Inhibition of clinical isolates of VTEC by colicinogenic strains of Escherichia coli

Abstract

Verotoxigenic Escherichia coli (VTEC), in particularserotype O157:H7, is responsible for producingdiarrhea, hemorrhagic colitis and hemolytic uremicsyndrome (HUS), Argentina has the highest globalincidence of the latter. Currently, new tools for controland prevention of strains associated with HUS arebeing sought. It has been observed that strains ofE.coli are capable of inhibiting the growth ofpathogenic strains (including serotype O157:H7) byproducing antibacterial peptides called bacteriocins,which are active against strains of the same or relatedspecies. In E.coli, they are classified by high and lowmolecular weight and called colicins and microcinsrespectively. These strains are potential probiotics andsources of new purifable antimicrobial compounds foruse against pathogensVerotoxigenic Escherichia coli (VTEC), in particularserotype O157:H7, is responsible for producingdiarrhea, hemorrhagic colitis and hemolytic uremicsyndrome (HUS), Argentina has the highest globalincidence of the latter. Currently, new tools for controland prevention of strains associated with HUS arebeing sought. It has been observed that strains ofE.coli are capable of inhibiting the growth ofpathogenic strains (including serotype O157:H7) byproducing antibacterial peptides called bacteriocins,which are active against strains of the same or relatedspecies. In E.coli, they are classified by high and lowmolecular weight and called colicins and microcinsrespectively. These strains are potential probiotics andsources of new purifable antimicrobial compounds foruse against pathogensFrom 60 VTEC strains, 59 wereinhibited by at least onecolicinogenic strain and 46 wereinhibited by all of them, only oneVTEC wasn?t inhibited by thecolicinogenic strains.The results obtained contribute in the search for new antibacterial compounds that allow to face thepresent limitations for the use of antibiotics in the food industry, as well as in public health, mainlydue to the appearance of resistant strains. The use of probiotic bacteria or their metabolites is aviable option to respond to this problem.