Abstract: The PCR assay and PCR-RFLP were applied to study the function of aroA gene on the detection and genotyping of Haemophilus parasuis. 18 strains of Haemophilus parasuis isolated from swine in Guangxi were detected successfully by using the PCR assay with primers targeted to aroA gene, and the sensitive test showed that the lowest amount of Hps detectable by this PCR-based test was 10². The aroA gene of the 18 strains was sequenced, and enzyme restriction analysis of the aroA sequences available was performed to define which restriction enzymes more practical. HindⅢ and FokⅠ were chosen to do RFLP analysis in all 18 Haemophilus parasuis strains and one reference strain. The result of the analysis showed that there were three patterns among the groups. The study suggests that the PCR assay and PCR-RFLP applied to detection and genotyping are useful to further research the biological characteristics and gene function of Haemophilus parasuis.

Key words: Haemophilus parasuis; pathogen detection; PCR-RFLP