In vitro effect of newly bacteriophages isolates against escherichia coli serogroups collected from the local hospital laboratory; their specific characterization and identification

Anotace: The aim of this study is to isolate a new bacteriophage with lytic effect against several serogroups of Escherichia coli that were isolated from different samples submitted to the local hospital laboratory. These serogroups are the main causative agents of bloodstream and urinary tract infections (UTIs) among Gram-negative bacteria. Three isolates of E. coli were used as a host to isolate phages from a hospital wastewater treatment plant. Eight phages were isolated and only three of them (EC-BSR1, EC-BSR2, and EC-BSR3) were considered for further characterization and identification. The three phages appear to belong to Myoviridae characterized by icosahedral heads, necks and contractile tails with tail fibers. Phage EC-BSR1 and EC-BSR2 had genome sizes of 67.06 and 68.04 kb, respectively. All three phages were lysed 100% of E. coli serogroups that was tested in vitro and 42.7%, 61.7% and 44.7% in vitro lyses of ECOR collection reference. Phages were resistant to pH from 5 to 9, and phage EC-BSR3 appeared to be more resistant than the other two phages to an acidic and alkaline environment. These phages have the pattern of homologous DNA fragments after being digested with Acc1 and EcoR1 restriction enzymes. It was concluded that these phages are highly coli lytic for the E. coli serogroups isolates.