Probing oral microbial functionality--expression of spxB in plaque samples.
The Human Oral Microbiome Database (HOMD) provides an extensive collection of genome sequences from oral bacteria. The sequence information is a static snapshot of the microbial potential of the so far sequenced species. A major challenge is to connect the microbial potential encoded in the metagenome to an actual function in the in vivo oral biofilm. In the present study we took a reductionist approach and identified a considerably conserved metabolic gene, spxB to be encoded by a majority of oral streptococci using the HOMD metagenome information. spxB encodes the pyruvate oxidase responsible for the production of growth inhibiting amounts of hydrogen peroxide (H2O2) and has previously been shown as important in the interspecies competition in the oral biofilm. Here we demonstrate a strong correlation of H2O2 production and the presence of the spxB gene in dental plaque. Using Real-Time RT PCR we show that spxB is expressed in freshly isolated human plaque samples from several donors and that the expression is relative constant when followed over time in one individual. This is the first demonstration of an oral community encoded gene expressed in vivo suggesting a functional role of spxB in oral biofilm physiology. This also demonstrates a possible strategy to connect the microbial potential of the metagenome to its functionality in future studies by identifying similar highly conserved genes in the oral microbial community.
Department of Periodontics, College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America.
Lin
L
Zhu
Department of Microbiology and Immunology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America ; Department of Surgical Oncology, The First Hospital of China Medical University, Shenyang, People's Republic of China.
Yifan
Y
Xu
Department of Microbiology and Immunology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America.
Joseph J
JJ
Ferretti
Department of Microbiology and Immunology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America ; Department of Oral Biology, College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America.
Jens
J
Kreth
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development; D017124:Conserved Sequence; D016208:Databases, Factual; D003773:Dental Plaque / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D064307:Microbiota / Q000235:genetics*; D008969:Molecular Sequence Data; D011771:Pyruvate Oxidase / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013291:Streptococcus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism
D001426:Bacterial Proteins; D006861:Hydrogen Peroxide; D011771:Pyruvate Oxidase