Clostridium difficile

Question 1

What kind of bacteria is C.difficile? (3)

Answer 1

• STRICT anaerobe (does not require oxygen to survive)
• gram-positive bacillus
• forms endospores

Question 2

What are 6 characteristics of C.difficile?

Answer 2

1. 3-5% people have this as a part of their normal gut flora
2. it is transmitted fecal-orally
3. spores are not “living”
4. spores survive for months in their environment
5. spores are not inactivated by alcohols or hand sanitizers (only removed by washing)
6. there is no vaccine for c.diff

Question 3

How does c.diff infect humans?

Answer 3

c. diff spores are generally ingested and they are not affected by stomach acid
- they germinate in the intestine after coming in contact with bile acids

Question 4

what are the virulence factors of c.diff?

Answer 4

c.diff has exotoxins (proteins secreted by bacteria and release OUTSIDE the cell) that are made when its in its vegetative state; this exotoxin damages intestina mucosa, kills cells and causes epithelium to leak which leads to watery diarrhea

Question 5

What are the 3 main types of c.diff?

Answer 5

1. TcdA or “toxin A”
2. TcdB or “toxin B”
3. CDT - c.diff binary toxin; sometimes found in epidemic strains

Question 6

What is different about the newly emerging NAP1/B1/027 strain of c.diff?

Answer 6

it is amore virulent strain of c.diff:

• 16X more toxic
• 3 - 4 X higher mortality rate
• faster sporulation
• high resistance to fluroquinolone antibiotics
• caused by a mutation in tcdC which is the toxin regulator gene

Question 7

What syndromes are common with c.diff?

Answer 7

1. dehydration
2. range of diseases in the gut due to c.diff ranging from mild - severe [AAD, AAC, CDAD, PMC, Toxic Megacolon and death]

children under 2 years never have symptomatic c.diff infection but they can harbor the bacteria

Question 8

What are the diseases associated with c.diff from mild to severe?

Answer 8

1. AAD (antibiotic associated diarrhea) [least severe]
2. AAC (antibiotic associated colitis) [colitis is an inflammation of the colon)
3. CDAD (Clostridium difficile associated diarrhea)
4. PMC (psuedomembraneous colitis)
5. Toxic megacolon (gangrene of the intestines) [pus cells lining the colon]
6. death [most severe]

Question 9

What are the conventional treatments for C.diff and what is their success rate?

Answer 9

antibiotics like vancomycin and metronidazole

- they have a 30- 50% relapse rate

Question 10

What are the two non-conventional treatments for c.diff and what is their success rates?

Answer 10

Non-conventional methods of treating c.diff revolve around the idea that if we line our gut with healthy flora, then the c.diff will not have an area to sit and grow; two ways of promoting gut flora:

1. probiotics –> not backed up by research to help out; usually goes away to normal levels after a while (low success rate)
2. Fecal implants –> take feces from someone with a healthy gut flora, and liquify it to make it into a capsule or a suppository for the patient with c.diff (this has a very high success rate of 90%)