Low toxic bacterial strain of Pasteurella multocid B26-T1200

Abstract

The invention relates the attenuated strain used for preparing pasteurella multocid vaccine, which is pasteurella multocid B26-T1200. The method comprises the following steps: adding the virulent strain B26 into martin soup containing the 0.1% splitting sheep whole blood to propagate at 37-45Deg.C, measuring the virulence and immunity of passage strain, and getting the pasteurella multocid B26-T1200 at the 1200 generation. The pasteurella multocid vaccine used by the said attenuated strain has high safety, good stability, and long immunity duration. The minimum immunizing dose of the strain is 13,000,000 viable bacteria.

Description

technical field [0001] The present invention belongs to Pasteurella multocida B 26 -T 1200 Field of attenuated strains. Background technique [0002] Avian pasteurellosis, also known as fowl cholera, is caused by Pasteurella multocida (Pm). It is a common acute infectious disease in chickens, ducks, geese and other poultry. one of the diseases. [0003] Foreign researches on the attenuated Pasteurella avian vaccine (bacteria) began in 1881. Since Pasteur successfully developed the attenuated vaccine for preventing fowl cholera for the first time, various attenuated Pasteurella avian strains with different immunity have emerged continuously. In 1918, Mannigen bred a non-toxic mutant strain by adding chemical mutagens to the culture medium, and it began to have immunity two days after immunization, and the immunity period was 6-8 weeks; in 1950, Barker passed the Serum agar medium was continuously cultured to obtain a non-toxic variant; Car...

AI Technical Summary

Problems solved by technology

The above-mentioned attenuated strains all have a certain immune effect, but there are some common problems, such as the safety of the vaccine is poor, the immunity period is short, the genetic performance of the strain is poor, and it is unstable; some vaccines have large side effects and have a certain impact on the egg production rate of poultry

[0005] Although there are many researches on Pasteurella avian attenuated vaccine at home and abroad, the production process route and process parameters of Pasteurella avian attenuated vaccine are difficult to master, which makes the production cost of the vaccine generally high, the product quality is unstable, and the qualified rate is low. Poor immunogenicity, short shelf life of vaccines, slow time for vaccines to produce immunity, etc., cannot meet the needs of the healthy development of the poultry industry