bacteriophages targeting multidrug- resistant pathogens_partB

We identified six unique bacteriophages active against a broad range of clinical isolates of E. coli and Shigella spp. and evaluated their host ranges against 270 pathogenic E. coli and 26 Shigella spp. isolates. Phage lysis was assessed using double-layer plate tests and growth curve kinetics. Most bacterial isolates were susceptible to at least one phage, with only 2.7% (8/297) resistant to all six. Phage FM10 was the most effective against E. coli, lysing 88.5% of isolates, while LF2 demonstrated the highest efficacy against Shigella spp., lysing 96% of isolates, followed by DP16. LF2 and DP16 inhibited the growth of multidrug-resistant Shigella spp. isolates in 72 hours, either alone or in combination. Whole genome sequencing and transmission electron microscopy revealed all six phages belonged to the Straboviridae family, with no pathogenicity or lysogenic genes identified. Phages with broad host ranges capable of lysing both E. coli and Shigella spp. clinical isolates offer a promising tool for addressing antibiotic-resistant infections and overcoming limitations in phage therapy.