Journal of Dental Research, Vol 65, 109-112, Copyright © 1986 by International & American Associations for Dental Research Online Journals
Incidence and characterization of anti-microbial effects produced by Actinomyces viscosus and Actinomyces naeslundii
G. R. Tompkins and J. R. Tagg
Sixty-two facultative Actinomyces strains isolated from dental plaque were
tested for the production of bacteriocin-like inhibitory effects by a
deferred antagonism method. When incubated anaerobically, all isolates
produced identical inhibitory patterns against 15 indicator organisms, but
under microaerophilic conditions, little inhibitory activity was observed.
Activity was not evident after anaerobic incubation on a medium buffered by
0.5% (w/v) calcium carbonate. Gas-liquid chromatographic analyses of agar
blocks removed from the inhibitory zones indicated that, compared with
microaerophilic conditions, anaerobic incubation encouraged production of
high concentrations of lactic and succinic acids, and the concomitant fall
in the pH was probably responsible for the inhibitory effects.
