Effect of Lectins from Diocleinae Subtribe against Oral Streptococci

Abstract

Surface colonization is an essential step in biofilm development. The ability of oral pathogens to adhere to tooth surfaces is directly linked with the presence of specific molecules at the bacterial surface that can interact with enamel acquired pellicle ligands. In light of this, the aim of this study was to verify inhibitory and antibiofilm action of lectins from the Diocleinae subtribe against Streptococcus mutans and Streptococcus oralis. The inhibitory action against planctonic cells was assessed using lectins from Canavaliaensi formis (ConA), Canavalia brasiliensis (ConBr), Canavalia maritima (ConM), Canavalia gladiata (CGL) and Canavalia boliviana (ConBol). ConBol, ConBr and ConM showed inhibitory activity on S. mutans growth. All lectins, except ConA, stimulated significantly the growth of S. oralis. To evaluate the effect on biofilm formation, clarified saliva was added to 96-well, flat-bottomed polystyrene plates, followed by the addition of solutions containing 100 or 200 µg/mL of the selected lectins. ConBol, ConM and ConA inhibited the S. mutans biofilms. No effects were found on S. oralis biofilms. Structure/function analysis were carried out using bioinformatics tools. The aperture and deepness of the CRD (Carbohydrate Recognition Domain) permit us to distinguish the two groups of Canavalia lectins in accordance to their actions against S. mutans and S. oralis. The results found provide a basis for encouraging the use of plant lectins as biotechnological tools in ecological control and prevention of caries disease.

Plant lectins as alternative tools against bacterial biofilms

“…The difference in crystalline structure between ConA and ConBr is only in two amino acids and neither of them is close to the carbohydrate binding site on both lectins. However, this difference makes ConBr structure more open than the Con A (Cavalcante et al, 2011).…”

“…Among these biological activities, it is noted that lectins exhibit antibacterial activity (Alencar et al, 2005;Holanda et al, 2005, Wong et al, 2010, and lectins have ability to interfere with process of microbial biofilms formation (Teixeira et al, 2006Islam et al, 2009;Cavalcante et al, 2011).…”

“…This is justified by property set translated by the ability to recognize structural elements of organizational surface from pathogens (Cavalcante et al, 2011). However, when it comes to interaction with bacterial biofilms, this strategy has been incipiently exploited (Lopes et al, 2005).…”

“…Studies on this subject also failed to respond effectively, and the physiological role of lectins are against the caries process. Some authors suggest various proposals regarding to this question and present meaningful data, especially with regard to the actions of lectins of higher plants Cavalcante et al, 2011;Klafke et al, 2013).…”

Biological Applications of Plants and Algae Lectins: An Overview

“…Studies of microbial biofilms through the interaction with lectins have two main objectives: visualization and characterization of polymeric matrix (EPS) formed by different species of microorganisms [162,163] and inhibition of oral biofilm formation by blocking the bacterial binding sites present in the pellicle of saliva in the form of glycoproteins and / or carbohydrates [164].…”