[ODP-007] Diversification of Porphyromonas gingivalis standard strains revealed by difference in proliferation
Porphyromonas gingivalis is one of the etiologic agents of chronic periodontitis. Minimal media are nutrient limited in order to allow the investigation of growth characteristics of bacteria. However, growth of P. gingivalis standard strains such as W83 and ATCC 33277 strains in minimal media was not always reproducible. To explain this phenomenon, we analyzed the growth of seven wild-type ATCC 33277 strains and two wild-type W83 strains in 10 minimal media and three complex media. All nine strains grew in LF (Lactalbumin-Ferric chloride), GC (bovine γ–immunoglobulin G-Calcium chloride), and mC (milk-Casein) minimal media. In contrast, other six minimal media containing bovine serum albumin (BSA) supported the growth of several less strains; among these, two media also showed lack of reproducibility in growth among ATCC 33277 strains. In complex media, two ATCC 33277 strains showed the difference in requirement for menadione, a growth factor for some P. gingivalis strains. In sum, four ATCC 33277 strains grew similarly in all 13 media, but two W83 and other three ATCC 33277 strains grew differently in at least one medium. These results suggest that the lack of reproducibility of P. gingivalis growth on minimal media is caused both by the presence of BSA, and, unexpectedly, by the difference among the identical P. gingivalis standard strains.