Urinary Tract Infections Flashcards
what causes most urinary tract infections?
bacteria
what are the requirements for a urinary tract infection?
uropathogenic bacteria in sufficient numbers
epithelial receptors
flagella
iron scavenging system
breakdown in normal host defense mechanisms
what in the urethra protects against urinary tract infections?
length, width, location
high-pressure zone
peristalsis
what are some anatomic structures that help to protect against upper urinary tract infections?
vesicoureteral valves
ureteral peristalsis
length of ureters
true/false: there is a normal flora/microbiome in the urinary tract that helps to protect against urinary tract infections
true
what are some antimicrobial properties of urine?
highly acidic and alkaline environment
high urine osmolality- especially cats
high concentration of urea and weak organic acids
Tamm-Horsfall mucoprotein
prostatic secretions
what does Tamm-Horsfall mucoprotein do?
impairs adhesion to uropathogenic E. coli to epithelial cells
bacteriostatic
what does activation of toll-like receptors on luminal surface of bladder epithelium produce?
IL-8
neutrophil chemoattractant
what are some contributing factors to urinary tract infections?
abnormal micturition
urinary catheters
what are some anatomic defects that can make an animal predisposed to urinary tract infections?
vesicoureteral reflux
ectopic ureters
ureterocele
urachal diverticulum/remnant
excessive perivulvar skin folds
damage to uroepithelium
what are some things that can cause immunosuppression or change in urine that can predispose to urinary tract infections?
renal failure
diabetes mellitus
hyperadrenocorticism
FeLV/FIV
chemotherapy
in cats, who is more likely to have a UTI?
older cats due to concurrent disease
what are some organisms that can cause urinary tract infections?
E. coli
Staphylococcus pseudointermidus
Enterococcus
Proteus
Steptococcus
Pseudomonus
Klebsiella
how prevalent are urinary tract infections in horses?
uncommon
what organisms are known to cause urinary tract infections in cattle?
Corynebacterium renale
E. coli
Trueperella
when should you avoid a cystocentesis?
if there is a risk of a transitional cell carcinoma
how should you confirm if you think you see cocci?
gram stain or wright stain
when is it difficult to identify a urinary tract infection?
small bacteria
low numbers of bacteria
can have contamination if got feces in urine sample
what are some fungi that can cause a urinary tract infection?
candida
cryptococcus
aspergillus
_____________ may be used to demonstrate the characteristic capsule of Cryptococcus?
india ink prep
what is cystitis?
inflammation of the bladder
what is urethritis?
inflammation of the urethra
what are the signs of upper urinary tract disease?
depression, anorexia
fever
vomiting
other signs of uremia
lumbar or abdominal pain
diary cattle: decreased milk
weight loss, pu/pd
azotemia
neutrophilia
what are the classifications for urinary tract infections?
sporadic
recurrent
subclinical bacteriuria
how do you diagnose sporadic bacterial cystitis?
lower urinary tract signs
concurrent urinalysis abnormalities
urinalysis to detect comorbidities
aerobic culture, especially in cats
what can cause relapsing urinary tract infection?
wrong antibiotic or dose or duration of therapy
lack of owner compliance
concurrent GI disease or decreased renal concentrating ability
failure to eliminate predisposing factors
what are some acute pathologic changes with lower urinary tract infection?
bladder thickened
focal hemorrhages, erosions, ulcerations
+/- emphysema
exudate or blood clots
subclinical bacteriuria is reported in _________ of healthy dogs and _________ of healthy cats
2-12%
1-13%
if an animal has bacteriuria, but no clinical signs of urinary tract infection, should you treat it?
no
when should you treat subclinical bacteriuria?
evidence of upper urinary tract infection
patients have urease-producing infections
patients have plaque-forming bacteria
patients have signs of emphysematous cystitis
what part of the kidney is more susceptible to infection?
medulla
what are some signs of chronic pyelonephritis?
poor doer
weight loss
pu/pd
may be asymptomatic
cattle: poor weight gain, diarrhea
how does leptosporosis do in the environment?
survives weeks to months
what is the most common manifestation of leptosporosis?
acute kidney injury
often hepatic involvement
in dogs, _______________ is the most common cause of a hematogenous bacterial infection
leptosporosis
when should you consider leptosporosis?
fever and unspecified illness
signs of renal disease
especially if renal disease is accompanied by signs of liver disease
what do calves and lambs get with leptosporosis?
severe, acute illness
fever
intravascular hemolysis, anemia, icterus
acute kidney injury (uncommon)
what do adult cattle get with leptosporosis?
mastitis
decreased milk production
abortion
acute kidney injury and hemolysis (uncommon)
what species of leptsporosis is most common in swine?
L. bratislava
what does leptosporosis cause in swine?
abortions
stillbirths or neonatal deaths
decreased fertility in sows
what does leptosporosis cause in equine?
recurrent uveitis
abortion
kidney failure in foals
what are the routes of infection for UTIs?
usually ascending infection from perineum
catheterization
hematogenous: uncommon
direct extension from infected site near urinary tract: uncommon
how do vesicoureteral valves prevent infection?
pressure of urination closes opening
prevents reflux and permits removal of all urine
how do bacteria in the host interfere with pathogenic bacteria?
occupy receptors for bacterial P-fimbriae
bacteriocidins
what are the mucosal defense barriers?
distal urethra has normal flora
proximal urethra: microplicae entrap bacteria
exfoliation of urothelial cells
production of antimicrobial molecules
antibody production
what does lipocalin and lactoferrin do as defense?
sequester iron from bacteria
produced by renal tubular epithelial cells
what cells produce antimicrobial proteins?
macrophages and epithelial cells
what antimicrobial protein does the bladder produce?
cathelecidins
what antimicrobial protein do the kidneys produce?
beta-defensins
what does activation of toll-like receptors on the luminal surface of bladder epithelium lead to?
production of IL-8
neutrophils help clear bacteria, in acute UTI, but ____________________
cause tissue damage
what is a vesicoureteral reflux?
valve remains open: puppies or acquired
what bacteria are most common in hematogenous infections of foals?
gram negatives
when do cattle get UTIs?
pyelonephritis after parturition
who is pyelonephritis most common in in swine?
farrowing sows
what are some parasites that infect the urinary tract?
Capillaria plica
Dioctophyme renale
Stephanurus dentatus
what makes a UTI recurrent?
three or more episodes of clinical cystitis within preceding 12 months
two or more within 6 months
what can cause recurrent bacterial cystitis?
alterations in host defenses
development of resistant bacteria
what are some chronic changes with lower urinary tract infection?
thickened bladder wall
can lead to polyploid cystitis
who has higher rates of subclinical bacteriuria?
diabetes mellitus, obesity, parvovirus, acute disc herniation, paralyzed dogs, dogs treated with cyclosporine or glucocorticoids
what bacteria causes plaques?
Corynebacterium urealyticum
what are some urease-producing bacteria?
Proteus spp
Klebsiella
Staphylococcus aureus
Staphylococcus pseudintermedius
how can you diagnose pyelonephritis?
isosthenuric urine
white blood cell casts confirm
radiographs and sonograms
why is the medulla more susceptible to infection?
poor inflammatory response
decreased blood flow
hyperosmolarity inhibits immune
low pH
hypoxic environment
what should you evaluate a patient with acute pyelonephritis for?
leptospirosis
what cells does leptospirosis have an affinity for?
renal proximal tubules, biliary tract, and vascular endothelium
what are the abnormalities on a chemistry profile associated with leptospirosis?
elevated BUN and creatinine
elevated ALT
elevated alkaline phosphatase
elevated bilirubin
what is leptospirosis like in cats?
inherently resistant
develop antibodies
