Journal Article

The Genome of Streptococcus mitis B6 - What Is a Commensal?

Reichmann, Peter, Selbmann, Peter, Zimmermann, Wolfgang, Henrich, Bernhard, Wambutt, Rolf, Hakenbeck, Regine, Schähle, Yvonne, Nuhn, Michael, Brückner, Reinhold, Denapaite, Dalia, Maurer, Patrick

2010

Overview

Streptococcus mitis is the closest relative of the major human pathogen S. pneumoniae. The 2,15 Mb sequence of the Streptococcus mitis B6 chromosome, an unusually high-level beta-lactam resistant and multiple antibiotic resistant strain, has now been determined to encode 2100 genes. The accessory genome is estimated to represent over 40%, including 75 mostly novel transposases and IS, the prophage phiB6 and another seven phage related regions. Tetracycline resistance mediated by Tn5801, and an unusual and large gene cluster containing three aminoglycoside resistance determinants have not been described in other Streptococcus spp. Comparative genomic analyses including hybridization experiments on a S. mitis B6 specific microarray reveal that individual S. mitis strains are almost as distantly related to the B6 strain as S. pneumoniae. Both species share a core of over 900 genes. Most proteins described as pneumococcal virulence factors are present in S. mitis B6, but the three choline binding proteins PcpA, PspA and PspC, and three gene clusters containing the hyaluronidase gene, ply and lytA, and the capsular genes are absent in S. mitis B6 and other S. mitis as well and confirm their importance for the pathogenetic potential of S. pneumoniae. Despite the close relatedness between the two species, the S. mitis B6 genome reveals a striking X-alignment when compared with S. pneumoniae.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Amides / Amino Acid Sequence / Aminoglycoside antibiotics / Analysis / Antibiotic resistance / Antibiotics / Bacterial genetics / Bacterial Proteins - genetics / Base Sequence / Beta lactamases / Bioinformatics / Choline / Chromosome Mapping / Chromosomes, Bacterial - genetics / Cloning / Comparative Genomic Hybridization / DNA microarrays / DNA Transposable Elements - genetics / DNA, Bacterial - chemistry / DNA, Bacterial - genetics / Enzymes / Gene clusters / Genes / Genetics and Genomics/Comparative Genomics / Genetics and Genomics/Genome Projects / Genetics and Genomics/Genomics / Genome, Bacterial - genetics / Genomes / Genomic analysis / Genomics / Hybridization / Laboratories / Localization / Microbial drug resistance / Microbiology/Microbial Evolution and Genomics / Molecular Sequence Data / Pathogens / Penicillin / Phages / Phylogeny / Pneumonia / Protein binding / Proteins / PspA protein / Sequence Analysis, DNA / Sequence Homology, Amino Acid / Species Specificity / Streptococcus agalactiae / Streptococcus infections / Streptococcus mitis / Streptococcus mitis - classification / Streptococcus mitis - genetics / Streptococcus mutans / Streptococcus pneumoniae / Streptococcus pneumoniae - genetics / Synteny / Virulence / Virulence factors / Virulence Factors - genetics