[Classify species of Pseudomonas pseudomallei into serotypes]

Species of P. pseudomallei can be classified into two serotypes, serotype I and serotype II, based on whether or not it contains a thermolabile antigen beside a thermostable one. Under the condition of lack of typing serum, by means of serum absorption test, we recognized a strain which contains a major thermolabile antigen. The antigen was purified by Sephadex G-200, and it was used to inoculate rabbits. With the immunoserum at hand, we identified 68 of the domestic chinese strains and 6 of alien strains for serotyping by bi-directional agar diffusion test. The results showed that 68 strains were identified serotype I, 3 strains serotype II, and the remaining 3 comparable with those reported indicating that strains of serotype I were found mostly in Asia, and that the serotype are unrelated to their existing environments, nor that of animal bodies, but connected with their existence in geographic distribution.