The latest issue of Clinical Microbiology and Infections published the results of a study by Swedish scientists A. Sullivan, B. Wretling and C.E. Nord. The objective of this work was to determine the effect of triclosan, which is part of the formulation of toothpaste, on the composition of normal microflora and the resistance to antibiotics of green streptococci living in the oral cavity.

In the study, 9 healthy volunteers used toothpaste containing triclosan (Colgate Total) twice a day for two weeks. Saliva samples for analysis were taken on the first and last day of the study. The composition of the normal microflora of the oral cavity has been quantified and for the three most important types of green streptococcus (Streptococcus salivarius, S.sanguis and S.mutans) MIC of triclosan and a number of other antibacterial drugs (penicillin, erythromycin, gentamicin, tetracycline, fusidine).

When analyzing the results, no clinically significant change in the composition of the normal microflora of the oral cavity, except for a slight decrease in the number of lactic acid bacteria, was found. The antibiotic streptococcal susceptibility profile also did not undergo any marked changes. There were no statistically significant differences in the values of IPC50, IPC90 and the IPC range of triclosan and other antibiotics after the end of the use of toothpaste with triclosan compared to the initial indicators.

Among the study participants, carriers of streptococcus strains with reduced sensitivity to antibacterial drugs were identified. With short-term use of triclosan toothpaste, it doesn't matter much. However, with the prolonged use of oral hygiene products containing manifestly low doses of triclosan, there is a risk of environmental imbalance and the emergence of multiresistant strains of green streptococci. This is particularly dangerous due to the possibility of transferring antibiotic resistance factors to the S. pneumoniae strains.

The authors do not recommend the use of triclosan in the context of hygiene products until the final clarification of its mechanisms of action and potential effects on the formation of drug resistance of microorganisms.