Streptococcus suis Serotype 2 (SS2 for short) double-gene deleted live vaccine and its application

Abstract

The invention relates to the technical field of the zoonotic vaccine preparation, and concretely relates to an SS2 double-gene deleted live vaccine and its application. An SS2 deltaEce1 / deltaSalk / R double-gene deleted stain is obtained by continuously deleting an Salk / R gene from a base SS2 field strain SC19 on the basis of the deletion of the a single gene Ece1 through a homologous recombination method, and the SS2 double-gene deleted live vaccine is prepared through adopting a bacterial liquid of the double-gene deleted strain and gelatin as primary materials. The SS2 SS2 deltaEce1 / deltaSalk / R strain is preserved in China Center for Type Culture Collection, and has a preservation number being CCTCC NO:M2010360. After the deletion of the Salk / R gene, the SS2 double-gene deleted live vaccine prepared in the invention has the advantages of greatly decreased toxicity, high safety, no risk of strong toxicity return, and high immunogenicity, and can protect immune pigs from the attack of 5*LD50 SS2 strongly-toxic bacterial strains.

Description

technical field [0001] The invention belongs to the technical field of animal genetic engineering. It relates to the technical field of gene vaccines, and the invention specifically relates to the construction of a Streptococcus suis type 2 double-gene deletion vaccine strain, vaccine preparation and application. Background technique [0002] Streptococcus suis Serotype 2 (SS2) caused by Streptococcus suis Serotype 2 (SS2) is an important zoonotic infectious disease. economic loss, and also pose a great threat to human health (Lun ZR, et al. Streptococcus suis: an emerging zoonotic pathogen. Lancet Infect Dis, 2007, 7: 201-209). In our country, the suis streptococcosis caused by Streptococcus suis type 2 also exists widely, and it has gradually increased in recent years. In 1998, streptococcus disease caused by Streptococcus suis type 2 occurred in Nantong, Jiangsu Province, causing 25 infections and 14 deaths (Yao Huochun et al. Identification of pathogenic characteristic...

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Problems solved by technology

Between July and August 2005, streptococcal disease caused by Streptococcus suis type 2 occurred in Ziyang, Sichuan, my country, causing 215 infections and 38 deaths (Tang J, et al. Streptococcal toxic shock syndrome caused by Streptococcus suisserotype 2.PLoS Med, 2006, 3: 668-676), not only caused a huge impact on my country's pig industry, but also brought serious threats to public health, and also caused huge pressure on people's psychology

Currently clinically, inactivated vaccines are mainly used for immune prevention (He Kongwang et al. Research Progress on Streptococcus suis Vaccines. Veterinary Tribune, 2009, 08: 21-22), but inactivated vaccines are difficult to provide complete protection for pigs, and High production cost and large side effects have seriously affected its development and application (HOLT ME, et al. Immunization of pigs with killed cultures of Streptococcus suis type 2. Res VetSci 1990, 48:23-27; Quessy S, et al. mice against Streptococcus suis type 2 infection using a live avirulent strain. Can J Vet Res, 1994, 58: 299-301)

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