Journal of Dental Research, Vol 70, 38-43, Copyright © 1991 by International & American Associations for Dental Research Online Journals
Enhancing the virulence of Streptococcus sobrinus in rats
K. M. Madison, W. H. Bowen, S. K. Pearson and J. L. Falany
University of Rochester, Department of Dental Research, New York 14642.
The purpose of this study was to explore the virulence of strains of
Streptococcus sobrinus that had been re-isolated from a desalivated rat.
Furthermore, we wished to determine the influence of desalivation on the
acidogenicity of fasting and sucrose-pulsed dental plaque in rats infected
by strains of S. sorbrinus. Experimental groups were formed and infected as
follows: Group 1, desalivated animals, S. sorbrinus ATCC27352; Group 2,
intact animals, infected as in Group 1; Group 3, desalivated animals, S.
sorbrinus re-isolated from a desalivated animal that had been infected with
the ATCC 27352 strain for five weeks; Group 4, intact animals, infected as
in Group 3; Group 5, desalivated animals, S. sobrinus re-isolated from a
desalivated animal that had been infected with the ATCC27352 strain for ten
weeks; Group 6, intact animals, infected as in Group 5; Group 7, intact
animals, no infection. All animals were fed cariogenic diet 2000 and
sucrose-sweetened drinking water ad libitum. After five weeks, desalivated
and intact animals that had been infected with isolates obtained from
desalivated animals had significantly higher (p less than 0.05)
smooth-surface-caries scores than did intact and desalivated animals
infected with cultures of the original stock ATCC strain. Moreover, fasting
plaque pH values were statistically lower in desalivated animals (Groups 1
and 3) than in intact animals (Groups 2, 6, and 7) (Turkey analysis, p less
than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
