Lect 19 Flashcards
pyelonephritis is infection of
- kidneys and ureters
cystitis is infection of
the bladder
list risk factors for UTI
- obstructions (kidney stone)
- immunosuppression
- sexual activity
- diaphragms as birth control
- enlarged prostate
- catheterization
- pregnancy
clinical presentation
- dysuria
- frequent urination
- urinary urgency
- cloudy, malodorous, or bloody urine
- lower abd pain
- mild fever
- burning with urination
lower UTI
clinical presentation
- high fever (>101)
- N/V, chills
- flank pain
pyelonephritis
Describe the URI-cult CLED/EMB
- EMB
- selective for G- (contains bile salts)
- CLED
- growth of both G- and +
- determines ability to ferment lactose
what UA microscopy findings are indicative of a UTI
- > 2 WBC
- > 15 bacteria
List the typical causes of UTIs
- E-coli
- Proteus
- staphylococcus saprophyticus
- streptococcus (group B)
- klebsiella
- enterococcus
- pseudomonas aeruginosa
what is the most common cause of UTI? what stain
- E-coli
- caused by UPEC (uropathogenic E-coli) strains
- bacteria access urinary tract following introduction of fecal contamination
E-coli
- gram status
- motile
- gram negative
- flagellated
E-coli possess what that allows them bind to uroepithelial cells and erythrocytes
- P fimbriae
- Dr. adhesins
E-coli produces what that results in lysis of both uroepithelial cells and erythrocytes
alpha and beta hemolysins
UPEC (uropathogenic e-coli) have capacity to produce what due to increased formation of biofilms
K (capsular) antigen
Proteus
- gram status
gram negative
which proteus species is community acquired? which species predominantly infects immunocompromised?
- P. mirabilis - community acquired
- P. vulgaris: immunocompromised
proteus spp. exhibit what on culture agar
“swarming”
where are proteus spp normally found
- can be part of normal human flora
- found in long term care facilites and hospitals
Virulence factors of Proteus
- Fimbrae: attachment
- induce apoptosis of host cell
- produce urease and makes urine more alkaline by hydrolyzing urea to ammonia
UTI caused by what organism can lead to formation of struvite stones
- proteus
- due to production of urease
Staphylococcus saprophyticus
- gram status
- where is it normally found
- gram positive
- normal flora of female genital tract
how is Staphylococcus saprophyticus differentiated diagnostically from other staph
Staphylococcus saprophyticus is coagulase negative
Staphylococcus saprophyticus normally affects what patient population
- female 17-27
- incidence increased in sexually active femals
Staphylococcus saprophyticus can present with honeymoon cystitis which is
- UTI occurring 24 hours after having sex
- may manifest with razor sharp pains during intercourse
virulence factors of Staphylococcus saprophyticus
- not very virulent
- possess adhesins (lactosamine)
- no exotoxins
- low bacterial numbers needed to infect
how is Staphylococcus saprophyticus differentiated diagnostically from other coagulase negative species
Staphylococcus saprophyticus is Novobiocin resistant
What is another name for Group B Streptococcus
Stretococcus agalactiae
Stretococcus agalactiae
- gram status
- what characteristics on blood agar
- gram positive
- gray-white colonies with a narrow zone of B-hemolysis
Stretococcus agalactiae affects what patient population
- colonizes vagina, GI tract and upper respiratory of healthy individuals
- infection in adults linked to immunodeficiences
- can pass to neonate delivered vaginally
virulence factors of Stretococcus agalactiae
- capsular polysaccharide
- hyaluronidase
- collagenase
- hemolysin
- will see blood in urine
how is Stretococcus agalactiae diagnosed
- definitive diagnosis requires isolation from urine, blood, or CSF
- lab test: detection of CAMP factor
- accentuation of hemolysis due to interaction with staph B-lysin
