Isolation and characterization of a novel Escherichia phage phiEco273 and its efficacy as an antibiofilm agent.

In recent years, Escherichia coli is frequently associated with food borne infections causing colibacillosis in both food animals and humans. Therefore, to secure a safe and healthy foods, there is a need of an alternative strategy. Bacteriophages due to their ability serve as a promising strategy for combating drug-resistant bacteria. In this study, a lytic Escherichia phage phiEco273 was isolated from a pond water sample targeting multidrug-resistant strain of E. coli. Escherichia phage phiEco273 showed lytic activity against 13/50 tested strains of E. coli of animal origin. Escherichia phage phiEco273 exhibit activity in acidic environment (pH3) and elevated temperature (70 °C). Escherichia phage phiEco273 is classified as the member of class Caudoviricetes based on their Electron micrograph and genome analysis. The Genome of Escherichia phage phiEco273 is 44.7 kb in size with 54.4 % GC content. Genome analysis predicted 59 open reading frames (ORFs), which were subsequently assigned to four functional categories based on their annotations: nucleotide regulation, structural, proteins involved in lysis mechanisms, and hypothetical proteins. Escherichia phage phiEco273 also eradicated the biofilm developed by the VTCCBAA252 bacterium on glass surface. Despite the narrow host range of Escherichia phage phiEco273, it could serve as a good candidate for targeting biofilm forming multidrug resistant bacteria. Also, the presence of a unique tail fiber domain containing protein distinct it from other known Dhillinovirus. However, further investigations required to clearly find out how the presence of CD35 affect the host range and infectivity of bacteriophage phiEco273, which might be helpful in enhancing the therapeutic potential of phiEco273.