Streptococcus agalactiae WC1535deltacps as well as construction and applications thereof

Abstract

The invention belongs to the technical field of gene engineering, and in particular relates to streptococcus agalactiae WC1535deltacps as well as construction and applications of the streptococcus agalactiae WC1535deltacps. The capsule deletion type fish-derived streptococcus agalactiae strain provided by the invention is streptococcus agalactiae WC1535deltacps, is preserved in the in the Guangdong Microbiological Culture Collection Center on June 30, 2017, and is assessed with the accession number of GDMCC NO: 60208. The strain is high in safety, the risk of virulence enhancement does not exist, meanwhile, the immunogenicity is high, the invasion of streptococcus agalactiae to immunized fish can be prevented, in addition, the attenuated live vaccine is easy to culture, easy to use, and low in production cost. The strain provided by the invention can be used for preparing attenuated live vaccines for streptococcicosis of fish, and has an extremely high commercial value.

Description

technical field [0001] The invention belongs to the technical field of genetic engineering, and in particular relates to a fish-derived Streptococcus agalactiae attenuated strain, Streptococcus agalactiae WC1535△cps, and its construction and application. Background technique [0002] Fish streptococcosis is mainly caused by Streptococcus agalactiae and Streptococcus iniae. At present, the prevention and control of fish streptococcosis mainly relies on antibiotics, disinfectants, probiotics and vaccine immunization. Due to the extensive use of antibiotics in the treatment process, the pathogenic bacteria have developed drug resistance, and the effect of drug treatment and prevention has been significantly reduced. Vaccines against fish streptococcosis are mainly inactivated vaccines. Inactivated vaccines are not only used in very limited scope due to the need for injection, inconvenient operation and unsatisfactory effects, etc.; and inactivated vaccines cannot be administer...

AI Technical Summary

Problems solved by technology

Due to the extensive use of antibiotics in the course of treatment, the pathogenic bacteria have developed drug resistance, and the effect of drug treatment and prevention has dropped significantly

The vaccines against fish streptococcosis are mainly inactivated vaccines. Inactivated vaccines not only require injection, inconvenient operation, and unsatisfactory effects, but the scope of use of vaccines is very limited; and inactivated vaccines cannot be carried out in animals after inoculation. Breeding, usually with a large immunization dose and a relatively short protection period, often requires multiple immunizations, and a single immunization cannot produce a strong immune protection effect

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