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 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. Non-black pigmented strains showed similar phenotypic characteristics with the parent strain, including production of hydrolytic enzymes and hemagglutinating activity. Cell suspensions of each of these strains reacted with antisera against vesicles (hemagglutinin) from strain E18. SDS-PAGE revealed that the protein patterns of all strains tested were quite similar. Bacteriophage similar in morphology and size were induced in these strains after irradiation by ultraviolet light. These results indicate that 1801, 1802 and 1803 are mutants derived from strain E18.