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Updated: May 17, 2026

Characterization of a Pathogenic Escherichia coli Strain Derived from Oreochromis spp. Farms Using Whole-Genome Sequencing
Published on: December 23, 2022
Occurrence and structure of cyclic Enterobacterial Common Antigen in Escherichia coli O157:H⁻
Eleonora Fregolino1, Radka Ivanova, Rosa Lanzetta
1Università di Napoli Federico II, Dipartimento di Scienze Chimiche, Complesso Universitario Monte Sant'Angelo, Via Cintia 4, 80126 Napoli, Italy.
Abstract:
Two cyclic forms of the Enterobacterial Common Antigen were isolated from Escherichia coli O157:H(-). These antigenic determinants were purified from the biomass through extensive chemical, enzymatic and chromatographic procedures whereas MALDI MS spectrometry indicated their cyclic nature with a polymerization degree of 4 or 5. The two species, denoted as ECA(CYC-4) and ECA(CYC-5), were assigned by NMR and showed no further substitution with other appendages such as acetyl groups as usually described for similar cyclic antigens from other Enterobacteriaceae.
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