|Thompson, Michael - USDA-ARS-NADC, AMES, IA|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 29, 1997
Publication Date: N/A
Technical Abstract: VSH-1 is a mitomycin C-inducible, lambdoid-like bacteriophage of S. hyodysenteriae (S. hyo), an enteropathogenic spirochete infecting swine. VSH-1 is unusual in several respects. Induced virions contain double- stranded DNA in linear fragments of 7.5 kb, a size too small to encode all proteins necessary for phage replication. These DNA fragments consist of randomly packaged host bacterial DNA. VSH-1 does not exhibit detectable lytic growth on cells of Serpulina spp, but serves as a generalized transducing phage of S. hyo cells. VSH-1 is the first reported transducing bacteriophage of a spirochete. To begin to investigate a role for VSH-1 in S. hyo ecology, we identified and sequenced viral genes within a 3.5 kb segment of the S. hyo B204 chromosome. The segment contained 3 ORFs encoding 13, 19, and 38 kDa proteins identified as head proteins of VSH-1 virions, and a fourth ORF encoding a putative 11.6 kDa protein. The 38 kDa protein appears to be the major VSH-1 head protein. A DNA probe was used to detect the 38 kDa protein gene in the genomes of various spirochetes. The gene was located within a single 110 kb region of the S. hyo B78 chromosome. The viral gene was present in Brachyspira aalborgi and in 29 Serpulina strains, representing 6 Serpulina species. The wide distribution of this gene among intestinal Serpulina-Brachyspira species suggests VSH-1 or related bacteriophages contribute significantly to the ecology and genetics of these intestinal spirochetes.