Microbiology : UTI Flashcards
Who is more at risk for UTI: Young Man or Elderly Female ?
Elderly Female . Much more
Females > Males
Elderly > Young, Adults
Old Woman = A walking UTI machine.
Which is the more common way for bacteria to get into the kidney: Ascending UTI Infection or hematogenous spread ?
Ascending UTI (Urethra –> Bladder–> Ureters –> Kidney)
What doe most renal infections seeding from bacteremia produce ?
Abscess !
Infection is usually seen in the parenchyma
What are common causes of Ascending UTI’s ?
Sexual Intercourse (Staph Saprophyticus)
Fecal Incontinence
Urinary Catheters (Staph epidermidis)
Retrograde Urine flow
Which local factors would render a person more susceptible to UTI ?
Physiological obstruction Infrequent voiding Neurogenic or Neuropathic bladder Detrusor muscle instability Congenital abnormality Retrograde urine flow Catheter Instrumentation Trauma Malnutrition Diabetes Hyperosmolality IC Tolerance to pathogen (cross-reactivity of host)
What is vesicoureteral reflux ?
Urine from the bladder flows retrograde back into the ureters and causes a backup of in the kidney. This flow of urine can lead to seeding of bladder infection into the kidneys .
Another variant is urethravesicular flow (urine flows from urethra into the bladder )
How does hyperosmolarity predispose someone for UTIs ?
Inhibits PMN migration to damaged tissue
Describe the inherent anti-microbial (UTI protection) in humans
Antibacterial activity of urine : low pH; high organic acids high urea concentration high urine osmolality Low vaginal pH Flushing mechanism of bladder Peristaltic movement of ureters Estrogen (young women) Anti-adherence effect of uromucoid Local secretion of immunoglobulins (IgA) Antibacterial activity of prostate secretions of post-pubescent males Long urethra in males
What do indwelling catheters form that lead to UTI susceptibility ?
A nidus.
Allows for bacterial colonization
What common disease state in older males may lead to UTI ?
Prostatic hyperplasia
What is the most important factor that allows for bacterial colonization in the urinary tract ?
ADHESION !
Adhesion determines the extent of bacterial colonization
What is adherence specificity >
The type of adhesion molecules determines where in the urinary tract a bacteria can colonize
p-Fimbrae and Pilli are bacterial constituents that allow for …
adhesion !
Mutant fimbrae –> decreased pathogenicty
Maternal ab’s protect against pFimbrae
Define K-antigens
capsular acidic polysaccharides that show resistance to bactericidal action of Ig and complement … mainly anti-phagocytic.
What is the most important adhesion molecule made by UTI causing E.coli ?
p-Fimbrae
Besides reflux, what allows for the ability to ascend in the GU system ?
Intrinsic motility of the organism
Where in the GU is Acute Cystitis often seen ?
Lower (bladder)
Typically a superficial infection
What demographic often gets Acute Cystitis ?
Young Women
Do individuals who get Acute Cystitis, often have physiologic or anatomical aberrations that lead to the infection ?
NOPE…
However, residual bladder urine is associated with it
What are common signs of acute cystitis ?
Frequent urination (urgency) Lower abdominal discomfort BURNING PAIN and Feeling of FULLNESS
May see hematuria but not always
Where is inflammation seen in Tuberointerstitial disease ?
Kidney parenchyma and renal pelvis.
What will be seen on the kidney in uberointerstitial disease ?
Small abscesses
What are common symptoms associated with uberointerstitial disease ?
Fever and back pain (may see renal dysfunction)
Describe the clinical onset of Acute Pyelonephritis
Abrupt onset
Chills, fever, headache, back pain
Tenderness over costovertebral angle
bladder irritation in Acute Pyelonephritis will lead to …
dysuria, frequency and urgency.
Proteus mirabilis invlovement in Acute pyelonephritis causes what to occur ?
Magnesium ammonium stones
What occurs to the renal pelvis in Chronic Pyelonephritis ?
Scarring and deformation of pelvis
Is chronic pyelonephritis a cause of renal failure ?
YES !
Loss of tubular function in Chronic Pyelonephritis leads to
Polyuria
Nocturia
Mild proteinuria
Acute Urethral Sndrome occurs in 50% of women who also show …
Dysuria and frequency
Acute urethral Syndrome usually always presents with …..
Acute Cystitis
What infections typically present like Acute Urethral Syndrome ?
Chlamydia and Herpes