Research On The Haemophilus Parasuis’s Drug Resistance And Corss-infection With PCV2 And PRRSV In Sichuan Province

Haemophillus parasuis is the pathogen of Glasser’s Disease, which causes serious illness in the weaned pigs by fibrinous polyserositis, arthritis and meningitis and leds to heavy economic loss. In this study, clinical samples were used to research on bacterial isolation and identification of Haemophilus parasuis, which were collected from Sichuan province. And make research on the Haemophilus parasuis’s drug resistance and cross-infection with PCV2 and PRRSV in Sichuan Province. The main results are as follows:1.The results of drug resistance and bacterial isolation of HPSFrom 2014 February to November,232 clinical samples were collected from 23 districts of Sichuan province which had suspected pathology damage with HPS disease. Total 48 strains of HPS were successfully isolated, and all isolates had positive results through Gram staining, biochemical identification, PCR identification. Selecting 7 HPS stains to compare with 16SrRNA gen, the homology of 16SrRNA’ sequences are at high level, which is more than 95.9%, when compare it to those from GenBank.Research on the 48 stains of Haemophilus parasuis’s drug resistance, most of the isolates were susceptible to florfenicol, cefotaxime, ceftriaxone, doxycycline and rifampin, and had severely resistance to cotrimoxazole, lincomycin, penicillin, ampicillin, gentamicin, amikacin, amoxicillin. And none of them have same drug resistance. While different stains from the same piggery keep the same resistance basically. The drug resistance of Haemophilus parasuis isolated from Sichuan province is normally higher than other areas in China.2. Investigate on the cross-infection of HPS and PCV2、PRRSVUsing PCR and RT-PCR diagnostic techniques to respectively detect PCV2 and PRRSV, the results show that:The overall positive rate of HPS and PCV2 in Sichuan Province in pigs was 64.6%, and the positive rate of HPS and PRRSV was 58.3%. Making investigation on the cross-infection of HPS and PCV2、PRRSV, and which results show that the positive rate was 29.1%.This research mainly collected serum samples of weaned pigs from Sichuan area in the year of 2014. Through making antibodies test to the serum samples by Enzyme Linked Immunosorbent Assay (ELISA). The results showed that the positive rate of Haemophilus parasuis antibody reached to 64.10%, and haemophilus parasuis spreads in all the sample areas of Sichuan province, and which reflects that none of the commercialization of HPS vaccine immunization. The results showed that the PCV2’s antibody positive rate was 42.06%. And the positive rate of PRRS’ antibody was 36.67%. HPS and PCV2 antibody cross-positive rate was 30.83%. HPS and PRRSV cross-positive rate of antibody was 30%. HPS. PCV2 and PRRSV’s antibody cross-positive rate was 29.12%.