犬支气管败血波氏杆菌的分离鉴定和灭活疫苗初步应用OA北大核心

Some Beagle dogs at a breeding farm exhibited symptoms of coughing,wheezing,and bleeding from the mouth and nose,with severe cases resulting in death.To investigate the cause and implement targeted measures,clinical samples including nasal swabs from affected dogs,lung tissue and tracheal secretions from affected dogs were collected for bacterial isolation and culture.The isolated bacteria were identified through morphological observation,Gram staining,and sequencing of the 16S rRNA and ptxA genes.Antibiotic sensitivity tests were conducted on selected strains.A virulent strain was used to prepare a Bordetella bronchiseptica inactivated vaccine with a propolis adjuvant,which was tested for immunoprotection in mice using doses of 1.0 mL and 0.5 mL,followed by challenge infection 21 days post-immunization.Emergency vaccinations were administered to clinically affected and healthy dogs in the breeding farm,with doses of 1.0 mL for dogs over 4 months old and 0.5 mL for dogs aged 2-4 months.Histopathological examinations were conducted on tissues from clinically deceased dogs and challenge deceased mice.The results showed that 30 strains of Bordetella bronchiseptica were isolated from nasal swabs,lung tissue,trachea,and nasal secretions of affected dogs.Antibiotic sensitivity tests revealed high susceptibility of clinical isolates to ciprofloxacin and minocycline,though clinical treatment was not markedly effective.In the immunoprotection test,the propolis-adjuvanted inactivated vaccine provided 100％protection in mice at both 1.0 mL and 0.5 mL doses.Following emergency vaccination,clinically affected dogs gradually recovered,and no new cases were observed among the healthy cohort,indicating effective vaccine protection.Histopathological findings in clinically deceased dogs and challenge deceased mice showed characteristic bronchopneumonia,pulmonary emphysema,and vacuolar degeneration of hepatocytes.The results indicate that Bordetella bronchiseptica was the causative agent of the respiratory disease outbreak in the breeding farm,and the propolis-adjuvanted inactivated vaccine effectively prevented and controlled Bordetella bronchiseptica infection in Beagle dogs.