From the Guidelines
The recommended treatment for Streptococcus gallolyticus bacteremia is intravenous penicillin G (12-18 million U/24 h) or ceftriaxone (2 g/24 h) for 4 weeks, as outlined in the American Heart Association guidelines 1.
Key Considerations
- For penicillin-allergic patients, vancomycin (30 mg/kg per 24 h) is an appropriate alternative, but its use should be guided by susceptibility testing and consultation with an infectious diseases specialist 1.
- Combination therapy with gentamicin (3 mg/kg per 24 h) may be considered for the first 2 weeks in cases of endocarditis, but its use should be carefully weighed against the risk of nephrotoxicity and ototoxicity 1.
- It's crucial to search for an underlying source, particularly colorectal cancer, as S. gallolyticus bacteremia is strongly associated with gastrointestinal malignancies, and a colonoscopy should be performed even in asymptomatic patients 1.
- Endocarditis is another common complication, occurring in a significant proportion of cases, so echocardiography is essential to guide treatment duration and intensity 1.
- Treatment duration should be extended to 4-6 weeks if endocarditis is confirmed, and the choice of antibiotic regimen should be guided by susceptibility testing and clinical response 1.
Antibiotic Regimens
- Penicillin G: 12-18 million U/24 h IV, either continuously or in 4-6 equally divided doses, for 4 weeks 1.
- Ceftriaxone: 2 g/24 h IV or IM, in 1 dose, for 4 weeks 1.
- Vancomycin: 30 mg/kg per 24 h IV, in 2 equally divided doses, for 4 weeks, with trough levels monitored to ensure efficacy and minimize toxicity 1.
- Gentamicin: 3 mg/kg per 24 h IV or IM, in 1 dose, for the first 2 weeks, with careful monitoring of renal function and auditory function 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Treatment of Strep gallolyticus Bacteremia
The treatment of Strep gallolyticus bacteremia typically involves the use of antibiotics. According to the study 2, Streptococcus gallolyticus was 100% sensitive to cefotaxime and vancomycin.
Antibiotic Sensitivities
- Cefotaxime: 100% sensitive 2
- Vancomycin: 100% sensitive 2
- Penicillin: 81.2% sensitive 3
- Ceftriaxone: all isolates were susceptible 3
- Ampicillin: resistance was seen in only one of the isolates 3
- Clindamycin, erythromycin, and tetracycline: highly resistant 2
Clinical Considerations
In addition to antibiotic treatment, it is essential to investigate for underlying conditions such as colon cancer, as there is a strong association between Strep gallolyticus bacteremia and colonic neoplasia 4, 5, 6. However, the study 3 found that colonic neoplasia and infective endocarditis were rare in their patients.
Patient Management
- Colonoscopy is recommended in patients with Strep gallolyticus endocarditis or bacteremia to evaluate the possibility of high-grade adenoma or colon cancer 4
- Preendoscopic antibiotics use can be considered in high-risk individuals 4
- Patients with Strep gallolyticus bacteremia should be thoroughly evaluated for underlying co-morbidities, such as diabetes mellitus and chronic liver disease 3