Genomic sequence analysis reveals new bacteriophage genome JH2

Abstract

In this study, an E. coli phage JH2 was isolated from swine feces on an industrial farm. Bacteriophage JH2 could carry 85% (n = 32) O8 ETEC (Enterotoxigenic Escherichia coli) strains when 81 alike-strains from Vietnam and China were tested. The genome size could be as large as JH2 had 77187 bps, a linear, double-stranded and CG = 38.89%. It shared a height similarity of 94.9% to Staphylococcus phage SA1 of GU169904 with 147303 bps, which is about double the size. JH2 carried 22 tRNA and no gene for known toxins. Under the electronic microscope the phage presented icosahedral heads, necks, contractile and long tails, and it belonged to the Myoviridae family. The phage demonstrated high stability to the physical and chemical factors, thermal sensitivity at 60 °C and acid and alkaline resistance (pH = 5-9). The genome of JH2 contained 131 putative open reading frames (ORFs). One hundred and twenty-six ORFs (out of 131) were predicted and 121 ORFs had putative functions. From database, 22 tRNAs were predicted in the JH2 genome. Staphylococcus phage SA1 contains an almost complete phage genome of JH2 phage. The complete genome sequence of JH2 was analyzed. Comparing the complete genome sequences of JH2 and Staphylococcus phage SA1 showed 94.9% similarity.