UTIs Flashcards
What causes UTIs?
Infection is most often due to bacteria from the patient’s own bowel flora
E. coli
What is an uncomplicated UTI?
Functionally normal urinary tracts (with normal renal imaging).
Here, persistent or recurrent infection seldom results in serious kidney damage
What is a complicated UTI?
Abnormal urinary tracts. Tracts with stones, or associated diseases such as diabetes mellitus which themselves cause kidney damage, may be made worse with infection
What are the signs of acute pyelonephritis?
The combination of fever, loin pain with tenderness and significant bacteriuria
Macroscopically, what can be seen on the kidney in pyelonephritis?
Small renal cortical abscesses and streaks of pus in the renal medulla are often present
Histologically, what can be seen in the kidney in pyelonephritis?
Focal infiltration by polymorphonuclear leucocytes and many polymorphs in tubular lumina
What is reflux nephropathy?
This was called chronic pyelonephritis or atrophic pyelonephritis, and it results from a combination of:
- vesicoureteric reflux, and
- infection acquired in infancy or early childhood.
In reflux nephropathy, what does the kidney look like?
Typically, there is papillary damage, tubulointerstitial nephritis and cortical scarring in areas adjacent to ‘clubbed calyces’
Diagnosis is based on CT scans
How is a UTI diagnosed?
This is based on quantitative culture of a clean-catch mid- stream specimen of urine and the presence or absence of pyuria
Dipstick tests positive for both nitrite and leucocyte esterase are highly predictive of acute infection
If you do a dipstick in a suspected UTI, what findings would confirm your diagnosis?
nitrite and leucocyte esterase
How would you manage a UTI?
3-5 day course
- amoxicillin (250 mg three times daily)
- nitrofurantoin (50 mg three times daily)
- trimethoprim (200 mg twice daily) or an oral cephalosporin.
What different antibiotics can be used for a UTI?
amoxicillin
nitrofurantoin
trimethoprim
What is the mechanism of action of amoxicillin?
Inhibition of cell wall biosynthesis and consequential cell death
What bacteria does amoxicillin work on?
Both gram pos and gram neg
What family of antibiotics is amoxicillin?
beta-lactam