Epidemiological Investigation And Control Of Bordetella Bronchiseptica Infection In North Anhui Province

Bordetella bronchiseptica (Bb) is an important pathogenic bacterium and can cause the widespread infection in poultry, livestock, wildlife and laboratory animals. Bb is found to infect numerous mammals, such as pigs, horses, cats, dogs, rabbits, mice and guinea pigs. Bb is also one of the pathogens which cause the AtroPhic Rhiniti. The clinical symptoms in pigs are manifested with sneezing, nosebleeds, facial deformation and nose askew. It can result in growth retardation and reducing feed conversion rate, thus causing significant economic losses in the swine industry worldwide. This study focused on the epidemiological investigation of Bb infection in twelve intensive pig farms of the north Anhui province. And the drug susceptibility test, the prevention and control effect of the traditional Chinese medicine, and the immuno-protection effect of the inactivated vacine were investigated.1. The epidemiological investigation to the Bb infection was carried out in twelve intensive pig farms. The effects of environment on the morbidity and mortality caused by Bb were investigated based on clinical diagnosis, pathological inspection, identification of pathogen and the PCR examination. The result showed that Bb was widespread in twelve intensive pig farms. The highest positive rate of samples was up to37.17%. This disease has obvious seasonal. The infection rates were25.63%and28.05%in winter and spring, respectively, which were significantly higher than those in summer and autumn. At the same time, the positive rate of30-60days old piglets was the highest, which is30.90%. Environmental hygiene, feeding factors, nutritional status, management level and other stress factors can become the causes. Therefore, some measures, including strengthening management, keeping ventilation, keeping feeding density, and ensuring feed of calcium, phosphorus and other substances, have a positive effect on the prevention of the disease.2.148samples from lungs and nasal swabs of swine were collected and used to perform the isolation and identification of Bordetella bronchiseptica. B. bronchiseptica was identified by morphological observation, cultural characteristics and biochemical tests. The drug susceptibility test to the12isolates was carried out, and the result showed that the12strains were most sesentive to florfenicol, doxycycline, streptomycin and gentamicin.They were moderately sesentive to erythromycin, ofloxacin, amikacin, tetracycline and ampicillin.They were not sensitive to the compound sulfamethoxazole, chloramphenicol, furazolidone, vancomycin, cefazolin and other drugs.3. The traditional Chinese medicine was used for the treatment and prevention of the Bb infection, and the result was compared with florfenicol medication.The results showed that the average preparation rate of traditional Chinese medicine was89.5%, which was higher than that of84.9%in the control group.The cure rate was79.2%, which was lower than that of88.0%in the control group. Therefore, the traditional Chinese medicine has a good efficacy in this area for the prevention and treatment of B. Bronchiseptica infection.4. An inactivated vaccine against B. bronchiseptica infection was prepared using dominant strain B1and used to immune piglets. The result was compared with that of commercial vaccine. The result showed that the morbidity of piglets was16%,22%and56%, respectively, in the inactivated vaccine, commercial vaccine and control group. So the inactivated vaccine is useful to control the Bb infection.