Complete Nucleotide Sequences of Plasmids pEK204, pEK499, and pEK516, Encoding CTX-M Enzymes in Three Major Escherichia coli Lineages from the United Kingdom, All Belonging to the International O25:H4-ST131 Clone
Complete Nucleotide Sequences of Plasmids pEK204, pEK499, and pEK516, Encoding CTX-M Enzymes in Three Major Escherichia coli Lineages from the United Kingdom, All Belonging to the International O25:H4-ST131 Clone
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DOI：
10.1128/aac.00688-09
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发表时间：
2009-10-01
影响因子：
4.9
通讯作者：
Livermore, David M.
中科院分区：
文献类型：
--
作者：
Woodford, Neil;Carattoli, Alessandra;Livermore, David M.
我们确定了三个质粒的完整核苷酸序列，编码CTX-M超广谱β-内酰胺酶（ESBLs）在脉冲场凝胶电泳法定义的英国变种（菌株A，C和D）的国际流行的大肠杆菌O25：H4-ST 131克隆。质粒pEK 499（菌株A; 117，536 bp）是FII型和FIA型复制子的融合体，并含有以下10种赋予对8种抗生素类的抗性的抗生素抗性基因：bla（CTX-M-15）、bla（OXA-1）、bla（TEM-1）、aac 6 ′ Ib-cr、mph（A）、catB 4、泰特（A）和整合子携带的dfrA 7、aadA 5和sul I基因。pEK 516（菌株D; 64，471 bp）属于不亲和群IncFII，携带7个抗生素抗性基因：bla（CTX-M-15）、bla（OXA-1）、bla（TEM-1）、aac 6 'Ib-cr、catB 4和泰特（A），均与pEK 499中相同。它还携带aac 3-IIa，赋予庆大霉素抗性，并与加拿大编码CTX-M-15酶的质粒pC 15 -1a高度相关。而pEK 204（C株; 93，732 bp）属于不亲和群IncI 1，仅携带两个抗性基因bla（CTX-M-3）和bla（TEM-1）。它可能是由Tn 3和ISEcp 1-bla（CTX-M-3）元件转座到pCOLIb-P9-like质粒中而产生的。我们的结论是：（i）英国变种的成功E。pEK 204和pEK 499/pEK 516上的bla（CTX-M-3）和bla（CTX-M-15）基因代表不同的逃逸事件;杆菌
We determined the complete nucleotide sequences of three plasmids that encode CTX-M extended-spectrum beta-lactamases (ESBLs) in pulsed-field gel electrophoresis-defined United Kingdom variants (strains A, C, and D) of the internationally prevalent Escherichia coli O25:H4-ST131 clone. Plasmid pEK499 (strain A; 117,536 bp) was a fusion of type FII and FIA replicons and harbored the following 10 antibiotic resistance genes conferring resistance to eight antibiotic classes:bla(CTX-M-15), bla(OXA-1), bla(TEM-1), aac6'Ib-cr, mph(A), catB4, tet(A), and the integron-borne dfrA7, aadA5, and sulI genes. pEK516 (strain D; 64,471 bp) belonged to incompatibility group IncFII and carried seven antibiotic resistance genes:bla(CTX-M-15), bla(OXA-1), bla(TEM-1), aac6'Ib-cr, catB4, and tet(A), all as in pEK499. It also carried aac3-IIa, conferring gentamicin resistance, and was highly related to pC15-1a, a plasmid encoding the CTX-M-15 enzyme in Canada. By contrast, pEK204 (strain C; 93,732 bp) belonged to incompatibility group IncI1 and carried only two resistance genes, bla(CTX-M-3) and bla(TEM-1). It probably arose by the transposition of Tn3 and ISEcp1-bla(CTX-M-3) elements into a pCOLIb-P9-like plasmid. We conclude that (i) United Kingdom variants of the successful E. coli ST131 clone have acquired different plasmids encoding CTX-M ESBLs on separate occasions, (ii) the bla(CTX-M-3) and bla(CTX-M-15) genes on pEK204 and pEK499/pEK516 represent separate escape events, and (iii) IncFII plasmids harboring bla(CTX-M-15) have played a crucial role in the global spread of CTX-M-15 ESBLs in E. coli.