UTI Flashcards
Definition of bacteruria
- Bacteria in MSU
- Single organism>105 CFU/ml
Pyuria definition
WBC or pus on urine
Predisposing factors
AGE, SEX
AGE
- Incidence increases with age
SEX
- Short female urethra→UTI by ascending route
- Symptomatic infection in females till age 50
- Significant male infections after 50
- Prostatic hypertrophy
- UT abnormalities
Predisposing Factors
Structural/meurological abnormalities of UT
- Vesico-uretric reflux
- Urethral valves or strictures
- Calculus formation
- Postatic hypertrophy
- Bladder diverticulum
- Neurogenic bladder
NOTE: these are associated with residual urine
Most frequent predisposing factor in hospital
Indwelling urinary cathetr
Host factors that predispose to UTI
- DM→risk of severe bacterial pyelonephritis
- Immunosupression, steroids, cytotoxic drugs→ recurrent UTI and with unusual bacteria
How do fecal flora reach urinary tract
Ascending route
Micturition, females and UTIs
During micturtion, organisims may reach neck of bladder esp after instrumentation
What causes majority of UTIs
E.coli setorypes O2, O4, O6
E. coli with K1 antigen
Capsular Ag
associated with pyelonephritis more than cystitis
Most common cause of hematogenous infecion of kidney
S. aureus
E. coli
Characteristics
Causes
- cystitis
- pyleonephritis
- Community and hospital inections
- M and F
Staphy saprophyticus
- Honeymoon cystitis
- NOVOBIOCIN RESISTANT
Proteus Species
P. mirabilis
- Indole negative
- most frequent cause of proteus UTI
P. vulgaris
- Indole positive
- AMPICILLIN RESISTANT
BOTH
- Associated with alkaline urine that encourages calculi formation (staghorn)
- Pyelonephritis
- Septecemia
Klebsiella, Enterobacter, Serratia
- recurrent or HCA UTI
- Assoicated with hospital outbreak
Psuedomonas
- Resistant to many antiobiotics
- Recurrent or HCA UTI
What is associated with renal or perinephric abcess
S. aureus
Adenovirus
- Acute hemorrhagic cystitis in children
- Allogenic BM transplant recipients
Candida common in
- Indwelling catheter
- On antibiotics
- DM
- Immunocompromised
Parisitic cause of UTI
Schistiosoma haematobium
- Free swimming
- Infective larval cercaria
- Burrows into human skin in contaminated waters
- Common in ME and Africa (EGYPT)
Midstream urnie use
To decrease number of urethral organisms
Catheter specimen urine
NOT bag