What is the best treatment for lactobacillus infections?

Treatment of Lactobacillus Infections

For lactobacillus infections, ampicillin is the first-line antibiotic treatment, with alternatives including cefazolin, cefotaxime, or vancomycin based on susceptibility testing. 1

Antimicrobial Selection

Lactobacillus species are generally considered beneficial microorganisms and are rarely pathogenic. However, when they do cause infections, proper antimicrobial therapy is essential. The selection of antibiotics should be guided by:

1. First-line options:

   • Ampicillin (high sensitivity across all lactobacillus strains)
   • Cefazolin (high sensitivity)
   • Cefotaxime (high sensitivity)
   • Vancomycin (high sensitivity)

2. Ineffective antibiotics (lactobacilli are naturally resistant to):

   • Metronidazole
   • Trimethoprim/sulfamethoxazole
   • Levofloxacin

3. Variable effectiveness (requires susceptibility testing):

   • Gentamycin
   • Clindamycin
   • Erythromycin
   • Ciprofloxacin
   • Tetracycline

Treatment Algorithm

1. Confirm diagnosis:

   • Proper culture and identification of lactobacillus as the causative pathogen
   • Rule out contamination (lactobacilli are normal flora in many body sites)

2. Assess infection severity:

   • For mild-moderate infections: Ampicillin
   • For severe infections: Consider combination therapy with ampicillin plus gentamicin (after susceptibility testing)

3. For beta-lactam allergic patients:

   • Vancomycin is the preferred alternative

4. Duration of therapy:

   • 7-14 days depending on infection site and severity
   • Longer courses may be needed for endovascular infections

Special Considerations

Immunocompromised Patients

Immunocompromised patients are at higher risk for lactobacillus infections. In these patients:

• Consider broader initial coverage until susceptibilities return
• Avoid probiotic supplementation containing lactobacilli 2

Endocarditis

For lactobacillus endocarditis:

• Combination therapy with ampicillin plus gentamicin (after susceptibility testing)
• Extended duration (4-6 weeks)
• Early surgical evaluation

Important Caveats

1. Probiotic-associated infections:

   • Probiotics containing lactobacilli should be avoided in immunocompromised patients, those with central venous catheters, cardiac valvular disease, and short-gut syndrome 2
   • Cases of bacteremia and fungemia have been reported with probiotic use in debilitated patients 2

2. Antibiotic resistance:

   • Some lactobacillus strains may carry antibiotic resistance genes 3
   • Susceptibility testing is important for guiding therapy in serious infections

3. Vaginal infections:

   • Treatment of bacterial vaginosis or other vaginal infections with antibiotics can disrupt normal lactobacilli flora 1
   • Consider probiotic supplementation after antibiotic therapy in immunocompetent patients to restore normal flora

Monitoring and Follow-up

1. Clinical response:

   • Assess for improvement in symptoms within 48-72 hours
   • Consider repeat cultures in persistent infections

2. Adjust therapy based on:

   • Susceptibility results
   • Clinical response
   • Infection site

Lactobacillus infections are rare but can occur, particularly in immunocompromised hosts. The key to successful treatment is proper identification, appropriate antibiotic selection based on susceptibility testing, and addressing any underlying predisposing factors.