Isolation And Identification Of Pathogen Of Swine Atrophic Rhinitis In Guizhou Province

Atrophic rhinitis is a chronic respiratory tract infectious disease of swine characterised by chronic rhinitis, snout deformation, atrophy of the nasal turbinate bones and reduced productivity, which is mainly caused by Bordetella bronchiseptica and /or Pasteurella multocida. AR belongs to B kind disease defined by Office International Epizooties (OIE) and a check item ruled by export and import animal sanitation test standard. According to the Livestock and Poultry Loimia History in Guizhou, there was no record about AR. However, in recent years, along with livestock breeding enlargement fast and mode of production development towards farming concentration and enlarged scale, with introduction from home and abroad again and again and frequent flow of livestock and poultry in the Guizhou province, the borderline cases like AR occurred some pig farms in Guiyang city, In order to know about epidemic condition in Guiyang pig herds, to make diagnose definitely about borderline cases, to trace infection sources of disease, we undertook epidemiological investigation and isolation and identification of pathogen in 11 pig herds during June, 2003 and July, 2006. The gained achievements of the research were as following:1. The research results made diagnose definitely about atrophic rhinitis in Guizhou province in three aspects that epidemiology, serology and bacteriology for the first time.2. In reseached 11 pig farms, there were typical symptom of AR in 6 pig farms, the average clinical morbility was 2.78%. It was no significant changes in blood routine index of sick swine. Adopting to latex agglutination diagnostic reagent detecting serum samples of different age pig herds, the results indicated serum antibody positive incidence was 42.8%(12/28) on average. On the basis of shape and atrophy pathological changes of turbinate bone, 4 types were divided in 17 dissected sick swine.3. 156 samples from nasal cavity secretion or lung of the swine, were used by bacteriology detection. The results showed that 39(25.0%) strains of Bordetella bronchiseptica and 13(8.3%) strains of Pasteurella multocida. There were 3 pig farms isolating Bb and Pm, which belong to PAR, the others isolating Bb only, which belong to NPAR, any bacteriria was no found in the rest farms. Meanwhile, every isolate was then studied on sentivity to antibiotics, which offered guide for productive practice.4. 13 strains of P.multocida were identified in subspecies, 6 strains were P.multocida Subsp. multocida, accounted for 46.2% (6/13), 7 strains were P. multocida Subsp. septica, accounted for 53.8% (7/13). P.multocida Subsp. gallicida was no found.5. 13 strains of Pm were isolated from pig herds showing clinical symptoms of atrophic rhinitis. The PCR assay was conducted with Pm species specific primers (KMT₁-KMT₂) and the results were in accordance with the identification of traditional biochemical reaction. No DNA fragment was amplified from other bacteria, which were common in nasal cavity and lung tissue of pig.The capsular PCR typing indicated that 8 strains were serotype A, accounted for 61.5%; 5 strains were serotype D, accounted for 38.5%; serotype B strain was not found.