FIG. 1.

Binding characteristics of wild-type A. actinomycetemcomitans strain IDH781 and isogenic aae mutant strain JK1046. (A) BEC binding assay. The bars indicate the mean numbers of A. actinomycetemcomitans (Aa) cells per BEC for duplicate samples, and the error bars indicate ranges. Plasmid pJAK16 was the vector, and plasmid pVK43 was pJAK16 containing aae. (B) Biofilm formation in the wells of a 96-well microtiter plate. The optical density at 590 nm [OD (590 nm)] was proportional to biofilm formation. Strain JK1047 is an isogenic flp-1 mutant of strain IDH781N that lacks adhesive pili. Plasmid pRA33 is pJAK16 containing flp-1. (C) Binding to BECs isolated from humans and various mammalian species. Solid bars, wild-type strain IDH781; open bars, aae mutant strain JK1046. The asterisks indicate Old World primates. The bars indicate the mean numbers of A. actinomycetemcomitans (Aa) cells per BEC for duplicate samples, and the error bars indicate ranges. The values for species lacking bars were <1 bacterial cell per 1,000 BECs.