Urinary Tract Infection (Cooke) Flashcards
1
Q
UTI and lower urinary tract disease
A
- Dogs: UTI common cause urinary tract disease in dogs
- Cats: UTI NOT common cause urinary tract dz cats
2
Q
Ascending infection
A
- primary route
- adherence and colonization necessary
3
Q
Hematogenous spread
A
not a major route of infection
4
Q
Bacterial virulence
A
- Adhesions
- Capsular antigens
- inhibit phagocytosis
- Hemolysins
- iron scavenging
- Plasmids
- Promote antibiotic resistance
- Can be passed from one species to another
- Urease
- proteus, staph, occ klebsiella
5
Q
Host defenses
A
- Micturition
- Anatomy
- Mucosal barrier
- Urine
6
Q
Host defense
normal micturition
A
- Adequate flow
- obstruction
- Complete emptying
- neurological disease
- Frequent voiding
7
Q
Host defense
Anatomy
A
- urethral length
- females more susceptible to cystitis than males
- urethral high pressure zone
- thought to inhibit urethrovesical reflux
- urothelium
- microplicae
- urethral and ureteral peristalsis
- proximal to distal
- Prostatic secretion
- antibacterial fraction: bactericidal to G- and G+ bacteria
- Ureterovesical flap valves (absent in ectopic ureters)
- angled path of ureter through bladder wall
- closes as bladder fills
8
Q
Host defense
Mucosal Barriers
A
- Glycosaminoglycans
- attract aqueous film
- non-specific inhibitor of adherence
- Immunoglobulin production
- mucosal IgA
- Cell exfoliation
- Commensal bacteria
- out-compete pathogenic bact
- can be altered with antibiotics
9
Q
Host defense
Urine
A
- pH
- high or low
- Osmolality
- Urea
- normally toxic to bacteria
- urease producing bacteria get around this
- Tamm-Horsfall protein
- can bind fimbriae
- Low MW carbohydrates
- may cause detachment and prevent reattachment of E. coli
10
Q
Clinical signs
Lower urinary tract
A
- Pollakiuria
- Stranguria
- Hematuria
- Strong odor
- Normal attitude, appetite
- unless prostatic involvement
11
Q
Clinical signs
Upper urinary tract
A
- variablel and non-specific
- anorexia, lethargy
- back pain
- PU/PD (chronic)
12
Q
Physical exam
Lower urinary tract
A
- Caudal abdominal pain
- Thickened bladder: chronic
- Palpation may stimulate stranguria
- Remainder of exam normal
- with uncomplicated infection
13
Q
Physical Exam
Upper urinary tract
A
- Depressed
- Fever
- T-L pain
- +/- large kidneys
- small dogs and cats
14
Q
Diagnostic eval
A
- urinalysis (35$)
- culture and sensitivity (65$)
- CBC (40$)
- Chem (55$)
- Rads (150$)
- Ultrasound (275$)
15
Q
Bloodwork
Lower urinary tract infection
A
- CBC
- normal / stress leukogram
- leukocytosis
- not just a bladder infection
- Chemistry
- normal
- +/- azotemia, hyperphosphatemia, hyper or hypokalemia, metabolic acidosis (renal involvement)
16
Q
Urinalysis
A
- specific gravity
- bacteria
- doesn’t localize infection
- absence doesn’t r/o infection
- casts
- suggestive renal involvement IF PRESENT
- = pyelonephritis
17
Q
Culture and Sensitivity
A
- Cystocentesis
- best way to select appropriate antibiotic
- Ideally lab should report MIC
- urine antibiotic >/= 4x MIC
- will not localize infection
- best way to monitor therapy
- esp. complicated infections
- don’t really repeat cultures in simple infections
18
Q
Imaging
(complicated/recurrent infections)
A
- survey films
- ultrasound
- excretory urogram (EU, IVP)
- renal size and margins
- dilation of ureters/renal pelvis
- blunting of diverticuli
- does not prove active infection
19
Q
Predisposing factors for cystitis
A
- incontinence
- ectompic ureters
- neuro dz
- malformed vulva
- cushings/ other systemic probs
- neoplasia
*I think these might be complicated UTIs
20
Q
Complicated UTIs
A
- All pyelonephritis
- All prostatitis
- predisposing factors
- can’t cure unless you correct underlying process
21
Q
Asymptomatic bacteriuria
A
- positive culture w/o CS
- cushings and chemo patients
- chronic kidney disease
- occasionally, chronically infected patients
22
Q
Therapy
A
- evaluate and treat underlying cause
- antibiotics
- based on C & S
- crucial if infection recurrent OR
- recent tx with antibiotics (last 4-6 weeks)
- Empiric therapy while waiting for C & S
- most common pathogens
- efficacy of antibiotics
- concentration in urine (cystitis)
- concentration in tissue (pyelonephritis)
- blood:prostate barrier (prostatitis)
- based on C & S
- 10-14 days for uncomplicated bacterial cystitis
- CS should resolve in 48-72 hours
- emphasize need to complete full course
- 4-8 weeks for complicated UTI
- including pyelonephritis and prostatitis
23
Q
MIxed infection
A
- Option 1
- treat with single antibiotic to which both organisms are sensitive
- Option 2
- treat with 2 antibiotics based on C & S
- Option 3
- treat predominant pathogen
- culture during therapy and treat second pathogen if still present
24
Q
Outcome
Cure
A
- eradication of microorganisms
- resolution of CS
- proven by negative culture
25
Q
Outcome
Presistence
A
- failure to eradicate organisms
- demonstrated by positive culture 3-5 days after initiation of antibiotic therapy
- same strain
- R/O inappropriate drug, inadequate dose, frequency, owner/patient compliance
- May still have initial resolution of CS
26
Q
Outcome
Relapse
A
- positive culture ~ 5-7 days after discontinuation of antibiotics
- same strain
- similar differentials as for persistence
- usually indicates inadequate duration of therapy
- Start looking for complicating factors
- Consider mixed infection and drug resistance
- Consider imaging
- treat for 4-8 weeks
27
Q
Outcome
Reinfection
A
- May be difficult to distinguish from relapse or persistence
- Culture different organism
- Re-evaluate for predisposing cause
- systemic disease
- imaging
- cytoscopy
- Base therapy on new culture and sensitivity
- Frequent re-infection generally due to chronic changes
28
Q
Outcome
Superinfection
A
- Develops while receiving antibiotics
- multi-drug resistant
- treatment
- based on C & S
- Weeks to months
*Don’t give dogs with indwelling catheters antibiotics if you can help it
29
Q
Frequent Reinfection
A
- Prophylactic antibiotic therapy
- resolve current infection (negative culture)
- select drugs excreted in high concentration in the urine
- treat 1/3-1/2 therapeutic dose given when drug likely to be retained (bedtime)
- Antiseptic
- Methanamine hippurate
- urinary antiseptic
- requires acidic urine (ammonium chloride: Uroeze)
- alternative to prophylactic Ab use
- Methanamine hippurate
30
Q
Real World
First time uncomplicated infection
A
- Empiric antibiotic therapy
- pick one drug
- treat for 10-14 days
- If CS persist > 3 days, or if rapid recurrence: CULTURE
31
Q
Summary
A
- imbalance between virulence and host defenses
- culture
- rational use of antibiotics
- re-evaluate if no improvements
