0%
Topic
Review Topic
0
0
N/A
N/A
Questions
7
0
0
0%
0%
Evidence
4
0
0
Topic
Snapshot
  • A 76-year-old woman presents to the emergency department for altered mental status. She currently lives in a nursing home and was brought to seek treatment by her daughter. She was noted to be more confused over the course of a few days and developed a fever. Her temperature is 101°F (38.3°C), blood pressure is 133/99 mmHg, pulse is 101/min, and respirations are 20/min. Physical examination is notable for being alert and oriented to self but not time or place and suprapubic abdominal pain. A urinalysis is remarkable for being leukocyte-esterase positive. Urine culture grows Escherichia coli.
Introduction
  • Classification
    • a gram-negative bacilli
  • Epidemiology
    • incidence
      • the most common cause of UTI in women
  • Microbiology
    • reservoir
      • gastrointestinal tract
    • transmission
      • fecal-oral
      • urethral ascension
      • catheter
      • aspiration
    • properties
      • enterotoxins
        • heat labile
          • increases cAMP
        • heat stable
          • increases cGMP
        • shiga-like toxin
          • inhibits the 60s ribosomal subunit, impairing protein synthesis 
      • fimbriae  
      • K-antigen (capsule) 
      • H-antigen (flagella)
  • Associated conditions
    • enterotoxigenic (ETEC)
    • enterohemorrhagic (EHEC)
      • can result in hemolytic uremic syndrome
    • enteroinvasive (EIEC)
    • neonatal meningitis
    • urinary tract infection (UTI)
Presentation
 
E. coli Clinical Presentation
Condition
Presentation
Diagnostic Studies Treatment
Enterotoxigenic (ETEC) 
  • Symptoms
    • watery diarrhea that occurs after returning from a resource-limited area
  • Clinical diagnosis and no diagnostic studies are required
  • Supportive treatment
Enterohemorrhagic (EHEC)
  • Symptoms
    • bloody diarrhea
    • no fever
  • Physical exam
    • abdominal tenderness
  • Hemolytic uremic syndrome (HUS)
    • associated with the strain O157:H7 
    • triad
      • acute renal failure
      • microangiopathic hemolytic anemia
      • non-immune mediated thrombocytopenia
  • Sorbitol-MacConkey agar
    • O157:H7 does not ferment sorbitol
  • Enzyme-linked immunosorbent assay (ELISA)
  • Polymerase chain reaction (PCR)
  • Supportive care
  • Antibiotics are generally not beneficial and its use has been associated with the development of HUS
Enteroinvasive (EIEC)
  • Symptoms
    • begins as watery diarrhea and can lead to bloody diarrhea with pus
      • the organism invades the intestinal cells to multiply intracellularly and then invade adjacent intestinal cells
  • Sereny test
  • Supportive care
Neonatal meningitis 
  • Symptoms
    • irritability
    • lethargy
    • poor tone
    • seizures
  • Physical exam
    • temperature instability
      • fever or hypothermia
    • bulging fontanelle
  • Lumbar puncture
  • Ampicillin
  • Cefotaxime or ceftazidime in ampicillin-resistant strains
Urinary tract infection (UTI)
  • Symptoms
    • dysuria
    • urinary frequency and urgency
  • Urinalysis and urine culture
  • Trimethoprim-sulfamethoxazole
  • Fosfomycin
  • Nitrofurantoin
 

Please rate topic.

Average 5.0 of 12 Ratings

Questions (7)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M1.MC.15.75) A 23-year-old woman goes to a walk-in clinic while on the fourth day of her honeymoon. She is very upset saying that her honeymoon is being ruined because she is in severe pain. She states that yesterday she began to experience severe pain with urination and seems to be urinating more frequently than normal. She does admit that she has been having increased sexual intercourse with her new husband while on their honeymoon. The physician diagnoses the patient and prescribes trimethoprim-sulfamethoxazole. Which of the following virulence factors is most likely responsible for this patient's infection?

QID: 106731
1

LPS endotoxin

8%

(24/293)

2

K capsule

12%

(36/293)

3

P fimbriae

63%

(185/293)

4

Flagella

8%

(24/293)

5

Exotoxin

7%

(20/293)

M 1 E

Select Answer to see Preferred Response

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M1.MC.13.13) A 27-year-old male suddenly develops severe abdominal cramping and bloody diarrhea. The patient reports consuming undercooked ground beef four days prior to the onset of the symptoms. Which of the following best describes the toxin-mediated mechanism of this disease process?

QID: 101472
1

Depolymerization of actin filaments in gastrointestinal mucosal cells, leading to mucosal cell death

11%

(38/351)

2

Increased pH of gastrointestinal lumen resulting in reduced mucosal absorption

1%

(3/351)

3

Increased intracellular cAMP in gastrointestinal mucosal cells, resulting in decreased absorption and increased secretion in the digestive tract

21%

(73/351)

4

Inhibition of elongation factor-2 (EF-2), resulting in decreased protein synthesis in gastrointestinal mucosal cells

15%

(54/351)

5

Inhibition of the 60S ribosomal subunit, resulting in decreased protein synthesis in gastrointestinal mucosal cells

51%

(178/351)

M 1 E

Select Answer to see Preferred Response

Evidence (4)
EXPERT COMMENTS (21)
Private Note