Identification and biological properties of a methicillin-resistant Staphylococcus aureus phage qdsa002

In order to develop an effective bio- controlling method against methicillin- resistant Staphylococcus aureus,one phage qdsa002 was isolated from sewage water gathered from Tuandao sewage treatment plant of Qingdao. Bacteriophage was identified by plaque shapes,restriction endonucleases analysis,electronic microscope technique.The physiological characteristics of the optimum MOI value,the growth curve,the p H value and the thermal stability were assayed.Results showed that the phage qdsa002 had linear double stand DNA and regular polyhedron symmetric head. The qdsa002 had a head of about 47 nm in diameter and tails of 120 nm,belonging to family Siphoviridae. The physiological characteristics showed plaques with transparent center in double agar plate.The optimum MOI value of qdsa002 was 0.001,one- step growth experiment showed that the latent time and burst time were 40 min and 180 min,respectively.The qdsa002 was stable over a wide range of p H( 5~9) and temperature( ≤50 ℃).The phage can be used in the prevention and treatment of MRSA infection.