title: Establishing a genetic system for ecological studies of Streptococcus oligofermentans.
abstract: Streptococcus oligofermentans is a newly characterized species belonging to the mitis group of oral streptococci. So far no correlation has been demonstrated between S. oligofermentans and dental caries. Furthermore, a reverse correlation has been observed between the number of S. oligofermentans and the number of Streptococcus mutans, a major cariogenic pathogen, in the oral cavity. These properties suggest that S. oligofermentans may have a potential to be used as a 'probiotics' for caries prevention. In this study, we aim to establish a genetic system in S. oligofermentans to further study the biology of this new species. Using homologous regions of the comCDE locus in other streptococci, the comC gene was isolated and sequenced. A synthetic competence-stimulating peptide (CSP) was synthesized and shown to be able to effectively induce competence in S. oligofermentans. This CSP-induced transformation system in S. oligofermentans was used to construct green fluorescent protein (gfp) and luciferase (luc) reporter systems, both of which are driven by the lactate dehydrogenase (ldh) promoter. These reporter systems were further shown to be highly expressed in planktonic and biofilm cells, suggesting that these reporter systems can be used in future ecological studies of S. oligofermentans.
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Huichun
authors.initials: H
authors.lastname: Tong
authors.forename: Baoli
authors.initials: B
authors.lastname: Zhu
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Fengxia
authors.initials: F
authors.lastname: Qi
authors.forename: Wenyuan
authors.initials: W
authors.lastname: Shi
authors.forename: Xiuzhu
authors.initials: X
authors.lastname: Dong
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D017753:Ecosystem; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics; D013291:Streptococcus / Q000235:genetics / Q000502:physiology*; D014169:Transformation, Bacterial
chemical_list: D001426:Bacterial Proteins; D008164:Luminescent Proteins; C423628:competence factor, Streptococcus; D049452:Green Fluorescent Proteins