Streptococcus Mutans and Streptococcus Sobrinus are Able to Adhere and Invade Human Gingival Fibroblast Cell Line

Abstract

Streptococcus mutans and Streptococcus sobrinus, the principal etiologic agents of caries decay of teeth, are generally acquired in oral cavity at the moment of tooth eruption. However, as S. mutans has been detected in oral cavity of predentate children, the eruption of teeth seems not to be a necessary prerequisite, suggesting that this species may be not confined to dental plaque. Here, we evaluate the ability of S. mutans and S. sobrinus in planktonic and biofilm lifestyle to adhere, invade and survive within human gingival fibroblast (HGF-l) cells. Planktonic and biofilm streptococci adhered and invaded host cells to different extents, showing higher efficiencies of biofilm than planktonic counterparts. Moreover, planktonic and biofilm streptococci showed the same percentage of survival within host cells. Transmission electron and confocal microscopy observations confirmed intracellular localization of planktonic and biofilm bacteria. The adhesion, invasion and survival abilities within human oral cells may be considered S. mutans and S. sobrinus virulence mechanisms to colonize and persist in the oral cavity in the absence of tooth surface.Streptococcus mutans and S. sobrinus belonging to the phylogenetic mutans group (1) are considered the principal etiologic agents of caries decay of teeth . (2-4). These bacterial species are characterized by common virulence factors, including the adhesion and colonization ability of teeth surfaces by sucroseindependent and sucrose-dependent mechanisms (6-8). Sucrose availability induces the up-expression of biofilm-associated genes thus promoting biofilm development on tooth surfaces (9-10). The biofilm lifestyle increases streptococcal resistance against antimicrobial substances allowing the survival and persistence in oral cavity (11)(12).Studies on timing of acquisition have shown that S. mutans and S. sobrinus can be acquired at any time from 6 months to over 3 years of age, corresponding to the eruption of teeth as they require a nonshedding surface to adhere, colonize and multiply (4-5, 13). However, tooth eruption seems not to be a necessary prerequisite for mutans streptococci

Zinc Oxide Nanorods-Decorated Graphene Nanoplatelets: A Promising Antimicrobial Agent against the Cariogenic Bacterium Streptococcus mutans

“…To this aim, the Safranin assay was performed and an almost 30% reduction of biofilm production was highlighted when challenging S. mutans with 100 µg/mL concentration of ZNGs with respect to the control (Figure 9B). This is in line with the notion that microorganisms in biofilms are more resistant to antibacterial agents than the planktonic form and much more concentrated biocide may be required for effective treatment [51]. In this case, the GNPs allow a more extended area that increases the nano-needles distribution, resulting in more efficient damage of a complex structure such as the biofilm.…”

“…However, as S. mutans has been detected in oral cavity of predentate children, the eruption of teeth seems not to be a necessary prerequisite, suggesting that this species may not be confined to dental plaque. In fact, it has been reported that S. mutans in planktonic lifestyle is able to adhere, invade, and survive within human gingival fibroblast cells [51]. …”

The Collagen Binding Protein Cnm Contributes to Oral Colonization and Cariogenicity of Streptococcus mutans OMZ175

“…As observed with HCAEC and HUVEC, we found that Cnm expression is directly linked to enhanced invasion of HGF-1 cells and HOK, suggesting that intracellular invasion may provide a protective reservoir for Cnm ϩ S. mutans strains. This would facilitate persistence in the oral cavity through mitigation of environmental challenges such as host defenses, administered antibiotics, competition with bacterial commensals, and mechanical/chemical removal (51). Moreover, attachment to, and invasion of, epithelial cells, particularly those directly involved in the healing process (e.g., gingival fibroblasts), may further facilitate the access of S. mutans to the bloodstream through injury sites.…”

Quantitative Evaluation of Bacteria Adherent and in Biofilm on Single-Wall Carbon Nanotube-Coated Surfaces

“…S. mutans and P. aeruginosa have been chosen as bacterial models for their well-known ability to adhere and grow in biofilm lifestyle and for their implication in human diseases, as discussed elsewhere [12–17]. …”