Anaerobes

Question 1

Anaerobes form the main component of _____________.

Answer 1

human endogenous flora

Question 2

List the most common anaerobes in the (1) oral cavity, (2), colon, (3) female genital tract, and (4) skin.

Answer 2

• Oral cavity: Bacteroides fragilis
• Colon: B. fragilis and Clostridium
• Female genital tract: Lactobacillus
• Skin: Propionibacterium

Question 3

Why is oxygen toxic to obligate anaerobes?

Answer 3

Most anaerobes lack catalase and superoxide dismutase, so the H2O2 and O2–•are highly destructive.

Question 4

What kind of bacteria is Bacteroides fragilis?

Answer 4

• Aerotolerant anaerobe
• Gram-negative rod
• Not a spore former
• Encapsulated
• Commensal colonic bacteria that commonly causes peritoneal infections following abdominal surgery
• Does not contain endotoxin
• Pleomorphic

Question 5

Which of the following can grow in anaerobic conditions? 
•Bacteroides
•Clostridium 
•Staphylococcus aureus
•E. coli
•Streptococcus
•Enterococcus

Answer 5

All of them!

Question 6

The classic presentation of anaerobic Gram-negative rods and anaerobic cocci is ______________.

Answer 6

polymicrobial abscess formation

Question 7

C. tetani germinates in ______________ tissue.

Answer 7

devitalized

Question 8

Give the Sketchy rundown on C. tetani.

Answer 8

• Gram-positive rod (purple gloves on scientists)
• Inhibits release of GABA and glycine from Renshaw cells in the spinal cord (monkey with wRENch and SAW)
• Obligate anaerobe (gas masks)
• Spore-forming (walnuts that monkeys are eating)
• Found in soil (spilled buckets of soil)
• Toxin cleaves snare protein (scientist with syringe in net)
• Vaccine is to toxin (like the orange scissors that are the same color as the orange syringe)

Question 9

One of the most common presentations of tetanus is now ___________.

Answer 9

neonatal tetanus (34,000 cases in 2015 with an 80% mortality)

Question 10

Give the Sketchy rundown on C. botulinum.

Answer 10

• Gram-positive rod (purple-eyed robots)
• Causes descending paralysis with prominent ptosis (robots with droopy eyes and falling heads)
• Spore-forming (bolts in honey)
• Obligate anaerobe (guy in gas mask)
• Toxin cuts snares that release acetylcholine at the NMJ (scissors cutting Ach battery)
• Found in canned food (can-shaped robots)

Question 11

Death from botulism most often results from ______________.

Answer 11

respiratory failure

Question 12

The treatment for C. botulinum is ____________.

Answer 12

equine antitoxin

Question 13

Sporulating C. tetani have a characteristic _____________ shape.

Answer 13

tennis-racquet

Question 14

In babies, ___________ can cause botulism while adults usually require _____________.

Answer 14

C. botulinum spores (which then germinate in the baby’s gut); preformed toxin

Question 15

Iraq made 19,000 liters of ______________.

Answer 15

weaponized botulinum toxin gas

Question 16

Which of the C. difficile toxins is an enterotoxin?

Answer 16

A

B is a cytotoxin.

Question 17

C. difficile B toxin is a _______________.

Answer 17

glucosyl transferase that adds a glucose to G proteins