A 57-year-old woman comes to the emergency department due to a day of worsening right-upper quadrant pain and fever. The patient has a history of untreated chronic hepatitis C infection. She smokes a pack of cigarettes a day and drinks 1 or 2 beers most nights; she used to inject methamphetamines but quit 12 years ago after developing a splenic abscess. Temperature is 38.8 C (101.9 F), blood pressure is 104/58 mm Hg, pulse is 118/min, and respirations are 20/min. Abdominal examination shows right-upper quadrant tenderness with positive Murphy sign. Ultrasonography reveals increased gall bladder wall thickness with intramural gas and pericholecystic fluid. No gallstones or biliary duct dilation is present. Intravenous fluids and broad-spectrum antibiotics are begun and a laparoscopic cholecystectomy for acute acalculous cholecystitis is performed. Blood cultures drawn at the time of admission grow Clostridium septicum. Which of the following is most appropriate to evaluate for associated conditions in this patient?
This patient with acute acalculous cholecystitis has bacteremia with Clostridium septicum, a gram-positive, spore-forming colonic bacterium. Although this pathogen rarely causes bacteremia and invasive infection (eg, gas-gangrene, tissue necrosis), the risk is significantly increased in those with colonic malignancy. This is because tumor cells frequently undergo anaerobic glycolysis, which creates an adequate environment for the germination of C septicum spores; and tumors damage the colonic mucosa, which allows sporulated bacteria to translocate into the bloodstream.
About 30% of patients with C septicum bacteremia have colon cancer; therefore, colonoscopy is required for those with no history of the tumor. Bacteremia with group D streptococci, particularly Streptococcus bovis, is also strongly associated with colon cancer and should prompt screening colonoscopy.
(Choice B) Cystoscopy is sometimes indicated for patients who have recurrent gram-negative bacteremia (eg, Escherichia coli) in the setting of bladder voiding symptoms. C septicum is not a common urinary tract pathogen; therefore, cystoscopy would not be indicated.
(Choice C) Spinal epidural abscess often develops in the setting of bacteremia with Staphylococcus aureus or gram-negative bacilli. Patients who have fever, localized back pain, and neurologic symptoms (eg, radicular pain, lower extremity motor/sensory/reflex changes, bowel/bladder dysfunction) require evaluation with MRI of the spine. Clostridial species do not generally attack the spine, and this patient has no back pain or neurologic symptoms.
(Choice D) Candidemia often leads to endophthalmitis; therefore, all patients with candidemia (with or without visual symptoms) require ophthalmologic evaluation. C septicum bacteremia is not associated with retinal infections and does not require ophthalmologic evaluation in the absence of visual symptoms.
(Choice E) S aureus bacteremia should prompt transthoracic echocardiogram (TTE) because the organism often seeds native (undamaged) and damaged valves. Although S bovis bacteremia is also strongly associated with infective endocarditis (and should prompt TTE), clostridial species do not typically attack the heart or heart valves; therefore, screening echocardiography is generally not necessary.
Educational objective:
Clostridium septicum bacteremia is strongly associated with underlying colon cancer. Therefore, patients with C septicum bacteremia require screening colonoscopy. Bacteremia with group D streptococci, particularly Streptococcus bovis, is also strongly linked to colon cancer.