High Frequency of a Novel Filamentous Phage, VCY{Phi}, within an Environmental Vibrio cholerae Population

TitleHigh Frequency of a Novel Filamentous Phage, VCY{Phi}, within an Environmental Vibrio cholerae Population
Publication TypeJournal Article
Year of Publication2012
AuthorsXue H, Xu Y, Boucher Y, Polz MF
JournalApplied and environmental microbiology
Volume78
Issue1
Start Page28
Pagination28-33
Date Published2011 Oct 21
Abstract

Environmental Vibrio cholerae strains isolated from a coastal brackish pond (Oyster Pond, Woods Hole, MA) carried a novel filamentous phage, VCYΦ, which can exist as a host-genome integrated (IF) and plasmid-like replicative form (RF). Outside the cell, the phage displays morphology typical of Inovirus with filamentous particles ∼1.8 μm in length and 7 nm in width. Four independent RF isolates had identical genomes except for 8 single nucleotide polymorphisms (SNPs) clustered in two regions. The overall genome size is 7,103 bp with 11 putative ORFs, organized into three functional modules (replication, structure and assembly, and regulation). VCYΦ shares sequence similarity with other filamentous phages (including cholera disease associated CTX) in a highly mosaic manner, indicating evolution by horizontal gene transfer and recombination. VCYΦ integrates in the vicinity of the putative translation initiation factor Sui1 in chromosome II of V. cholerae. A screen of 531 closely related host isolates showed that ∼40% harbored phage with 27% and 13% carrying the IF and RF, respectively. The relative frequency of RF and IF differed among strains isolated from the pond or lagoon of Oyster Pond suggesting that host habitat influences the intracellular phage biology. The overall high prevalence within the host population shows that filamentous phages can be an important component of the environmental biology of V. cholerae.

DOI10.1128/AEM.06297-11