Micro - UTI

Question 1

Urinary Tract Defenses

Answer 1

1. Urine flow = desquamation
2. Urine chemistry = acidity, lysozymes (blocks peptidoglycan), lactoferrin (binds iron)
3. Different cell surface proteins on epithelial cells in urinary vs GI
4. Secretory IgA (adaptive immune response)
5. Normal flora (prevent other microorganisms from colonizing)

Question 2

Major Threats to Urinary System

Answer 2

1. Microorganisms from GI to Urinary tract –> community acquired
2. Catheters –> hospital acquired (nosocomial)
3. Immune dysfunction –> glomerular nephritis

Question 3

Urethritis

Answer 3

infection of urethra

Question 4

Cystitis

Answer 4

infection of bladder

Question 5

Pyelonephritis

Answer 5

infection of kidney

Question 6

UTI signs and symptoms

Answer 6

sudden onset, dysuria, urgency, cloudy urine (WBC, bacteria), hematurai (sloughing cells)
back pain indicates pyelonephritis

Question 7

E. Coli

Answer 7

Main causative organism of UTIs

- NOT same E. Coli that causes GI problems

Question 8

Acute infections of urinary tract

Answer 8

Risk factors: sex, catheterization

Children –> anatomic of functional abnormality

Question 9

Pyelonephritis

Answer 9

Ascending infections

Flank pain, fever, dysuria, N/V, malaise

Question 10

Culture Media

Answer 10

supplies nutritional needs of microorganisms
Selective = contains compounds that selectively inhibit growth of some microbes but not others
Differential = contains indicator, usually dye that detects particular chemical reactions occuring

Question 11

Tell between Staph or Strep?

Answer 11

Catalase test (staph (+), strep (-))
catalase converts hydrogen peroxide to water and oxygen
rapid release of oxygen bubbles on media

Question 12

Staph aureus or staph saprophyticus?

Answer 12

Coagulase test (aureus (+), sapro (-))
Bound coagulase reacts directly with fibrinogen –> clumping cells in suspension
Free coagulase is extracellular protein that causes the formation of clot

Question 13

Staph epidemidis or staph saprophyticus?

Answer 13

Novobiocin test (sapro resistant, epi sensitive)
Novobiocin inhibits bacterial DNA gyrase in susceptible microorganisms

Question 14

MacConkey Agar

Answer 14

Selective and Differential

• inhibits growth of gram (+) organisms
• indicates lactose fermentation

Question 15

Indole Test

Answer 15

distinguishes E. Coli (+) from Klebsiella (-) based on ability to degrade tryptophan