Updated: 3/6/2019

Enzyme Tests

Topic
Review Topic
0
0
Overview
  • The presence or absence of specific enzymes can be used to distinguish bacteria in the laboratory
    • urease
    • catalase
    • coagulase
    • oxidase
Urease
  • Catalyzes the hydrolysis of urea into carbon dioxide and ammonia
  • Increase in urine pH leads to renal calculi
  • Urease positive bugs ("Urease Contaminates Kidneys. Now Peeing HurtS.")
    • Proteus spp.
    • Helicobacter pylori
    • Klebsiella pneumoniae
    • Ureaplasma urealyticum
    • Nocardia spp.
    • Cryptococcus neoformans
    • S. epidermis and S. saprophyticus
Catalase
  • Decomposes hydrogen peroxide before the host can use it to fight infection
    • H2O2 normally converted to microbicidal products by the enzyme myeloperoxidase
    • particularly a problem in people with chronic granulomatous disease (NADPH oxidase deficiency)
      • diseased host does not make enough H2O2
  • Catalase positive
    • Staphylococci (all species)
      • "they have enough 'staff' to make catalase"
    • Nocardia spp.
    • Pseudomonas
    • Listeria
    • Aspergillus
    • Candida
    • E. coli
    • Burkholderia cepacia
    • Serratia marcescens
    • H. pylori
    • Aspergillus spp.
  • Catalase negative
    • Streptococci (all species)
    • most anaerobes
Coagulase
  • Coagulase positive
    • Staphylococcus aureus
    • Yersinia pestis
Oxidase
  • Oxidase positive
    • Neisseria spp.
    • most Gram-negative bacteria
  • Oxidase negative
    • Enterobacteriaceae
 

Please rate topic.

Average 5.0 of 2 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
ARTICLES (2)
Topic COMMENTS (6)
Private Note