Institute of Microbiology and Epizootics, Freie Universität Berlin, Philippstr. 13, 10115 Berlin, Germany.
J Antimicrob Chemother. 2010 Apr;65(4):651-60. doi: 10.1093/jac/dkq004. Epub 2010 Jan 29.
In view of the intercontinental emergence of Escherichia coli clone O25:H4-ST131 producing CTX-M-15 extended-spectrum beta-lactamase (ESBL) in human clinical settings it would be of great interest to explore its existence in animals to unravel a possible reservoir function and the origin and transmission of this group of multiresistant strains.
A total of 177 clinical phenotypically ESBL-producing E. coli isolates, mainly obtained from companion animals with urinary tract infections, wound infections and diarrhoea, were collected in a veterinary diagnostic laboratory covering a European-wide service area. They were screened for molecular subtype O25b and multilocus sequence type 131. O25b-ST131 isolates were subsequently tested for ESBL types, and phenotypic and genotypic resistance determinants. Further characterization of the strains was performed by PFGE and virulence gene typing.
Ten (5.6%) of 177 phenotypically ESBL-producing E. coli isolates, nine strains from dogs and one strain from a horse, were allocated to the B2-O25b-ST131 lineage. Nine of these isolates harboured a CTX-M-15-type beta-lactamase enzyme while one strain possessed an SHV-12-type ESBL. Macrorestriction analysis revealed a cluster formation of six of the animal CTX-M-15-type ESBL-producing strains from five different European countries together with a human control strain constituting a group of clonally related strains at a similarity value of 87.0%.
Our findings demonstrate that the group of clonally related human B2-O25:H4-ST131 CTX-M-15-type ESBL-producing E. coli strains is present in companion animals from various European countries. This highlights the possibility of inter-species transmission of these multiresistant strains from human to animal and vice versa.
鉴于产 CTX-M-15 型超广谱β-内酰胺酶（ESBL）的大肠杆菌 O25:H4-ST131 克隆在人类临床环境中的洲际出现，探索其在动物中的存在将具有重要意义，以揭示其可能的储库功能以及这些多耐药菌株的起源和传播。
在一个覆盖整个欧洲服务区域的兽医诊断实验室中，共收集了 177 株临床表型产 ESBL 的大肠杆菌分离株，主要来自患有尿路感染、伤口感染和腹泻的伴侣动物。对这些分离株进行 O25b 和多位点序列型 131 的分子亚型筛查。随后对 O25b-ST131 分离株进行 ESBL 类型、表型和基因型耐药决定因素的检测。通过 PFGE 和毒力基因分型对菌株进行进一步特征描述。
177 株表型产 ESBL 的大肠杆菌分离株中，有 10 株（5.6%）被归为 B2-O25b-ST131 谱系，其中 9 株来自狗，1 株来自马。这 10 株分离株均携带 CTX-M-15 型β-内酰胺酶，其中 1 株携带 SHV-12 型 ESBL。宏观限制分析显示，来自五个不同欧洲国家的六株动物 CTX-M-15 型产 ESBL 分离株与一株人类对照株聚集在一起，相似度为 87.0%，构成了一组具有克隆相关性的菌株。
我们的研究结果表明，具有克隆相关性的人类 B2-O25:H4-ST131 CTX-M-15 型产 ESBL 大肠杆菌菌株存在于来自不同欧洲国家的伴侣动物中。这突显了这些多耐药菌株从人类传播到动物以及反之的种间传播的可能性。
