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
QUESTIONS 1 of 7 1 2 3 4 5 6 7 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK 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 Type & Select Correct Answer 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 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic 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 Type & Select Correct Answer 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 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic