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Pigs exudative dermatitis is a suckling piglets and weanling piglets acute or hyperacute contagious disease caused by Staphylococcus sick piglets is the main clinical features the exudative, fever, dehydration and death, with The rapid spread and high mortality. The disease seriously affect the growth and development of the piglet, causing large economic losses to the aquaculture industry in China. This study for the South China surrounding areas suspected of suffering from exudative dermatitis of pigs Staphylococcus Isolation, identification and classification; shedding toxin gene PCR detection method by detection of toxin genes screened seven pigs aureus shedding ; identified EXHC gene cloning and expression. By microscopic examination, biochemical identification preliminary separation to 16 aureus; animal pathogenic trials, pigs aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus squirrel source aureus, chromogenic aureus test mice mortality were: 100%, 83.3%, 66.7%, 100%, 16.7%, and Staphylococcus simulans Coriolis aureus experimental group there is no death of the individual; susceptibility testing of these strains to cephalosporins, novobiocin highly sensitive to antibiotics such as penicillin antibiotics resistance. Reference aureus Gap (glyceraldehyde-3-phosphate dehydrogenases glyceraldehyde - Three-phosphate dehydrogenase) and 16S rRNA gene universal primers preliminary identification of 16 staphylococcal gene cloning and sequence analysis. Gap Clone sequencing results on NCBI Blast analysis of the isolated 16 strains can be classified as Staphylococcus hyicus, Staphylococcus epidermidis, Staphylococcus chromogenes, Staphylococcus simulans is, was Staphylococcus sciuri, was Staphylococcus cohnii, Staphylococcus haemolyticus, its homology to 100% , 99%, 93%, 100%, 98%, 96%, 99%, isolated above 7 strains with different subspecies between the homology of 75.6 to 99%. 16S rRNA gene clone and sequence alignment analysis shows no obvious differences between different subspecies of Staphylococcus nucleotide homology of 92% or more. 3, using the established PCR method on the separation of seven swine aureus shedding detection of the toxin gene. The results show SHETA the detection rate of 100%; EXHA detection rate was 28.7%; EXHC EXHB the detection rate were 14.3%. Of separate GDZC strains Gap gene cloning and sequence analysis, and the EXHC gene cloning and expression. The results showed that the strains Gap gene with Genbank the published pig aureus (AF495492) strains nucleotide homology of 99%; published on EXHC gene with Genbank Danish isolates (AF515455) nucleotide sequence homology as 100%. EXHC gene into pET-28a () vector after digestion and sequencing analysis successfully constructed pET-28a ()-EXHC prokaryotic expression vector.
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