VanE, a new type of acquired glycopeptide resistance in Enterococcus faecalis BM4405
VanE, a new type of acquired glycopeptide resistance in Enterococcus faecalis BM4405
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DOI：
10.1128/aac.43.9.2161
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发表时间：
1999-09-01
影响因子：
4.9
通讯作者：
Courvalin, P
中科院分区：
文献类型：
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作者：
Fines, M;Perichon, B;Courvalin, P
粪肠球菌BR BM4405对低浓度万古霉素(MIC)耐药，对替考拉宁(MIC)敏感。以该临床分离株的总DNA为模板，以糖肽抗性基因Vana、vanB、vanC和Vand为模板，未扩增出扩增产物。而使用V1和V2简并引物，以HindIII为模板对总DNA进行双酶切，获得了一条604bp的片段。对该产物进行克隆和测序。推导的氨基酸序列与VanC的同源性(55%)高于Vana(45%)、VanB(43%)或Vand(44%)。这与BM4405合成的终止于D-丝氨酸残基的肽聚糖前体是一致的，在万古霉素诱导后，BM4405的细胞质提取物中检测到微弱的D，D-二肽酶和青霉素不敏感的D，D-羧基肽酶活性，而膜制剂中则检测到丝氨酸消旋酶活性。这种新的获得性糖肽抗性被命名为Vane。
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 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 in D-serine residues, after induction with vancomycin, weak D,D-dipeptidase and penicillin-insensitive D,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.