title: Enhancement of UV light sensitivity of a Vibrio parahaemolyticus O3:K6 pandemic strain due to natural lysogenization by a telomeric phage.
abstract: The Vibrio parahaemolyticus O3:K6 pandemic clonal strain was first observed in southern Chile in 2004 and has since caused approximately 8,000 seafood-related diarrhea cases in this region. The massive proliferation of the original clonal population offers a unique opportunity to study the evolution of a bacterial pathogen in its natural environment by detection and characterization of emerging bacterial variants. Here, we describe a group of pandemic variants characterized by the presence of a 42-kb extrachromosomal DNA that can be recovered by alkaline extraction. Upon treatment with mitomycin C, these variants lyse with production of a myovirus containing DNA of equal size to the plasmid but which cannot be recovered by alkaline extraction. Plasmid and phage DNAs show similar restriction patterns corresponding to enzyme sites in a circular permutation. Sequenced regions showed 81 to 99% nucleotide similarity to bacteriophage VHML of Vibrio harveyi. Altogether these observations indicate that the 42-kb plasmid corresponds to a prophage, consisting of a linear DNA with terminal hairpins of a telomeric temperate phage with a linear genome. Bacteria containing the prophage were 7 to 15 times more sensitive to UV radiation, likely due to phage induction by UV irradiation as plasmid curing restored the original sensitivity. The enhanced UV sensitivity could have a significant role in reducing the survival and propagation capability of the V. parahaemolyticus pandemic strain in the ocean.
authors.affiliation: Instituto de Nutrición y Tecnología de los Alimentos, Universidad de Chile, El Líbano 5524, Macul, Santiago, Chile 6903625.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Zabala
authors.forename: Katherine
authors.initials: K
authors.lastname: García
authors.forename: Romilio T
authors.initials: RT
authors.lastname: Espejo
mesh_terms: D000477:Alkylating Agents / Q000494:pharmacology; D001433:Bacteriolysis; D001435:Bacteriophages / Q000235:genetics / Q000502:physiology*; D002677:Chile; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D050296:Microbial Viability / Q000528:radiation effects*; D016685:Mitomycin / Q000494:pharmacology; D008969:Molecular Sequence Data; D010957:Plasmids; D039002:Prophages / Q000235:genetics / Q000502:physiology*; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D014466:Ultraviolet Rays; D014736:Vibrio parahaemolyticus / Q000235:genetics / Q000528:radiation effects* / Q000821:virology*; D014771:Virion / Q000302:isolation & purification / Q000648:ultrastructure
chemical_list: D000477:Alkylating Agents; D004279:DNA, Viral; D016685:Mitomycin; D004262:DNA Restriction Enzymes