Proteomics of <it>Porphyromonas gingivalis </it>within a model oral microbial community

• Main Authors: Wang Tiansong, Xia Qiangwei, Hendrickson Erik L, Kuboniwa Masae, Xie Hua, Hackett Murray, Lamont Richard J
• Format: Article
• Language: English
• Published: BMC 2009-05-01
• Series: BMC Microbiology
• Online Access: http://www.biomedcentral.com/1471-2180/9/98

<p>Abstract</p> <p>Background</p> <p><it>Porphyromonas gingivalis </it>is a periodontal pathogen that resides in a complex multispecies microbial biofilm community known as dental plaque. Confocal laser scanning microscopy showed that <it>P. gingivalis </it>can assemble into communities in vitro with <it>Streptococcus gordonii </it>and <it>Fusobacterium nucleatum</it>, common constituents of dental plaque. Whole cell quantitative proteomics, along with mutant construction and analysis, were conducted to investigate how <it>P. gingivalis </it>adapts to this three species community.</p> <p>Results</p> <p>1156 <it>P. gingivalis </it>proteins were detected qualitatively during comparison of the three species model community with <it>P. gingivalis </it>incubated alone under the same conditions. Integration of spectral counting and summed signal intensity analyses of the dataset showed that 403 proteins were down-regulated and 89 proteins up-regulated. The proteomics results were inspected manually and an ontology analysis conducted using DAVID. Significant decreases were seen in proteins involved in cell shape and the formation of the cell envelope, as well as thiamine, cobalamin, and pyrimidine synthesis and DNA repair. An overall increase was seen in proteins involved in protein synthesis. HmuR, a TonB dependent outer membrane receptor, was up-regulated in the community and an <it>hmuR </it>deficient mutant was deficient in three species community formation, but was unimpaired in its ability to form mono- or dual-species biofilms.</p> <p>Conclusion</p> <p>Collectively, these results indicate that <it>P. gingivalis </it>can assemble into a heterotypic community with <it>F. nucleatum </it>and <it>S. gordonii</it>, and that a community lifestyle provides physiologic support for <it>P. gingivalis</it>. Proteins such as HmuR, that are up-regulated, can be necessary for community structure.</p>