UTI,Diarrhea Flashcards
-UTI -Diarrhea
Asymptomatic bacteriuria:
-Exceptions to Treatment
- Pregnant
- Undergoing Urologic Instrumentation
Diagnosis of Asymptomatic bacteriuria:
- Women
- Men
- Catherterized patients
- 2 consecutive Voided urines with isolation of same species, >10^5 cfu/mL
- Men just 1 voided urine
- Catheter (M&F) - 1 specimen with single species, >10^2
MCC of UTI.
E.coli (85% of all community acquired UTIs)
Other enterobacteriaceae:
- Klebsiella
- Enterobactor
Organism common in young sexually active women.
Staphylococcus saprophyticus
Population of patients more susceptible to Enterococcus UTIs.
Older males with obstruction
Organisms ass. w/ Culture Neg. UTI (3)
- Ureaplasma urealyticum
- Chlamydia species
- Mycoplasma hominis
Fungal UTI organism and association.
Candida spp.
- Indwelling catheters
- Antibiotics
Hemorrhagic cystitis:
- Pathogen
- Population
- Adenovirus (type 11)
- BM Transplant
T/F: Culture is the Gold Standard for UTI diagnosis.
True
Urine Dipstick - Leukocyte Esterase:
- Sensitivity
- Specificity
- 70-95% (sensitivity)
- 70% (specificity)
Urine Diptick - Nitrite:
- Positive in which organisms?
- Negative “”
POSITIVE
-Coliforms – capable of reducing nitrate to nitrite
NEGATIVE
- S. saprophyticus
- Enterococci
MCC of Infectious diarrhea.
Viruses
- Norovirus
- Rotavirus
- Norwalklike viurs
- Enteric Adenovirus
Infectious Diarrhea:
- Cold Weather Outbreaks
-Rotavirus (“winter vomiting disease”)
Noninflammatory (Watery, NO fever) Diarrhea:
-Organisms (5)
- Vibrio cholera
- ETEC
- C. perfringens
- S. aureus
- B. cereus
what does ETEC produce?
Choleralike toxin
WHat is MCC of “Traveler’s Diarrhea”?
ETEC
Cholera:
- Features
- Serogroups
- Culprit
- Voluminous water diarrhea w/ flecks of white mucus (“rice water stool”)
- Serogroup O1 and O139
- Shellfish
Inflammatory (dysenteric) Diarrhea:
-Organisms (8)
- Shigella
- Campylobacter
- Salmonella
- EHEC
- C. diff
- Aeromonas
- Yesrinia
- Vibrio (noncholera)
What does EHEC produce?
-Shiga Toxin
How is EHEC acquired?
Undercooked ground beef
Also:
- Milk
- Fruit
- Vegetables
Most common strain of EHEC?
O157:H7
Complication of EHEC?
Hemolytic Uremic Syndrome (HUS)
T/F: Enteroinvasive E. coli (EIEC) does not produce Shiga toxin.
True
How is Salmonella contracted?
Animal contact (live or in food)
- Milk
- Chickens
- Eggs
Population at greatest risk for Salmonella bacteremia?
- Age Extremes (young and old)
- Immunosuppressed
What is the most common cause of bacterial enteritis in the US? How is it acquired?
Campylobacter jejuni
-Food (chicken) or water
Complications ass. w/ Campylobacter jejuni? (2)
- Guillain-Bare
- Reactive arthropathy (enteropathic arthritis) in persons with HLA-B27
Organisms associated with Rapid onset vomiting/diarrhea. (2)
- Clostridium perfingens
- S. aureus
- B. cerues
C. diff:
- virulent strain
- gene affected
- BI/NAP1/027 strain
- deletion of tcdC gene (regulatory gene) – Increased production of toxins A&B
What is the reference method for C.diff diagnosis?
Cytotoxicity assay
toxin production, not growth is diagnostic of C.diff colitis
C. diff Antigenic toxin assays (ELISA):
-Sensitivity
60-80%
PCR for what toxin genes, has a sensitivity and specificity of 95-100%? (4)
- tcdA (toxin A)
- tcdB (toxin B)
- tcdC (toxin C)
- A/B regulator gene
Organism ass. w/ Antibiotic ass. ischemic/hemorrhagic colitis.
Klebsiella oxytoca
Parasites commonly causing diarrhea in developed countries. (3)
- Giardia
- Entamoeba
- Cryptosporidium
Prolonged diarrhea or in a recent traveler (or immigrant) who presents with blood diarrhea.
Entamoeba histolytica
Best method for diagnosis of Entamoeba histolytica.
Stool EIA (high sens/spec)
*Stool microscopy only 50% sensitive (specificity limited by morphologically identical but nonpathogenic Entamoeba dispar)
What assay can substitute for a microscopic search for leukocytes?
Stool lactoferrin (product of neutrophils)
T/F: ELISA methods can substitute for stool ova and parasite examination in most instances in the US.
True
Organisms susceptible to routine stool culture. (6)
- Salmonella spp.
- Shigella spp.
- E. coli
- Campylobacter spp.
- Yersinia enterocolitica
- Vibrio spp.
