COAGGREGATION AND COAGGREGATION INHIBITION BETWEEN PERIO-PATHOGENIC AND CARIOGENIC BACTERIA

Objective To screen the coaggregating pairs between perio-pathogenic and cariogenic bacteria and to investigate the susceptibility of these coaggregations to inhibitors. Methods 4 strains of perio-pathogenic bacteria, Fusobacterium nuleatum （Fn） ATCC 10953, Actinobacilllus actinomycetem comitans （Aa） Y4, Porphyromonas gingivalis （Pg） ATCC 33277,Prevotella intermedia （Pi） ATCC 25261 and 4 strains of cariogenic bacteria, Streptococcus mutans （Sm） lngbritt, Streptococcus sanguis （Ss） 34, Actinomyces viscosus （ Av） 19246 and Lactobacillus acidophilus （La） ATCC 4356 were used to determine the coaggregating degrees of various combinations of the above bacteria by a visual assay and a turbidimetric assay. Then more than ＋ 2 （ or 20% ） coaggregation degrees＇ pairs were used to investigate the inhibitory effect of lactose and arginine and to identify the minimum of their coaggregation-inhibitory concentration. Results The coaggregation degrees of Fn-Av, Pg-Av, Fn-Sm, Fn-Ss, Fn-La and Pg-Ss pairs were higher than ＋ 2 （ 20% ）. 3.0 - 6.0mmol/L of arginine were considerably effective to the above pairs except Fn-Av pair and the disaggregation degrees were 49% - 92%. The maximum of their disaggregation degree to Fn-Av pair was just 18%. 120 - 300mmol/L of lactose were significantly effective to Pg-Ss pair, the disaggregation degrees were 57% - 91%. They partially inhibited Pg-Av pair and were almost ineffective to FnG^＋pairs. Conclusion The coaggregations between perio-pathogenic and cariogenic bacteria are highly specific. Most of them are relatively sensitive to arginine.