Coaggregation between pairs of microorganisms was found to be inhibited by
chelating agents, such as acetylacetone, citrate, EDTA and carboxymethylcel
lulose. Assays were conducted on eight pairs of periodontopathogens and one
pair consisting of Escherichia coli and Saccharomyces cerevisiae. The inhi
bitory effects of the chelating agents were reversible except for Actinomyc
es naeslundii 12104, the adhesin of which was irreversibly inactivated. Eve
n though the bacteria possessed different kinds of adhesins, their sensitiv
ity to chelating agents appears to be a common property. Non-toxic chelatin
g agents, such as carboxymethylcellulose and citrate, may prove to be usefu
l anti-adhesins. (C) 2000 Published by Elsevier Science B.V. on behalf of t
he Federation of European Microbiological Societies.