ACTA VETERINARIA ET ZOOTECHNICA SINICA ›› 2017, Vol. 48 ›› Issue (4): 699-705.doi: 10.11843/j.issn.0366-6964.2017.04.013

Previous Articles     Next Articles

Study on Colonization and Pathological Changes of Chick Respiratory Tract Induced by Bordetella avium Virulent Isolate

YANG Ping-ping1, YUAN Peng1, WEI Kai1, HU Li-ping2, ZHU Rui-liang1*   

  1. 1. College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai'an 271000, China;
    2. Shandong Animal Disease Prevention and Control Center, Jinan 250022, China
  • Received:2016-10-25 Online:2017-04-23 Published:2017-04-23

Abstract:

Bordetella avium (B. avium), one of the members of Bordetella genus, Alcaligenes Branch, mainly causes birds cough and other respiratory symptoms. To explore its invasive procedure by respiratory tract and regular pattern of lesions development, SPF chicks were challenged by nasal infection with a screened virulent B. avium strain. After infection, bacteria quantity in trachea and lungs were detected at different times. Tracheas colonization and lesions were observed by SEM. Lungs colonization pattern were detected by indirect immunoenzymatic staining. Histopathological changes in lung and bronchus were detected by pathological examination. It was found that bacterial infection of the trachea was in larger quantities, and only a small amount in the lungs at the beginning. And then the amount of bacteria in trachea and lungs showed a clear upward trend. B. avium had colonized on the cilia of trachea, and cilia began to fall off on 1 d after infection. To 5 d after infection, tracheal mucosal surface mottled, cilia fell off in a large area, and even holes appeared. Lungs colonization were detected on 2 d after infection, and B. avium were mainly distributed in the cytoplasm of lung housing and respiratory capillary walls. Positive signals were increasing with the extension of time. Pathological changes in the lungs and bronchi appeared on 5 d after infection, mainly showed congestion. To 10 d after infection, a large number of cell necrosis appeared. In conclusion, this B. avium isolate has a strong tropism on chick respiratory tract. Especially it has priority colonization on cilia of tracheal epithelial cells, and subsequently causes a series of histopathological changes in the trachea, bronchi and lungs.

CLC Number: