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 with no pus 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 ferments sorbitol slowly 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 6 1 2 3 4 5 6 Previous Next Lab Values Blood Hematologic Cerebrospinal Sweat, Urine, and BMI Blood, Plasma, Serum Reference Range ALT 8-20 U/L Amylase, serum 25-125 U/L AST 8-20 U/L Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL Calcium, serum (Ca2+) 8.4-10.2 mg/dL Cholesterol, serum Rec: < 200 mg/dL Cortisol, serum 0800 h: 5-23 μg/dL //1600 h: 3-15 μg/dL 2000 h: ≤ 50% of 0800 h Creatine kinase, serum Male: 25-90 U/LFemale: 10-70 U/L Creatinine, serum 0.6-1.2 mg/dL Electrolytes, serum Sodium (Na+) 136-145 mEq/L Chloride (Cl-) 95-105 mEq/L Potassium (K+) 3.5-5.0 mEq/L Bicarbonate (HCO3-) 22-28 mEq/L Magnesium (Mg2+) 1.5-2.0 mEq/L Estriol, total, serum (in pregnancy) 24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL 28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL Ferritin, serum Male: 15-200 ng/mLFemale: 12-150 ng/mL Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL Female: premenopause: 4-30 mIU/mL midcycle peak: 10-90 mIU/mL postmenopause: 40-250 pH 7.35-7.45 PCO2 33-45 mmHg PO2 75-105 mmHg Glucose, serum Fasting: 70-110 mg/dL2-h postprandial:<120 mg/dL Growth hormone - arginine stimulation Fasting: <5 ng/mLProvocative stimuli: > 7ng/mL Immunoglobulins, serum IgA 76-390 mg/dL IgE 0-380 IU/mL IgG 650-1500 mg/dL IgM 40-345 mg/dL Iron 50-170 μg/dL Lactate dehydrogenase, serum 45-90 U/L Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL Female: follicular phase: 5-30 mIU/mL midcycle: 75-150 mIU/mL postmenopause 30-200 mIU/mL Osmolality, serum 275-295 mOsmol/kd H2O Parathyroid hormone, serume, N-terminal 230-630 pg/mL Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L Phosphorus (inorganic), serum 3.0-4.5 mg/dL Prolactin, serum (hPRL) < 20 ng/mL Proteins, serum Total (recumbent) 6.0-7.8 g/dL Albumin 3.5-5.5 g/dL Globulin 2.3-3.5 g/dL Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h Thyroxine (T4), serum 5-12 μg/dL Triglycerides, serum 35-160 mg/dL Triiodothyronine (T3), serum (RIA) 115-190 ng/dL Triiodothyronine (T3) resin uptake 25%-35% Urea nitrogen, serum 7-18 mg/dL Uric acid, serum 3.0-8.2 mg/dL Hematologic Reference Range Bleeding time 2-7 minutes Erythrocyte count Male: 4.3-5.9 million/mm3Female: 3.5-5.5 million mm3 Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/hFemale: 0-20 mm/h Hematocrit Male: 41%-53%Female: 36%-46% Hemoglobin A1c ≤ 6 % Hemoglobin, blood Male: 13.5-17.5 g/dLFemale: 12.0-16.0 g/dL Hemoglobin, plasma 1-4 mg/dL Leukocyte count and differential Leukocyte count 4,500-11,000/mm3 Segmented neutrophils 54%-62% Bands 3%-5% Eosinophils 1%-3% Basophils 0%-0.75% Lymphocytes 25%-33% Monocytes 3%-7% Mean corpuscular hemoglobin 25.4-34.6 pg/cell Mean corpuscular hemoglobin concentration 31%-36% Hb/cell Mean corpuscular volume 80-100 μm3 Partial thromboplastin time (activated) 25-40 seconds Platelet count 150,000-400,000/mm3 Prothrombin time 11-15 seconds Reticulocyte count 0.5%-1.5% of red cells Thrombin time < 2 seconds deviation from control Volume Plasma Male: 25-43 mL/kgFemale: 28-45 mL/kg Red cell Male: 20-36 mL/kgFemale: 19-31 mL/kg Cerebrospinal Fluid Reference Range Cell count 0-5/mm3 Chloride 118-132 mEq/L Gamma globulin 3%-12% total proteins Glucose 40-70 mg/dL Pressure 70-180 mm H2O Proteins, total < 40 mg/dL Sweat Reference Range Chloride 0-35 mmol/L Urine Calcium 100-300 mg/24 h Chloride Varies with intake Creatinine clearance Male: 97-137 mL/minFemale: 88-128 mL/min Estriol, total (in pregnancy) 30 wks 6-18 mg/24 h 35 wks 9-28 mg/24 h 40 wks 13-42 mg/24 h 17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 hFemale: 2.0-8.0 mg/24 h 17-Ketosteroids, total Male: 8-20 mg/24 hFemale: 6-15 mg/24 h Osmolality 50-1400 mOsmol/kg H2O Oxalate 8-40 μg/mL Potassium Varies with diet Proteins, total < 150 mg/24 h Sodium Varies with diet Uric acid Varies with diet Body Mass Index (BMI) Adult: 19-25 kg/m2 Calculator ( ) xy AC 7 8 9 ÷ 4 5 6 × 1 2 3 - 0 . = + 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.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? Review Topic QID: 106731 1 LPS endotoxin 6% (12/202) 2 K capsule 9% (19/202) 3 P fimbriae 68% (138/202) 4 Flagella 8% (17/202) 5 Exotoxin 6% (13/202) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 3 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.MC.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? Review Topic QID: 101472 1 Depolymerization of actin filaments in gastrointestinal mucosal cells, leading to mucosal cell death 11% (31/280) 2 Increased pH of gastrointestinal lumen resulting in reduced mucosal absorption 0% (1/280) 3 Increased intracellular cAMP in gastrointestinal mucosal cells, resulting in decreased absorption and increased secretion in the digestive tract 22% (61/280) 4 Inhibition of elongation factor-2 (EF-2), resulting in decreased protein synthesis in gastrointestinal mucosal cells 17% (47/280) 5 Inhibition of the 60S ribosomal subunit, resulting in decreased protein synthesis in gastrointestinal mucosal cells 48% (135/280) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 5