Term
| Microbiology of C.difficle |
|
Definition
| Gram positive spore-forming anaerobic bacteria |
|
|
Term
| What is the natural habitat of C. difficle? |
|
Definition
|
|
Term
| How do you identify C.difficle? |
|
Definition
| Not normally in stool; has difficult growing |
|
|
Term
| Pathogenesis of C.difficile? |
|
Definition
Large proteins that destroy the cytoskeleton, killing the cell
Some have a defective gene for toxin A, make only B
Non-toxigenic strains lack both genes
Toxin is made in the vegetative state stationary phase |
|
|
Term
| What is the general epidemiology of C.difficiles? |
|
Definition
| Asymptomatic colonization, colonization increases with length of stay. |
|
|
Term
| CDAD was associated with what types of people? |
|
Definition
| Elderly and long length of stay inpatients and nursing homes |
|
|
Term
| CDAD was associated with use of what type of antibiotics? |
|
Definition
| Clindamycin and cephalosporins |
|
|
Term
| The CDAD antibiotic spectrum is mostly associated with what? |
|
Definition
| diarrhea with/without colitis, colitis with/without pseudomembrane formation, Fulminant colitis. |
|
|
Term
| Hospital acquired C. difficile infection increased risk of death by 3-fold as an independent risk factor, meaning what? |
|
Definition
One in 10 patients died
Median day of detection was 12 days after admission (range 7-24 days)
Risk of acquiring C. difficile was 1% |
|
|
Term
| What is the old model epidemiology of the disease? |
|
Definition
| CDAD was carried into the hospital, antibiotics during hospitalization caused overgrowth and introduced toxin production. An iatrogenic disease but not a nosocomial infection. |
|
|
Term
| How was the old model proved false? |
|
Definition
| Tested by culture of hospitalized patients on admission and then weekly (did they carry it in, then did it grow out?) |
|
|
Term
| What is the new epidemiology model? |
|
Definition
| The organism is not endogenous, antibiotics during hospitalization predispose the patient to colonization, the organism is acquired in the hospital, causes disease; a nosocomial infection. |
|
|
Term
| Colonization with C. difficile prior to hospitalization was what against C. difficile disease? |
|
Definition
|
|
Term
| Babies often carry the organism but lack the receptors for the toxin, do not get disease. True or False |
|
Definition
|
|
Term
| What are some common incident agents? |
|
Definition
| beta-lactams, clindamycin, fluoroquinolones |
|
|
Term
| What are some least common inciting agents? |
|
Definition
| Timentin, tetracyclines, SXT, aminoglycosides |
|
|
Term
| What are some of the risk factors? |
|
Definition
Advanced age, underlying illness, immunologic susceptibility (low antibody, not cellular immunity)
NEW FACTOR: Protein pump inhibitors |
|
|
Term
| What is it to difficult to detect CDAD in a stool sample? |
|
Definition
| The culture is too difficult |
|
|
Term
|
Definition
| Fast, but less sensitive, can get toxin A or A+B tests |
|
|
Term
| What is the most common type of test for toxin in stool? |
|
Definition
|
|
Term
| What was the first report of the first new strain of CDAD? |
|
Definition
| 2001, old man died of fatal |
|
|
Term
| What are some ways of control an CDAD outbreak? |
|
Definition
Prompt diagnosis
Hand washing
Stop unneeded antibiotics
Good environmental cleaning |
|
|
Term
| What are some characteristics of the new strand of CDAD? |
|
Definition
Appears to be a single epidemic strain by toxin and DNA fingerprinting
A mutant strain with a new toxin and a deleted toxin repressor (18 base pair) gene (also makes A and B)
New toxin is called binary toxin, unrelated to C. difficile toxins A or B, but related to C. perfringens iota toxin E
Most outbreak strains carry all three toxins now
The new strain produces toxins in the log phase of cell growth; it doesn’t wait for stationary phase
The new strain produces 16 times more A and 23 times more B toxin, plus binary toxin |
|
|
