Isolation of Escherichia coli specific Lytic Phages from Waste Water and evaluation of its antimicrobial effect In Vitro and Chicken meat

Nowadays due to the harmfulness of chemical preservatives, the use of natural preservatives has increased. Bacteriophages are bacterial mandatory parasites that are harmless for human and animals and can, therefore, be used as appropriate antimicrobial agents in food. The aim of this study was to isolate the Escherichia coli lytic phage from wastewater, identify and evaluate its efficiency in controlling E. coli infection in chicken meat.

E. coli (PTCC: 1330) was obtained from Iranian Science and Technology Research organization. Phage isolated from the wastewater of Malayer dairy factory and its antimicrobial effect was investigated through plaque formation. TEM microscopy was used to observe the phage morphology and to determine its possible family. Host spectrum against 6 E. coli strains and its effect? against Salmonella enterica, Staphylococcus aureus and Yersinia enterocolitica were also evaluated .The effect of E. coli lytic phage on the amount of inoculated E. coli to contaminate the chicken meat was examined.

The isolated phage was tailless and had round capsid, possibly belonging to the Tectiviridae family. The target phage had antimicrobial activity against 5 selected E. coli strains, unlike the other genera tested. The effect of the phage on the E. coli contamination in chicken meat showed that the bacterial count was reduced from 3 log10   to 1.8 log10 after 24 h and reached less than 1 log cycle after 4 days.

The isolated phage had strong antimicrobial effect against E. coli. Therefore, it can be a good preservative candidate for use in foods.