Evaluating Streptococcus mutans Strain Dependent Characteristics in a Polymicrobial Biofilm Community

Abstract

Aim: The purpose of this study was to investigate strain dependent differences of the cariogenic biofilm forming Streptococcus mutans within both simple and complex communities.Methods: A mono-species containing representative S. mutans clinical isolates (caries and non-caries), and a multispecies in vitro caries biofilm model containing Lactobacillus casei, Veillonella dispar, Fusobacterium nucleatum and Actinomyces naeslundii, and either of two representative S. mutans clinical isolates (caries and non-caries), was developed as a comparison model. Compositional analysis of total and live bacteria within biofilms, and transcriptional analysis of biofilm associated virulence factors were evaluated by live/dead PCR and quantitative PCR, respectively. Scanning electron microscopy (SEM) was used to analyze the architecture of biofilm. One-way analysis of variance and t-tests were used to investigate significant differences between independent groups of data.Results: Within a mono-species biofilm, different S. mutans strains responded similarly to one another during biofilm formation in different carbohydrate sources, with sucrose showing the highest levels of biofilm biomass and galactose showing the lowest. Within the polymicrobial biofilm system, compositional analysis of the bacteria within the biofilm showed that S. mutans derived from a caries-free patient was preferentially composed of both total and viable L. casei, whereas S. mutans derived from a caries patient was dominated by both total and viable S. mutans (p < 0.001). Normalized gene expression analysis of srtA, gtfB, ftf, spaP, gbpB, and luxS, showed a general upregulation within the S. mutans dominant biofilm.Conclusion: We were able to demonstrate that individual strains derived from different patients exhibited altered biofilm characteristics, which were not obvious within a simple mono-species biofilm model. Influencing the environmental conditions changed the composition and functionality S. mutans within the polymicrobial biofilm. The biofilm model described herein provides a novel and reproducible method of assessing the impact on the biofilm microbiome upon different environmental influences.

A nanocarrier system that potentiates the effect of miconazole within different interkingdom biofilms

“…To assess the effect of IONPs-CS-MCZ on pathogenic biofilms, three different in vitro multi-species biofilm models were tested, representative of caries, denture and gingivitis developed as previously described [4,27,28]. For all biofilm models, the bacterial and fungal cells were adjusted to 1 × 10 7 cells/mL in Todd Hewitt Broth (THB) medium supplemented with 0.01 mg/mL hemin and 2 µg/mL menadione [29].…”

Identification and localization of proteins associated with the formation of Streptococcus gordonii and Fusobacterium nucleatum biofilms

“…The oral cavity is a complex bacterial ecosystem composed of multiple microorganisms that intimately coexist [26][27][28][29][30]. Bio lms are one way they coexist [31,32], and they develop thanks to multiple mechanisms associated with protein expression [33][34][35][36][37]. However, the literature on this subject is still scarce [18,37,38].…”

Antibacterial activity of silver nanoparticles biosynthesized using Spirulina platensis microalgae extract against oral pathogens

“…Among oral bacteria, Streptococcus mutans are Gram positive bacteria most frequently found in the oral cavity's normal flora (Azizi et al, 2015). They has been reported as a primary cariogenic bacterial pathogen due to their ability to metabolize different carbohydrates of sugar (Zhou et al, 2018). Saphylococcus aureus is also an abundant Gram-positive bacteria which has a strong connection to dental implant infections (Wang and Ren, 2017).…”