Tigecycline susceptibility report from an Indian tertiary care hospital

Treatment of serious life threatening infections due to multi-drug resistant pathogens presents a difficult challenge due to the limited therapeutic options. Therefore, we studied the in vitro susceptibility of tigecycline, a new glycylcycline with promising broad spectrum of activity against Gram positive and Gram negative bacteria at a tertiary care hospital in north India.

A total of 75 multi-drug resistant isolates of methicillin resistant Staphylococcus aureus (21), vancomycin resistant enterococci (14), vancomycin resistant Streptococcus spp. (3), extended spectrum beta lactamase producing Gram negative bacteria (11) and multi-resistant Acinetobacter spp. (26) were tested for tigecycline susceptibility by the E-test and disc diffusion methods. An additional 83 multi-resistant Gram negative clinical isolates were screened by disc diffusion method alone.

All the isolates of MRSA, VRE, vancomycin resistant Streptococcus spp. and ESBL producing enteric bacteria were sensitive to tigecycline by the E-test and disc diffusion methods. However, only 42 per cent of Acinetobacter spp. were found to be sensitive to tigecycline by the E-test method.

In conclusion, tigecycline was found to be highly effective against Gram-positive bacteria and Gram-negative members of Enterobacteriaceae, but a high prevalence of resistance in members of Acinetobacter spp. is worrisome.