Urinary Tract Infections goal 9

Question 1

normal defense mechanisms

Answer 1

flushing of urine, physical barrier, acidic pH, antimicrobial substances, desquamation

Question 2

normal flora of kidney, ureters, bladder

Answer 2

sterile

Question 3

normal flora of lower urethra, external meatus

Answer 3

many bacteria and yeast, like on skin

Question 4

urethritis

Answer 4

infection of urethra (gonorrhea, chlamydiasis)

Question 5

cystitis

Answer 5

infection and inflammation of urinary bladder

Question 6

pyelonephritis

Answer 6

infection and inflammation of renal pelvis and kidneys (upper UTI)

Question 7

types of UTI

Answer 7

ascending descending, asymptomatic symptomatic rucurrent, uncomplicated complicated, nosocomial community acquired

Question 8

gram negative bacteria

Answer 8

escherichia coli (mc), Klebsiella, Proteus, Pseudomonas aeruginosa, Serratia, Enterobacter

Question 9

gram positive bacteria

Answer 9

staphylococcus saprophyticus, enterococcus spp, staphylococcus aureus

Question 10

miscellaneous bacteria

Answer 10

mycobacterium tuberculosis

Question 11

virus

Answer 11

adenovirus, BK polyoma, CMV

Question 12

Fungi

Answer 12

Candida, Histoplasma capsulatum

Question 13

parasite

Answer 13

schistosoma hematobium

Question 14

predisposing factors for UTI

Answer 14

DM, female (4:1, 16-35), pregnancy, congenital/structural/functional abnormalities of urinary tract, obstructions, nephrolithiasis, bladder dysfunction, urinary stasis, poor hygiene, catheter, stent, prolonged hospital stay, ICU stay, broad spectrum antibiotics

Question 15

symptoms of lower UTI: Cystitis

Answer 15

dysuria, urgency, frequency, suprapubic pain/tenderness, fever

Question 16

symptoms of upper UTI: Pyelonephritis

Answer 16

fever, chills, rigors, nausea, vomiting, anorexia, loin/flank pain, costo-vertebral angle tenderness

Question 17

E coli

Answer 17

gram negative bacilli, motile, facultative anaerobe, lactose fermenter, pink on macConkey agar, iridescent green colonies on EMB agar, produces Indole
P fimbriae: (attach to gal-gal) uroepithelial cells of bladder and helps in ascending to kidney
Type 1 pili: attach to uro-epithelial cells (mannose)
capsule inhibits phagocytosis
endotoxin (lipid A of Lipo-polysaccharide)-sepsis, DIC
Hemolysin
Aerobactin

Question 18

Virulence of E coli

Answer 18

colonization of introitus with type 1 pili
adherence to uroepithelium with P fimbriae
Production of Hemolysins-cause cytokine release with inflammatory response
OMPs: resistance to complement mediated lysis
Capsule and Biofilm

Question 19

Proteus mirabilis

Answer 19

gram negative pleomorphic bacilli
highly motile
Growth in culture media show confluent films of growth-swarming on agar
lactose non fermenting
pale colonies MConkeys agar
fishy odor
urease positive

Question 20

Proteus mirabilis MOA

Answer 20

raises urine pH (alkalinization)-facilitates renal stone formation-damages uroepithelium
renal calculi
staghorn calculi-composed of magnesium ammonium phosphate (struvite)
calculi serve as site for proteus attachment
sepsis-mediated by endotoxin (lipo-polysaccharide/LPS)

Question 21

other enterobacteriaceae (gram neg rods)

Answer 21

klebsiella pneumoniae
enterobacter species
serratia marcescens-forms red pigmented colonies on agar

Question 22

Pseudomonas aeruginosa

Answer 22

gram neg motile bacilli
community and hospital
catheterization
oxidase positive
lactose non fermenter
obligate aerobe
pyocyanin and pyoverdin pigments (green)
biofilm formation within catheters
multiantibiotic resistant
virulence factors: exotoxin A - interferes with EF2, elastases, capsule, flagella, pili
endotoxin=lipopolysaccaride, LPS-sepsis, DIC

Question 23

Enterococcus fecalis, fecium

Answer 23

normal fecal flora, most resistant among all strep, gram pos oval or spherical cocci in pairs/short chains at acute angles, gamma hemolytic on blood agar
virulence factors: surface adhesins cytolysin, gelatinase, serine protease
catalase negative, PYP positive, resistant to bile salts
hydrolyzes Esculin
resistant/tolerance to NaCl, high temp, antibiotic resistant (oxacillin, cephalosporin)

Question 24

Staphylococcus saprophyticus

Answer 24

gram pos cocci in clusters, catalase pos, coagulase neg, causes 10-20% UTI in young women
virulence factors: adhesion to uro-epithelial cells via surface associated proteins and lipotechoic acid, hemagglutinin that binds, hemolysin production, production of extracellular,
test for id: novobiocin sensitivity test

Question 25

Candida

Answer 25

biofilms in catheters
ability to adhere to host cells and invade with hyphae and enzymes
budding yeasts with pseudohyphae-forms germ tubes in vitro in serum
may or may not lead to blood stream infection

Question 26

schistosoma haematobium

Answer 26

endemic in africa, middle east, japan
trematode, adult male and female (male resides in groove of female) worms found in venous plexus around bladder, larval cercaria infective and penetrate skin, eggs elongated with clear shell and distinct terminal spine, dysuria with terminal hematuria, eggs cause inflammation to mucosa
immune response: Th2 pathway, IL 4,5,13, 10, IgE, eosinophils
IL 4, 13-granuloma formation and intense fibrosis
chronic cases lead to squamous cell carcinoma of bladder

Question 27

adenoviral hemorrhagic cystitis

Answer 27

dsDNA, icosahedral, naked, penton fibers (spike proteins), rare etiology of UTI, causes hemorrhagic cystitis in children
suprapubic pain, hematuria
urine culture negative, PCR required for confirmation
self-limiting
infection limited to bladder

Question 28

virus induced nephropathy

Answer 28

BK polyma virus and CMV cause nephropathy in immunocompromised renal/other transplant recipients
often results in/aggravates renal graft rejection

Question 29

Prostitis

Answer 29

e coli, k pneumoniae, p aeruginosa, enterobacter spp, proteus spp, enterococcus spp
reflux from urethra, depletion of prostatic antibacterial factor
fever, prostate tenderness, perineal and low back pain, dysuria and increased frequency, ascending route, hematogenous spread, chronic UTI in males greater than 50 yo

Question 30

Post Streptococcal GlomeruloNephritis PSGN

Answer 30

bacterial inf with group A strep (pyogenes)
tea colored urine
immune complex deposit in GBM (type 3)
complement activation
excessive C3
acute-C3 is depleted in PSGN
markers: anti DNAse B titers, ASO, Immunoflourescence for IgG & C3

Question 31

Pyuria

Answer 31

greater than 5 PMNs/hpf in urine

Question 32

leukocyte esterase

Answer 32

indicates WBCs in urine

Question 33

Nitrite test

Answer 33

indicates gram neg rod infection-e coli, Klebsiella, Proteus (Urase producing so alkaline urine), Serratia, Pseudomonas

Question 34

significant bacteriuria

Answer 34

more than 100,000 CFU/ml of a single type of uropathogen

Question 35

uncomplicated treatment of cystitis

Answer 35

3-7 days
nitrofurantoin
Trimethoprim-sulfamethoxazole
Fosfomycin
Pivmecillinam
Enterococcus-Amoxicillin-clavulanate

Question 36

complicated UTI (pyelonephritis, cystitis)

Answer 36

10-14 days
Fluroquinolones (Levofloxacin, Ciprofloxacin)
iv Ceftriaxone
Trimethoprim-sulfamethoxazole
If perinephric abscess is present, surgical drainage is required
Higher antibiotics such as Cephalosporins/Vancomycin may be given if indicated

Question 37

Prevention of UTIs

Answer 37

stay well hydrated and urinate regularly
take showers instead of baths
minimize douching, sprays, powders in genital area
cranberry juice-proanthocyanidins (PACs) prevents sticking to bladder wall
toilet hygiene (front to back to females)
good catheter care (avoid when possible, minimum duration, intermittant if possible, good aseptic technique, closed drainage system, maintain gravity drain, topic antiseptics around female meatus, wash hands)
empying bladder soon after intercourse