| Streptococcus Suis (SS) has35serotypes, in which, SS serotype2(SS2) is widespread and can infect human beings, and is regarded as an important zoonosis pathogen both for human beings and animals. Swine streptococcosis caused by SS2is diverging or endemic, with high disease rate and mortality, and has a severe impact on swine production.Isolation of the pathogen is an important precondition for diagnosis and prevention of the disease and for epidemiological investigation. At present bacterial isolation depends on the direct inoculation of the suspected samples to the normal THB. The selective medium was used to improve the isolation efficiency. However, the vulnerability of actinobacillus pleuropneumoniae, which reduces the number of live pathogen in the samples, limits the traditional methods. And also it is difficult to isolation the SS2when its’concentration is very low in the system. Therefore, it will be much easier for the isolation of SS2if we can highten the comcentration of SS2in the system and for the further study on SS2. So the study to develope a novel method to improve the bacterial isolation will contribute to the research on this disease and set up an exemplary for the isolation on other disease.Immunomagnetic bead technique has becoming a new popular immunological technology in recent years. It possesses a lot of advantages of solid reagen, such as good specificity, rapidness, highly efficacy, and repeatability. It is also a cost-effective method due to no requirement of expensive instruments during the detection. These merits contribute to its wider application in the fields of lmmunodetectlon, immunoadsorption, cell detachment, cultivation and so on.In this experiment, the rabbit polyclonal antibody against Streptococcus Suis type2was produced by using the nactivated vaccine. The purified polyclonal antibody was used for coating the magnetic beads, which was called SS2-IMB. The optimal concentration of the polyclonal antibody and the time for coating magnetic beads were determined. Also the procession for the isolation of SS2was developed. The analytical sensitivity of the assay was100times higher than regular isolation mathods. This technique could also isolated SS2from the liver of artificial infected mice. Finally, clinical samples were tested by this technique and one suspected SS2was isolated and then it was identified to be SS2by treble PCR. These results indicated the establishment of SS2-IMB technique can be used to detect and isolate SS2. |
