ABSTRACT
OBJECTIVE Through investigation of the changes in biological characteristics of an E scherichia coli bacteriophage with broad host range,to study the mechanism of phage-host specificity and the bactericidal efficacy on sewage water samples.METHODS In this study,one strain of E.coli bacteriophages with broad host range was screened from natural environment using the E.coli 285.Then,in order to analyze the difference of biologic effects before and after the host range changed,we made a comparison of biological properties between the phage with broad host range and the phage f2.RESULTS The ultrastructure under electron microscope showed that the two phages were round-shaped particles,but phage XY′s diameter between 20-90 nm,short-tailed and occasionally visible;the anti-serum K value of phages f2 and XY was 30.1 and 41.5,respectively;whereas,between phages XY and f2,there was a low correlativity(K value