UTIs Flashcards
What is cystitis?
Bladder inflammation
Urethritis
Inflammation of urethra
Pyelonephritis
Infection of kidneys that ascended from the bladder
What in terms of urien flow can lead to bacterial growth
Retention
What are parts of the urinary tract mucosa?
Defensins
GAGs reduce adherence
Tamm-Horsfall protein inhibits fimbriae action
IgA
Lactoferrin (iron sequestration)
When people age does the expression of Tamm-Horsfall protein increase or decrease?
Decrease
What are structural abnormalities that pose a risk for UTIs? They increase retention
Urethreal valves, stenosis of ureters/urethra, vesicoureteral reflux, calculi (stones)
What is vesicouretral reflux
Reflux of urine from bladder back to ureters
What increases in urine for diabetics?
Glucose
Pathogenesis of UPEC in bladder
- Adhesion: Type 1 pili binds mannosylated uroplakins –> invasion.
- Form quiescent intracellular reservoirs which are cells deeper in the layer beneath umbrella cells which are slow metabolic cells which store the bacteria.
- Formation of intracellular bacterial communities (IBCs) –> protection and further invasion.
- Cell damage and death: Reveal transitional cells, iron/nutrients are released.
UPEC pathogenesis in kidney?
- P (pap) pili are required for pyelonephritis (kidney infection)
- Adhesion
- Suppression of IgA secretion.
- Pili interfere with TLR preventing PIGR expression which could aid in the Ab related response.
Pathogenesis of Proteus in bladder
Organism is introduced by catheterisation, breach of anatomical defences.
Urease production –> change to alkaline pH –> crystal formation (Struvite)
Struvite stones (crystalline biofilm) are a focus of infection, difficult to eradicate.
Proteus split urea to form ammonia, raises pH, precipitation of inorganic salts in alkaline urine, forms calculus (stones).
What in urine is a sign of hepatitis?
Dark frothy urine
What can UTIs mimic?
STDs and actute appendicitis
What does proteus mirabilis lead to in UTIs
Renal stones
What does S. aureus lead to in UTIs
Renal abscesses
What does M. tuberculosis lead to in UTIs
Renal TB, pyria and sterile upon normal culture
Types of sample
Midstream urine
Catheter urine
Bag urine (poor)
Supra-pubic aspirate (best)
What acid is used to help store urine
Boric acid
What do dipsticks identify
Nitrate reducing bacteria, leukocytes, blood and Hg breakdown products
What does CLED stand for
Cysteine lactose electrolyte deficient agar
What can CLED grow
All possible urinary pathogens
Colours of CLED (pH)
Yellow in case of acid during lactose fermentation, or deep blue in alkalinisation
What agar limits mobility of Proteus
CLED
Treatment of uncomplicated cystitis
Nitrofurantoin, fluorquinolones, beta-lactam antibiotics
Treatment for pyelonephritis
Same as cystitis but no nitrofurantoin, and also add aminoglycosides and carbapenems
What is Proteus intrinsically resistant to?
Nitrofurantoin
How to prevent UTIs
Methenamine, restrict sperimicides and topic estrogens
What is methenamine converted to in urine
Formaldehyde in acidic urine
What do sperimicides impact
Host microbiota
What are topical estrogens for?
Reversal of pre-menopausal microbiata
