Flashcards in UTIs Deck (52)
What are the normal UTI tract defence mechanisms?
Regular flushing during voiding to remove organisms from distal urethra
Antibacterial secretions into urine and urethra
Urine osmolality (high)
High urine pH
What host factors are there which allow for infection?
Shorter urethra in females
Obstruction due to stones, enlarged prostate, pregnancy or tumours
Neurological - incomplete emptying
Why does incomplete emptying increase chance of infection?
Residual urine is left in the b,added and some can be forced back up the ureters
What bacterial factors allow for infection?
Ability to adhere to epithelial cells - determines degree of virulence
How do E. coli get into and adhere to the urinary tract?
Have flagellae for motility
Aerobactin for iron acquisition in an iron-poor environment
Haemolysin - pore forming
Adhesins on fimbrae and on cell surface
What are the more cellular urinary tract defence mechanisms?
Neutrophils which are activated by adhesions. Found on mucosal surfaces
Complement activation with IgA production by urothelium
Urothelium has proteins in the mucus which interfere with bacterial binding
What predisposes people to a UTI?
Trauma - due to catheterisation, sex because it affects the urothelium
Pus in urine
What is pyelonephritis?
Infection of the kidneys
What are the symptoms of pyelonephritis?
What can be seen with imaging in pyelonephritis?
CT scan shows wedge shaped areas of inflammation
Small renal cortical abscesses and streaks of pus in the renal medulla
Focal infiltration of polymorphonuclear leukocytes and polymorphs in tubular lamina
Complications of acute pyelonephritis if left untreated?
Significant permanent kidney damage (rare)
Inflammation in renal cortex
How does reflux nephropathy occur?
Combination of vesicoureteric reflux and infection acquired in infancy and early childhood
Vesicoureteric valve normally prevents reflux of urine when bladder empties but in some children, the mechanism can be void
Secondary consequence is incomplete emptying as urine returns to bladder - predisposes to infection and kidney damage
How is reflux nephropathy diagnosed?
CT scan showing irregular renal outlines and a reduction in renal size
Can be unilateral or bilateral
Affect all or part of the kidney
When does urine reflux normally stop?
What can occur if damage persists from reflux nephropathy?
Progressive renal fibrosis
Further loss of function in severe cases
Predisposed to hypertension in later life
Who does reflux nephropathy normally affect?
Suspect it if they 'fail to thrive'
What is chronic interstitial nephritis?
Renal impairment following chronic inflammation
Can be caused by infection or an adverse reaction to drugs
What is bacterial cystitis?
Inflammation of the bladder caused by bacteria
Common in women as a result of sexual intercourse
Symptoms of bacterial cystitis?
Frequency and dysuria
What is prostatitis?
Inflammation of the prostate gland
Symptoms of prostatitis?
Perineal and lower back pain
Symptoms of an upper UTI?
Symptoms of a lower UTI?
Frequency and dysuria
Production of abnormally small amounts of urine
What are possible complications of UTIs?
Long term renal damage
Common source of life threatening Gram negative bacteraemia
What is covert bacteriuria?
Asymptomatic bacteria in the urine
When is covert bacteriuria important to detect and how is it detected?
Children and pregnancy