title: Phage-host interactions in Streptococcus thermophilus: Genome analysis of phages isolated in Uruguay and ectopic spacer acquisition in CRISPR array.
abstract: Three cos-type virulent Streptococcus thermophilus phages were isolated from failed mozzarella production in Uruguay. Genome analyses showed that these phages are similar to those isolated elsewhere around the world. The CRISPR1 and CRISPR3 arrays of the three S. thermophilus host strains from Uruguay were also characterized and similarities were noted with previously described model strains SMQ-301, LMD-9 and DGCC7710. Spontaneous bacteriophage-insensitive S. thermophilus mutants (BIMs) were obtained after challenging the phage-sensitive wild-type strain Uy02 with the phage 128 and their CRISPR content was analyzed. Analysis of 23 BIMs indicated that all of them had acquired at least one new spacer in their CRISPR1 array. While 14 BIMs had acquired spacer at the 5'-end of the array, 9 other BIMs acquired a spacer within the array. Comparison of the leader sequence in strains Uy02 and DGCC7710 showed a nucleotide deletion at position -1 in Uy02, which may be responsible for the observed ectopic spacer acquisition. Analysis of the spacer sequences upstream the newly acquired ectopic spacer indicated presence of a conserved adenine residue at position -2. This study indicates that natural strains of S. thermophilus can also acquire spacers within a CRISPR array.
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Biociencias, Facultad de Química, Universidad de la República, Montevideo, Uruguay.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Achigar
authors.affiliation: Département de Biochimie, de Microbiologie et de Bioinformatique &PROTEO, Faculté des Sciences et de Génie, Félix d'Hérelle Reference Center for Bacterial Viruses &GREB, Faculté de Médecine Dentaire, Université Laval, Québec City, Québec, G1V 0A6, Canada.
authors.forename: Alfonso H
authors.initials: AH
authors.lastname: Magadán
authors.affiliation: Département de Biochimie, de Microbiologie et de Bioinformatique &PROTEO, Faculté des Sciences et de Génie, Félix d'Hérelle Reference Center for Bacterial Viruses &GREB, Faculté de Médecine Dentaire, Université Laval, Québec City, Québec, G1V 0A6, Canada.
authors.forename: Denise M
authors.initials: DM
authors.lastname: Tremblay
authors.affiliation: Laboratorio de Microbiología Molecular, Departamento de Biociencias, Facultad de Química, Universidad de la República, Montevideo, Uruguay.
authors.forename: María
authors.initials: M
authors.lastname: Julia Pianzzola
authors.affiliation: Département de Biochimie, de Microbiologie et de Bioinformatique &PROTEO, Faculté des Sciences et de Génie, Félix d'Hérelle Reference Center for Bacterial Viruses &GREB, Faculté de Médecine Dentaire, Université Laval, Québec City, Québec, G1V 0A6, Canada.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Moineau
mesh_terms: D000898:Antibiosis / Q000235:genetics; D001483:Base Sequence; D002611:Cheese / Q000382:microbiology / Q000821:virology; D002874:Chromosome Mapping; D064112:Clustered Regularly Interspaced Short Palindromic Repeats; D004269:DNA, Bacterial / Q000235:genetics*; D021901:DNA, Intergenic / Q000235:genetics; D005285:Fermentation; D005524:Food Technology / Q000191:economics; D063990:Gene Ontology; D016679:Genome, Viral; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D058977:Molecular Sequence Annotation; D009154:Mutation; D016415:Sequence Alignment; D017108:Streptococcus Phages / Q000235:genetics* / Q000472:pathogenicity* / Q000648:ultrastructure; D048249:Streptococcus thermophilus / Q000235:genetics* / Q000276:immunology / Q000821:virology; D014583:Uruguay; D014774:Virulence
chemical_list: D004269:DNA, Bacterial; D021901:DNA, Intergenic