The authors give an overview about recent advances in the research of avian pneumoviruses (APV). They summarize the knowledge about the characteristics of the viral genome and the phylogenetic relationship between APV and mammalian Pneumoviruses. The importance of opportunistic pathogens (first and foremost E. coli) largely contributing to the characteristic clinical pictures is highlited. One of the most important features of APV is that it has been subgrouped into type A and B viruses based on the nucleotide and amino acid sequence heterogeneity of the attachment (G) glycoprotein. This separation has been proven by data obtained from other regions of the APV genome. The two subtypes behave differently in experimental infections: although no differences can be seen between the subtypes for respiratory signs, or macroscopic and microscopic lesions in the respiratory tract, there are variations in the site and extent of virus replication. Only subtype A is able to invade the lower parts of the respiratory tract. This strain infects twice as many epithelial cells at all levels of the upper respiratory tract than does subtype B. There is evidence of the high variability of the APV genome. The British isolates collected during the late eighties were closely related and belonged to the subgroup A. However, isolates from the nineties have proven to be consistently type B viruses, suggesting a "genetic switch" in the prevalent APV strains. Recent reports have described isolates of APV in the USA significantly different from the previously detected APV isolates in Europe. Taken together the above findings, the diagnostic laboratory should be prepared to detect very different kinds of APV in order to gain an accurate diagnosis. For this purpose, they apply the polymerase chain reaction based on the findings of BAYON-AUBOYER et al. (2). The system they use targets the highly conservative nucleocapsid region of the APV genome for detection, and the region coding for the attachment protein (G) for typing purposes. They strongly recommend the PCR as a diagnostic tool, because beyond its inherited benefits, samples as simple as oesophageal swabs can be collected, dried and transported to the diagnostic laboratory to be investigated by this technique. The application of "reverse genetics" should contribute to the better understanding of APV pathogenicity, and, consequently to better vaccination strategies.
|Translated title of the contribution||Recent advances on the research of avian pneumoviruses|
|Number of pages||5|
|Journal||Magyar Allatorvosok Lapja|
|Publication status||Published - Dec 1 2000|
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