title: Complete sequence and comparative genome analysis of the dairy bacterium Streptococcus thermophilus.
abstract: The lactic acid bacterium Streptococcus thermophilus is widely used for the manufacture of yogurt and cheese. This dairy species of major economic importance is phylogenetically close to pathogenic streptococci, raising the possibility that it has a potential for virulence. Here we report the genome sequences of two yogurt strains of S. thermophilus. We found a striking level of gene decay (10% pseudogenes) in both microorganisms. Many genes involved in carbon utilization are nonfunctional, in line with the paucity of carbon sources in milk. Notably, most streptococcal virulence-related genes that are not involved in basic cellular processes are either inactivated or absent in the dairy streptococcus. Adaptation to the constant milk environment appears to have resulted in the stabilization of the genome structure. We conclude that S. thermophilus has evolved mainly through loss-of-function events that remarkably mirror the environment of the dairy niche resulting in a severely diminished pathogenic potential.
authors.affiliation: Génétique Microbienne. Centre de Recherche de Jouy en Josas, Institut National de la Recherche Agronomique, 78352 Jouy en Josas Cedex, France.
authors.forename: Alexander
authors.initials: A
authors.lastname: Bolotin
authors.forename: Benoît
authors.initials: B
authors.lastname: Quinquis
authors.forename: Pierre
authors.initials: P
authors.lastname: Renault
authors.forename: Alexei
authors.initials: A
authors.lastname: Sorokin
authors.forename: S Dusko
authors.initials: SD
authors.lastname: Ehrlich
authors.forename: Saulius
authors.initials: S
authors.lastname: Kulakauskas
authors.forename: Alla
authors.initials: A
authors.lastname: Lapidus
authors.forename: Eugene
authors.initials: E
authors.lastname: Goltsman
authors.forename: Michael
authors.initials: M
authors.lastname: Mazur
authors.forename: Gordon D
authors.initials: GD
authors.lastname: Pusch
authors.forename: Michael
authors.initials: M
authors.lastname: Fonstein
authors.forename: Ross
authors.initials: R
authors.lastname: Overbeek
authors.forename: Nikos
authors.initials: N
authors.lastname: Kyprides
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Purnelle
authors.forename: Deborah
authors.initials: D
authors.lastname: Prozzi
authors.forename: Katrina
authors.initials: K
authors.lastname: Ngui
authors.forename: David
authors.initials: D
authors.lastname: Masuy
authors.forename: Frédéric
authors.initials: F
authors.lastname: Hancy
authors.forename: Sophie
authors.initials: S
authors.lastname: Burteau
authors.forename: Marc
authors.initials: M
authors.lastname: Boutry
authors.forename: Jean
authors.initials: J
authors.lastname: Delcour
authors.forename: André
authors.initials: A
authors.lastname: Goffeau
authors.forename: Pascal
authors.initials: P
authors.lastname: Hols
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002874:Chromosome Mapping / Q000379:methods*; D017124:Conserved Sequence; D019143:Evolution, Molecular; D016680:Genome, Bacterial; D042822:Genomic Instability / Q000235:genetics*; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D013290:Streptococcal Infections / Q000235:genetics*; D048249:Streptococcus thermophilus / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D037521:Virulence Factors / Q000235:genetics*; D015014:Yogurt / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors