The Study Of Bordetella Avium Biology Character And The Exploration Of Serotyping

Bordetalla avium has been studied rather intimately now, but low in the aspect of serotyping, and their cross infection and the pathogenicity's difference among kinds of serotyping were unknown, so we can't prevent and cure them overall. All these caused the widespread of Bordetalla avium in every place domestic and foreign and resuled in a severe economic loss to the poultry raising business. A systematic serotyping method was urgently needed so as to type the isolates quickly and precisely. Antiserum was prepared by the strains of the Bordetella avium. And then I and II mono-specific antisera had been acquired by cross absorption test. Further investigations indicated that the serotype of the isolates of Bordetella avium all belonged to serotype I and serotype II identified by using the two mono-specific antisera.Part One:The study of Bordetella isolate's molecular biology character2009, the chick embryo of large scale farm in Shandong were caused to death, low hatchability and chicken's death suddenly. The main symptom was ophthalmitis and nasosinusitis with eyelid swelling, much off-white chessy material or gray in eye's conjunctiva and accessory nasal cavity, mucous hyperemia, anabrosis. After the epidemiological investigation, the disease incidence was 30%, the mortality was 5%-30%. Most of the sick chickens show growth retardation, low feed conversion resulted in great economic losses. Two suspected strains were isolated from the chick embryo, The morphological, cultural, biochemical, serological characters indicate the isolates are Bordetella avium which is gram-negative small bacilli without spores. We designed a pair of primers referred to Genbank, the EcoRâ… , Pstâ… sites were designed in. After sequencing we compared the difference of 23 SrRNA amplication. We analysis and compare the sequencing result in the GenBank database, and found that the homology of gene sequence of 23SrRNA from the isolated strains with the corrensponding parts of Bordtella avium 167904 recored in GenBank was higher, which was 92.4%.Part Two:The preparation and application of mono-specific serum of Bordetella aviumIn this test, the 14 Bordetella strains of the bacteria were prepared for the corresponding immunogen, and immune 1Kg healthy rabbits. At last we get the blood to produce antibodies. 14 anti-serum titer determination are concentrated in 1:4800 ~ 1:3200. We get the mono-specific serum named type I and type II by using cross-absorption test, the two single-factor titer was 1:800 and 1:1024, respectively. Different serotypes of single-factor and other serum does not agglutinate serotype strains. Further investigations indicated that the serotype of the isolates of Bordetella avium in our laboratory belonged to serotype I and serotype II identified by using the two mono-specific serum. And the result indicated that these mono-specific serum can be used in serotyping. This study was setting a foundation for carrying on the serotyping system further, and the differences of the pathogenic among kinds of serum, understood the molecular biology character of the main strains and found out the pathogenesis and immunologic mechanism of Bordtella avium.