Novel GES/IBC extended-spectrum beta-lactamase variants with carbapenemase activity in clinical enterobacteria.
Novel GES/IBC extended-spectrum beta-lactamase variants with carbapenemase activity in clinical enterobacteria.
复制标题
在临床肠杆菌中具有碳青霉烯酶活性的新型 GES/IBC 广谱 β-内酰胺酶变体。
DOI：
10.1111/j.1574-6968.2004.tb09535.x
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发表时间：
2004
影响因子：
2.1
通讯作者：
L. Tzouvelekis
中科院分区：
文献类型：
--
作者：
S. Vourli;P. Giakkoupi;V. Miriagou;E. Tzelepi;A. Vatopoulos;L. Tzouvelekis
研究了两种对碳青霉烯类药物敏感性降低的临床分离株，即大肠杆菌和肺炎克雷伯菌。这种表型与新型 GES/IBC 变体 β-内酰胺酶的产生相关，命名为 GES-3（来自大肠杆菌）和 GES-4（来自肺炎克雷伯菌），表现出碳青霉烯酶活性。这两种酶在 Ambler 的 170 位上都具有 Ser，而不是缺乏碳青霉烯酶活性的 β-内酰胺酶 GES-1 和 IBC-1 中的 Gly。此外，GES-4 中的位置 104 被 Lys 占据，如 IBC-1 中一样。 bla(GES-3) 和 bla(GES-4) 作为基因盒出现在质粒携带的 1 类整合子的可变区中。 GES-4 编码整合子的结构与之前描述的 IBC-1 整合子的结构相似。 GES-3 编码整合子很可能在 3' 保守片段处被截短。
Two clinical isolates, an Escherichia coli and a Klebsiella pneumoniae, with decreased susceptibility to carbapenems were studied. This phenotype was associated with production of novel GES/IBC variant beta-lactamases, designated GES-3 (from E. coli) and GES-4 (from K. pneumoniae), exhibiting carbapenemase activity. Both enzymes possessed Ser at Ambler's position 170 instead of Gly found in the beta-lactamases GES-1 and IBC-1 that lack carbapenemase activity. Additionally, position 104 in GES-4 was occupied by a Lys as in IBC-1. bla(GES-3) and bla(GES-4) occurred as gene cassettes in the variable regions of class 1 integrons carried by plasmids. The structure of the GES-4-encoding integron was similar to that of previously described IBC-1 integrons. The GES-3-encoding integron was, most likely, truncated at the 3' conserved segment.