UTI-Pathogens Flashcards

Question 1

Q

UTI-General Clinical info

Answer

A

UTI = significant bateruria of greater than 10⁵
Urethritis-Infection & inflammation of urethral mucosa
- _{^{Symptoms: Discharge & pain (dysuria) during urination}}
Cystitis-Infection/inflammation of bladder _{^{(no discharge)}}
- _{^{Symptoms: urgency increased frequency, dysuria}}
- _{^{Small vol, smelly (ammonia), Pyuria, Suprapubic tenderness w/low back discomfort}}
Prostaitis-Infection/Inflammation of prostate _{^{(Cystitis like)}}
- _{^{Symptoms: FEVER, perirectal/low back pain, painful ejaculation}}
Pyelonephritis- kidney & renal parenchyma _⁽^_pelvis)
- _{^{Follws UTI (ascending-chronic), Fever, flank pain, WBC casts}}
Tamm-Horsfall mucoprotein=WBC casts

Question 2

Q

UTI-Risk Factors

Answer

A

Gender-Common in young women
- _{^{Men have additional defense from Zinc (prostate)}}
Sex-Increases chance & w/use of diaphragm or sperimicide
Pregers-_{^{dilatation and decreased peristalsis of the ureters=Poor bladder emptying}}
Age:
females estrogen reduction _{^{(change in normal flora & thining of membrane)}}
males 5th decade of life-Prostate hypertrophy
Blood group P1 Ag-Expressed on urothelium
- _{^{(E.coli frequently binds)}}
AB blood group-MORE resistant _{^{(Bind to e.coli prevent infection)}}
Catheters-More frequent put in Higher the risk

Question 3

Q

Etiologic Agents of UTI

Answer

A

E-coli 90%
Staphylococcus Sapro 10-20%
- _{^{Common among sexually active women}}
Klebsiella, Proteus spp, Enterococcus fecalis 5%
Complicated UTI: Anatomic obstructions or from catheterizations
- _{^{E. Coli, Klebsiella, Proteus spp, Enterococcus sp}}
Misc: Candida albicans (diabetics)
Hemorrhagic cysitis-Children _{^{(Adenovirus 11/21-DNA Naked)}}

Question 4

Q

UTI Diagnosis

Answer

A

Specimen: Mid-stream catch (risk of contamination)
Direct microscopic exam-_{^{Oil immersion field w/centrifuged urine}}
Greater than 1 bacterium per oil = **Greater 10⁵ **
After 3-4 oils find 1 bacterium = Less 10⁴
Chemical tests (dipsticks):
Leukocyte esterase released from inflammatory cells
Nitrate made by bacterial metab _{^{(NO3 to NO2)}}
- _{^{Nitrate conv=E.Coli (best taken in morning-4 hours for conversion)}}
Cant detect bacteruria below 10⁵
Culture methods-Quantitative _{^{(calibrated loop)}} & semi
Plate & dip culture - isolation & ID of causative agent

Question 5

Q

E. Coli (Uropahtogenic)

Answer

A

Gram (-) lactose fermenter-Oxidase (-)
- _{^{Produces indole from trytophan}}
- _{^{Decarboxylates Lysine}}
- _{^{Use of acetate as SOLE carbon source}}
- _{^{Motile (virulence factor)}}
Transmission: fecal contamination of urethra _^(catheter)
Virulence factors _{^{(can stay dorment bladder)}}:
Pili/Fimbrae-
Type 1 (FimH) binds to mannose residue of glycoprotein on Facet urothelial cells (Acute cystitis)
PAP binds to dimers of galactose (GAL-GAL) on P1 ag of epi cell of UT (Pyelonephritis)-_{^{Mannose resistant}}
Diagnose: MacConkey agar _{^{(lactose fermenter-Indole from tryptophan)}}

Question 6

Q

Staphylococcus Saprophyticus

Answer

A

Gram (+) cocci-Catalase (+)
Coag (-) non-hemolytic/non-mannitol fermenter
Novobiocin resistant _{^(cathomycin)}
- _{^{S. aureus & S. epidermis novobiocin sensitive}}
Transmission-Inoculation from skin _{^{(sexually acitive women)}}
Disease: Acute urethral syndrome, Cystitis & RARE cases of pyelonephritis
_ Diagnose:_ Catalase test (+) w/Novobiocin culture

Question 7

Q

Enterococcus faecalis/faecium

Answer

A

Group D Ag-Gram (+)-chains/pairs & PYR +
Catalase (-) & bacitracin/optochin resistant
Grow in 6.5% NaCl & 40% bile _{^{(hydrolyzes it)}}
Found in urethra, female GT _{^{(endogenous/exogenous)}}
High risk: Hospital (catheter), broad spectrum antibios (vancomycin)
Disease: Cystitis & pyelonephritis
_{^{Misc-Soft tissue infections after colon surgery/trauma (bacteremia & endocarditis)}}
Diagnose: Bile Esculin agar (black=hydrolize)
- _{^{PYR + =Detection ofenzyme pyrolidonyl arylamidase}}
Treat: Dual w/aminoglycosides & cell wall antibios
- _{^{Resistance to vancomycin growing}}

Question 8

Q

Kelbsiella pneumoniae (enterobacteria)

Answer

A

Question 9

Q

Proteus Species (UTI)

Answer

A

HIGHLY motile swarming colonies - ^{enterobacteriacae}
P. Mirabilis _{^{(sensitive to penicillin)}}
P. Vulgaris _{^{(HIGHLY resistant to antibios)}}
Gram (-) rod, non-lactose fermenter, Urease (+)
Normal flora of colon found in Nosocomial (hospital)
Disease: Cystits & pyelonephritis
Nephrolithiases-Large Stag horn ^{_{(kidney stones)}}
- _{^{Prevention w/prompt treatment of cystitis or recurrent infections}}
Virulence factors:
Urease-Urea to NH3 + CO2 increase pH precipitation of Mg phos = Struvite stones - Obstruct urine flow
- _{^{Bacteria hide inside stones (escape antibiotics)}}
- _{^{Makes urine alkaline=favorable for other bacteria to grow}}
- _{^{High pH or smell indicative of proteus}}
LPS-Inflammation & tissue damage
Culture: _{^{Swarming colonies, Urease (+)-coffin crystals, Lactose fermenter}}

Question 10

Q

BK Virus (BKV)

Answer

A

Papovaviridae-Polyomavirus _{^{(related to JC virus)}}
Naked ds DNA - latent infection in kidney & lymph
Disease found in immunocompromised-_{^{Spread though resp}}
High risk: Renal & BM transplant, pregers, old age
Pathogenesis: replicated in URT->spread in blood
Seeds in renal tissue & lymph-_{^{remains latent in lymph}}
Disease: BK-assoc nephro (BKAN)
Hemorrhagic cysitis
- Ureteral stenosis ^{_{(pain on urination)}}
Tubulo nephritis-Inflammation of spaces between tubules-Lead to renal failure

Question 11

Q

BK Virus (BKV)-Clinical

Answer

A

Diagnose: Detection appear 3+ months after transplant
Urine sample-infected epi cells exfoliate _{^{(decoy cells)}}appear w/intranuclear inclusion bodies
Renal biopsy-cytopathic changes not specific
- _{^{Confirmation w/stains or PCR}}
Treatment: Decrease immunosupression therapy
- Cidofovir (nucleotide analog)

(11 cards)