A 6-year-old previously healthy girl is brought to the emergency department due to a day of fever, abdominal pain, and diarrhea. The symptoms began abruptly with high fever and cramping, periumbilical abdominal pain and were quickly followed by low-volume diarrhea mixed with blood and mucus. The patient has had no sick contacts and has not traveled recently; the family had dinner at a buffet restaurant 3 days ago. Temperature is 38.9 C (102 F). Physical examination reveals mild diffuse abdominal tenderness with no guarding or rebound tenderness. Bowel sounds are hyperactive. Stool occult blood testing is positive, and there are numerous leukocytes in the stool. Culture of the stool yields gram-negative, oxidase-positive, curved rods. Which of the following is the most likely pathogen responsible for this patient's symptoms?

Question

A 6-year-old previously healthy girl is brought to the emergency department due to a day of fever, abdominal pain, and diarrhea.  The symptoms began abruptly with high fever and cramping, periumbilical abdominal pain and were quickly followed by low-volume diarrhea mixed with blood and mucus.  The patient has had no sick contacts and has not traveled recently; the family had dinner at a buffet restaurant 3 days ago.  Temperature is 38.9 C (102 F).  Physical examination reveals mild diffuse abdominal tenderness with no guarding or rebound tenderness.  Bowel sounds are hyperactive.  Stool occult blood testing is positive, and there are numerous leukocytes in the stool.  Culture of the stool yields gram-negative, oxidase-positive, curved rods.  Which of the following is the most likely pathogen responsible for this patient's symptoms?

Quizplus · Accepted Answer

11ec160b_3805_fa9b_9249_41a32e00a8db_MD0001_00 Campylobacter jejuni is a motile, oxidase-positive, curved, gram-negative rod that is a leading cause of bacterial gastroenteritis in the United States. This pathogen resides in the gastrointestinal tract of a wide range of mammals and is transmitted via the fecal-oral route. Most cases arise when humans ingest contaminated food, particularly undercooked poultry or unpasteurized milk, but a minority of infections is caused by close contact with domesticated animals (eg, dogs, farm animals). C jejuni is enteroinvasive and typically causes fever, abdominal pain, and diarrhea that may or may not be bloody. Stool studies usually reveal inflammation (blood, leukocytes); culture of the stool (enriched media at 42 C [107.6 F] and microaerophilic conditions) is diagnostic. Most cases are self-limited and resolve with supportive treatment within 5 days. (Choice B) Escherichia coli causes many forms of gastroenteritis, including enterotoxin-mediated watery diarrhea (enterotoxigenic), Shiga toxin-mediated hemorrhagic colitis (enterohemorrhagic), and invasive colitis (enteroinvasive). Although this pathogen is a gram-negative enteric rod, it is oxidase-negative and not typically described as curved. (Choice C) Non-typhoidal Salmonella (S enterica) is a common cause of bacterial gastroenteritis. This enteroinvasive pathogen frequently causes self-limited abdominal pain, fever, and watery diarrhea (bloody diarrhea is less common but can occur). However, Salmonella is oxidase-negative and not typically described as curved. (Choice D) Shigella is a highly virulent bacterium that is often transmitted via the fecal-oral route in day care centers or other areas of communal habituation. It causes inflammatory colitis with fever; abdominal pain; and mucoid, bloody, and/or watery diarrhea. Shiga toxin, which irreversibly inhibits host cell protein synthesis, is a major virulence factor. However, Shigella is oxidase-negative and is not typically described as curved. (Choice E) Vibrio cholerae is also a curved, oxidase-positive, gram-negative enteric rod and can therefore occasionally be misidentified as a Campylobacter species. However, V cholerae causes massive watery diarrhea (due to cholera toxin) that is noninflammatory (no fecal leukocytes or erythrocytes). Educational objective: Campylobacter jejuni is an oxidase-positive, curved, gram-negative rod that is a leading cause of gastroenteritis. The pathogen is a zoonotic organism most commonly contracted by consuming contaminated, undercooked poultry. Cases are marked by fever, abdominal pain, and diarrhea that may be bloody.

A 6-Year-Old Previously Healthy Girl Is Brought to the Emergency