What antibiotics are effective against Peptostreptococcus (anaerobic Gram-positive cocci) infections?

From the Guidelines

Peptostreptococcus infections can be effectively treated with ampicillin, which is useful for coverage of susceptible enteric aerobic organisms, as well as for gram-positive organisms, such as Peptostreptococcus species 1. The choice of antibiotic depends on the severity and location of the infection, as well as the patient's medical history and potential allergies.

• Ampicillin is a suitable option for treating Peptostreptococcus infections, as it provides coverage against gram-positive organisms, including Peptostreptococcus species 1.
• Clindamycin is also effective against anaerobes and aerobic gram-positive cocci, including most S. aureus serogroups, and can be used as an alternative or in combination with ampicillin 1.
• Other options, such as metronidazole, may be considered for their anaerobic spectrum, but ampicillin and clindamycin are generally preferred due to their broader coverage 1.
• In cases of mixed infections, combination therapy with ampicillin-sulbactam, clindamycin, and ciprofloxacin may be necessary to ensure adequate coverage against both aerobes and anaerobes 1.
• The duration of treatment typically ranges from 7-14 days, but may extend longer for deep-seated infections like abscesses, and drainage of any abscesses is often necessary alongside antibiotic therapy for complete resolution.

From the FDA Drug Label

Clindamycin has been shown to be active against most of the isolates of the following microorganisms, both in vitro and in clinical infections: Anaerobic bacteria Peptostreptococcus anaerobius The following in vitro data are available, but their clinical significance is unknown At least 90 percent of the following bacteria exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for clindamycin against isolates of a similar genus or organism group. However, the efficacy of clindamycin in treating clinical infections due to these bacteria has not been established in adequate and well-controlled clinical trials Anaerobic bacteria Finegoldia (Peptostreptococcus) magna Micromonas (Peptostreptococcus) micros

The list of antibiotics that treat Peptostreptococcus includes:

• Clindamycin 2 Key points to consider:
• Clindamycin is effective against Peptostreptococcus anaerobius
• Clindamycin also has activity against other Peptostreptococcus species, including Finegoldia (Peptostreptococcus) magna and Micromonas (Peptostreptococcus) micros 2

From the Research

Antibiotics for Treating Peptostreptococcus

• The following antibiotics have been found to be effective against Peptostreptococcus:
  • Imipenem 3, 4
  • Vancomycin 3
  • Linezolid 3
  • Metronidazole 3
  • Amoxicillin-clavulanic acid 5
  • Cefmetazole 4
  • Cefoperazone/sulbactam 4
  • Faropenem 4
• Some Peptostreptococcus species have shown resistance to certain antibiotics, including:
  • Penicillin 5
  • Ampicillin 5
  • Ciprofloxacin 5
  • Levofloxacin 5

Antibiotic Susceptibility Testing

• It is recommended to perform antimicrobial susceptibility testing (AST) on Peptostreptococcus isolates due to their unpredictable AST patterns 5
• AST can help guide the selection of effective antibiotics for treatment 3, 5, 4