UGI 1 Flashcards
only areas of the urogenital tract that are colonized by bacteria
anterior urethra and vagina
everywhere else is sterile
host defense of urogenital tract
high volume urinary flow so less residual volume, lining of bladder, exfoliation of uroepithelial cells, structures that prevent backflow
amount of urine we let out a day
1.5L per day
symptoms of urethritis
burning with urination
symptoms of cystitis (inflammation of bladder)
pelvic pressure, lower abdomen discomfort, frequent painful urination, low grade fever
symptoms of acute pyelonephritis
upper back and side (flank) pain
high fever
shaking and chills
nausea and vomiting
big difference between presentation of acute pyelonephritis and cystitis
acute pyelonephritis presents with high fever while cystitis presents with low grade fever
normal flora of urethra
lactobacillus, coagulative neg staph, strep
normal flora of vagina
compromised mainly of lactobacillus
when does lactobacillus become more prominent in vagina
at puberty hence vaginal flora is very diverse before puberty and after menopause
features of lactobacillus
gram positive rods that are non spore forming
facultative or strick anaerobe
produces lactic acid thereby making pH of vagina 4
who is more prone to UTIs and why
women because of shorter urethra
why is it that women in the US who develop a UTI are more likely to have reoccurence
immune status and genetics
what happens with pregnant women with untreated UTI
increased risk of delivering a low birth weight or preemie infant
why are pregnant women more prone to UTIs
smooth muscle relaxation
urethral dilation
greater chance to progress to acute pyelonephritis
which type of UTI is more common
ascending UTI so microorganism travels from urethra –> bladder –> kidney
UTIs present with malaise, burning sensation when urinating, frequent urge to urinate, or even asymptomatic. What does it signify if UTI presents with fever
microorganism has traveled all the way to the kidney
why do nearly all patients with indwelling catheter with open drainage for more than 48 hours get a UTI
bypassing all host defenses
most common microbe that causes UTI
E. coli and when there is a re-infection, it is with a new strain of E. coli
what is reasoning for difference between complicated and uncomplicated UTI
complicated UTI has predisposing anatomic, functional, or metabolic abnormalities hence requires more aggressive evaluation and follow up
other than UTI, what are other complications of long term use of catheters
- obstruction –> bacterial glycocalyx
- encrustation and infection stones containing urea
- local infections like urethritis, periurethral abscesses etc
what are biofilms
microorganisms growing on surfaces encased in slime like catheters
microorganisms in uncomplicated UTI
E. coli, S. saphrophyticus, Klebsiella pneumoniae, Proteus mirabilis
KEPS
microorganisms in complicated UTI
E. coli, K. pneumoniae, P. mirabilis, enterococcus species, pseudomonas aeruginosa
KEEPP
virulence factors contributing to UTI
– Adhesins (pili, fimbriae, etc.)
– Ig proteases
– Hemolysins (get cytokine release, inflammation)
– Ureases (i.e. P. mirabilis)
– Siderophore expression
– Factors promoting colonization and movement
primary cause of UTIs
uropathogenic e. coli (UPEC)
key virulence factors of UPEC (uropathogenic e. coli) and additional
key: Type I (cystitis) and P pili (pyelonephritis)
additional: alpha hemolysin, siderophore, pathogenicity islands
within the lumen of the bladder, what are the host defense
- antimicrobial peptides
- competition with iron sequestering proteins
- Tamm-Horsfall Protein
function of Tamm-Horsfall Protein
- binds specifically to type I fimbriated e. coli
- it is basically a key urinary anti adherence factor that serves to prevent type I fimbriated e. coli from binding to the urothelial receptors
when does lactobacillus decrease
bacterial vaginosis and helps control overgrowth of other bacteria that can cause disease/UTI
organisms predominantly responsible for remaining UTIs
– Staphylococcus saprophyticus – Proteus mirabilis – Klebsiella species – Mycoplasma and Ureaplasma – Candida
staphylococcus saprophyticus is cause of UTIs in what population
young sexually active women
what time of the year is s. saphrophyticus usually seen
summer
pathogenicity of s. saphrophyticus is due to what
- UREASE
- redundant uro-adaptive transport systems
- novel cell wall anchored adhesins
virulence factors of Proteus Mirabilis
- Proteases
- Haemolysins
- Biofilm formation
- Urease production
what does the urine in proteus mirabilis smell like and why? what is the importance of that?
- smells like ammonia because urease turns urea to ammonia
- increase in pH due to ammonia causing precipitation of certain compounds out of the urine; also increased pH is toxic to the kidney
mycoplasma genitalium causes UTI more commonly in what population
men – it is symptomless in women
since there is no clear diagnostic test for mycoplasma genitalium, what situations will make you suspect mycoplasma genitalium
- persistent/recurrent urethritis
- persistent/recurrent cervicitis
- PID: pelvic inflammatory diseases
