Influence of Helicobacter pylori culture supernatant on the ecological balance of a dual-species oral biofilm

Abstract Dental caries is a chronic progressive disease occurring in the tooth hard tissue due to multiple factors, in which bacteria are the initial cause. Both Streptococcus mutans and Streptococcus sanguinis are main members of oral biofilm. Helicobacter pylori may also be detected in dental plaque, playing an important role in the development of dental caries. Objective The aim of this study was to investigate the effect of H. pylori culture supernatant on S. mutans and S. sanguinis dual-species biofilm and to evaluate its potential ability on affecting dental health. Material and methods The effect of H. pylori supernatant on single-species and dual-species biofilm was measured by colony forming units counting and fluorescence in situ hybridization (FISH) assay, respectively. The effect of H. pylori supernatant on S. mutans and S. sanguinis extracellular polysaccharides (EPS) production was measured by both confocal laser scanning microscopy observation and anthrone-sulfuric acid method. The effect of H. pylori supernatant on S. mutans gene expression was measured by quantitative real-time PCR (qRT-PCR) assays. Results H. pylori supernatant could inhibit both S. mutans and S. sanguinis biofilm formation and EPS production. S. sanguinis inhibition rate was significantly higher than that of S. mutans. Finally, S. mutans bacteriocin and acidogenicity related genes expression were affected by H. pylori culture supernatant. Conclusion Our results showed that H. pylori could destroy the balance between S. mutans and S. sanguinis in oral biofilm, creating an advantageous environment for S. mutans, which became the dominant bacteria, promoting the formation and development of dental caries.

Amibas de vida libre Acanthamoeba, Balamuthia, Naegleria, Sappinia y Paravahlkampfia: agentes de infección en humano y transmisoras de microorganismos / Free-living amoebae Acanthamoeba, Balamuthia, Naegleria, and Paravahlkampfia Sappinia: agents of human infection and transmission of microorganisms

Se han reportado como agentes causales de enfermedad en humanos: Naegleria fowleri, agente causal de meningoencefalitis amibiana primaria en individuos inmunocompetentes: varias especies de género Acanthamoeba que pueden producir encefalitis granulomatosa amibiana en individuos inmunosuprimidos, úlceras corneales, lesiones en piel y otros órganos en personas inmunocompetentes; Ballamuthia mandrillares agente causal de encefalitis y lesiones en piel en personas inmunocompetentes, Sappinia pedata responsable de un caso de encefalitis en un individuo inmunocompetente y Paravahlkamphfia sp en un caso de queratitis y Paravahlkamphfia francinae en un caso de meningoencefalitis aminiana primera, en paciente en paciente inmunocompetente. No se conoce totalmente los factores de los que depende que las enfermedades producidas por amibas de vida libre se presenten, influyen la presencia de algunas enfermedades, contacto con aguas en las cuales se encuentran estas amibas, y la presencia de enzimas capaces de ejercer efecto citopático. Además el uso de lentes de contacto, algunas costumbres y necesidades humanos rompen el equilibrio ecológico, aumentando así la probabilidad de contacto del hombre con estas amibas. Se han evidenciado en ellas microorganismo en un proceso de endosimbiosis lo que por lo que amibas de vida libre intervienen en la transmisión de ciertos microorganismos patógenos y las amibas se transforman en un incubador potencial y transmisorasde agentes infecciosos. Debe investigarse sobre aspectos biológicos y la relación con el humano.

Have been reported as causative agents of disease in humans: Naegleria fowleri, the causative agent of primary amoebic meningoencephalitis in immunocompetent individuals, several species of Acanthamoeba that con cause granulomatous amoebic encephalitis in immunosuppressed individuals, corneal ulcers, skin lesions and other organs in people immunocompetent; Ballamuthia madrillares causative agent of encephalitis and skin lesions in immunocompetent persons, Sappinia pedata, responsible for a case of encephalitis in an immunocompetent individual Paravahlkamphfia sp in a case of keratitis and Paravanhlkamphfia francinae in a case of primary amoebic meningoencephalitis in an immunocompetent patient. Not fully understood the factors that it depends on diseases caused by free-living amoebae are present, influencing the presence of some diseases, contact with water where are these amoebae, and the presence of enzymes capable of the cytopathic effect. Furthermore, the use of contact lenses, some customs and human needs break the ecological balance, thereby increasing the likelihood of human contact with these amoebae. Have been evidenced in these microorganisms in the process of endosymbiosis that so the free-living amoebae in the transmission of certain pathogenic microorganisms and amoebas and become a potential incubator and transmission of infectious agents. Biological aspects should be investigated and the relationship with the human.