From the FDA Drug Label
Other groups, including group D (enterococcus) are resistant
- Intrinsic resistance in Streptococcus species refers to the natural resistance of certain groups of Streptococcus to penicillin.
- Specifically, groups other than A, C, G, H, L, and M, such as group D (enterococcus), are inherently resistant to penicillin 1.
From the Research
Streptococcus species are intrinsically resistant to several important antimicrobial classes, including aminoglycosides, metronidazole, and trimethoprim, due to various mechanisms such as poor drug uptake, lack of necessary enzymes, and ability to use exogenous folates. The intrinsic resistance patterns of Streptococcus species are crucial for selecting appropriate antimicrobial therapy when treating streptococcal infections. These medications will be ineffective regardless of susceptibility testing results and should generally be avoided as monotherapy options. The most recent and highest quality study, 2, highlights the challenges in treating Group A Streptococcus infections, including the emergence of strains with reduced susceptibility to beta-lactams and other antibiotics. Key points to consider when treating Streptococcus infections include:
- Intrinsic resistance to aminoglycosides, metronidazole, and trimethoprim
- Reduced susceptibility to polymyxins in Streptococcus pneumoniae
- Emergence of strains with reduced susceptibility to beta-lactams and other antibiotics
- Importance of selecting appropriate antimicrobial therapy based on intrinsic resistance patterns. The study 2 provides the most recent and relevant information on the topic, and its findings should be prioritized when making treatment decisions.