Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BDS 3 IHD-P1 Microbiology > anaerobic organisms > Flashcards

anaerobic organisms Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

categories of anaerobic organsims

A

obligate anaerobes
faculatative anerobes
microaerophiles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

obligate anerobes

A

harmed by the presence of oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

facultative anerobes

A

can grow without oxygen but uses oxygen if present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

microaerophiles

A

grow in atmosphere of low oxygen less than 5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the terminal e- acceptor in anaerobic respiration

A 
lactic acid (organic)
inorganic (sulphate nitrate)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

fermentation products and products from incomplete fermentation

A 
lactic acts
(feeds NAD back into muscles when there is oxygen starvation

products from incomplete fermentation

1) Vingear
2) propionic acid
3) some yeast produce alcohol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

aerobic respiration vs anaerobic respiraton

A

1) Aerobic respiration - ATP is released as electrons are transported along chain to final acceptor O2 (forms water)
2) Anaerobic respiration uses electron transport chain but the final electron acceptor is not O2
• Nitrate (NO3- reduced to nitrite NO2-, or N2)
• Ferric iron (Fe3+ reduced to Fe2+)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what do organisms have to stop oxygen radicals and what do they do

A

superoxide dismutase
catalase
perioxdase

convert radicals to water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what can be used for study of anaerobes

A

Obligate anaerobes can process the metronidazole, allows diagnosis of anaerobic organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

lab diagnosis of anaerobes

A 
Sugar fermentation (species specific?)
Toxin production (clostridia)
Gas liquid chromatography measures fatty acid end products (VFAs)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

major anaerobic bacteria in humans

A

1) clostridia
2) Bacteroides
3) fusobacterium
4) porphryromonas and black pigmenters
5) Gardnerella and GPACs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

clostridium species

A
  • large, straight, gram + bacilli
  • produce endospores
  • produce exo toxins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

important clostridium species in prominent diseases

A

1) Cl. perfringens
- gas gangrene
- food poisoning
2) Cl. Botulinum
- botulism (food)
- uses in botox
3) Cl. tetani
- tetaus (Environmental)
4) Cl. difficile
- pseudomembranous colitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

cl perfringens

A
  • Capsulate
  • non motile
  • gram + rod
  • polysaccharide capsule
  • spreading, fast growing, double BETA hemolytic colonies on BA (also has some alpha hemolysis)
  • i.e. several types of hemolysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

exo toxins of cl perfringens

A

5 toxigenic types A-E

major toxin is alpha toxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what can exo toxins lead to

A
  • phospholipase C/lecithinase
  • lyses RBCs, platelets, leukocytes and endothelial cells
  • inflammation and major swelling
  • oedema, bleeding (antiplatelet activity)
  • haemolysise
  • kidney damage- renal failure
  • myocardial dysfunction
17
Q

enterotoxin

A
  • pore forming
  • heat labile
  • produced upon sporulation of ingested bacteria in stomach acid reaction (important in diarrhoeas)
  • activated in the stomach
18
Q

toxin detection what is used and positive test

A

nagler reaction/plate
Alpha toxin – used to confirm perfringens
- Antitoxin on one side of plate, not on the other side
- presence of the toxin leads to precipitate when toxin is present
- neutralised with antitoxin, no ppt
- sporogenes does not produce toxin therefore no difference

19
Q

treatment of gas gangrene and what causes it

A

cl perfringens

surgery(amputation) antibiotic

20
Q

what causes food poisoning

A

clos perfrigens enterotoxins

21
Q

what causes tetanus / what is tetanus

A

cl tentant

Acute spastic paralysis caused by a potent bacterial neuro-exotoxin (muscles contract uncontrollably)

22
Q

cl tentani and how does it spread/track

A

Motile
Gram + rods
- thin spreading film on agar
- drum stick spores

toxin released into body, tracks along nerves to CNS

23
Q

tetanus toxin and how it works etc

A 
Classic A-B neurotoxin
-	Tetanospasmin, TeNT
2 domains
–	A domain contains active site
–	B domain> Carbohydrate receptor binding- Sialic acid containing poly-sialic-gangliosides (found on the outside of nerve cells)
Zinc endopeptidase (A-domain)
-	Prevents release of inhibitory transmitter (Gamma-aminobutyric acid- muscle relaxant)
Absorbed from infectious focus
–	Travels along a-fibres to CNS
24
Q

treatment and prevention of tetnus

A 
Treatment
-antitoxin/immunoglobulin +penicillin +metronidazole
Prevention
-	immunisation
-	tetanus toxoid
25
Q

botulism and symptoms

A 
Caused by ingestion of preformed toxin from contaminating Cl.Botulinum 
Symptoms
-	drooping eyelids
-	progressive motor loss
-	flaccid paralysis
Neurological sypmtoms
-	diziness
-	respiratory and cardiac failure
26
Q

cl botulinum type of bacteria

A

Endospore that is subterminal

  • motile gram + bacillus
  • subterminal spores

Toxin released as progenitor complex to protect during passage through stomach, intestine then bloodstream

27
Q

botulinum toxin and how it works

A

7 types A-G
A B and E most common
- A domain contains active site
- B domain – carbohydrate receptor binding – sialic acid containing DL – sialic- gangliosides
Zinc endopeptidase
- affects peripheral cholinergic synapses
- blocks release of acetylcholine (blocks stimulatory molecule)
- irreversible binding, relaxation
- stronger binding than tentaus toxin

28
Q

treatment of botulism

A
  • remove toxin

- polyvalent antitoxin

29
Q

antibiotic/hospital associated diarrhoea

A

Cl. difficle
- spores of the organisms germinate and can overwhelm gut flora can cause psudomemntanous colitis (lesiosn in the gut)
- need to give a narrow rather than broad antibiotic
Antibiotic associated diarrhoea
- associated with broad spectrum antibiotic use, clindamycin and ampicillin
- outcompetes rest of population after antiobtic course complete

30
Q

psudomembranous colitis

A

Antibiotic associated diarrhoea

Adherent membrane of inflammatory cells and necrotic debris

31
Q

cl difficile toxins and how do they work

A

Produces TcdA and TcdB
- glucosyltransferases
- toxin present in patients stool (primary diagnostic marker)
Cell receptor for TcdA disaccharide GalB I – 4GlcNac (bind via glycoproteins)
Inactivates Rho (family of GTPases)
- actin condensation, rounding of cells, membrane blebbing and apoptosis of cell
- leads to neutrophil infiltration, disruption of tight junctions, fluid accumulation

32
Q

treatment and prevention of c difficile

A

Therapy is vancomycin or metronidazole
- + remove offending broad spectrum, selective antibiotic eg clindamycin

  • cleaning
  • hand washing (to remove transmission of spores)
  • quarantine
    Limit use of broad spectrum antibiotics in at risk patients
33
Q

bacteroides fragilis

A 
Gram – bacillus
-	capsulate (CPA, LPS)
Toxigenic strains
-	some cuase diarrhoea
-	toxin cleaves E- cadherin
34
Q

what is bactericides fragilus resistant to

A
  • clindamycin

- metronidazole (some strains)

35
Q

prevotella

A

black pigmented anaerobe
gram -
non motile
rod shaped

36
Q

porphyrumonoas

A

black pigmented anaerobe

  • non motile
  • gram –
  • rod shaped
  • PDD – gingivalus commoly found in biofilm with other spp (eg T forsythia)
  • forms black colonies on blood agar
37
Q

fusobacterium and treatment

A
  • long rod shaped spindle shaped bacilli, gram –
  • associated with PDD, skin ulcers, respiratory infections
  • highly effective at biofilm formation
    black pigmented anerobe

treatment
- antibiotics clindamycin

38
Q

black pigmented anerobe examples

A 
prevotella
porphymonas
fusobacterium
GPAC- peptostreptococcus
eubacteria and bifidobacterium
39
Q

b fragilis

A

causes 25% of non clostridia anaerobic infections

BDS 3 IHD-P1 Microbiology (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions