Nephrolithiasis

Question 1

Fluoroquinolones “-floxacin”

Answer 1

inhibit DNA replication
- bind bacterial topo II (gram -) –> prevents relaxation of DNA
- bind bacterial topo IV (gram +) –> no separation of chromatids
BROAD spectrum (gram +,-)
bactericidal
adjust dose for renal function because floxacin’s are excreted in the urine

Question 2

Sulfamethoxazole

Answer 2

PABA analog, competitively inhibits dihydropteroate synthase
bacteriostatic
SE = crystalluria –> acute renal failure, kernicteris (accumulation of bilirubin in brain)

Question 3

Trimethoprim

Answer 3

inhibits bacterial dihydrofolate reductase
bacteriostatic
SE = bone marrow suppression and hyperkalemia

Question 4

TMP/SMX

Answer 4

sequential blockage of folate synthesis pathway
bacteriocidal together
Broad specturm coverage

Question 5

How can infection with urease positive organism cause stone?

Answer 5

Urease splits urea into ammonia and CO2
Ammonia becomes hydrolyzed into ammonium ion and CO2 into HCO3
Urine pH increases leading to precipitation of magnesium ammonium phosphate

Question 6

Upper UTI symptoms

Answer 6

pyelonephritis

flank pain, fever, malaise (systemic symptoms)

Question 7

Lower UTI symptoms

Answer 7

urethritis, cystitis, prostatitis

urination frequency and pain

Question 8

Tamsilosin

Answer 8

alpha 1 blocker - reduces vasospasms - relax the ureter for easier passage

Question 9

Nafidipine

Answer 9

Ca2+ blocker –> relaxes ureter –> easier passage

Question 10

Asymptomatic Bacteriuria

Answer 10

UTI that is asymptomatic

- still have presence of bacteria in the urinary tract accompanied by WBCs and inflammatory mediators

Question 11

Gold Standard for diagnosis of UTI

Answer 11

positive bacterial urine culture

Question 12

Normal mechanisms that resist UTI

Answer 12

acidity of urine
act of urination
immunological and physical barriers (mucosal lining and sphincter)

Question 13

E. Coli

Answer 13

Gram -, most frequent cause of UTI
VF = P. fimbrae - hair like protein that binds to surface receptors on renal epithelial cells -> invasion and infection
Type 1 pillus fimbrae - all E. coli have this in gemone, not all express protein. It binds to uroplakins to set up shop for infection on epithelium

Question 14

Staph saprophyticus

Answer 14

Gram + cocci

more frequently in younger women (uncomplicated UTI)

Question 15

Klebsiella pneumoniae

Answer 15

gram (-) rod, urease (+)

Question 16

enterobacter

Answer 16

gram (-) rod

Question 17

Proteus mirabilus

Answer 17

Gram (-) rod, urease (+)