Experimental protection of ESBL producing Salmonella typhi bacteremic induced mice model by GRCST; a therapeutic approach

Salmonella typhi specific bacteriophage i.e. phi GRCST exhibited potential bacteriolytic activity against n=4, ESBL producing S. typhi isolates in vitro. The phi GRCST possesses an icosahedral head with 50 nm size and contractile tail belongs to Myoviridae Vi01-like family. The experimental outcome of in vivo studies in BALB/c mice induced with S. typhi bacteraemia treated with 1.5x10(7) PFU phi GRCST showed 100% survival with zero causality was recorded. On contrary, only 67% and 83% survival rate was observed in the group of mice which received standard antibiotic ciprofloxacin. The IgG and IgM titres of anti-phage GRCST antibodies were detected, with increased 4100 fold, 600 fold respectively. This result demonstrates that the antibodies elicited by phi GRCST are non-neutralizing.