Micro Unit 2: Chapter #6 Flashcards
(23 cards)
Define chemoheterophs
Gets energy from chemicals/ eukaryotic
Define mesophiles
Pathogenic by temperature
(20- 40°C)
Define neutrophiles
Pathogenic by pH
(6.5 - 7.5)
List + describe 4 categories of bacteria classified by oxygen requirements
- Obligate aerobes
- Obligate anaerobes
- Facultative anaerobes
- Capnophiles or aérotolerant
Define obligate aerobes
Require oxygen for survival
Define obligate anaerobes
Killed by oxygen
Define facultative anaerobes
Grow with or without oxygen
- live either way
Define aerotolerant anaerobes
Are unaffected by oxygen levels
Define non-selective and differential media
- Non-selective: Growth of most bacteria of clinical significance
- Differential: hemolytic
- NO “fastidious” organisms
EX: BAP
Define non-selective enriched media
- Non-selective: more enriched + most non-selective
- grows “fastidious” organisms: neisseria and haemophilus
- isolates pathogens diff. to grow
EX: CAP
Define selective media
-Selective: isolates neisseria gonorrhoea
EX: MTM
Define selective- differential media
-Selective: by gram stain
-Differential: see hemolytic or lactose patterns
EX: CNA, MAC, HE
Describe the 3 hemolytic patterns
- Beta: complete destruction (clear)
- Alpha: partial destruction (green)
- Gamma: N/A:
List the 3 conditions incubators provide for the culture of bacteria
-optimum temp: 35 -37°C
- proper humidity levels
- right atmospheric gases
What is a multi-test system?
Integrated systematically to work as a unit
Ex: enterotube: unknown oxidase for gram (-) and rod shaped
What is an automated method?
Instrument reads test results
Ex: Vitek + Microscan systems
What are the advantages of automated methods?
- Identify larger variety of bacteria
- Higher accuracy
-Faster: 8-20 hrs
What are biochemical tests used for?
Used as single tests and identify limited bacteria group
What is a serological test? Give main uses and the viral infections.
They use known antigens to identify antibodies in blood
Uses: diagnose diseases by detecting antibodies
Infections: HIV and hepatitis
What is a serotyping test? Give its main use and its common pathogens.
Use known antibodies to complete identification
- Replaces biochemical tests
Common pathogens: Neisseria and S. pneumoniae
What is a gene probe and explain its main usage
They detect unique segments of DNA
Uses: Chlamydia and Gonorrhea
Alt. for TB diagnosis
Give 3 advantages of gene probes over biochemical
- identifies directly on specimen
- works dead or alive
- results faster
Which term describes an organism that cannot exist in oxygen
Obligate anaerobe
