VanE, a New Type of Acquired Glycopeptide Resistance in Enterococcus faecalis BM4405

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Abstract
Enterococcus faecalis BM4405 was resistant to low levels of vancomycin (MIC, 16 μg/ml) and was susceptible to teicoplanin (MIC, 0.5 μg/ml). No PCR product was obtained when the total DNA of this clinical isolate was used as a template with primers specific for glycopeptide resistance genes vanA,vanB, vanC, and vanD. However, a 604-bp PCR fragment was obtained when V1 and V2 degenerate primers were used and total DNA was digested with HindIII as a template. The product was cloned and sequenced. The deduced amino acid sequence had greater identity (55%) with VanC than with VanA (45%), VanB (43%), or VanD (44%). This was consistent with the fact that BM4405 synthesized peptidoglycan precursors that terminated ind-serine residues. After induction with vancomycin, weakd,d-dipeptidase and penicillin-insensitived,d-carboxypeptidase activities were detected in cytoplasmic extracts of BM4405, whereas a serine racemase activity was found in the membrane preparation. This new type of acquired glycopeptide resistance was named VanE.