Term
| The 5 ways nosocomial infections are spread from person to person. |
|
Definition
Healthcare workers hands
Contact of patient with contaminated environment
Poorly cleaned equipment
Airborne transmission
Blood administered at hospital
22-2 |
|
|
Term
| Name the 4 most common nosocomial infections. |
|
Definition
Bloodstream infections from lines
Urinary tract infections from catheters
Pneumonia; many from ventilators
Surgical wound infections
22-2 |
|
|
Term
| This organism is the most common cause of hospital acquired diarrhea. |
|
Definition
| Clostridium difficile
22-2 |
|
|
Term
| Name the 3 toxins of C. difficile |
|
Definition
Toxin A
Toxin B
Binary toxin
22-3 |
|
|
Term
| An enterotoxin made by C. difficile that disrupts signal transduction, and can provoke intense inflammation:
a. alpha toxin
b. toxin A
c. toxin B
d. Binary toxin |
|
Definition
|
|
Term
| A toxin made by C. difficile that induces cytopathic effect on tissue culture cells, enabling diagnosis:
a. alpha toxin
b. toxin A
c. toxin B
d. Binary toxin |
|
Definition
|
|
Term
| A toxin made by C. difficile that acts upon actin by adding ADP-ribose. It is associated with more severe disease:
a. alpha toxin
b. toxin A
c. toxin B
d. Binary toxin |
|
Definition
|
|
Term
| What 2 drugs are used to treat C. difficile infection? |
|
Definition
Metronidazole (oral or IV)
Vancomycin (oral only, not IV)
22-4 |
|
|
Term
| Name 2 antibiotics that retain activity against VRE. |
|
Definition
|
|
Term
| Contact with non-visually contaminated skin of a patient could transfer this GNR that colonizes patients skin, and colonize our hands for about 15 minutes. |
|
Definition
|
|
Term
| Name 4 (of the 8) components of an effective strategy for preventing nosocomial infections. |
|
Definition
Hand hygiene before and after contact
Isolation for patients with transmissible disease
Cleaning of hospital rooms
Adequate cleaning of equipment
Perioperative antibiotics
Rational antibiotic use
Screen blood supply
Vaccinate healthcare workers
22-6
22-5 |
|
|
Term
| This precaution requires private negative pressured rooms, and N-95 mask worn by providers. |
|
Definition
|
|
Term
| This precaution requires that the patient have a private room and visitors wear a surgical mask. |
|
Definition
|
|
Term
| This precaution requires a private room, and visitors use gloves, gowns, and dedicated stethoscopes. |
|
Definition
|
|
Term
Which of the following does NOT describe the pathogen that is the most common cause of bacteria in the hospital?
a) It is gram-negative
b) It forms spores
c) It is anaerobic
d) It causes diarrhea due to toxin formation. |
|
Definition
a) Clostridium difficile is the most common cause of diarrhea in the hospital. It is gram-positive. All other facts listed are true.
22-2 |
|
|
Term
Which of the following is the LEAST effective way to prevent C. difficile from spreading in hospitals?
a) Contact precausions
b) Restricting the use of antibiotics
c) Designating thermometers and stethoscopes to infected patients
d) Using antibacterial gels. |
|
Definition
d) Antibacterial gels will not kill C. diff spores, which is why handwashing must be enforced.
22-3. Not explicitly stated, but emphasized in slides and lecture. |
|
|
Term
| What is the gold standard for diagnosing C. difficile? |
|
Definition
Detection of toxins using cell culture cytotoxicity assay or a toxin ELISA
22-4 |
|
|
Term
| What is Toxin A? How does it compare to Toxin B? |
|
Definition
Toxin A is an enterotoxin of C. difficile. Disturbs actin cytoskeleton of intestinal epithelial cells, rendering htem leaky. Can provoke inflammation. Toxin B is nearly identical.
22-3 |
|
|
Term
| What would you expect to see on microscopy of stool in a patient with C. difficile? |
|
Definition
Elevated fecal leukocytes (due to proinflammatory effects of toxin A and B).
22-3 |
|
|
Term
| What is the spectrum of clinical manifestations of C. difficile? |
|
Definition
Asymptomatic carriage --> acute diarrhea --> pseudomembranous colitis --> toxic megacolon and colon perforation --> relapsing diarrhea
22-3 and slides |
|
|
Term
| How do you treat C. difficile? |
|
Definition
| oral or IV metronidazole or oral vancomycin (NOT IV) |
|
|
Term
| What can Enterococcus faecalis and faecium cause? |
|
Definition
Line-related bloodstream infections, endocarditis, and catheter related UTIs.
22-4 |
|
|
Term
| How are Enterococci transmitted? |
|
Definition
They are natural colonizers of the lower GI tract. In hospital setting, can colonize the skin of sick people and be transferred from person-to-person via hand carriage.
22-4 |
|
|
Term
| What is used to treat vancomycin resistant Enterococci? |
|
Definition
Linezolid and daptomycin
22-4 |
|
|
Term
| Fill in the blanks: MRSA is Gram ______, catalase _______, and coagulase ________. |
|
Definition
|
|
Term
| What does MRSA commonly cause? |
|
Definition
Wound infections, abscesses, and blood stream infections.
22-4 |
|
|
Term
| Which pathogen is particularly problematic in ICUs? |
|
Definition
|
|
Term
| What do you need to consider in determining treatment for Klebsiella? |
|
Definition
Whether the strain has extended-spectrum beta-lactamase. All Klebsiella pneumoniae isolates are resistant to ampicillin, but those with ESBL are resistant to all beta-lactams except carbapenems.
22-5 and slide |
|
|
Term
| What are universal precautions? |
|
Definition
Gloves worn when touching body fluids, secretions (except sweat), nonintact skin, mucous membranes.
Wash hands between patients and after glove use.
Eye protection when danger of body fluid splashing.
Do NOT recap needles - dispose in containers.
22-6 |
|
|
Term
| What does contact isolation require? |
|
Definition
Patient is put in private room.
Healthcare workers use gloves and gown
Patient-dedicated stethoscopes
22-6 |
|
|
Term
| What are airborne precautions? |
|
Definition
Private room with monitored negative pressure.
All visitors must wear N-95 mask.
22-6 |
|
|
Term
| What are droplet precautions? |
|
Definition
Private room
All visitors must wear a surgical mask. (Different from airborne precautions because droplets are larger particles)
22-6 |
|
|
Term
| Which disease require contact precautions? |
|
Definition
MRSA, C. difficile, VRE, eteritis, rotavirus, HAV, RSV, lice and scabies
22-6 |
|
|
Term
| Which diseases require droplet precautions? |
|
Definition
Meningococcus, influenza, pertussis, mumps, and rubella
22-6 |
|
|
Term
| Which disease require airborne precautions? |
|
Definition
Tuberculosis, measles, and varicella
22-6 |
|
|
Term
| What organism specifically grows on Thayer-Martin media? |
|
Definition
|
|
Term
| What does Thayer-Martin media select against? How? |
|
Definition
selects against Gram +ves as well as many organisms normally found in the vaginal flora.
Colistine kills the Gram +ves and the normal vaginal (nonpathogenic) flora. |
|
|
Term
| What do you use chocolate agar for? Which specific organism did we use it for? |
|
Definition
| fastidious organisms. We used it for N. gonorrhoeae. |
|
|
Term
| Describe the principle of the ELISA test. |
|
Definition
Add antigen to the well
Add person's blood etc. with antibodies to antigen (if they have the disease)
Add secondary antibody conjugated to something you can see (immunofluoresence, color change) that will attach to the primary antibody if present. |
|
|
Term
| What's the commonly used substrate used in ELISA so that you can see if patient has disease? |
|
Definition
| TMB (tetramethylbenzidine) a chromagen that yields a blue color when oxidized with hydrogen peroxide. This is what's conjugated to the secondary antibody. |
|
|
Term
| Describe the process of Western Blotting. What is it generally used for? |
|
Definition
Used to confirm ELISA results to decrease probability of false positives.
You're looking at antigen proteins here.
Denature proteins with a detergent that also gives them a negative charge
Put them in a gel, and turn on a current so they run towards the positive electrode
Smallest proteins will move furthest
Add patients blood etc., if they have antibodies to the antigen, they'll adhere.
Add secondary antibody conjugated to something that you can see. |
|
|
Term
| oxidase test for N. gonhorroeae? |
|
Definition
|
|
Term
| What disease has characteristic pseudomembranes and is so called "pseudomembraneous colitis"? |
|
Definition
|
|
Term
| What is a prereq of development of C. difficile associated diarrhea? |
|
Definition
|
|
Term
| What's the problem with using Metronidazole to treat C. diff? |
|
Definition
|
|
Term
| Does Klebsiella form spores? |
|
Definition
|
|
Term
| Klebsiella: oxygen requirement? |
|
Definition
|
|
Term
| Where is Klebsiella spp. normally found? |
|
Definition
| It's a normal inhabitant of the lower GI tract. |
|
|
