Is tigecycline an effective weapon against newly emerging gram negative threats?

The most feared mechanisms of emerging gram negative resistance are ESBLs, AmpC beta lactamases and carbapenemases. From a systematic review of tigecycline for the treatment of these infections:

Twenty-six microbiological and 10 clinical studies were identified. Tigecycline was active against more than 99% of 1936 Escherichia coli isolates characterized by any of the above resistance patterns…

The degree of microbiological activity of tigecycline against 576 MDR Enterobacter spp. isolates was moderate. In clinical studies, 69.7% of the 33 reported patients treated with tigecycline achieved resolution of an infection caused by a carbapenem-resistant or ESBL-producing or MDR Enterobacteriaceae.

Conclusions: Tigecycline is microbiologically active against almost all of the ESBL or MDR E. coli isolates and the great majority of ESBL or MDR Klebsiella spp. isolates.

So it shows promise. It is likely to be combined with other agents in empiric use.