How extensive is tigecycline's activity against anaerobes?

Tigecycline has broad in vitro activity against anaerobes and is considered to cover most clinically relevant anaerobes.

- Covers: Most Gram-negative anaerobes (especially Bacteroides fragilis group, Prevotella, Porphyromonas, Fusobacterium) and many Gram-positive anaerobes (Peptostreptococcus species, anaerobic streptococci, and some Actinomyces). Clostridium species are generally susceptible as well.
- Not universal: A minority of anaerobes may show reduced susceptibility, and resistance mechanisms can occur (less common with B. fragilis group). Breakpoints and local susceptibility patterns matter.
- Limitations: Tigecycline is not useful for Pseudomonas aeruginosa or many other nonfermenters, and its use is limited for bacteremia due to low serum concentrations. It’s bacteriostatic rather than bactericidal.
- Clinical relevance: Its broad anaerobic activity supports its use in complicated intra‑abdominal infections and certain polymicrobial skin/soft tissue infections, usually as part of a multi-drug regimen.

If you want, I can summarize the activity by organism group (e.g., Bacteroides fragilis, Prevotella, Peptostreptococcus, Clostridium) with typical susceptibility trends.