ISSN:
1432-8798
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Growth characteristics of a wide range of influenza A viruses from different mammals and bird species were examined in an established line of canine kidney (MDCK) cells at an ordinary (37°C) and a high temperature (42°C). Although all viruses employed in the present study possessed a capability of replicating at 37°C, virus growth at 42°C showed considerable variation and reflected differences in the natural hosts of the isolates. All reference strains and isolates from bird species grew well in the MDCK cells maintained at 42°C, but human viruses did not, showing an asymmetrical growth behavior. In contrast to this, growth of swine and equine viruses showed growth characteristics intermediate between human and avian viruses. Of the two swine viruses examined, replication of one strain occured equally well at both temperatures and another failed to grow at 42°C. Similarly, two of the three equine viruses tested belonging to H3N8 antigenic subtypes grew at 42°C. However, the results obtained from comparison of plaque sizes and growth curves indicated that the replication of the above swine and equine viruses was restricted under a stringent temperature when compared to avian viruses. The detailed analysis of cloned viruses revealed that some of the swine and equine viruses contained two variants which are readily distinguished by growth behavior at 42°C. Genome analysis of parental and virus clones by oligonucleotide mapping and migration profiles of RNA segments did not detect any differences among the above variants exhibiting the asymmetrical growth characteristics at 42°C.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01487686
