uti Flashcards
What is a UTI?
Urinary tract infection (UTI) is a common type of infection in
the human urinary system. It can involve any part of the urinary
system, including the urethra, ureters, bladder and kidneys
Most UTIs can be treated with an antibiotic.
Introduction
What is the urinary tract?
The urinary tract includes two kidneys, two
ureters, a bladder, and a urethra.
The urinary tract is the body’s drainage
system for removing wastes and extra fluid.
How do we classify UTI’s?
A UTI is classified as “ simple/uncomplicated”
or “complicated”.
Uncomplicated UTIs will usually affect the
bladder.
Complicated UTIs describe resistant infections
that require stronger medications, or those
that affect the kidneys.
Types of Bacteria
UTIs are caused by Gram negative and Gram positive bacteria, as well
as fungi.
Uncomplicated UTIs typically affect women, children and elderly
patients.
Complicated UTIs are usually associated with indwelling catheters,
urinary tract abnormalities, immunosuppression or exposure to
antibiotics.
What causes UTI’s?
Specific viruses/bacterium
The most common causative agent is Escherichia coli
Other causative agents are Klebsiella pneumoniae , Staphylococcus
saprophyticus , Enterococcus faecalis , group B Streptococcus (GBS),
Proteus mirabilis , Pseudomonas aeruginosa , Staphylococcus aureus
and Candida spp .
What does dysuria mean?
Uncomfortable pee
What does polyuria mean?
Frequent urge to urinate
What does cystitis mean?
Inflammation of bladder
What is pyelonephritis
Inflammation of kidneys and ureters
Symptoms of UTI
Frequent need to urinate
Burning/painful urine
Cloudy looking urine
Pelvic pain
Blood in urine
Strong smelling
What is the bodies defence mechanisms?
The first lines of host defence to urinary pathogens are the
unidirectional flow of urine and the presence of antimicrobial
factors in the urine.
Human urine is frequently inhibitory and sometimes bactericidal.
The epithelial cells lining the urinary tract secrete pro
inflammatory cytokines and antibacterial agents that are
important for the phagocytosis.
The secretion of glycosaminoglycans by bladder transitional cells
forms a surface layer of mucin that acts as an anti adherence
factor.
Another mechanism used by the bladder to reduce bacterial load
is shedding of the superficial epithelial cell layer.
Exogenous regulation of hormones.
Facts about UTI’s
150 mil people affected each year
50% of all women in UK had one
20-30% reoccur
Pathogenesis of UTI
- Contamination of the periurethral area with a uropathogen from the gut
- Colonisation of the urethra and migration to the bladder
- Colonisation and invasion of bladder, mediated by pili and adhesions and/or inflammatory response in bladder and fibrinogen accumulation in the catheter
- Neutrophil infiltration
- Bacterial multiplication and immune system subversion
- Biofilm formations
- Epithelial damage by bacteria toxins and proteases
- Ascension to the kidneys
- Colonisation of the kidneys
- Host tissue damage by bacterial toxins
- Bactercaemia
Risk factors with UTI
Aging
A previous UTI
D iabetes mellitus
Impaired immune response
Females: short urethra, use of contraceptives that alter
normal bacteria flora of vagina and perineal tissues
Sexual activity
Pregnancy
Males: prostatic hypertrophy, bacterial prostatitis
Urinary tract obstruction: tumour or calculi
What is pyelonephritis
Kidney infection