UTI Flashcards
(41 cards)
what is UTI?
infection in the urinary system that can involve :
Urethra - Urethritis
Kidney - Pyelonephritis
Bladder - cystitis
90% OF infections are cystitis
caused by microorganism usually bacteria that enter the urethra and bladder causing inflammation and infection
UIT are the leading causes of gram negative sepsis in hospital patients
UTI (cauti )among most common hospital acquired infection
What is the leading cause of UTI?
E-COLI
second most common community acquired UIT- staphylococcus saprophyticus
what is the most common causing hospital acquired UIT?
E. coli
proteus
Klebsiella pneumonia
Psuedomonas aeruginosa
what is the greatest risk factor for developing UTI?
Catheter
why is the healthy urinary tract resistant to bacterial colonization ?
Urethra has resident flora but rest of urinary tract sterile
urine is sterile and when passed through urethra , urine gets contaimanted
The PH chemical content and flushing mechanism of urine help to dispose of organisms out of urinary tract
when is urine sample collecteD?
since urine is sterile and becoems contaminated as it passes through the urethra
a midstream urine sample is collected
This means initial portion of urine - potentially carrying urethral flora is discarded
by doing so we obtain a cleaner sample that more accurately reflects the causative agent of infection
what are the predisposing factors for UTIS?
female anatomy
UT abnormalities
Disruption of normal urine flow ( incomplete emptying of the bladder, blockage of tract, kidney stone , enlarged prostate )
pregnancy - progesterone
sexual activity - HONEYMOON CYSTITIS
Co-morbidities like supressed immune system, diabetes
facilitation of access of microorganisms to the bladder — cathererization indwelling catheter use , recent urinary procedure
what is honeymoon cystitis ?
form of UTI that occurs after woman first sexual encounter
describe the pathogenesis of UTIS?
urinary tract consists of kidneys ureter, bladder,urethra
60% of adult women will have UTI some time during their lifetime with 30:1 ratio middle aged women : men
Females :
short urethra and its close proximity to the perirectal region allows bacteria to reach bladder more easily
-Sexual intercourse and pregnancy increase incidence
- Less common in men cuz the extra urethral length prevents bacterial colonization of the bladder
an UTI in men is a warning sign because its uncommen
what are the classification of UTI?
Uncomplicated and Complicated
Uncomplicated :
Occur in healthy host and readily respond to antimicrobial agents
Complication :
Occur in patients with risk factors , like men, diabetes, pregnant, indwelling urinary catheter , recent tract instrumentation
Community acquired :
E.coli most common followed by staph coccus saprophyticus
Hospital acquired :
E.coli , klebsiella, proteus, psuedomonas , entercoccoi and candida
leading cause is catheter ( most important factor )
what is the family of E coli, klebsiella, proteus?
being to enterobacteriaceae family
group of gram - facultative anerobes
what is the classification of entercocci?
previously classified as group D streptococci
but now they have distinct genus : gamma hemolytic
describe catheter associated urinary tract infection?
most common type of healthcare associated infection
Up to 20% of adult hospital in patients will have an indwelling urinary catheter at some point during hospitalization
Each day the indwelling urinary catheter remains, the patients has 3-7% increased risk of acquired CAUTI
Prevention :
No catheter - no CAUT
use only when necessary
review and document indication of use daily
Remove it ASAP
Describe urethritis ?
infection of urethera
frequency and dysuria – Pain/Burning during urination
more of STI :
Chlamydia trachomatis
Neisseria gonorrnhoea
Trichomonas vaginalis
describe Cystitis ?
Infection of bladder
Frequency, Urgency, Dysuria ( FUD )
90% of all UTIS
Hemorrhagic cystitis :
Large quantities of visible blood in the urine
Can be caused by infection , radiation , chemotherapy , immunosuppressants
describe pyelonephritis ?
ascension of bacteria to kidney or hematogenous spread
Fever , chills , flank pain , FUD ( frequency, urgency, dysuria )
in contrast to cystitis , pyelonephritis is an INVASIVE DISEASE
Blood culture positive in up to 20% OF CASES( cuz bacteria enter the blood stream )
more invasive infection that can lead to bacteremia
describe acute urethral syndrome ?
Sexually active young women experiencing FUD
Urine culture reveals LESS THAN 10^5 bacteria but have 8 or more pus cells of urine on microscopic examination pyurua
Diagnostic threshold is more than 10^5 BUT if we have more than than 8 pus cells we can use it as diagnostic
describe asymptomatic bacteriuria ?
Specified quantity of bacteria in urine from a person without signs and symptoms of UTI
clinical significance is controversial except in pregnancy
less than 10^5 bacteria
most common 5 bacteria causing UIT?
E coli ( most common in both community and hospital )
Pseudomonas aerugnosa
Klebsella pneumonae
Proteus marbilis
Staph coccus saprohyticus ( Second common community acquired )
more than 70% of cases
All are GRAM NEGATIVE
describe E. coli?
Uropathogenic E. coli (UPEC )
Uses PILI/FIMBRIAE to bind to urinary tract endothelial cells and colonise the bladder
Have the ability to :
Form K antigen , capsular polysaccharides that contribute to : BIOFILM FORMATION
ITS LACTOSE FERMENTING
Describe Klebsiella pneumonia ?
LACTOSE FERMENTING ( like E. coli )
2nd most frequent cause of gram - bacteremia and UTI ( second to E.coli )
Non motile
have prominent polysaccharide CAPSULE that is responsible for MUCOID APPEARANCE of isolated colonies and enhanced virulence of organisms in VIVO
describe proteus mirabilis ?
NON LACTOSE FERMENTING ( opposite to e coli and klebsiella )
MOTILE SPECIES ( opposite to klebsiella )
Swarming motility characteristic
Produce large quantities of urease which raises the urine pH —–> KIDNEY STONES
Urease POSITIVE
HIGH PH IN URINE USUALLY INDICATE PROTEUS INFECTION
Describe pseudomonas aeruginosa?
non lactose fermenting ( like proteas )
MUCOID polysaccharide CAPSULE
OXIDASE POSITIVE
Grow at 42 and produce GREENISH PIGMENT with sweet grape like fruity odour
PRODUCES BIOFIL ( like E. coli )
Ubiquitous in nature and environment hospital sites ( FLOWERS, SINKS, TOILETS, VENTILATION, DIALYSIS EQUIPMENT )
Infection of urinary tract seen primarily in patients with long-term indwelling urinary catheters ( multiple courses of antibiotics )
Key pathogen in patients with BURN, CYSTIC fibrosis , iv Drug users
Multidrug resistance
describe staphylococcus saprophyticus ?
Implicated in 10-20% of UTIS in young females
Second most common causative agent of acute UTIS after E. COLI ( community )
Bacteria may reside in urinary tract and bladder of sexually active females
REFERED TO AS HONEYMOONERS UTI DUE ITS ASSOCIATION WITH INTERCOURSE
