UTI,Diarrhea

Question 1

Asymptomatic bacteriuria:

-Exceptions to Treatment

Answer 1

• Pregnant

- Undergoing Urologic Instrumentation

Question 2

Diagnosis of Asymptomatic bacteriuria:

• Women
• Men
• Catherterized patients

Answer 2

• 2 consecutive Voided urines with isolation of same species, >10^5 cfu/mL
• Men just 1 voided urine
• Catheter (M&F) - 1 specimen with single species, >10^2

Question 3

MCC of UTI.

Answer 3

E.coli (85% of all community acquired UTIs)

Other enterobacteriaceae:

• Klebsiella
• Enterobactor

Question 4

Organism common in young sexually active women.

Answer 4

Staphylococcus saprophyticus

Question 5

Population of patients more susceptible to Enterococcus UTIs.

Answer 5

Older males with obstruction

Question 6

Organisms ass. w/ Culture Neg. UTI (3)

Answer 6

• Ureaplasma urealyticum
• Chlamydia species
• Mycoplasma hominis

Question 7

Fungal UTI organism and association.

Answer 7

Candida spp.

• Indwelling catheters
• Antibiotics

Question 8

Hemorrhagic cystitis:

• Pathogen
• Population

Answer 8

• Adenovirus (type 11)

- BM Transplant

Question 9

T/F: Culture is the Gold Standard for UTI diagnosis.

Answer 9

True

Question 10

Urine Dipstick - Leukocyte Esterase:

• Sensitivity
• Specificity

Answer 10

• 70-95% (sensitivity)

- 70% (specificity)

Question 11

Urine Diptick - Nitrite:

• Positive in which organisms?
• Negative “”

Answer 11

POSITIVE
-Coliforms – capable of reducing nitrate to nitrite

NEGATIVE

• S. saprophyticus
• Enterococci

Question 12

MCC of Infectious diarrhea.

Answer 12

Viruses

• Norovirus
• Rotavirus
• Norwalklike viurs
• Enteric Adenovirus

Question 13

Infectious Diarrhea:

- Cold Weather Outbreaks

Answer 13

-Rotavirus (“winter vomiting disease”)

Question 14

Noninflammatory (Watery, NO fever) Diarrhea:

-Organisms (5)

Answer 14

• Vibrio cholera
• ETEC
• C. perfringens
• S. aureus
• B. cereus

Question 15

what does ETEC produce?

Answer 15

Choleralike toxin

Question 16

WHat is MCC of “Traveler’s Diarrhea”?

Answer 16

ETEC

Question 17

Cholera:

• Features
• Serogroups
• Culprit

Answer 17

• Voluminous water diarrhea w/ flecks of white mucus (“rice water stool”)
• Serogroup O1 and O139
• Shellfish

Question 18

Inflammatory (dysenteric) Diarrhea:

-Organisms (8)

Answer 18

• Shigella
• Campylobacter
• Salmonella
• EHEC
• C. diff
• Aeromonas
• Yesrinia
• Vibrio (noncholera)

Question 19

What does EHEC produce?

Answer 19

-Shiga Toxin

Question 20

How is EHEC acquired?

Answer 20

Undercooked ground beef

Also:

• Milk
• Fruit
• Vegetables

Question 21

Most common strain of EHEC?

Answer 21

O157:H7

Question 22

Complication of EHEC?

Answer 22

Hemolytic Uremic Syndrome (HUS)

Question 23

T/F: Enteroinvasive E. coli (EIEC) does not produce Shiga toxin.

Answer 23

True

Question 24

How is Salmonella contracted?

Answer 24

Animal contact (live or in food)

• Milk
• Chickens
• Eggs

Question 25

Population at greatest risk for Salmonella bacteremia?

Answer 25

- Age Extremes (young and old) | - Immunosuppressed

Question 26

What is the most common cause of bacterial enteritis in the US? How is it acquired?

Answer 26

Campylobacter jejuni | -Food (chicken) or water

Question 27

Complications ass. w/ Campylobacter jejuni? (2)

Answer 27

- Guillain-Bare | - Reactive arthropathy (enteropathic arthritis) in persons with HLA-B27

Question 28

Organisms associated with Rapid onset vomiting/diarrhea. (2)

Answer 28

- Clostridium perfingens - S. aureus - B. cerues

Question 29

C. diff: - virulent strain - gene affected

Answer 29

- BI/NAP1/027 strain | - deletion of tcdC gene (regulatory gene) -- Increased production of toxins A&B

Question 30

What is the reference method for C.diff diagnosis?

Answer 30

Cytotoxicity assay | toxin production, not growth is diagnostic of C.diff colitis

Question 31

C. diff Antigenic toxin assays (ELISA): | -Sensitivity

Answer 31

60-80%

Question 32

PCR for what toxin genes, has a sensitivity and specificity of 95-100%? (4)

Answer 32

- tcdA (toxin A) - tcdB (toxin B) - tcdC (toxin C) - A/B regulator gene

Question 33

Organism ass. w/ Antibiotic ass. ischemic/hemorrhagic colitis.

Answer 33

Klebsiella oxytoca

Question 34

Parasites commonly causing diarrhea in developed countries. (3)

Answer 34

- Giardia - Entamoeba - Cryptosporidium

Question 35

Prolonged diarrhea or in a recent traveler (or immigrant) who presents with blood diarrhea.

Answer 35

Entamoeba histolytica

Question 36

Best method for diagnosis of Entamoeba histolytica.

Answer 36

Stool EIA (high sens/spec) *Stool microscopy only 50% sensitive (specificity limited by morphologically identical but nonpathogenic Entamoeba dispar)

Question 37

What assay can substitute for a microscopic search for leukocytes?

Answer 37

Stool lactoferrin (product of neutrophils)

Question 38

T/F: ELISA methods can substitute for stool ova and parasite examination in most instances in the US.

Answer 38

True

Question 39

Organisms susceptible to routine stool culture. (6)

Answer 39

- Salmonella spp. - Shigella spp. - E. coli - Campylobacter spp. - Yersinia enterocolitica - Vibrio spp.