Spectrophotometric Analysis of Streptococcus mutans Growth and Biofilm Formation in Saliva and Histatin-5 Relate to pH and Viscosity

Abstract

Objective: To analyze the ability of saliva in controlling the growth and the biofilm formation of Streptococcus mutans (S. mutans) as well as the effect of histatin-5 anti-biofilm relate to pH and saliva viscosity. Material and Methods: The S. mutans biofilm assayed by crystal violet 1% and its growth measured by spectrophotometer. The saliva viscosity was analyzed by viscometer, and pH of saliva was measured by pH meter. Results: Based on the optical density values, growth of S. mutans in saliva ranged <300 CFU/mL (0.1 nm) at concentrations of 25%, 12.5% and 6.25% for 24 hours. Whereas at the 48 h and 72 h period of incubation shown an increase in growth of S. mutans ranged 300-600 CFU/mL (0.2-0.36 nm). The inhibitory biofilm formation of S. mutans in saliva was significantly higher at concentrations of 12.5% and 6.25% at 24 h incubation times on a moderate scale, whereas the histatin-5 was effective to inhibit S. mutans biofilm on the 50 and 25 ppm. The saliva possessed a higher inhibitory of biofilm S. mutans than histatin-5 and good level viscosity (0.91-0.92 cP). Conclusion: The saliva was able to control the growth of S. mutans, and histatin-5 can inhibit the biofilm formation S. mutans. Furthermore, the saliva was also able to respond to the pH change with good viscosity of saliva.

Keywords

• Saliva
• Histatins
• Viridans Streptococci
• Biofilms
• Hydrogen-Ion Concentration