Isolation and Molecular Identification of Avibacterium paragallinarum in Suspected Cases of Poultry

Infectious Coryza (IC) is an infectious upper respiratory disease of chickens and birds, caused by Avibacterium paragallinarum (Av. Paragallinarum). It is characterized by facial swelling and nasal discharge. Here, the study aimed to identify the causative agent of infectious coryza from diseased cases using conventional and molecular methods, forty-one different samples (swollen heads and nasal discharges) from layers and broiler chickens were examined bacteriologically for isolation of Av. Paragallinarum. The total isolation percentage was 9.75%, and the percentage was 66.7% from total layer samples. The samples underwent examination by polymerase chain reaction (PCR) using HPG-2. Three samples were confirmed by PCR with a percentage of 7.3% (3/41). Multiplex PCR was used for typing the tested strains using HMTp210 gene thus, all strains were of type B. sequence analysis showed a maximum identity percentage (100%) between the tested strains of Av. paragallinarum. In conclusion, typical signs for IC diseases were appeared and identified bacteriologically as Av. paragallinarum also three strains were only confirmed by PCR and identified type B strains. PCR technique is a reliable and sensitive test for confirmation.