Development of phage cocktail for controlling colistin-resistant Escherichia coli harboring mcr-1 and its biofilm formation in retail raw chicken

Abstract

The rise and dissemination of colistin-resistant Escherichia coli harboring mcr-1 has become a global health threat. Bacteriophage (Phage) has been considered as an alternative to antibiotics in the treatment of antibiotic-resistant bacteria. Here, we report the effective control of colistin-resistant Escherichia coli harboring mcr-1 in retail raw chicken using a phage cocktail. Three novel phages, named HEMP1, HEMP4, and HEMP5, were isolated from environmental samples using E. coli harboring mcr-1 as host bacteria. Morphological and genomic analysis revealed that HEMP1 and HEMP5 have Myovirus-like morphology, while HEMP4 has Podovirus-like morphology, without any known genes associated with lysogeny and virulence. These phages exhibited high stability across wide temperatures and pH levels and showed rapid adsorption to their host strain. The phage cocktail, composed of three phages, effectively suppressed the growth and controlled biofilm formation of E. coli harboring mcr-1. Moreover, the phage cocktail significantly inhibited the growth of the bacteria on chicken meat at room (25°C) and refrigeration (4°C) temperatures. These results indicate that the phage cocktail could serve as a biological control method for colistin-resistant E. coli strains harboring mcr-1 in the food industry.