Molecular and Genetic Characterization of Colicinogenic Escherichia coli Strains Active against Shiga Toxin-Producing Escherichia coli O157:H7

GARCÍA, MAURO D.; RUIZ, MARÍA J.; MEDINA, LUIS M.; VIDAL, ROBERTO; PADOLA, NORA L.; ETCHEVERRIA, ANALÍA I.

Foods

MDPI

Lugar: Basel; Año: 2023 vol. 12

Abstract: The objective of this work was to molecularly and genotypically characterize and testthe inhibitory activity of six colicinogenic Escherichia coli strains (ColEc) and their partially purifiedcolicins against STEC O157:H7 isolated from clinical human cases. Inhibition tests demonstrated theactivity of these strains and their colicins against STEC O157:H7. By PCR it was possible to detectcolicins Ia, E7, and B and microcins M, H47, C7, and J25. By genome sequencing of two selectedColEc strains, it was possible to identify additional colicins such as E1 and Ib. No genes coding forstx1 and stx2 were detected after analyzing the genome sequence. The inhibitory activity of ColEcagainst STEC O157:H7 used as an indicator showed that colicins are potent growth inhibitors of E. coliO157:H7, being a potential alternative to reduce the presence of pathogens of public health relevance.