title: Novel Variants of Streptococcus thermophilus Bacteriophages Are Indicative of Genetic Recombination among Phages from Different Bacterial Species.
abstract: Bacteriophages are the main cause of fermentation failures in dairy plants. The majority ofStreptococcus thermophilusphages can be divided into eithercos- orpac-type phages and are additionally characterized by examining the V2 region of their antireceptors. We screened a large number ofS. thermophilusphages from the Chr. Hansen A/S collection, using PCR specific for thecos- orpac-type phages, as well as for the V2 antireceptor region. Three phages did not produce positive results with the assays. Analysis of phage morphologies indicated that two of these phages, CHPC577 and CHPC926, had shorter tails than the traditionalS. thermophilusphages. The third phage, CHPC1151, had a tail size similar to those of thecos- orpac-type phages, but it displayed a different baseplate structure. Sequencing analysis revealed the genetic similarity of CHPC577 and CHPC926 with a subgroup ofLactococcus lactisP335 phages. Phage CHPC1151 was closely related to the atypicalS. thermophilusphage 5093, homologous with a nondairy streptococcal prophage. By testing adsorption of the related streptococcal and lactococcal phages to the surface ofS. thermophilusandL. lactisstrains, we revealed the possibility of cross-interactions. Our data indicated that the use ofS. thermophilustogether withL. lactis, extensively applied for dairy fermentations, triggered the recombination between phages infecting different bacterial species. A notable diversity amongS. thermophilusphage populations requires that a new classification of the group be proposed.IMPORTANCEStreptococcus thermophilusis a component of thermophilic starter cultures commonly used for cheese and yogurt production. Characterizing streptococcal phages, understanding their genetic relationships, and studying their interactions with various hosts are the necessary steps for preventing and controlling phage attacks that occur during dairy fermentations.
authors.affiliation: Bacterial Physiology and Improvement, R&D Microbial Platform, Chr. Hansen A/S, Hørsholm, Denmark.|Department of Food Science, University of Copenhagen, Frederiksberg, Denmark.
authors.forename: Paula
authors.initials: P
authors.lastname: Szymczak
authors.affiliation: Bacterial Physiology and Improvement, R&D Microbial Platform, Chr. Hansen A/S, Hørsholm, Denmark dkthj@chr-hansen.com.
authors.forename: Thomas
authors.initials: T
authors.lastname: Janzen
authors.affiliation: Bacterial Physiology and Improvement, R&D Microbial Platform, Chr. Hansen A/S, Hørsholm, Denmark.
authors.forename: Ana Rute
authors.initials: AR
authors.lastname: Neves
authors.affiliation: Department of Environmental Science, Aarhus University, Roskilde, Denmark.
authors.forename: Witold
authors.initials: W
authors.lastname: Kot
authors.affiliation: Department of Environmental Science, Aarhus University, Roskilde, Denmark.
authors.forename: Lars H
authors.initials: LH
authors.lastname: Hansen
authors.affiliation: Department of Food Science, University of Copenhagen, Frederiksberg, Denmark.
authors.forename: René
authors.initials: R
authors.lastname: Lametsch
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Kiel, Germany.
authors.forename: Horst
authors.initials: H
authors.lastname: Neve
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Kiel, Germany.
authors.forename: Charles M A P
authors.initials: CMAP
authors.lastname: Franz
authors.affiliation: Department of Food Science, University of Copenhagen, Frederiksberg, Denmark.
authors.forename: Finn K
authors.identifier: http://orcid.org/0000-0003-2151-7802
authors.initials: FK
authors.lastname: Vogensen
mesh_terms: D017103:Bacillus Phages; D002611:Cheese / Q000382:microbiology / Q000821:virology; D043302:Cultured Milk Products / Q000382:microbiology / Q000821:virology; D042003:DNA Packaging; D004279:DNA, Viral; D005285:Fermentation; D005516:Food Microbiology; D016679:Genome, Viral; D013294:Lactococcus lactis / Q000821:virology; D046529:Microscopy, Electron, Transmission; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D017108:Streptococcus Phages / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification / Q000648:ultrastructure; D048249:Streptococcus thermophilus / Q000821:virology*; D015678:Viral Structural Proteins / Q000302:isolation & purification; D015014:Yogurt / Q000382:microbiology / Q000821:virology
chemical_list: D004279:DNA, Viral; D015678:Viral Structural Proteins
keywords: Streptococcus thermophilus; bacteriophages; classification; structural genes