CDI

Question 1

Describe CDi under a the microscope

Answer 1

Gram-positive-> thicker layer of peptidoglycan than gram negative
Spore-forming->
Anearobic bacillus

Question 2

Describe CDI toxin production

Answer 2

Toxin A-> enterotoxin and cytotoxin
Toxin B-> Cytotoxin
Binary Toxin-> found in 5% of isolates, in 100% of BI/NAP/027 epidemic strain

Question 3

What does CDI cause?

Answer 3

Diarrhea and colitis in susceptible patients. High risk environments where use of antibiotics is high.

Question 4

Resistance of concern

Answer 4

The bacteria spreads rapidly because it is naturally resistant to many drugs used to treat other infections.

Question 5

Which factor is commonly associated with CDI infections?
a. Chemo
b. ACE inhibitors
c. Prophylactic antibiotics or antibiotics to treat a primary bacterial infection
d. Antiviral medication to treat a primary viral infection

Answer 5

C

Question 6

What is/are the highest risk antimicrobial(s) associated with causing CDI?
a. third-generation cephalosporins
b. fluoroquinolones
c. clindamycin and vancomycin
d. metrodnidazole

Answer 6

A. Third-generation cephalosporins have supplanted clindamycin as the highest risk antimicrobials associated with CDI.
Extra question: What class of antibiotics do cephalosporins belong to?
A. Fluoroquinolones B. Beta-lactam drugs. C. Macrolides D. Aminoglycocides
B
Why are remaining answers incorrect?
Fluorquinolones- emerging tred for CDI
Clindamycin, vancomycin and metrodnidazole used as treatment options.

Question 7

CDI detective

Answer 7

1. Does she meet CDI Criteria?
   Presence of 3 or more unformed watery stools in a 24-hour period in a hospitalized patient is sufficient indication to submit a specimen for C-difficile testing.
2. Travel History:

Question 8

What is the gold standard for CDi diagnostic testing?

a. stool culture
b. cell cytotoxic assay
c. enzyme immunoassay for Toxins A and B
d. PCR

Answer 8

A. Culture is the most sensitive test of stool available, but has some false-positive results due to the presence of nontoxigenic C.difficile isolates. It is generally considered the gold standard for CDI diagnostic test because of it’s sensitivity but the turn around time of 7 days prevents it from being employed in the clinical setting

Question 9

What has become the predominant method of diagnostic testing utilized for identification of CDI?

Answer 9

Nucleic Acid amplification tests (NAATs) have become the predominant diagnostic tests for CDI diagnosis in the United States, which has impacted reported rates due to increased sensitivity and increased awareness of asymptomatic colonization with CDI.

Question 10

What are the complications of CDI?

Answer 10

Ileus- a painful obstruction of the ilium or other part of the intestine
Toxic megacolon

Question 11

Treatment options for CDi

Answer 11

1. First line of treatment is to discontinue the provoking antimicrobials if they are still in use.
2. Metronidazole x 10 days
3. Oral Vanco
   4.

Question 12

CDI infection control key questions

Answer 12

1. Is the patient on antibiotics?
2. Does the patient have a roommate?
3. Potential risk of spread of disease due to lack of proper PPE utilization?

Question 13

Widespread environmental disinfection with hypochlorite solutions has not been evaluated sufficiently for efficacy and has potential major drawback because of the odor, respiratory, skin irritation (cutaneous) and damage to the surfaces.

Asymptomatic patient’s should NOT be tested for CDI.

Answer 13

Hypochlorite
Odor
Cutaneous
Respiratory

Question 14

True or False
1. 50% of infants through about 1 year of age habor the organism and its toxin without any GI tract symptoms

2. 60% of hospitalized patients of all ages asymptomatically carry toxigenic and nontoxigenic strains of CDI in their stool.

Answer 14

1. True
2. False- 20% of hospitalized patients asymptomatically carry toxigenic and nontoxigenic strains of CDI in their stool.

Question 15

Which of the following treatments has been shown to significantly improve the prevention of recurrence of CDI infection?
a. fecal transplants
b. subtotal colectomy
c. colon cleansing
d. antimicrobial therapy

Answer 15

A. Fecal Transplants

Question 16

The IP provides an in-service to the ICU nurses on CDI. Which of the following statements is true regarding bacterial spores and should be emphasized?
a. They allow the bacteria to multiply in adverse conditions
b. they are resistant to antibiotics
c. They are usually formed by gram-negative bacteria
d. They can be identified in gram stains.

Answer 16

B. If you have a spore in a condition where they are being threatened they are not multiplying. They are being protected in that environment until they can multiply again.