VanE, a new type of acquired glycopeptide resistance in Enterococcus faecalis BM4405

Enterococcus faecalis BR BM4405 was resistant to low levels of vancomycin ( MIC, 16 mu g/ml) and was susceptible to teicoplanin (MIC, 0.5 mu g/ml). No PCR product was obtained when the total DNA of this clinical isolate was us ed as a template with primers specific for glycopeptide resistance genes va nA, 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 Hind III as a template. The product was cloned and sequenced. The deduced amino acid sequence had greater identity (55%) with VanC than with VanA (45%), Va nB (43%), or VanD (44%). This was consistent with the fact that BM4405 synt hesized peptidoglycan precursors that terminated in D-serine residues, afte r induction with vancomycin, weak D,D-dipeptidase and penicillin-insensitiv e D,D-carboxypeptidase activities were detected in cytoplasmic extracts of BM4405, whereas a serine racemase activity was found in the membrane prepar ation. This new type of acquired glycopeptide resistance was named VanE.