Characterization Of The Virus Causing "Trembling Disease" In Eriocheior Sinesis

The virions were isolated from trembling crabs(Eriocheir sinensis). The same virions were recovered by artificial infection of purified virions from trembling crabs. The globose virions were about 150nm of diameter, with envelope and spikes, and the viral nucleic acid was single stranded by electron microscope(EM) observation. The electrophoretogram of the purified viral nucheic acid in 0.8% agarose showed only one band, with the size of about 15-16kb. The nucleic acid had the sensitivity to Rnase and Mung Bean Nuclease, but not sensitivity to Dnasel. The above data demonstrated that the nucleic acid should be a ssRNA. It suggested that the virus causing "trembling disease" was a member of Paramyxoviridae.In this paper we reported the electron microscope(EM) examination of "Trembling disease Virus" in Eriocheir sinensis and its' nucleic acid. The virions were globose , with envelope and spikes, and about 150nm of diameter by EM observation. The purified nucleic acid was treated with 8mol/L urea and the viral nucleic acid was transferred to the EM grids by aqueous technique. The viral nucleic acid was single stranded under EM observation. The molecular weight of the viral nucleic was calculated to be about 5.055× 106. The electrophoretogram of the purified viral nucleic acid in 0.8% agarose showed only one band, with the size of about 15-16kb. The nucleic acid had the sensitivity to Rnase and Mung Bean Nuclease, but not sensitivity to Dnasel. The above data demonstrated that the nucleic acid should be a ssRNA.To detect the virus causing "trembling disease" in Eriocheir sinensis samples by double antibody sandwich enzyme-linked immunosorbent assay(ELISA), the positive rate was 92.5%(37/40). Ten arbitrary primers of 10 bp were used to amplify DNA of crabs suffered from "trembling disease" and healthy crabs. One primer was filtrated, the product of RAPD was cloned into pUCm-T vector. Sequence analysis demonstrated that the product shared 85% identity with the sequence of Pseudomonas putida .One pair of primers was designed on the basis of those sequences to detect the crabs suffered from "trembling disease" and healthy crabs, the positive rate was 33%(8/24).Using UP(universal primer)PCR technique to examine the crabs suffered from "trembling disease" and healthy crabs, the positive rate was 33%(8/24). The results suggested that crabs suffered from "trembling disease" presented second infection of Pseudomonas sp.