title: Partial recN gene sequencing: a new tool for identification and phylogeny within the genus Streptococcus.
abstract: Partial sequences of the recN gene (1249 bp), which encodes a recombination and repair protein, were analysed to determine the phylogenetic relationship and identification of streptococci. The partial sequences presented interspecies nucleotide similarity of 56.4-98.2 % and intersubspecies similarity of 89.8-98 %. The mean DNA sequence similarity of recN gene sequences (66.6 %) was found to be lower than those of the 16S rRNA gene (94.1 %), rpoB (84.6 %), sodA (74.8 %), groEL (78.1 %) and gyrB (73.2 %). Phylogenetically derived trees revealed six statistically supported groups: Streptococcus salivarius, S. equinus, S. hyovaginalis/S. pluranimalium/S. thoraltensis, S. pyogenes, S. mutans and S. suis. The 'mitis' group was not supported by a significant bootstrap value, but three statistically supported subgroups were noted: Streptococcus sanguinis/S. cristatus/S. sinensis, S. anginosus/S. intermedius/S. constellatus (the 'anginosus' subgroup) and S. mitis/S. infantis/S. peroris/S. oralis/S. oligofermentans/S. pneumoniae/S. pseudopneumoniae. The partial recN gene sequence comparison highlighted a high percentage of divergence between Streptococcus dysgalactiae subsp. dysgalactiae and S. dysgalactiae subsp. equisimilis. This observation is confirmed by other gene sequence comparisons (groEL, gyrB, rpoB and sodA). A high percentage of similarity was found between S. intermedius and S. constellatus after sequence comparison of the recN gene. To study the genetic diversity among the 'anginosus' subgroup, recN, groEL, sodA, gyrB and rpoB sequences were determined for 36 clinical isolates. The results that were obtained confirmed the high genetic diversity within this group of streptococci.
authors.affiliation: Laboratoire de Bactériologie - Virologie, Hôpital de la Timone, CNRS UMR 6236, IFR48, 264 rue Saint-Pierre, 13385 Marseille, Cedex 05, France.
authors.forename: Olga O
authors.initials: OO
authors.lastname: Glazunova
authors.affiliation: Laboratoire de Bactériologie - Virologie, Hôpital de la Timone, CNRS UMR 6236, IFR48, 264 rue Saint-Pierre, 13385 Marseille, Cedex 05, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.affiliation: Laboratoire de Bactériologie - Virologie, Hôpital de la Timone, CNRS UMR 6236, IFR48, 264 rue Saint-Pierre, 13385 Marseille, Cedex 05, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Roux
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D015373:Bacterial Typing Techniques; D004262:DNA Restriction Enzymes / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013291:Streptococcus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D004262:DNA Restriction Enzymes; C047879:RecN protein, Bacteria