Abstract: In order to provide a scientific prevention and treatment of Haemophilus parasuis (Hps) disease in pig farms of the Tianjin area, pigs with suspected Haemophilus parasuis disease were anatomized and observed pathological changes.The most common results were cellulose pleurisy and peritonitis, and there were more yellow viscous liquid in joint cavity section.The bacteria were isolated from 36 diseased pig swine organs which were suspected of Hps, and 9 strains of Hps were obtained through staining, satellite test, catalase reaction test, biochemical reaction and PCR.The 9 strains of Hps showed multi morphology and gram negative through staining; Satellite phenomenon was significant; All of the catalase reaction test were positive; D-ribose, sorbitol, fructose, arabinose and hydrogen sulfide of micro biochemical reaction were negative, but maltose, glucose, sucrose, mannitol and urease were positive, only 1 of 9 strains was positive sorbitol and xylose of micro biochemical reaction, 5 strains were positive for beta galactose;PCR result showed an objective fragments of 822 bp.The separation rate was 25%.The drug screening were done with 16 kinds of antimicrobial agents against 9 strains of Hps, drug sensitivity results showed that ceftriaxone sodium and levofloxacin had good antibacterial effects.The results of this study could provide the basis for prevention and control of Hps disease in Tianjin.

Key words: Haemophilus parasuis; isolation; identification; drug screening