Porphyromonas gingivalis and Treponema denticola Exhibit Metabolic Symbioses

PLoS Pathogens

Malcolm J. McConville¹  Jenny L. Chambers¹  Nada Slakeski²  James S. Pyke²  Helen L. Mitchell²  Steven M. Cleal²  Christine A. Seers²  Eric C. Reynolds²  Kheng H. Tan²  Vincent Meuric²  Stuart G. Dashper² 

[1] Department of Biochemistry and Molecular Biology, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia;Oral Health CRC, Melbourne Dental School, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia

关键词: Glycine;    Gene expression;    Amino acid metabolism;    Biosynthesis;    Microarrays;    Catabolism;    Thiamine;    Biological transport;   

DOI  :  10.1371/journal.ppat.1003955

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Porphyromonas gingivalis and Treponema denticola are strongly associated with chronic periodontitis. These bacteria have been co-localized in subgingival plaque and demonstrated to exhibit symbiosis in growth in vitro and synergistic virulence upon co-infection in animal models of disease. Here we show that during continuous co-culture a P. gingivalis:T. denticola cell ratio of 6∶1 was maintained with a respective increase of 54% and 30% in cell numbers when compared with mono-culture. Co-culture caused significant changes in global gene expression in both species with altered expression of 184 T. denticola and 134 P. gingivalis genes. P. gingivalis genes encoding a predicted thiamine biosynthesis pathway were up-regulated whilst genes involved in fatty acid biosynthesis were down-regulated. T. denticola genes encoding virulence factors including dentilisin and glycine catabolic pathways were significantly up-regulated during co-culture. Metabolic labeling using 13C-glycine showed that T. denticola rapidly metabolized this amino acid resulting in the production of acetate and lactate. P. gingivalis may be an important source of free glycine for T. denticola as mono-cultures of P. gingivalis and T. denticola were found to produce and consume free glycine, respectively; free glycine production by P. gingivalis was stimulated by T. denticola conditioned medium and glycine supplementation of T. denticola medium increased final cell density 1.7-fold. Collectively these data show P. gingivalis and T. denticola respond metabolically to the presence of each other with T. denticola displaying responses that help explain enhanced virulence of co-infections.

【 授权许可】

CC BY