M3 - Anaerobic bacteria

Question 1

what are obligate anaerobes

Answer 1

• organisms unable to grow in presence of O2

- require low reduction/oxidation potential (Eh)

Question 2

what are facultative anaerobes

Answer 2

• organisms grow under aerobic or anaerobic conditions

E.coli, staphylococci, streptococci

Question 3

what are obligate aerobes

Answer 3

• organisms unable to grow in absence of O2

pseudomonas, Nesisseria

Question 4

what are microaerophiles

Answer 4

organisms that need small amount of O2 (less than normal atmospheric level)
(Helicobacter)

Question 5

what are capnophiles

Answer 5

organisms that need 5-10% CO2 for growth

Brucella

Question 6

what are the 4 ways to cultivate anaerobes

Answer 6

1. anaerobic jars
2. anaerobic cabinets
3. roll-tube techniques/Hungate method
4. robertons cooked meat (RCM) medium

Question 7

how do anaerobic cabinets work to cultivate anaerobes

Answer 7

▹ provides complete working chamber for anaerobes
▹ contains atmos of 80%N2, 10% H2, 10 CO2
▹ pass materials in + out via air lock

Question 8

how do anaerobic jars work to cultivate anaerobes

Answer 8

a) vacuum replacement method
- remove air with vacuum pump
- replace atmos with gas mix
- include palladium catalyst

b) gas-generating sachets
- add water, H2+CO2 form

Question 9

what are 3 groups in gram + bacteria

Answer 9

1. cocci
2. spore forming rods
3. non-sporing rods

Question 10

what is example of cocci in gram+

Answer 10

peptostreptococcus

Question 11

what is example of spore-forming rods in gram+ bacteria

Answer 11

clostridium

Question 12

what are 4 examples of non-sporing rods in gram+ bacteria

Answer 12

• propionibacterium
• eubacterium
• actinomyces
• bifidobacterium

Question 13

what are 3 groups in gram - bacteria

Answer 13

1. cocci
2. rods + filaments
3. spirochaetes

Question 14

what is example of cocci in gram-

Answer 14

veillonella

Question 15

what are 5 examples of rods + filaments in gram+ bacteria

Answer 15

• bacteriodes
• fusobacterium
• prevotella
• campylobacter

Question 16

what is 2 examples of cocci in gram-

Answer 16

• spirochaetes

- treponema

Question 17

what are dentoalveolar/periapical abscesses

Answer 17

abscesses that develop around apices of teeth with necrotic + infected root canals
- oral streptococci + oral anaerobes
(obligate anaerobes predominate)

Question 18

what is osteomyelitis and caused by what

Answer 18

rare disease -> inflammation of jaw bone cavity

anaerobic gram- rods + streptococcus spp.

Question 19

what is chronic marginal gingivitis

Answer 19

inflammation confined to soft tissues of gingival as results of plaque accumlating

Question 20

what is acute ulcerative gingivitis (AUG) and what is it caused by

Answer 20

grey gingival pseudomembrane - easily removed revealing bleeding area +destruction of interdental papillae

• spirochaetes (Treponema), prevotella + Fusobacterium

Question 21

what is periodontitis + what is it caused by

Answer 21

gingival inflammation to deep tooth structures with destruction of periodontal ligament + alveolar bone

• porphyromonas gingivalis, aggregatibacter, prevotella intermedia

Question 22

what is pericoronitis and what is ti caused by

Answer 22

inflammation of soft tissue that surround crown of partially erupted tooth (esp lower 3rd molars)

• oral anaerobes (P. intermedia + Fusobacterium nucleatum)

Question 23

what is peri-implantits + what is it caused by

Answer 23

inflammation around implant systems that replace missing teeth

• oral anaerobes esp P.gingivalis + P.intermedia

Question 24

what is actinomycosis + cause by what

Answer 24

formation of chronic granuloma with swelling
chronic - discharging sinuses can be seen

• actinomyces israelii

Question 25

what is sialadenitis + caused by what

Answer 25

infection of salivary glands | - streptococcus spp, staphylococcus + gram- anaerobes

Question 26

where can infection with non-sporing aerobes occur

Answer 26

head + neck respiratory GI+GU tracts in abscesses + wound infections - can associated with bad smelling pus + discharge

Question 27

what is clostridium

Answer 27

▹ gram +pos large anaerobic rods ▹ produce endospores - allows organisms to survive in adverse conditions (soil/skin) ▹human/animal intestine + plant/animal matter

Question 28

what are 4 important species of clostridium

Answer 28

``` C.botulinum = (botulism) C.perfringens = gas (gangrene/food poisoning) C.tetani = (tetanus) C.difficle = (pseudomembranous colitis) ```

Question 29

what causes tetanus and how is it caused

Answer 29

▹ clostridium tetani ▹ after contamination of deep wound/injury ▹ spores in soil + env ▹ C.tetani preoduce tetanospasmin (neurotoxin) & tetanolysin (haemolysin)

Question 30

what happens when you get tetanus and how is it prevented

Answer 30

▹ trismus (lockjaw) dysphagia, muscle spasms ▹ death by resp/cardiac failure ▹ prevent by vaccine with tetanus toxoid (inactivated) IF UNEXPOSED ▹ IF EXPOSED = passive immunisation with HTIG (toxin antibody)

Question 31

what is botulism caused by and how

Answer 31

▹ clostridium botulinum ▹ after ingestion of pre-formed toxin in food (meats + cans) ▹ makes potent neurotoxins (types A-G)

Question 32

what types of neurotoxins cause human botulism

Answer 32

types A, B, E

Question 33

how does C.botulinum toxins affect the body

Answer 33

▹ bacteria produces extremely potent neurotoxins | ▹ toxin blocks release of Ach from peripheral motor nerve endings

Question 34

what are the symptoms of botulism and how is it prevented

Answer 34

▹ vomit, thirst, muscle paralysis ▹ death by resp/cardiac failure ▹ prevent = control processed foods

Question 35

what is gas gangrene caused by

Answer 35

▹ polymicrobial infection of wounds | ▹ histotoxic clostridia -> produce range of lethal + necrotising toxins

Question 36

what species of clostridia can cause gas ganrene

Answer 36

C.perfringens C.novyi C.septicum

Question 37

what are the 3 stages of infection during gas gangrene

Answer 37

contamination clostridial cellulitis myonecrosis (gas gangrene)

Question 38

what are the symptoms of gas gangrene and how is it prevented

Answer 38

▹ gas forms in tissue ▹ fever, shock, coma death ▹ treatment can mean amputation ▹ prevented = proper wound management