Abstract: According to the published Stenotrophomnas maltophilia 16S rDNA gene sequences in NCBI, we designed a pair of primers. Two suspected Stenotrophomnas maltophilia strains (PSM-5, PSM-6) were amplified by PCR using the primer. The PCR products were cloned into pMD18-T vectors and transformed into competent cell DH5α. The recombinant plasmid was identified by PCR and restriction enzyme and then sequenced,identifying from the molecular level. The nucleotide identity of 16S rDNA gene (GQ267816, GQ267817） amplified from PSM-5 or PSM-6 strain was of above 96.79%, up to 99.93% compared to those of the Stenotrophomonas maltophilia, found in the GenBank, which were isolated from different environment. The experiment provides a reference to identify the Stenotrophomonas maltophilia via the 16S rDNA gene, while it lays the foundation of bacteriology for the diagnosis and treatment of the swine high fever, and it makes further discussion of the pathogenesis as well.

Key words: swine high fever; Stenotrophomonas maltophilia strain; 16S rDNA; gene cloning; molecular identification