MID 3 - UTIs, Diarrhea, Anaerobes Flashcards
(40 cards)
What is the definition of complicated UTI?
UTI with functional or structural abnormalities such as indwelling catheters, renal calculi; UTI in diabetics, immunosuppressed patients.
What are clinical symptoms of lower tract UTI (cystitis)
dysuria, urinary urgency and frequency, bladder fullness/discomfort; hemorrhagic cystitis in 10% of cases.
What are clinical symptoms of upper tract UTI (pyelonephritis)
Fever, sweating, nausea, vomiting, flank pain, dysuria; dehydration / hypotension; urinary freqency, urgency, dysuria.
What is the gold standard for UTI diagnosis?
microbiological analysis with bacterial count > 10^5 per mL.
When is it indicated to collect a urine sample for urine culture in suspected UTIs?
pyelonephritis; complicated UTIs; children, men, pregnant women
What is the primary cause of uncomplicated UTI in sexually active women?
80% E. coli, 11% Staph saprophyticus.
What are the primary host defenses against UTI?
urine flow / micturition; high osmolality and low pH of urine; inflammatory response; inhibitors of bacterial adherence such as Tamm-Horsfall protein
What are the symptoms and treatment of acute bacterial prostatitis?
Symptoms are similar to UTI + warm, swollen, tender prostate on rectal exam, positive urine culture, pyuria. Treatment consists of longer course of antibiotics and pain control.
What organisms are responsible for UTIs of patients with structural abnormalities or instrumentation?
35% E. coli, enterobacter, serratia and pseudomonas are also common. Also, gram positive enterococcus species and coagulase-negative staph.
What organisms are response for UTIs in uncomplicated patients?
80% E. coli; 10% staph saprophyticus.
What factors in young women predispose to UTIs?
short urethra; sexual intercourse without post-coital voiding; diaphragm use (physical manipulation may promote bacterial colonization; spermicide use (raises vaginal pH).
On a urine dipstick, what is indicative of a UTI?
nitrites and leukocyte esterase
What are the first line treatments for UTI in uncomplicated patients and what are their modes of action?
1) trimethoprim-sulfamethoxazole (folate inhibitor)
2) nitrofurantoin (contraindicated if pyelonephritis is suspected)
3) fosfomycin (contraindicated if pyelonephritis is suspected)
What role does P-fimbriae play for E. Coli urinary tract infections?
P-fimriae blocks phagocytosis, adhere, persist and invade the kidney, inducing bacteremia and resulting in pyelonephritis.
What role does Type 1-fimbriae play for E. Coli urinary tract infections?
Type 1-fimbriae facilitate adherence to the bladder epithelium.
Why is Staph saprophyticus more likely to cause UTI than S. Aureus or S. epidermidis?
Adheres significantly better to uroepithelium.
What are ideal antimicrobials for uncomplicated UTI?
trimethoprim/co-trimoxazole, flouoroquinolones.
What roles to anaerobes play in humans?
bacteroides fragilis synthesizes vitamin K and deconjugates bile acids; fermentation of undigested carbs; trains immune system
What anaerobic gram-positive cocci causes infection and where is it found?
peptostreptococcus; skin
What gram-negative cocci anaerobe causes infection and where is it found?
Veillonella; oral flora
What gram-positive bacilli anaerobe causes infectionand where is it found?
Clostridium perfringens, tetani, botulinum, difficile (intestines); propionibacterium (skin, upper respiratory tract).
What gram-negative bacilli anaerobe causes infection, and where is it found?
Bacteroides fragilis (intestines), thetaiotaomicron
What species causes acne and where does it reside?
propionibacterium acnes; resides in sebaceous follicles.
What type of infection is characterized by chronic granulomatous lesions that become suppurative and form sinus tracts?
actinomycosis, caused by poor oral hygiene, oral trauma, invasive dental procedure, treated by surgical debridement and prolonged penicillin.
