Characterization of Non-Black Pigmented Prevotella intermedia

Abstract

Prevotella intermedia strain E18 possesses non-fimbriated hemagglutinin that is closely related to pathogenicity. We found several strains subcultured from Prevotella intermedia strain E18 (1801, 1802 and 1803) that lost the ability to produce black pigment on blood agar plates. We examined the pheno- and geno-typic characteristics of these strains.
      The non-black pigmented strains had phenotypic characteristics similar to Prevotella intermedia strain E18. These included production of alkaline and acid phosphatase, phosphoamidase and α-glucosidase in an API ZYM system, and production of hydrolytic enzymes such as β-lactamase, DNase, lecithinase and lipase. As well, they had hemagglutinating activity. Fimbriae-like structures on the cell surfaces were not observed in either non-black pigmented strains or Prevotella intermedia strain E18 cells. Cell suspensions of each of these strains reacted with antisera against vesicles (Fractions B and C) and a purified hemagglutinin (derived from Fraction A) from Prevotella intermedia strain E18. SDS-PAGE and pulse-fielded gel electrophoresis revealed that the protein and chromosomal DNA patterns of all strains tested were quite similar. Bacteriophage similar in morphology and size were induced in these strains after irradiation with ultraviolet light. No plasmid bands were detected in any of the strains tested.
      These results indicate that strains 1801, 1802 and 1803 are mutants of Prevotella intermedia strain E18.