Phylogenetic diversity of Escherichia coli strains producing NDM-type carbapenemases
Phylogenetic diversity of Escherichia coli strains producing NDM-type carbapenemases
复制标题
DOI：
10.1093/jac/dkr226
复制
发表时间：
2011-09-01
影响因子：
5.2
通讯作者：
Woodford, N.
中科院分区：
文献类型：
--
作者：
Mushtaq, S.;Irfan, S.;Woodford, N.
背景资料：携带CTX-M超广谱β-内酰胺酶的大肠埃希菌在全球的积累部分反映了克隆谱系的传播，特别是ST 131和ST 405。最近，E。已经出现了产生NDM碳青霉烯酶的大肠杆菌。我们试图确定E.方法：对18株NDM阳性的大肠杆菌进行酶联免疫吸附试验，并与巴基斯坦和印度的分离株进行比较。大肠杆菌分别来自英国（n = 10）、巴基斯坦（n = 7）和印度（n = 1）的医院。通过系统发育分组、多位点序列分型和XbaI酶切DNA的PFGE对分离株进行比较。结果：分离菌株中绝大多数属于B1（n = 9）或D（n = 7）系统发育群，2株属于A组，0株属于B2组。来自英国和巴基斯坦的9个分离物属于B1谱系ST 101，其中7个通过PFGE聚类在>77%相似性处。其他谱系包括ST 405（n = 3，D组）、ST 648（n = 3，D组）、ST 23复合体（ST 90和ST 410各一个，均为A组）和ST 156（n = 1，D组）。18株大肠埃希菌中16株携带第1组CTX-M基因，13株携带CIT型获得性AmpC基因，16株同时携带阿尔马和rmtC基因。产NDM-1碳青霉烯酶的大肠杆菌菌株属于6种序列类型，包括不同的克隆谱系。然而，B1-ST 101的分离株占了收集的一半，包括来自英国和巴基斯坦的分离株。没有菌株属于ST 131或B2群。
Background: The global accumulation of Escherichia coli with CTX-M extended-spectrum beta-lactamases partly reflects the dissemination of clonal lineages, notably ST131 and ST405. More recently, E. coli have emerged that produce NDM carbapenemase. We sought to determine the clonal diversity of E. coli with this enzyme from English hospitals, and to compare them with isolates from Pakistan and India.Methods: The 18 NDM-positive E. coli were from hospitals in England (n = 10), Pakistan (n = 7) and India (n = 1). Isolates were compared by phylogenetic grouping, multilocus sequence typing and PFGE of XbaI-digested DNA. Isolates were screened by PCR for acquired AmpC genes, bla(CTX-M), and the 16S rRNA methylase genes armA and rmtC.Results: Most of the isolates belonged to phylogenetic groups B1 (n = 9) or D (n = 7); two were group A and none was group B2. Nine isolates from England and Pakistan belonged to the B1 lineage ST101, with seven of these clustering at >77% similarity by PFGE. Other lineages included ST405 (n = 3, group D), ST648 (n = 3, group D), the ST23 complex (one each of ST90 and ST410, both group A) and ST156 (n = 1, group D). Sixteen of 18 isolates had a group 1 CTX-M gene, 13 had a CIT-type acquired AmpC, and 16 had either or both of armA and rmtC.Conclusions: The E. coli isolates producing NDM-1 carbapenemase belonged to six sequence types and included diverse clonal lineages. Nevertheless, isolates of B1-ST101 accounted for half the collection, and included isolates from both England and Pakistan. None of the isolates belonged to ST131 or to phylogroup B2.