Bacteria Sensitive to Tigecycline
Tigecycline, a glycylcycline antibiotic, targets a broad range of bacteria by inhibiting protein synthesis, particularly effective against multidrug-resistant strains. It shows in vitro sensitivity against many Gram-positive, Gram-negative, and anaerobic bacteria.[1]
Gram-Positive Bacteria Covered
Sensitive species include methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE like Enterococcus faecium), streptococci (Streptococcus pneumoniae, S. pyogenes, S. agalactiae), and Listeria monocytogenes. It penetrates biofilms well, aiding skin and soft tissue infections.[1][2]
Gram-Negative Bacteria Covered
Covers Escherichia coli (including extended-spectrum beta-lactamase producers), Klebsiella pneumoniae, Acinetobacter baumannii (multidrug-resistant), Haemophilus influenzae, and some Pseudomonas aeruginosa strains, though not reliably. Effective against complicated intra-abdominal infections from these pathogens.[1][3]
Anaerobes and Atypicals
Strong activity against anaerobes like Bacteroides fragilis, Clostridium species, and Prevotella. Also inhibits atypicals such as Mycoplasma pneumoniae and Legionella pneumophila.[1][2]
Key Resistance Patterns and Limits
Tigecycline lacks activity against Pseudomonas aeruginosa, Proteus species, Providencia species, and Burkholderia cepacia due to efflux pumps or poor uptake. Stenotrophomonas maltophilia shows variable sensitivity. Resistance emerges via tet(A) or tet(X) genes in some Enterobacteriaceae.[3][4]
Clinical Use and Testing Sensitivity
Approved for complicated skin/skin structure infections, intra-abdominal infections, and community-acquired pneumonia. Sensitivity tested via MIC (minimum inhibitory concentration) ≤2 mcg/mL for most Enterobacteriaceae and staphylococci per CLSI breakpoints. Consult local antibiograms for resistance trends.[1][4]
[1]: FDA Label for Tygacil (tigecycline)
[2]: Clinical Infectious Diseases - Tigecycline Review
[3]: EUCAST Tigecycline Breakpoints
[4]: CDC Antibiotic Resistance Threats Report