Abstract Phenotypic, chemotaxonomic and genotypic data from 12 strains of Escherichia coli were collected, including carbon source utilisation profiles, ribotypes, sequencing data of the 16S–23S rRNA internal transcribed region (ITS) and Fourier transform-infrared (FT-IR) spectroscopic profiles. The objectives were to compare several identification systems for E. coli and to develop and test a polyphasic taxonomic approach using the four methodologies combined for the sub-typing of O157 and non-O157 E. coli. The nucleotide sequences of the 16S–23S rRNA ITS regions were amplified by polymerase chain reaction (PCR), sequenced and compared with reference data available at the GenBank database using the Basic Local Alignment Search Tool (BLAST) . Additional information comprising the utilisation of carbon sources, riboprint profiles and FT-IR spectra was also collected. The capacity of the methods for the identification and typing of E. coli to species and subspecies levels was evaluated. Data were transformed and integrated to present polyphasic hierarchical clusters and relationships. The study reports the use of an integrated scheme comprising phenotypic, chemotaxonomic and genotypic information (carbon source profile, sequencing of the 16S–23S rRNA ITS, ribotyping and FT-IR spectroscopy) for a more precise characterisation and identification of E. coli. The results showed that identification of E. coli strains by each individual method was limited mainly by the extension and quality of reference databases. On the contrary, the polyphasic approach, whereby heterogeneous taxonomic data were combined and weighted, improved the identification results, gave more consistency to the final clustering and provided additional information on the taxonomic structure and phenotypic behaviour of strains, as shown by the close clustering of strains with similar stress resistance patterns.

中文翻译：

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O157 和非 O157 大肠杆菌血清型的鉴定和分型方法的比较及其与多相分类方法的整合

摘要 收集了 12 株大肠杆菌的表型、化学分类和基因型数据，包括碳源利用概况、核糖型、16S-23S rRNA 内部转录区 (ITS) 和傅里叶变换红外 (FT-IR) 光谱图谱的测序数据。 . 目的是比较几种大肠杆菌的识别系统，并使用四种方法组合用于 O157 和非 O157 大肠杆菌的亚型，开发和测试多相分类方法。16S-23S rRNA ITS 区域的核苷酸序列通过聚合酶链反应 (PCR) 进行扩增、测序并使用基本局部比对搜索工具 (BLAST) 与 GenBank 数据库中可用的参考数据进行比较。包括碳源利用在内的其他信息，还收集了核糖体图谱和 FT-IR 光谱。评估了将大肠杆菌鉴定和分型到物种和亚种水平的方法的能力。数据被转换和整合以呈现多相层次聚类和关系。该研究报告了使用包含表型、化学分类学和基因型信息（碳源概况、16S-23S rRNA ITS 测序、核糖体分型和 FT-IR 光谱）的综合方案来更精确地表征和鉴定大肠杆菌。结果表明，通过每种方法鉴定大肠杆菌菌株主要受参考数据库的扩展和质量的限制。相反，多相方法将异构分类数据组合并加权，提高了识别结果，