The Anti-Biofilm Role of Triclosan on the Activity of Streptococcal Isolates containing Sortase A in Control of Dental Caries

One of the most common childhood problems is tooth decay and Streptococcus mutans is the most common bacterium that cause the infection. The purpose of the study was to investigate the effect of triclosan on biofilm formation due to streptococcal sortase A enzyme activity in the control of dental caries.

In this experimental study, 150 samples were taken from the buccal and lingual surfaces of posterior teeth of pupils in Gorgan in 2019. S. mutans strains were identified using conventional microbiological and biochemical tests. The SrtA gene was identified using polymerase chain reaction (PCR) with specific primers. Minimum inhibitory concentration (MIC) of triclosan against the isolates was determined by the broth microdilution method. Biofilm formation and antibiofilm effect of triclosan were assessed using the modified microtiter plate assay.

The frequency of S. mutans was 15.3%, of which, 87% were capable of biofilm production. 19 isolates (82.6%) with srtA gene were identified. The concentration of triclosan, that inhibited 50% growth of isolates (MIC50) was 8μg /ml , which was 8-fold less than the concentration required to inhibit the growth of 90% of isolates (MIC90=64μg/ml), so that 90% of the isolates lacked the ability to form biofilms at MIC concentration (P<0.05).

The results showed that there is a relationship between the presence of sortase A and the formation of bacterial biofilm and triclosan showed a good anti-biofilm effect in vitro condition.