Zerovalent bismuth nanoparticles inhibit Streptococcus mutans growth and formation of biofilm

Rene Hernandez-Delgadillo¹, Donaji Velasco-Arias², David Diaz², Katiushka Arevalo-Niño¹, Marianela Garza-Enriquez¹, Myriam A De la Garza-Ramos1, Claudio Cabral-Romero^1
1Instituto de Biotecnologia, Centro de Investigacion y Desarrollo en Ciencias de la Salud, CIDICS, Facultad de Odontologia, Universidad Autonoma de Nuevo Leon, UANL, Monterrey, Nuevo Leon, ²Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Distrito Federal, Mexico

Background and methods: Despite continuous efforts, the increasing prevalence of resistance among pathogenic bacteria to common antibiotics has become one of the most significant concerns in modern medicine. Nanostructured materials are used in many fields, including biological sciences and medicine. While some bismuth derivatives has been used in medicine to treat vomiting, nausea, diarrhea, and stomach pain, the biocidal activity of zerovalent bismuth nanoparticles has not yet been studied. The objective of this investigation was to analyze the antimicrobial activity of bismuth nanoparticles against oral bacteria and their antibiofilm capabilities.
Results: Our results showed that stable colloidal bismuth nanoparticles had 69% antimicrobial activity against Streptococcus mutans growth and achieved complete inhibition of biofilm formation. These results are similar to those obtained with chlorhexidine, the most commonly used oral antiseptic agent. The minimal inhibitory concentration of bismuth nanoparticles that interfered with S. mutans growth was 0.5 mM.
Conclusion: These results suggest that zerovalent bismuth nanoparticles could be an interesting antimicrobial agent to be incorporated into an oral antiseptic preparation.

Keywords: zerovalent bismuth nanoparticles, antimicrobial agent, biofilm, Streptococcus mutans