Characterization of the
            <i>cro-ori</i>
            Region of the
            <i>Streptococcus thermophilus</i>
            Virulent Bacteriophage DT1

Lamothe, Geneviève; Lévesque, Christian; Bissonnette, Frédéric; Cochu, Armelle; Vadeboncoeur, Christian; Frenette, Michel; Duplessis, Martin; Tremblay, Denise M.; Moineau, Sylvain

doi:10.1128/aem.71.3.1237-1246.2005

Cited by 15 publications

(11 citation statements)

References 63 publications

(54 reference statements)

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“…Until now (see above and reference 2), the study of S. thermophilus CRISPR1 was performed with a single host and two phages, i.e., S. thermophilus DGCC7710 and virulent pac-type phages 2972 and 858 (and their phage mutants). To determine whether the main conclusions described above apply to another S. thermophilus phage-host system, we isolated BIMs from S. thermophilus SMQ-301 challenged with the virulent cos-type phage DT1 (40), one of the best-characterized cos-type phages in S. thermophilus (15,16,17,26). The analysis of the CRISPR1 locus of wild-type phage-sensitive strain S. thermophilus SMQ-301 revealed the presence of 16 unique spacers, half the number found in DGCC7710.…”

Section: Resultsmentioning

confidence: 99%

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Phage Response to CRISPR-Encoded Resistance in Streptococcus thermophilus

Barrangou²,

et al. 2008

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Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated genes are linked to a mechanism of acquired resistance against bacteriophages. Bacteria can integrate short stretches of phage-derived sequences (spacers) within CRISPR loci to become phage resistant. In this study, we further characterized the efficiency of CRISPR1 as a phage resistance mechanism in Streptococcus thermophilus. First, we show that CRISPR1 is distinct from previously known phage defense systems and is effective against the two main groups of S. thermophilus phages. Analyses of 30 bacteriophage-insensitive mutants of S. thermophilus indicate that the addition of one new spacer in CRISPR1 is the most frequent outcome of a phage challenge and that the iterative addition of spacers increases the overall phage resistance of the host. The added new spacers have a size of between 29 to 31 nucleotides, with 30 being by far the most frequent. Comparative analysis of 39 newly acquired spacers with the complete genomic sequences of the wild-type phages 2972, 858, and DT1 demonstrated that the newly added spacer must be identical to a region (named proto-spacer) in the phage genome to confer a phage resistance phenotype. Moreover, we found a CRISPR1-specific sequence (NNAGAAW) located downstream of the proto-spacer region that is important for the phage resistance phenotype. Finally, we show through the analyses of 20 mutant phages that virulent phages are rapidly evolving through single nucleotide mutations as well as deletions, in response to CRISPR1.

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Section: Resultsmentioning

confidence: 99%

“…As indicated above, it is possible that the CRISPR-mediated resistance somehow targets the mRNA. Knowing that many S. thermophilus phage genes are transcribed as part of a polycistronic mRNA (26,42), inactivating larger transcripts may prevent the translation of essential phage proteins.…”

Section: Discussionmentioning

confidence: 99%

Phage Response to CRISPR-Encoded Resistance in Streptococcus thermophilus

Barrangou²,

et al. 2008

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“…Known antiphage systems from another bacterium (Lactococcus) can be introduced into S. thermophilus (Moineau, Walker, Holler, Vedamuthu, & Vandenbergh, 1995;Tangney & Fitzgerald, 2002). Antiphage mechanisms have also been engineered using S. thermophilus phage genetic elements such as a phage origin of replication (ori) located on a plasmid, which attracts phage replication factors (Foley, Lucchini, Zwahlen, & Brüssow, 1998;Lamothe et al, 2005;Stanley, Walsh, van der Zwet, Fitzgerald, & van Sinderen, 2000). Antisense RNA targeting a conserved phage gene was also used to confer phage resistance to S. thermophilus (Sturino & Klaenhammer, 2002;Sturino & Klaenhammer, 2004a).…”

Section: Phage-resistant S Thermophilus Strainsmentioning

confidence: 98%

Streptococcus thermophilus bacteriophages

Quiberoni

Moineau

Rousseau

et al. 2010

International Dairy Journal

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“…S1A). Furthermore, ori sequences are known to contain repeat regions (29) and, indeed, two sets of direct repeats (5=-GTTACCKT and 5=-TAAATAAA) and one imperfect inverted repeat (5=-TTATTTATATATT-N 5 -AATAAATAAATAA) were found in region 2 (Fig. S1B).…”

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confidence: 99%

YMC-2011, a Temperate Phage of Streptococcus salivarius 57.I

Chou

Huang

Chiu

et al. 2017

Appl Environ Microbiol

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Streptococcus salivarius is an abundant isolate of the oral cavity. The genome of S. salivarius 57.I consists of a 2-Mb chromosome and a 40,758-bp circular molecule, designated YMC-2011. Annotation of YMC-2011 revealed 55 open reading frames, most of them associated with phage production, although plaque formation is not observed in S. salivarius 57.I after lytic induction using mitomycin C. Results from Southern hybridization and quantitative real-time PCR confirmed that YMC-2011 exists extrachromosomally, with an estimated copy number of 3 to 4. Phage particles were isolated from the supernatant of mitomycin C-treated S. salivarius 57.I cultures, and transmission electron microscopic examination indicated that YMC-2011 belongs to the Siphoviridae family. Phylogenetic analysis suggests that phage YMC-2011 and the cos-type phages of Streptococcus thermophilus originated from a common ancestor. An extended Ϫ10 element (p L ) and a 70 -like promoter (p R ) were mapped 5= to Ssal_phage00013 (encoding a CI-like repressor) and Ssal_phage00014 (encoding a hypothetical protein), respectively, using 5= rapid amplification of cDNA ends, indicating that YMC-2011 transcribes at least two mRNAs in opposite orientations. Studies using promoter-chloramphenicol acetyltransferase reporter gene fusions revealed that p R , but not p L , was sensitive to mitomycin C induction, suggesting that the switch from lysogenic growth to lytic growth was controlled mainly by the activity of these two promoters. In conclusion, a lysogenic state is maintained in S. salivarius 57.I, presumably by the repression of genes encoding proteins for lytic growth.IMPORTANCE The movement of mobile genetic elements such as bacteriophages and the establishment of lysogens may have profound effects on the balance of microbial ecology where lysogenic bacteria reside. The discovery of phage YMC-2011 from Streptococcus salivarius 57.I suggests that YMC-2011 and Streptococcus thermophilus-infecting phages share an ancestor. Although S. salivarius and S. thermophilus are close phylogenetically, S. salivarius is a natural inhabitant of the human mouth, whereas S. thermophilus is commonly found in the mammary mucosa of bovine species. Thus, the identification of YMC-2011 suggests that horizontal gene transfer via phage infection could take place between species from different ecological niches.KEYWORDS Streptococcus salivarius, temperate phage, lysogeny, plasmid, Siphoviridae family P hages, prokaryotic viruses, are the most abundant biological entities on the planet (1). Although phages have been isolated from the oral cavity (2, 3), relatively little is known about the phages of oral streptococci, compared to those of other lactic acid bacteria, particularly Lactococcus lactis and Streptococcus thermophilus. To date, the better characterized phages of oral streptococci are the virulent phage M102AD of Streptococcus mutans (4) and the temperate phage SM1 of Streptococcus mitis (5). A Streptococcus salivarius-infecting phage of the family Cystoviridae wa...

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Characterization of the cro-ori Region of the Streptococcus thermophilus Virulent Bacteriophage DT1

Cited by 15 publications

References 63 publications

Phage Response to CRISPR-Encoded Resistance in Streptococcus thermophilus

Phage Response to CRISPR-Encoded Resistance in Streptococcus thermophilus

Streptococcus thermophilus bacteriophages

YMC-2011, a Temperate Phage of Streptococcus salivarius 57.I

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