A 45-year-old woman is brought to the emergency department by her husband due to fever and confusion. He notes that the patient began having fever, headache, nausea, and vomiting yesterday. She was also disoriented and made many odd statements to her children. The patient has a history of type 1 diabetes mellitus and chronic kidney disease and underwent simultaneous pancreas-kidney transplantation 2 years ago. She takes maintenance immunosuppressive therapy.
Temperature is 38.9 C (102 F) , blood pressure is 108/60 mm Hg, pulse is 105/min, and respirations are 21/min. The patient is lethargic and ill-appearing. No skin rash is present. The lungs are clear to auscultation, and there are no heart murmurs. The abdomen is soft and nontender. The patient is oriented only to self and moves all extremities to pain. No nuchal rigidity or signs of meningismus are elicited.
Leukocyte count is 15,500/mm³, serum creatinine is 0.9 mg/dL, and plasma glucose is 90 mg/dL. Blood cultures are obtained, and empiric antibiotics are administered. CT scan of the head shows no hemorrhage or mass, and lumbar puncture is subsequently performed. Cerebrospinal fluid (CSF) results are as follows:
CSF Gram stain reveals numerous gram-positive bacilli. Which of the following is the best treatment?

Question

A 45-year-old woman is brought to the emergency department by her husband due to fever and confusion. He notes that the patient began having fever, headache, nausea, and vomiting yesterday. She was also disoriented and made many odd statements to her children. The patient has a history of type 1 diabetes mellitus and chronic kidney disease and underwent simultaneous pancreas-kidney transplantation 2 years ago. She takes maintenance immunosuppressive therapy.
Temperature is 38.9 C (102 F) , blood pressure is 108/60 mm Hg, pulse is 105/min, and respirations are 21/min. The patient is lethargic and ill-appearing. No skin rash is present. The lungs are clear to auscultation, and there are no heart murmurs. The abdomen is soft and nontender. The patient is oriented only to self and moves all extremities to pain. No nuchal rigidity or signs of meningismus are elicited.
Leukocyte count is 15,500/mm³, serum creatinine is 0.9 mg/dL, and plasma glucose is 90 mg/dL. Blood cultures are obtained, and empiric antibiotics are administered. CT scan of the head shows no hemorrhage or mass, and lumbar puncture is subsequently performed. Cerebrospinal fluid (CSF) results are as follows:

CSF Gram stain reveals numerous gram-positive bacilli. Which of the following is the best treatment?

Quizplus · Accepted Answer

This patient with fever, headache, and altered mental status has 3 of the 4 classic manifestations of acute bacterial meningitis. All 4 manifestations (including neck stiffness) are present in <45% of cases. Priorities of care include the pursuit of a microbial diagnosis by blood cultures and cerebrospinal fluid (CSF) Gram stain/culture and prompt initiation of empiric antimicrobial treatment to limit risk of neurologic sequelae and death. CSF Gram stain has a sensitivity of 60%-90% and a specificity of >97% when lumbar puncture is performed prior to antibiotic therapy. Patients who receive antibiotics prior to lumbar puncture may have lower yields. Positive Gram stain (or culture) should prompt the transition from empiric to targeted antibiotic therapy. This patient has gram-positive bacilli in the CSF, indicating likely Listeria monocytogenes meningoencephalitis, which most commonly affects neonates, adults age >50, and those with immunocompromise (eg, immunosuppressive treatment). Empiric therapy should now be narrowed to intravenous ampicillin or penicillin G. An aminoglycoside is sometimes added for synergy. (Choice B) Cefepime monotherapy is primarily used to treat bacterial meningitis when CSF Gram stain shows gram-negative (not gram-positive) bacilli, and patients are at risk for resistant organisms (eg, Pseudomonas, Acinetobacter) due to immunocompromise, a neurosurgical device, or recent neurosurgery or head trauma. (Choices C, D, and E) Vancomycin is primarily used in the treatment of bacterial meningitis to cover for cephalosporin-resistant strains of Streptococcus pneumoniae (gram-positive cocci) or when Staphylococcus aureus or coagulase-negative staphylococcus is likely (eg, recent head trauma, neurosurgery, neurosurgical device). It is also used in combination with cefepime and ampicillin to empirically treat bacterial meningitis when patients are immunocompromised. Listeria is almost universally sensitive to ampicillin and penicillin G; vancomycin is not required at this time. Educational objective: Patients with suspected bacterial meningitis who have a positive cerebrospinal fluid Gram stain should have empiric therapy narrowed to target the likely organism. Patients with gram-positive bacilli are likely to have Listeria monocytogenes meningoencephalitis; first-line treatment consists of ampicillin or penicillin G with or without a synergistic aminoglycoside. __________

A 45-Year-Old Woman Is Brought to the Emergency Department by Her