Molecular and Genetic Characterization of Colicinogenic <i>Escherichia coli</i> Strains Active against Shiga Toxin-Producing <i>Escherichia coli</i> O157:H7
Mauro D. García,
María J. Ruiz,
Luis M. Medina,
Roberto Vidal,
Nora L. Padola,
Analía I. Etcheverria
Affiliations
Mauro D. García
Laboratorio de Inmunoquímica y Biotecnología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET, CICPBA, Facultad de Ciencias Veterinarias, UNICEN-Campus Universitario, Tandil B7000, Argentina
María J. Ruiz
Laboratorio de Inmunoquímica y Biotecnología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET, CICPBA, Facultad de Ciencias Veterinarias, UNICEN-Campus Universitario, Tandil B7000, Argentina
Luis M. Medina
Food Science and Technology Department, Faculty of Veterinary Medicine, Universidad de Cordoba, 14071 Córdoba, Spain
Roberto Vidal
Instituto de Ciencias biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
Nora L. Padola
Laboratorio de Inmunoquímica y Biotecnología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET, CICPBA, Facultad de Ciencias Veterinarias, UNICEN-Campus Universitario, Tandil B7000, Argentina
Analía I. Etcheverria
Laboratorio de Inmunoquímica y Biotecnología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET, CICPBA, Facultad de Ciencias Veterinarias, UNICEN-Campus Universitario, Tandil B7000, Argentina
The objective of this work was to molecularly and genotypically characterize and test the inhibitory activity of six colicinogenic Escherichia coli strains (ColEc) and their partially purified colicins against STEC O157:H7 isolated from clinical human cases. Inhibition tests demonstrated the activity of these strains and their colicins against STEC O157:H7. By PCR it was possible to detect colicins Ia, E7, and B and microcins M, H47, C7, and J25. By genome sequencing of two selected ColEc strains, it was possible to identify additional colicins such as E1 and Ib. No genes coding for stx1 and stx2 were detected after analyzing the genome sequence. The inhibitory activity of ColEc against STEC O157:H7 used as an indicator showed that colicins are potent growth inhibitors of E. coli O157:H7, being a potential alternative to reduce the presence of pathogens of public health relevance.
