Novel OXA-10-Derived Extended-Spectrum β-Lactamases Selected In Vivo or In Vitro
Novel OXA-10-Derived Extended-Spectrum β-Lactamases Selected In Vivo or In Vitro
复制标题
在体内或体外选择的新型 OXA-10 衍生的广谱 β-内酰胺酶
DOI：
10.1128/aac.42.12.3113
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发表时间：
1998
影响因子：
4.9
通讯作者：
E. Collatz
中科院分区：
文献类型：
--
作者：
Pierre Mugnier;I. Casin;A. Bouthors;E. Collatz
铜绿假单胞菌临床分离株PAe 191对所有抗β-内酰胺类抗生素（亚胺培南除外）高度耐药，对氨基糖苷类抗生素也耐药。它产生β-内酰胺酶（表观pI为7.6），不受克拉维酸抑制。β-内酰胺酶基因的克隆和表征表明，它编码一种新的超广谱OXA-10变体，称为OXA-19，与OXA-10有9个氨基酸的差异，与OXA-13有2个氨基酸的差异，即，在位置73处的Asn（Asn 73）代替Ser并且Asp 157代替Gly。位置157的天冬酰胺与头孢他啶耐药性有关，而在该变体中，位置73的氨基酸似乎调节青霉素耐药性水平。oxa 19基因以典型的整合子结构插入到编码氨基糖苷乙酰转移酶变异体的anaac（6′）-Ib基因的下游，称为AAC（6′）-Ib 9。
ABSTRACT A clinical isolate of Pseudomonas aeruginosa, PAe191, was found to be highly resistant to all anti-Pseudomonasβ-lactam antibiotics (except imipenem) and resistant also to aminoglycosides. It produced a β-lactamase (with an apparent pI of 7.6) which was not inhibited by clavulanic acid. Cloning and characterization of the β-lactamase gene showed that it coded for a novel extended-spectrum OXA-10 variant, called OXA-19, which differed from OXA-10 by nine amino acids and from OXA-13 by two, i.e., Asn in position 73 (Asn73) instead of Ser and Asp157 instead of Gly. Asparagine in position 157 is implicated in resistance to ceftazidime, while the amino acid in position 73, in this variant, seems to condition the level of resistance to penicillins. The oxa19gene was found to be inserted, in a typical integron structure, immediately downstream from anaac(6′)-Ib gene coding for an aminoglycoside acetyltransferase variant, which was called AAC(6′)-Ib9.