Urinary Tract Infections Flashcards
Bacteruria definition
Bacteria in urine. Present in all Urinary Tract Infections
Pyuria
White blood cells in urine
Significant bacteruria
10^5 bacteria in urine
Dysuria
Burning on urination
Lower Urinary Tract Infection
self explanatory
Urethritis
Inflammation of the urethra
pyelonephritis
renal pelvis/ kidney infection
Acute Urethral syndrome
frequent urination
Classic cystitis ( bacteria count over 10^5) accounts for what percentage of cases of dysuria
50%
UTIs are the most common bacterial infection
true
most common causative organism?
E.Coli
UTI’s are more prevalent in which sex during infancy?
Males
UTI’s are more prevalent in which sex from ages 3-50?
Females greatly outnumber males
Lower UTI symptoms
- frequency of urination
- dysuria
- turbid urine
- suprapubic discomfort
- hematuria
Upper UTI
- flank pain or CVA tenderness
- fever, chills
Birth control usage corresponds strongly to the presence of Urinary tract infections in sexually active individuals
truth
Spermicidal foam changes the microflora of the vagina
truth
Diaphragms change the angle of the urethra
truth
Antibiotics for pyelonephritis
Aminoglycosides like topamycin concentrate in high amounts in the infected kidney
Pathogenesis of UTI
95% are from an ascending route.
- Urethral Trauma
- Intercourse
- Instrumentation
- Diaphragm use
5% of UTI’s are from hematogenous spread
ok
Uropathogenic E. Coli
Cause most UTI’s. Express a number of virulence factors
Type 1 Fimbriae- mannose-sensitive fimbrae, blocked by manos sugar
P- Fimbriae- “pyelo-fimbrae” cause pyelonephritis if the bacteria expresses them
Type 1 Fimbrae
attach to mannose in the lower urinary tract
P- fimbrae
Attch to p- blood group in upper urinary tract. Will cause pyelonephritis
First step in diagnosis of UTI?
microscopic urinalysis
Pathogenesis of UTI
Adhesion, Colonization, Invasion, Phase Variation
ACIP
What is the rate limiting step for bacterial growth?
What do bacteria such as E. Coli do to overcome this?
Iron availability
They release exotoxins such as alpha hemolysin which lyse red blood cells to remove iron
What is the name of the capsule that prevents uropathogenic E coli from being killed due to WBC invasion
K- antigen
Important to remember that the poly’s coming in as an immune response have receptors for mannose which helps them find and bind the bacteria. How do the bacteria respond to this?
PHASE VARIATION. They quit making type 1 fimbriae and start making P- fimbriae.
Host defense mechanism
- Bacterial growth inhibition
- urine flow
- epithelial cell turnover
- antibodies
Things that can predispose to UTI
- urine flow obstruction
- abnormal flow
- trauma
- reflux
- intrumentation
- general health
When the ureter dialates it is called?
Hydroureter. occurs when flow out is blocked
How long are males treated for a lower urinary tract infection?
1 week
How long are females treated for lower UTIs
1-3 days
Upper tract infection
1-6 weeks of treatment…IV then oral
Asymptomatic bacteriuria?
NOT TREATED… Especially in the elderly…KNOW
