Tigecycline susceptibility in multidrug resistant Acinetobacter isolates from Turkey

The present study aimed to evaluate antimicrobial activity of tigecycline against 84 multidrug resistant (MDR) Acinetobacter spp. strains by disc diffusion and E-test methods. The results of disc diffusion test were compared according to two different interpretation ways. In addition, E-test results and the disc diffusion results that interpreted by both the methods were checked for compatibility. According to the disc diffusion test, 3 strains (3.57%) were found resistant to tigecycline when considering breakpoints suggested by Food and Drug Administration (FDA). On the other hand, none of the strains was found resistant to the evaluation criteria recommended by Jones et al. (2007). Considering E-test results of tigecycline, MIC₅₀ and MIC₉₀ values of tigecycline for Acinetobacter spp. were 0.75 and 1 mg/l, respectively. Based on FDA defined breakpoints for Enterobacteriaceae, any resistant isolate was detected. In conclusion, although there are some differences in the results, tigecycline was found quite effective on Acinetobacter spp. isolates with reference to the both disc diffusion and the E-test methods.