VII- Bacterial UTI

Question 1

3 host defenses vs UTIs

Answer 1

1. ph of 5.5
2. chemical content
3. flushing mechansim/stream of urine

Question 2

risk factors

Answer 2

1. females bc shorter urethras
2. catheterization
3. sex
4. any condition that disrupts bladder emptying so preg, kidney stones, tumors
5. lack of circumcision in male infants

Question 3

lower UTI pathogenesis

Answer 3

1. bacteria from skin or rectum
2. travel up urethra to bladder

Question 4

upper UTI pathogenesis

Answer 4

1. bacteria ascend thru urethra and bladder
2. ascend up ureter to kidney = pylelonephritis

OR town down thru aorta and renal artery but less common

Question 5

acute lower symptoms

Answer 5

1. urethritis
2. cystitis- inflamm bladder
3. dysuria - burning pain when urinate
4. urgency to urinate
5. in frequency
6. 50% have hematuria
7. pyuria

Question 6

urine culture cutoff

Answer 6

pos urine culture of 10^5 CFU/mL or higher
-anything lower not considered positive

Question 7

acute prostatitis symptoms

Answer 7

1. prostatitis
2. perineal and lower back pain
3. high fever, chills
4. same symps as lower UTI

Question 8

pyelonephritis symptoms

Answer 8

1. dysuria/urgency/freq
2. fever, chills
3. flank pain
4. costovertebral angle tenderness
5. if severe then diarrhea, vomit, tachycardia

Question 9

asymptomatic bacteriuria

Answer 9

no symptoms but culture above cutoff
-only treat if preg or undergoing urologic procedure

Question 10

most common community acquired agents

Answer 10

1. E. Coli (by a landslide)
2. staph saprophyticus

Question 11

E.Coli characteristics

Answer 11

1. gram neg rod
2. oxidase neg
3. lactose ferment pos

Question 12

most common strain of E.Coli

Answer 12

UPEC- uropathogenic E.Coli, extraintestinal pathogenic

Question 13

unique E.Coli virulence factors

Answer 13

1. adherins - type I pili + P pili
2. capsular acid polysac K antigen
3. hemolysin H1yA

Question 14

E.Coli adherins mechanism

Answer 14

1. Type I pili bind perineum and bladder weakly, can be flushed out
2. P pili bind bladder and kidney epithelia, abundant receptors in bladder so stronger adherence

Question 15

capsular acid polysacc K antigen function

Answer 15

1. induce inflamm associated with pyelonephritis
2. inhibit phagocytosis

Question 16

H1yA function

Answer 16

lyses erythrocytes > cytokine release = inflamm
associated with kidney damage

Question 17

Staph. Sap characteristics

Answer 17

1. gram pos cocci
2. catalase pos
3. coagulase neg
4. novobiocin resistant

Question 18

Staph. Sap virulence factors

Answer 18

1. urease production so can grow in urine
2. adhesions for binding to uroepi

Question 19

common hospital acquired agents

Answer 19

1. E. Coli
2. Proteus mirabilis
3. Pseudomonas aeruginosa
4. Enterococcus spp

Question 20

proteus mirabilis characteristics

Answer 20

1. enterobacteriaceae
2. gram neg rod
3. non lactose ferment
4. oxidase neg
5. forms H2S
6. swarming motility on agar

Question 21

proteus mirabilis virulence factors

Answer 21

1. fimbriae - 6 types
2. potent urease production
3. biofilms on catheters or indwelling devices

Question 22

kidney stone pathway

Answer 22

1. urea metabolized by urease to CO2 + ammonia
2. inc urine pH
3. uroepithelial cell toxicity from ammonia
4. precipitate Mg and Ca crystals
5. kidney stones

Question 23

kidney stone symptoms

Answer 23

1. sudden onset severe pain radiating from side of back or abdom to groin
2. may be intermittent
3. stones pass on own

Question 24

pseudo. aeruginosa characteristics

Answer 24

1. gram neg rod
2. not ferment lactose
3. oxidase pos
4. blue green colony color
5. many strains antibiotic resistant

indwelling catheters

Question 25

enterococcus characteristics

Answer 25

1. gram pos cocci 2. catalase neg 3. tolerance to bile salts 4. optochin insensitive Entero. faecalis or faecium

Question 26

collecting UTI samples

Answer 26

1. improper storage lead to propogation of bacteria 2. mid stream urine standard to reduce gathering bacteria in lower urethra

Question 27

urinalysis methods

Answer 27

urine dipstick test for 1. nitrite - enterobacteriaceae convert nitrate to nitrite 2. leukocyte esterase 3. pH levels- alkalinity seen with proteus mirabilis | also microscopy and culture

Question 28

treating uncomplicated cystitis

Answer 28

aka acute lower UTI trimethoprim-sulfamethoxazole

Question 29

treating pyelonephritis

Answer 29

1. amoxicillin if gram pos 2. fluoroquinolone if gram neg 3. inpatient care if severe

Question 30

indicated asymp bacteriuria treatment

Answer 30

amoxicillin, cephalexin, or nitrofurantoin