From more than ten provinces and cities in China, 32 strains of Haemophilus parasuis were isolated from swines which characterized by polyserositis and fibrinopurulent polyarthritis, based on morphologic characteristics, cultural characteristics and biochemical characteristics of Haemophilus parasuis . According to the sequence of bacterium's 16S rRNA, a PCR test to diagnose Haemophilus parasuis was developed, and it was used to identify the isolations. The 822 bp amplicon was cloned into a T-vector a...