Exam #6: UTI Flashcards
What are the mechanisms that defend against UTI?
pH below 5.5
High urea
Mechanical flushing with urination
What is the difference between nephritis, pyelonephritis, ascending UTI, cystitis, urethrtis, prostatis?
Nephritis= inflammation of the kidney Pyelonephritis= Inflammation of the kidney & upper urinary tract, also known as an ascending UTI Cystitis= inflammation of the bladder Urethritis= inflammation of the urethra Prostatitis= inflammation of the prostate
What are the symptoms of uretheritis & cysititis?
Dysuria
Frequency
Urgency
*Note that there is usually no discharge with these, unlike STD
What are the symptoms of prostatits?
Lower back pain
Pain in perirectal area
Testicular pain
What are the symptoms of pyelonephritis?
Flank pain
Fever
Sx of cystitis
Diarrhea
Vomiting
Tachycardia
Why is pyelonephritis dangerous in pregnant women?
Can cause premature birth
How are UTI’s diagnosed?
Symptoms
Urine dip-stick
What is leukocyte esterase? What is pyuria?
Presence of WBCs
> 10 wbc per cubic millimeter
What does a positive nitrite test indicate?
Some bacteria can reduce nitrate to nitrite
Why is UTI more common in women than men?
Shorter urethra
*****Note that cystitis in [young] men is rare & implies a pathological process, such as renal stones, prostatitis, or chronic urinary retention
What increases the risk for UTI?
Sexual intercourse CA-UTI= catheterization BPH GU malformation DM Pregnancy
What are community acquired UTIs associated with?
Colonization of the urinary tract by fecal flora
- E. coli
- Staphylococcus saprophyticus
What are hospital acquired UTIs associated with?
Catheterization
- Klebsiella, Enterobacter, Serratia, Pseudomonas aerugenosa, Enterococcus
What are enteric bacteria?
Bacteria routinely found in the GI tract of human or other animals
- Gram -
- LPS
How can the enterobacteriaceae be identified serologically?
O= polysaccharide antigens of LPS K= capsular antigens H= flagellar antigens
What are the common virulence factors associated with Enterobacteriae?
Endotoxin (LPS)
Antimicrobial resistance
What causes most of the community acquired UTIs?
E.coli (UPEC)
What else can E. coli cause?
Gastroenteritis
UTI
Spesis
Neonatal meningitis
What is the second most common cause of community acquired UTI?
Coagulase negative staph i.e. S. saprophyticus
What are the virulence factors of E. Coli?
Adhesin= attachment
Hemolysin= lyses erythrocytes –> inflammation
Endotoxin= inflammation
What special characteristics of UPEC allows for attachment?
- Type I pili that binds to mannose residues commonly present on epithelial surfaces
- P pili that binds sugar residues on uroepithelial cells
What is the difference between Staph & strep?
Catalase test
Staph = +
What is the difference between coagulase +/- staph?
\+= epidermis -= saprophyticus
What are the characteristics of S. saprophyticus?
Normal GI flora
UTIs
Novobiocin resistance (vs. epidermidis)
What the most common causative agents of HAC UTI?
Klebsiella
Proteus
Pseudomonas
List the characteristics of proteus mirabilis.
Gram negative enteric
What virulence factors are associated with Proteus?
Urease
- Hydrolyzes urea to ammonia & results in alkanalization of urine
- Alkalization–>precipitation of organic & inorganic compounds & real stones
What are the symptoms of renal stones?
Sudden onset of severe pain that radiates from side of back or abdomen & into the groin
How is Proteus UTI treated?
TMP-SMX
List the characteristics of Peudomonas aeruginosa.
Gram - rod
aerobic
motile
Minimalist
*Frequently seen in hospital UTI
How is pseudomonas aeruginosa diagnosed?
Blue green pigment
How is pseudomonas aeruginosa infection treated?
Multiple antibiotics
List the characteristics of Enterococcus.
Cram + cocci Catalase negative Group D carbohydrate Tolerates high salt & bile Optochin resistant
What risk factors are associated with enterococus?
- Hospitalization
- Treatment with broad spectrum abx
What other infections are associated with enterococcus?
UTI
Peritonitis
Endocarditis
When do you treat asymptomatic bacteriura?
Three situations:
1) Pregnant women
2) Prior to urologic surgery
3) After renal transplant
When do you NOT treat asymptomatic bacteriuria?
Eldery
How is uncomplicated cystitis treated?
TMP-SMX
How is pyeloephritis treated?
Gram (-)= Fluoroquinolones
Gram (+)= Amoxicillin
How is asymptomatic bacteriuria treated (when treating it)”
Amoxicillin
Cephalexin
Nitrofurantoin
