Ultrastructural Changes of the Chickens Lungs after Aerosol Vaccination Against Newcastle Disease

ABSTRACT

The ultrastructural changes flowing in the lung of broiler chickens at 25 days of age after aerosol vaccination with B1 strain of Newcastle disease virus (NDV) was studied. The dynamics of the ultrastructural changes of the surfactant and cells take part in its production and metabolism were investigated on the 24^th, 48^th 72^nd hours, 6^th, 8^th 15^th and 21^st days after the aerosol vaccination. The results of electron microscope studies confirmed that almost all components of lung connected with production and recycling of surfactant were affected by aerosol vaccination. The absence or chaotic state of surfactant, apoptotic changes of pneumocytes II type, desquamation of some of them and presence of serofibrinous exudate in most of the air capillaries on the 24^th - 72^nd hours after aerosol vaccination have proved that the interaction of the vaccine virus and components of the lung with attitude toward surfactant were started during the first few hours. As a result an embarrassed breading, depression, gasping, coughing, sneezing and refuse of feeding were provoked. In the next 6–8 days the changes were connected with compensation processes of surfactant production and activation of lung defense system. During 15–21 days after vaccination the lung structure was restored which demonstrate the reversible type of apoptotic changes provoked by aerosol vaccination in contrast to the cases of wild NDV infection.

Keywords:

• NDV
• chickens
• aerosol vaccination
• electron microscopy
• lungs
• surfactant