Lecture 17. Infections of the Urogenital System 5

what is a UTI

bacterial colonization urine or any urinary tract organ (except distal urethra)

UTIs

what disease can this pathogen cause

what gram negative rod bacteria is urease negative

E. coli

what gram negative coccobacilli is rapid urease positive

Proteus spp.

what gram negative small rod is delayed urease positive

Klebsiella spp. (think a kurb causes a delay in traffic)

what gram positive cocci in bunches is urease positive

(looks like grape clusters P fror positive and purple)

Staphylococcus spp.

what gram positive cocci in chains is urease negative

(think strep like stretched out)

Streptococcus spp.

what is the primary pathogen involved with canine UTIs

E. coli, proteus, klebsiella

what is the primary pathogen found in cats with UTI

E. coli, Proteus, Staphylococcus aureus, Pasteurella multocida

what are the most common species found in horse UTIs

E. coli, Staphylococcus aureus, Streptococcus

what are the most common species found in cattle/sheep/goats UTIs

E. coli, Trueperella pyogens, and Corynebacterium spp.

UTI pathogens are typically a normal flora of the lower UT and are considered...

opportunistic infections

what determines the outcome of a UTI

virulence factors and host defense

what is the most common method of entry for a UTI

ascension into the urethra

what are some of the host defenses against UTIs

1. urine flow (number 1)

2. anti-adherence mechanisms

what is the role of the urinary oligosaccharide anti-adherence mechanism

coat bacteria to prevent receptor binding

what is the role of the bladder glycosaminoglycan anti-adherence mechanism

coat transitional epi

what is the role of the epithelial cell exfoliation anti-adherence mechanism

removed even if they bind

what is the role of the urine osmolality anti-adherence mechanism

bacteriostatic effects

what conditions can decrease urine osmolality

renal failure, cushing's, diabetes mellitus

what are some of the risks for host defense mechanisms

urinary stasis, foreign body, epi surface damage, and pressure from uterus during gestation

what are the C/s associated with UTI

1. pollakiuria (increased frequency)

2.stranguria (straining to urinate)

3. dysuria (irregular urination)

what is the most common rule out of dysuria

urethrocystitis

what can recurrent cystitis lead to

PN or prostatitis

what are the main ways to Dx. UTIs

1. urinalysis

2. quantitative culture

what is observed on urinalysis that indicates a UTI

1. PE: red/brown, turbid, foul odor

2. chemical: protein (+), glucose (+), occult blood, acidic pH

3. microscopic bacteria + pyuria

red/brown urine

what c/s is shown to indicate UTIs

turbid w/ leukocytes/bacteria/crystals

what c/s is shown to indicate UTIs

what is the best way to collect urine for a culture

cystocentesis

why is catheterization not an ideal way to collect urine for a culture

risk of contamination

a culture showing >100,000/mL w/ signs likely indicates...

UTI

a culture showing <1,000/mL likely indicates...

contamination

what does culture interpretation include

species (multiple = contamination), numbers, consistent urinalysis results

what pathology is associated with UTIs

hematuria, pyuria, bacteriuria

when it comes to antibiotic selection...

antibx. sensitivity may not reflect susceptibility in UT

since the urinary tract is a conditionally susceptible site antibiotics must be...

concentrated

how often do antibiotics have to be given for UTIs

10-14 days

when administering antibiotics it is important to consider...

toxicity

when treating UTIs w/ antibiotics it is important to...

re-culture @48hrs to check for bacteria growth

if antibiotics fail to treat UTIs, it can lead to recurrent cystitis due to...

1. relapse: infection w/ same organism

2. reinfection: infection w/ new organism

in a case of chronic bacterial cystitis antibiotics may be needed...

4-6wks and recultured @48hrs and every 6mo till 24mo