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Characterization of a ViI-like phage specific to Escherichia coli O157:H7

Permanent URL:
http://handle.nal.usda.gov/10113/57319
Abstract:
Phage vB_EcoM_CBA120 (CBA120), isolated against Escherichia coli O157:H7 from a cattle feedlot, is morphologically very similar to the classic phage ViI of Salmonella enterica serovar Typhi. Until recently, little was known genetically or physiologically about the ViI-like phages, and none targeting E. coli have been described in the literature. The genome of CBA120 has been fully sequenced and is highly similar to those of both ViI and the Shigella phage AG3. The core set of structural and replication-related proteins of CBA120 are homologous to those from T-even phages, but generally are more closely related to those from T4-like phages of Vibrio, Aeromonas and cyanobacteria than those of the Enterobacteriaceae. The baseplate and method of adhesion to the host are, however, very different from those of either T4 or the cyanophages. None of the outer baseplate proteins are conserved. Instead of T4’s long and short tail fibers, CBA120, like ViI, encodes tail spikes related to those normally seen on podoviruses. The 158 kb genome, like that of T4, is circularly permuted and terminally redundant, but unlike T4 CBA120 does not substitute hmdCyt for cytosine in its DNA. However, in contrast to other coliphages, CBA120 and related coliphages we have isolated cannot incorporate 3H-thymidine (3H-dThd) into their DNA. Protein sequence comparisons cluster the putative “thymidylate synthase” of CBA120, ViI and AG3 much more closely with those of Delftia phage W-14, Bacillus subtilis phage SPO1, and Pseudomonas phage YuA, all known to produce and incorporate hydroxymethyluracil (hmdUra).
Author(s):
Elizabeth M. Kutter , Kyobi Skutt-Kakaria , Bob Blasdel , Ayman El-Shibiny , Anna Castano , Daniel Bryan , Andrew M. Kropinski , Andre Villegas , Hans-Wolfgang Ackermann , Ana L. Toribio , Derek Pickard , Hany Anany , Todd Callaway
Subject(s):
Aeromonas , Bacillus subtilis , DNA , Delftia , Escherichia coli O157 , Pseudomonas phages , Salmonella enterica subsp. enterica serovar Typhi , Shigella , Vibrio phages , adhesion , amino acid sequences , bacteriophages , cattle , cytosine , feedlots , genome , hosts , nucleotide sequences , sequence analysis , structural proteins , viral morphology , viral proteins
Source:
Virology Journal 2011 9 29 v.8
Language:
English
Year:
2011
Collection:
Journal Articles, USDA Authors, Peer-Reviewed
File:
Download [PDF File]
Rights:
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.