Lecture 14: Urinary Tract Infections Flashcards
(32 cards)
Cystitis
Infection of the bladder
Pyelonephritis
Infection in the Kidney - fever, flank tenderness (upper urinary tract infection)
Urethritis
Inflammation of the urethra
Organisms from the perianal region to the urethra -
Normal flora includes:
- Lactobacillus
- Staphylococcus (skin flora)
- Corynebacterium (skin flora)
- Enterococcus (gram +’ve cocci in chains, found in gut)
What are catheters prone to?
Biofilm formation - lead to continuous seeding + urine is contaminated with bacteria from the catheter
-> Id catheter infected - fix catheter before taking urine sample otherwise just getting catheter bacteria
What can happen if UTI’s are untreated?
Can lead to urosepsis, meaning leaking into blood (causes bad outcomes)
What are symptoms of a UTI?
Urgency, frequency, pyuria (WBC’s in the urine), pain (abdominal, lower back, upon urination [dysuria]), occasional fevers (not with cystitis - more associated with upper urinary tract infections)
Uncomplicated UTI age + gender risk factors
Female gender - very prone
Older age - most prone
Younger age - least prone for females
Nonspecific mechanism
Urine - if prevented then bacteria builds up quickly because cannot be washed out
Complicated UTI Risk factors
Indwelling catheters, immunosuppression, urinary tract abnormalities, antibiotic exposure
*Males automatically go to
Getting a sample (common) steps of a UTI diagnoses
- Take sample
- Dipstick
- Dipstick +’ve
- Hangs out in nursing station + bacteria growing (2-4 hours)
- Goes to lab, # of bacteria significantly increased from when nurse took the swab
How many bacteria constitute a UTI
10-100 x 106 /mL (107-108/L)
Variables that make it hard to diagnose UTI’s
Hydration, time urine is in the bladder, antibiotic use, collection method and storage conditions
- Majority of uncomplicated UTIs (90%) are mono microbial while urine cultures in catheterized patients tend to be poly-microbial (could indicated colonization on catheter
- Urine colonized by bacteria without leading to an inflammatory response…defined as “asymp bacteriuria”
- Rapid screening tests are not great for the diagnosis of UTI’s
- Organisms that cause UTI’s are the same ones that are seen in individuals with asym bacteriuria
Dipsticks
Rapid tests to test for pyuria (cells) and nitrites (bacteria metabolize nitrate to nitrites)
Uncomplicated UTI definition
Defined as occurring in healthy adult non-pregnant women
Which gender more often gets UTI’s + why
Females, bc shorter urethra than men (more common in elderly
Complicated UTIs (cUTI’s)
Occur in all sexes and age groups and are frequently associated with structural or functional urinary tract abnormalities
More Risk factors of UTI’s
- Male vs Female
- Altered Vaginal Flora
- Sex
- Diaphragm / spermicide
- Mechanical obstruction
- Catheters (lack of usual symptoms, fevers are often the only sign)
- Age (prostate)
Asymptomatic Bacteriuria
- Not an infection - colonization, treatment indicated only in pregnancy or for those undergoing urinary instrumentation
- Treatment: selecting for resistant organisms. (Trimethoprim sulfamethoxazole, ciprofloxacin, and ampicillin are most commonly used drugs for therapy)
What happens to catheterized patients colonized with bacteria
- Catheterized patients - colonized with bacteria - change the catheter and re-collect urine
Contamination vs UTI
- Midstream urine specimen, In/out catheter
- Transport sample within 2hrs to lab, otherwise store in fridge and transport within 24 hrs
- Educate patients on collecting a clean catch midstream urine
Treatment/Prevention of UTI’s
- Decent evidence cranberry juice can reduce UTI’s
- Frequent urination
- Increased risk after first infection of relapse
- Treatment; typically high dose antibiotics x3 days in uncomplicated infections
Urine Dipstick
- Nitrite levels are specific for gram -‘ves that metabolically convert nitrate to nitrite
- Leukocyte esterase produced by neutrophils
- Clinical symptomatic have better sensitivity results
How fast can bacteria in urine double?
Every 20 min
