophomonas maltophilia,
Acinetobacter spp.
– Negative: Pseudomonas spp., Aeromonas
spp

Answer 4

Oxidase Test

Question 5

– Indicator Aldehyde: Kovac’s Reagent
– Positive Color: Red
– Positive: Escherichia coli, Edwardsiella tarda,
Klebsiella ornithinolytica, Klebsiella oxytoca
– Negative: Klebsiella pneumoniae

Answer 5

Indole Test

Question 6

– Ammonia – Increase in pH
– Positive: Pinkish Red
– Positive: Proteus spp., Corynebacterium
urealyticum, Helicobacter pylori

Answer 6

Urease Test

Question 7

– Enzyme: L-pyrroglutamyl-aminopoeptidase
– L-pyrrolidonyl-β- naphthylamide à β-
naphthylamine
– β-naphthylamine + Cinnamaldehyde à Bright
Red
– Positive: Streptococcus pyogenes,
Enterococcus spp.
– Negative: Other Streptococcus spp

Answer 7

PYR Test

Question 8

– Enzyme: Hippuricase (Hippurate à Glycine)
– Glycine (Oxidation by Ninhydrin) à Deep Purple
– Positive: Gardnerella vaginalis, Streptococcus
agalactiae, Campylobacter jejuni, Listeria
monocytogenes

Answer 8

Hippurate Hydrolysis

Question 9

– Oxidative Processes: Require Oxygen
– Fermentative Processes: Does not require
Oxygen
– Medium: Semi-solid (Peptone,
Carbohydrate)
– Inoculate into 2 glucose OF tubes (one with
mineral oil)
– Oxidative spp.: Pseudomonas
– Fermentative spp.: Enterobacteriaceae

Answer 9

Oxidation-Fermentation Test

Question 10

– Cleave the Carboxyl group from Amino Acids à
Amines
■ Lysine à Cadaverine
■ Ornithine à Putrescine
– Increased Alkalinity
– Environment: Anaerobic process, requires Acid
environment for activation
– Reagent: Moeller Decarboxylase Base (Glucose
+ AA substrate of Interest + pH Indicator

Answer 10

Decarboxylation

Question 11

– Amino Acid: Phenylalanine
– Phenylalanine + 10% Ferric
Chloride -> Phenylpyruvic Acid
(Green Color)
– Lysine Iron Agar Media

Answer 11

Deamination

Question 12

Organisms grown in a single nutrient or carbon source

Answer 12

Single Substrate Utilization

Question 13

TAT for Rapid Identification

Answer 13

4 hours or within the day (Overnight Incubation)

Question 14

– Potential tool for microbial identification and diagnosis
– Peptide placed on a matrix, causing the peptide to form crystals (Crystalline matrix)
– Identification: Matching the masses of Biomarkers of unknown organisms with the Proteome database

Answer 14

Matrix-Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF)