Newly isolated coliphages for bio-controlling multidrug-resistant Escherichia coli strains

• Coliphages isolated from Rosetta branch of River Nile and associated drains outlets. • Coliphages exhibited a wide host range pattern against wild E. coli strains. • Coliphages cocktail controlled the growth of wild MDR E. coli strains and coliforms. • Total and fecal coliforms load revealed a reduction post-treatment with coliphages. • Coliphages-treated wastewater showed reducing levels in physiochemical properties. This study presents a novel coliphage-based approach for biocontrol of Multidrug-Resistant (MDR) Escherichia coli ( E. coli ) and coliforms in wastewater and improve the physicochemical water quality . Newly isolated coliphages and E. coli strains were isolated from the Rosetta branch of River Nile and outlet points of five associated drains. Coliphages were characterized by transmission electron microscopy and coat protein-gene analyses. The isolated coliphages PR01, PR02, and PR03 belonged to the Siphoviridae , Myoviridae, and Podoviridae families, respectively. They exhibited, separately or in a cocktail, a wide host range pattern against wild E. coli strains with higher specificity to strains isolated from drains (87%) than those of the Rosetta branch (72%). Phage-sensitive E. coli strains exhibited elevated antibiotics resistance patterns, suggesting that they are MDR strains. Interestingly, the efficacy of phages cocktail (PR01/PR02/PR03) controlled the growth of wild MDR E. coli strains and coliform populations under laboratories conditions. The kinetic trend in removal efficiency (%) for coliforms was gradually increasing in a time-dependent manner and peaked at 12 h post incubation with phages mixture. In all water samples, total and fecal coliforms revealed at least a 30-fold reduction post 12 h of treatment with a mixture of coliphages. Physicochemical analyses of phage-treated wastewater showed reducing levels in biological oxygen demand (BOD), chemical oxygen demand (COD), turbidity, electric conductivity (EC), ammonia (NH 3 ), total dissolved solids (TDS) and nitrate (NO3), while rising in dissolved oxygen (DO) content compared to untreated wastewater. Overall, this study suggests that phage-based treatment could be an effective and cheap alternative approach for the reduction of water pollutants in drainage drainage and waste water and thus eventually enhance the physicochemical quality of water.