ence strain. The 1.5 kb 16S rDNA fragment was identical in E. faecalis V583 and UW6940 (data not shown). The sequenced fragment covered all relevant sites of interaction between tigecycline and the 16S rDNA of the 30S ribosomal subunit in the model bacterium Thermus thermophilus. The strain was grown for 2 weeks ( 400–500 generations) on BHI agar plates and in BHI liquid broth without any selective pressure in order to test the stability of tigecycline resistance. Progenies were sampled after the first and second weeks of passage. MICs of tigecycline for all progenies remained stable at 1 mg/L (data not shown). The resistance trait was not transferable in vitro irrespective of the test method or recipient used. Molecular typing using MLST revealed ST6. ST6 belongs to MLST clonal complex 2 combining mainly isolates from hospital outbreaks. Our preliminary results show stable tigecycline resistance in an epidemic, hospital-adapted E. faecalis strain type from an intensive care unit patient after prolonged tigecycline therapy. The basis of tigecycline resistance is not due to mutations in the 16S rDNA, tetX-encoded or efflux-mediated. The exact mechanism of resistance could not be elucidated.