Among the different treatments, EDTA and proteinase K resulted in reduction of co-aggregation. Proteinase K reduced the co-aggregation percentage from 77.3 to 49.9 which is about 35% reduction. A similar calculation for EDTA shows 31% reduction. Jenkinson et al. (1990) observed inhibition of co-aggregation of human pathogenic bacteria upon EDTA treatment and the treated cells failing to restore aggregation after adding sugars. Later, Burdman et al. (1998) confirmed the role of membrane proteins in cell adhesion. The results observed in our study with proteinase K and EDTA treatment supports the same.