Anaerobic Bacteria Flashcards
1
Q
Anaerobic Bacteria
A
- obligate anaerobes
- can be aerotolerant of facultative
- use other flashcards about fermentation pathways-inefficient, intermediate waste product,leave energy in final, waste is organic acid or alcohol, repertoires
2
Q
common sources of pathogen 1
A
- normal flora escape normal compartment
- actinomyces, B corrodens, P melaninogenica in mouth
- B fragilis in colon and vagina
- abcess fills with bacteria and dead neutrophils, swells, becomes painful
3
Q
common source of pathogens 2
A
- soil-spores enter through wounds, germinate, produce exotoxins
- C tetani
- C perfringens
- C botulinum
4
Q
Route of entry 2 from soil
A
- spores germinate in vacuum packed foods
- C perfringens in food poisoning:bacteria briefly survive in gut and release enterotoxin
- C botulinum in infants-bacteria survive briefly in gut and release neurotoxin
- Botulism in foodborne-bacteria do not survive in gut but already filled food with neurotoxin
5
Q
anaerobes in lab
A
- sample must be handles anaerobically and labeled as such
2. standard clinical labs are anaerobic culture, gram stain, gas chromatography
6
Q
liquid culture
A
- innoculate test tube of media
- add a reducing agent like thoglycolate to eliminate dissolved oxygen
- fill completely, stopper tightly and incubate WITHOUT SHAKING
- aerobe grows on top, anaerobe on bottom, both in middle
7
Q
agar plates
A
- quickly streak onto agar media with usual benchtop sterile technique
- place plates in anaerobic culture jar
- add a chemical system to remove oxygen from jar’s atmosphere and color indicate successful removal (Gas-Pak)
- airtight seal
- place whole jar in incubator for 48 hours
- note that colonies will die very shortly after removal from jar unless using a glovebox
8
Q
glovebox
A
- box with oxygen free atm
- airlock for bringing plates and instruments in and out (flood with nitrogen)
- gloves attached to box for manipulations within
9
Q
Identifying anaerobes
A
- gram stain
- chemical testing-ability to ferment, hydrolize various macromolecules
- gas chromatography
10
Q
gas chromatography
A
- analyzes organic acids being produced by the anaerobes fermentation pathways
- extracts from culture or pus sample are run against control mixes
11
Q
treatment of anaerobic infections
A
- surgical care for abscess
- antitoxin for toxigenic disease-tetanus/botulism
- antibiotics-penicillin G, cefotoxin, chloramphenicol, clindamycin
- metronidazole-specific for anaerobic bacteria-broken down to active form where the bacteria are
12
Q
clostridium
A
- clostridium all gram pos and rods and in soil, except C dif
- spores to survive transfer
- all make exotoxins
13
Q
GNAB
A
- gram neg anaerobic bacilli-normal flora gone bad
- bacteriodes and prevotella
- rods
- no spores
14
Q
actinomyces
A
- gram pos
- long rod
- no spores
15
Q
C. tetani
A
- spores are environmental: soil, dust, manure, some human skin and GI
- gram pos
- spore-forming
- transmitted to humans by soil contamination of wounds-splinters, thorns, punctures, IV septic surgery, septic handling of umbilical cord
- insertion beneath the skin surface limits air contact
- spores germinate- vegetative cells release exotoxin tetanospasmin
- large and small subunit, small unit delivered, retrograde axonal transport to CNS
- acts as protease, cleaves synaptobrevin in inhibitory motor nerves of CNS, no inhibitory motor neuron activity
- can’t stop contracting
