Department of Clinical Microbiology, Hillerød Hospital, Hillerød, Denmark.
J Clin Microbiol. 2012 Nov;50(11):3703-11. doi: 10.1128/JCM.01909-12. Epub 2012 Sep 12.
In 1991, multiresistant Escherichia coli O78:H10 strains caused an outbreak of urinary tract infections in Copenhagen, Denmark. The phylogenetic origin, clonal background, and virulence characteristics of the outbreak isolates, and their relationship to nonoutbreak O78:H10 strains according to these traits and resistance profiles, are unknown. Accordingly, we extensively characterized 51 archived E. coli O78:H10 isolates (48 human isolates from seven countries, including 19 Copenhagen outbreak isolates, and 1 each of calf, avian, and unknown-source isolates), collected from 1956 through 2000. E. coli O78:H10 was clonally heterogeneous, comprising one dominant clonal group (61% of isolates, including all 19 outbreak isolates) from ST10 (phylogenetic group A) plus several minor clonal groups (phylogenetic groups A and D). All ST10 isolates, versus 25% of non-ST10 isolates, were identified by molecular methods as enteroaggregative E. coli (EAEC) (P < 0.001). Genes present in >90% of outbreak isolates included fimH (type 1 fimbriae; ubiquitous in E. coli); fyuA, traT, and iutA (associated with extraintestinal pathogenic E. coli [ExPEC]); and sat, pic, aatA, aggR, aggA, ORF61, aaiC, aap, and ORF3 (associated with EAEC). An outbreak isolate was lethal in a murine subcutaneous sepsis model and exhibited characteristic EAEC "stacked brick" adherence to cultured epithelial cells. Thus, the 1991 Copenhagen outbreak was caused by a tight, non-animal-associated subset within a broadly disseminated O78:H10 clonal group (ST10; phylogenetic group A), members of which exhibit both ExPEC and EAEC characteristics, whereas O78:H10 isolates overall are phylogenetically diverse. Whether ST10 O78:H10 EAEC strains are both uropathogenic and diarrheagenic warrants further investigation.
1991 年，多耐药性大肠杆菌 O78:H10 菌株在丹麦哥本哈根引发了尿路感染爆发。爆发分离株的系统发生起源、克隆背景和毒力特征，以及根据这些特征和耐药谱与非爆发 O78:H10 菌株的关系，尚不清楚。因此，我们广泛描述了 51 个存档的大肠杆菌 O78:H10 分离株（来自七个国家的 48 个人类分离株，包括 19 个哥本哈根爆发分离株，以及 1 个牛、禽类和来源不明的分离株），收集于 1956 年至 2000 年。大肠杆菌 O78:H10 是克隆异质性的，由一个主要的克隆群（包括所有 19 个爆发分离株）组成，其 ST10（系统发育组 A）加上几个较小的克隆群（系统发育组 A 和 D）。所有 ST10 分离株，而非 ST10 分离株的 25%，通过分子方法被鉴定为肠聚集性大肠杆菌（EAEC）（P<0.001）。在>90%的爆发分离株中存在的基因包括 fimH（1 型菌毛；大肠杆菌中普遍存在）；fyuA、traT 和 iutA（与肠外致病性大肠杆菌 [ExPEC] 相关）；以及 sat、pic、aatA、aggR、aggA、ORF61、aaiC、aap 和 ORF3（与 EAEC 相关）。一个爆发分离株在小鼠皮下脓毒症模型中具有致死性，并表现出特征性的 EAEC“堆积砖”粘附于培养的上皮细胞。因此，1991 年哥本哈根的爆发是由广泛传播的 O78:H10 克隆群（ST10；系统发育组 A）内一个紧密的、非动物相关的亚群引起的，该亚群的成员具有 ExPEC 和 EAEC 的特征，而 O78:H10 分离株总体上具有不同的系统发育多样性。ST10 O78:H10 EAEC 菌株是否同时具有尿路致病性和腹泻性，需要进一步研究。
