Urinary Tract Infections Flashcards
What are the symptoms of urethritis and cystitis?
Dysuria with increased frequency and urgency. Will have positive urine culture.
What are the symptoms of prostatitis?
Lower back pain in perirectal area and testicles. Will have positive urine culture.
What bacterial count must be made for a urine test to show positive for a UTI?
The presence of at least one bacterium per microscopid oil-immersion field. Correlates to 100,000 CFU/mL.
A positive nitrite test in urine correlates to infection by what sort of bacteria?
A positive nitrate test correlates to infection by gram negative organism (Typically E.coli)
Because Cystitis in men is rare, a male with cystitis is often indicitive of what?
Indicitive of infected stones, prostatitis, or chronic urinary retention requiring further investigation.
What attribute does E.coli have that is unique compared to shigella and salmonella?
E. coli ferments lactose.
What sort of bacteria are the family Enterobacteriaceae and where are they most often found?
These are gram-negative rods that are normal intestinal flora of most animals.
Can ferment glucose, reduce nitrate, are catalase positive, and oxidase negative!
What is the number one bacterial cause of UTI?
Eschericia Coli followed by Coagulase negative staphylococci.
What are the virulence factors for E.coli UTI?
Adhesins (P. pilli)
Hemolysin (HlyA) - RBC lyse
Endotoxin - inflammation
Most E.coli express what type of pili and what are they responsible for?
Type 1 pilli responsible for binding to mannose residues on epithelial surfaces.
What does P. pili bind specifically to?
Bind to sugar residues specifically on uroepithelial cells.
S. epidermidis is known to infect what specifically in Humans?
Typically infects implanted devices causing bacteremia/ device failure through formation of Biofilms.
S. saprophyticus is known for what two attributes?
Second most common bacteria to cause UTI and is Novobiocin resistant (inhibitor to bacterial DNA gyrase)!!
What is unique about proteus mirabilis?
This bacteria is found among UTI isolates from chrpnically catheterized patients (20-45%)
How does Proteus mirabilis cause kidney stones?
Proteus species employ urease which changes urea into ammonia. This causes alkalization of the urine increasing the chances of inorganic compounds appearing in the renal calculi.
Also produces biofilms.
TMP - SMX displays excellent activity against what species of bacteria?
Proteus species in which 90-100 isolates are suceptible.
What species are Group D cell wall positive?
Enterococcus faecalis, and faecium as well as S. Bovis.
How is Enterococcus seperated from S pneumo?
Tolerates high salt and bile content and is not sensitive to optochin culturing.
What are the risk factors for enterococcus?
Prolonged hospitilization with treatment of broad spectrum antibiotics.
Allows spread from GI to other surfaces as highly resistant to most antibiotics.
What sorts of pt will display a UTI caused by Enterococcus?
Pt with long indwelling catheters that are under broad spectrum antibiotics.
What population of pt is asymptomatic bacteruria typically found in?
Eldery women and men.
Under what three conditions is it reccomended to treat asymptomatic bacteriuria?
Pregnant women
Prior to urological surgery
And after renal transplant surgery.
What is the recommended treatment for uncomplicated cystitis?
Trimethoprim/Sulfamethoxazole
What is the recommended treatment for pyelonephritis?
Agressive antimicrobial treatment, possibly inpatient care.
Fluoroquinones for gram negatives.
Amoxicillin for Gram posiives
Asymptomatic bacteriuria is treated with what?
No treatment or amoxicillin, cephalexin or nitrofurantoin.
What does MacConkey agar select for?
Gram negative bacteria that are able to lactose ferment (Form pink coloration if can ferment lactose)
