Which specific bacteria does tigecycline struggle against?

Tigecycline is broad-spectrum but has notable gaps. It tends to struggle against or be unreliable for these bacteria:

- Pseudomonas aeruginosa (intrinsic resistance; not active)
- Proteus spp. (Proteus mirabilis/vulgaris)
- Providencia spp.
- Morganella morganii
- Stenotrophomonas maltophilia (generally not reliably susceptible)
- Burkholderia cepacia complex (variable/inconsistent activity)
- Acinetobacter baumannii in some settings (activity is variable; rely on susceptibility testing)

In practice, tigecycline is often considered for MDR Gram-positive infections (MRSA, VRE) and many Enterobacterales, but not for Pseudomonas or the Proteae group, and it’s not ideal for bloodstream infections due to low serum concentrations. Always rely on local susceptibility data and guidelines for specific pathogens. If you have a particular organism or infection in mind, I can tailor the info.