Antibiotic Treatment for Listeriosis

Recommended Antibiotics

• Ampicillin or amoxicillin are preferred antibiotics for the treatment of listeriosis, according to the Centers for Disease Control and Prevention and the American College of Physicians, with a recommended dose of 2g IV every 4 hours for 21 days 1, 2, 3, 4
• Erythromycin is an option for pregnant women with penicillin allergy, as recommended by the Centers for Disease Control and Prevention 1
• Fluoroquinolones are not recommended for the treatment of listeriosis, according to the Centers for Disease Control and Prevention 1
• Alternative options include trimethoprim-sulfamethoxazole (10-20 mg/kg of trimethoprim component) in divided doses, as suggested by the Journal of Infection guidelines and the Clinical Microbiology and Infection society 2, 3, 4

Special Considerations

• Immunocompromised patients may require longer treatment courses and closer monitoring for treatment failure, as recommended by the Clinical Microbiology and Infection society and the ESCMID 2, 4
• Pregnant women require essential treatment as Listeria infection during pregnancy can lead to pregnancy loss, with ampicillin or amoxicillin as preferred options and fluoroquinolones to be avoided, as recommended by the ESCMID and other guidelines 5
• Higher risk population for Listeria infection may require dose adjustments based on renal function, and monitor for adverse effects of antibiotics more closely, as recommended by the Infectious Diseases Society of America, and consider fetal monitoring during treatment in pregnant patients, as suggested by the Journal of Infection guidelines and the ESCMID 2, 3, 4, 5

Diagnostic Considerations

• Blood culture sensitivity for Listeria is moderate (10-75%), and multiple sets of blood cultures should be obtained before starting antibiotics when possible, as recommended by the Infectious Diseases Society of America and the Clinical Microbiology and Infection society 2
• A lumbar puncture should be performed in all patients with Listeria bacteremia to rule out meningitis, including CSF studies such as cell count and differential, protein and glucose, Gram stain, culture, and consider PCR testing if available, following the recommendations of the Clinical Microbiology and Infection society 2

Treatment Duration and Monitoring

• Higher doses of ampicillin may be required, and longer treatment courses (>21 days) may be necessary, with closer monitoring for treatment failure, as suggested by the Clinical Microbiology and Infection society, and daily clinical assessment for fever, neurological symptoms, and repeat blood cultures to document clearance, and if meningitis is present, consider repeat lumbar puncture to document CSF sterilization in cases of poor clinical response 2
• The following treatment options are recommended by the ESCMID:

2, 4

Avoided Treatments

• Cephalosporins should be avoided as they have no activity against Listeria, according to the Clinical Microbiology and Infection society, and dexamethasone should be discontinued if initially started for suspected bacterial meningitis once Listeria is identified, as recommended by the Clinical Microbiology and Infection guidelines and the ESCMID 2, 4