Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
26 Cards in this Set
- Front
- Back
|
What must a person be on in order for Clostridium difficile to infect them?
|
Long systemic antibiotic therapy which reduces normal flora in GI tract, allowing C. diff to colonize
|
|
|
T or F: C. difficile is resistant to many broad spectrum antibiotics.
|
True
|
|
|
What percentage of hospitalized patients in the US have C difficile diarrhea?
|
About 30%
Hospital acquired C diff associated diarrhea (CDAD) increases risk of death for inpatients with IBD |
|
|
What percent of C difficile infections are acquired in the hospital?
|
Only about 25%
Rest are community acquired in nursing homes, outpatient, etc |
|
|
What are the characteristics of C. difficile?
|
Anaerobic
Gram positive rod *Spore forming* Produces toxin A and B |
|
|
What is the pathogenesis of C difficile?
|
Antibiotics reduce normal flora
C. difficile overgrows Produces toxins Inflammation with pus and mucus results in pseudomembrane |
|
|
Describe C. difficile toxin A.
|
Enterotoxin
Alters membrane permeability Cells die by stimulation of host cell MAP-kinases Kills cells in colon wall |
|
|
Describe C. difficile toxin B.
|
Cytotoxin
Inactivates proteins that regulate actin filament assembly to cause depolymerization of actin filaments |
|
|
When are C. difficile toxin levels cytotoxic?
|
Only when the organism is predominant.
C. diff only produces a small amount of toxin |
|
|
What are the clinical manifestations of a C. difficile infection?
|
Vary from asymptomatic to fulminant colitis, related to toxin levels
Most common symptom is watery diarrhea Pseudomembranous colitis: water diarrhea plus pseudomembrane Fulminant colitis in 2-3% of patients - severe morbidity and mortality |
|
|
How is a C. difficile infection diagnosed?
|
History of antibiotic use in past month
ELISA on feces for toxin A and B Stools contain WBC half the time Stool is usually heme positive PCR of toxin genes in stool sample |
|
|
What are some measures that can be taken to prevent C difficile infection?
|
No vaccine....yet
Track and limit use of antibiotics Cleaning of patient rooms ( keep C diff patients in separate area) Restore normal flora |
|
|
What are probiotics? What are they useful for?
|
Live microbial food ingredients that benefit human health
Can reduce frequency and or duration of gastroenteritis *Useful in C. diff infections* |
|
|
What are two common probiotic bacteria?
|
Lactobacillus sp
Bifidobacterium sp |
|
|
What are some ideas for the mechanism by which probiotics work?
|
Suppression of growth or epithelial binding/invasion of pathogens
Improved intestinal barrier function Modulation of immune system |
|
|
What is a fecal transplant and why is it useful?
|
Healthy donor fecal matter (usually a relative) is filtered and given as an enema to a recipient
Useful to restore the normal flora of the GI tract which will restore balance |
|
|
Which drugs most frequently are associated with antibiotic associated colitis?
|
Fluoroquinilones
Clindamycin Broad spectrum penicillins Broad spectrum cephalosporins |
|
|
What is the best way to prevent C. difficile spread and infection?
|
Hand washing with soap and water!
*Alcohol will NOT kill spores* |
|
|
How is C. difficile infection treated?
|
Stop inciting antibiotic treatment
Begin appropriate drug therapy Fluid/electrolytes |
|
|
What drug is used for mild to moderate antibiotic associated colitis? Severe?
|
Mild - Metronidazole
SeVere - Vancomycin *Fidaxomycin if neither of those work, but it is very expensive* |
|
|
What is the MOA of metronidazole?
|
Disrupts DNA's helical structure
|
|
|
What are some adverse reactions to metronidazole?
|
Nausea/vomiting
Metallic taste Abdominal pain |
|
|
What are the drug interactions of metronidazole?
|
Alcohol - disulfiram like reaction
Warfarin |
|
|
T or F: Metronidazole is safe to use during pregnancy
|
True
It is only category B, but many do NOT recommend using it, especially in first trimester *Not recommended if breast feeding |
|
|
What is the MOA of vancomycin?
|
Bactericidal
Slow Attacks cell wall and cytoplasmic membrane |
|
|
What are the adverse effects of vancomycin?
|
Nephrotoxicity
Ototoxicity "Red neck" |
