Isolation and screening of Staphylococcus Aureus Phage

The phages of Staphylococcus aureus were isolated from the sewage and stool sample after two times enrichment with host strain.The isolated phage was purified using the two layer plates and was identified by plaque observation and the electron microscopy.The titer and RTD values of the purified phage were evaluated and the host range was preliminary analyzed.The results showed that the plaques of the sensitive phage of Staphylococcus aureus were formed transparent clear zones and their sizes were 1～2mm in diameter. The titer of phage was 3.2 × 1010 PFU /mL and the RTD value was 10-3 .Electron microscope observation showed that the phage had an isometric head ( 30nm in diameter) and a tail ( approximately 50nm in length) .The phage could lyse the host bacteria and other two Staphylococcus aureus, but not Escherichia coli, Salmonella typhimurium and shigella dysenteriae.These data enabled us to explore more properties of Staphylococcus aureus phage.It would be a good agent for detecting foodborne Staphylococcus aureus and an efficient antimicrobial source for Staphylococcus aureus infection.