Simple and complicated UTIs Flashcards
What is a UTI
lower urinary tract infection - cystitis/urethritis
Ascending UTI
Pyelonephritis
Most common bacterium causing UTI
E.coli
How do e.coli adhere to cells?
Fimbrae
How does proteus spp adhere to cell
urease - promotes urolithiasis (stone formation) - allows organism to stay in tract
Risk factors for UTIs
- Young women (sexual activity, short urethra)
- Older gentlemen (enlarged prostate)
- Diabetes
- Benign prostatic hypertrophy
- Dehydration (reduced flushing)
Sexual activity (transfer of microorganism)
Impaired immune response - Causes delirium in elderly
- Can lead to sepsis
Symptoms of UTIs
- Frequent urination
- Painful/difficult urination
- Suprapubic discomfort
- Cloudy urine
- Undifferentiated sepsis
pathology of UTIs
- Gram -ve = ascending and systemic
- Endotoxin - inflammatory response
- Vasodilation reduces BP and results in inadequate end organ perfusion = septic shock
- Renal abscess/collection may occur
- Early morning sample - microorganisms in contact with urine overnight
- Leukocytes and nitrites in urine are important - staph can’t convert nitrates to nitrites
Investigations for UTI
- Urine dipstick
- Agar
- Midstream urine for MC
- Separates e.coli from other bacteria dependent on whether can metabolise lactose - MacConkey agar
- Blood test
- Renal tract imaging
Leukocytes in urine
Immune reaction
Nitrites in urine
Bacterial presence
Protein in urine
Renal disease
Glucose in urine
Elevated serum glucose
Ketones in urine
Fat metabolism
Function of type 1 fibrae
Allow e.coli to stick together
How does sepsis occur
e.coli spread to bloodstream and secrete endotoxins
Lipopolysaccharides
Endotoxins (lipopolysaccharide) are integrated parts of bacterial cell wall of gram -ve bacteria
Is c.diff +ve or -ve
+ve
Two types of toxins
endotoxins - integral parts of bacterial cell wall of gram -ve bacteria
secreted exotoxins
Standard drug for UTI
Nitrofurantoin
Drug for recurrent UTI
Nitrofurantoin
Drug for pyelonephritis
Cefalexin
What does a dipstick showing only leukocytes indicate?
Immune reaction but no evidence of bacteria infection
Why might a urine dipstick only show leukocytes?
- Microorganism doesn’t reduce nitrate to nitrite
- Limited time for microorganisms to reduce nitrate
- Interstitial cystitis
Why might a urine dipstick only show nitrites?
microoganism present but no evidence of immune reaction or asymptomatic bacteria
Where is lower UTI felt?
Hypogastric region
Where is kidney infection felt?
R or L lumbar region
