PROVE DI LISOGENIA CON VIRUS BATTERIOFAGI VETTORI DEL GENE STX2 IN CEPPI ENTEROPATOGENI DI ESCHERICHIA COLI ISOLATI DA ALIMENTI

Lambda(λ)-phages can be vector of gene codifying for synthesis of Shiga-toxins and are suspected to be involved in the virulence evolution of Vero-Toxin producing Escherichia coli. They can induce lysogenic cycles only in few strain of Escherichia coli that allow integration of sequences of phages in proximity of the RHO bacterial gene. The integration of Stx2 gene in enteropathogenic strains of Escherichia coli, which also have genes for the production of adhesion factors, give rise to new recombinant strains that can be pathogenic to humans. Our research was aimed at verify if enteropathogenic strains of Escherichia coli O157 or O26 isolated from milk, who were eae positive, but Stx negative, can be lysogenized by Stx2 phages.