Effects of Antimicrobial Peptide GH12 on the Cariogenic Properties and Composition of a Cariogenic Multispecies Biofilm.

Dental caries is a biofilm-mediated disease that occurs when acidogenic/aciduric bacteria obtain an ecological advantage over commensal species. In previous studies, the effects of the antimicrobial peptide GH12 on planktonic bacteria and monospecies biofilms were confirmed. The objectives of this study were to investigate the effects of GH12 on a cariogenic multispecies biofilm and to preliminarily explain the mechanism. In this biofilm model, Streptococcus mutans ATCC 70061 was the representative of cariogenic bacteria, while Streptococcus gordonii ATCC 35105 and Streptococcus sanguinis JCM 5708 were selected as healthy microbiota. The results showed that GH12 was more effective in suppressing S. mutans than the other two species, with lower MIC and minimal bactericidal concentration (MBC) values among diverse type strains and clinical isolated strains. Therefore, GH12, at no more than 8 mg/liter, was used to selectively suppress S. mutans in the multispecies biofilm. GH12 at 4 mg/liter and 8 mg/liter reduced the cariogenic properties of the multispecies biofilm in biofilm formation, glucan synthesis, and lactic acid production. In addition, GH12 suppressed S. mutans within the multispecies biofilm and changed the bacterial composition. Furthermore, 8 mg/liter GH12 showed a selective bactericidal impact on S. mutans, and GH12 promoted hydrogen peroxide production in S. sanguinis and S. gordonii, which improved their ecological advantages. In conclusion, GH12 inhibited the cariogenic properties and changed the composition of the multispecies biofilm through a two-part mechanism by which GH12 directly suppressed the growth of S. mutans as well as enhanced the ecological competitiveness of S. sanguinis and S. gordoniiIMPORTANCE Dental caries is one of the most prevalent chronic infectious diseases worldwide, with substantial economic and quality-of-life impacts. Streptococcus mutans has been considered the principal pathogen of dental caries. To combat dental caries, an antimicrobial peptide, GH12, was designed, and its antibacterial effects on planktonic S. mutans and the monospecies biofilm were confirmed. As etiological concepts of dental caries evolved to include microecosystems, the homeostasis between pathogenic and commensal bacteria and a selective action on cariogenic virulence have increasingly become the focus. The novelty of this research was to study the effects of the antimicrobial peptides on a controlled cariogenic multispecies biofilm model. Notably, the role of an antimicrobial agent in regulating interspecific competition and composition shifts within this multispecies biofilm was investigated. With promising antibacterial and antibiofilm properties, the use of GH12 might be of importance in preventing and controlling caries and other dental infections.

Coompreendendo a Cárie Dental / Understanding the dental carie

Introdução: a cárie dental é uma doença infecciosa de caráter multifatorial e por sua grande incidência na sociedade moderna, é considerada ainda hoje um problema de saúde pública. Objetivo: este artigo visa apresentar, através de uma revisão bibliográfica, a organização de informações sobre a doença cárie, sua incidência, a influência da cárie na autoestima das pessoas, seus fatores imunológicos e microbiológicos, bem como a promoção de sua prevenção. Método: trata-se de um estudo de revisão bibliográfica. Resultados e Discussão: vários aspectos levantados durante esta pesquisa demonstram que, apesar de ser amplamente estudada e haverem postulados desde 1960 sobre a doença cárie, ainda é necessário um intenso trabalho Recebido em: 08/11/2017 para que sua incidência diminua, principalmente em países e regiões mais pobres. Conclusão: o conhecimento sobre a cárie é importante para o planejamento odontológico de seu tratamento, os quais auxiliarão estudantes, cirurgiões dentistas e demais membros da comunidade, na busca da prevenção da referida patologia.

Introduction: dental caries is an infectious disease of multifactorial character and for its great impact on modern society, is regarded today as a public health problem. Objective: this paper aims to present concepts about the caries disease, its focus, the influence of tooth decay in people's self-esteem, its immunological and microbiological factors, as well as the promotion of its prevention. Method: the sutudy was done through a bibliographical review. Results and Discussion: various aspects raised during this study shows that, despite being widely studied and they had been postulated since 1960 on the caries disease, it is still necessary to work greater for its incidence decrease, mainly in poorer countries and regions. This article is a completely bibliographical research and seeks to bring to the odontology scholars, a tool for the study of the knowledge of dental caries. Conclusion: knowledge about caries is important for the dental planning of its treatment, which will help students, dental surgeons and other members of the community, in the search for the prevention of this pathology.