Daptomycin and tigecycline susceptibility of vancomycin resistant enterococci isolated from rectal swab cultures

Objective: Vancomycin resistant enterococci (VRE) are important healthcare associated multidrug resistant organisms because of their easily spread in the hospital environment, difficulty to cure and high mortality rate. The aim of this study was to evaluate in vitro activity of daptomycin and tigecycline against VRE strains isolated from rectal swab samples of hospitalized patients. Methods: Sixty non-duplicate VRE strains isolated from rectal swabs of hospitalized patients between October 2010 and February 2013 at Ankara Training and Research Hospital were included into the study. Ankara Training and Research Hospital in Ankara in Turkey is a 600-bed, tertiary care, teaching hospital. Minimum inhibitory concentration (MIC) values of daptomycin and tigecycline were determined by E-test method (bioMerieux, France). Results: All of the strains were susceptible to daptomycin, three of them (5%) were resistant to tigecycline. MIC50 and MIC90 values of daptomycin were 1.5 μg/ml and 2 μgr/ml, and of tigecycline were 0.64 μg/ml and 0.125 μg/ml, respectively. Conclusion: As a result; all of the strains were susceptible to daptomycin. On the other hand, resistance to tigecycline was exhibited by 5% of VRE isolates. Clinicians should be aware of the possibility of the emergence of tigecycline nonsusceptibility and should closely monitor tigecycline MICs of enterococci. J Microbiol Infect Dis 2014; 4(3): 107-110