Candida-streptococcal mucosal biofilms display distinct structural and virulence characteristics depending on growth conditions and hyphal morphotypes.

Candida albicans and streptococci of the mitis group form communities in multiple oral sites, where moisture and nutrient availability can change spatially or temporally. This study evaluated structural and virulence characteristics of Candida-streptococcal biofilms formed on moist or semidry mucosal surfaces, and tested the effects of nutrient availability and hyphal morphotype on dual-species biofilms. Three-dimensional models of the oral mucosa formed by immortalized keratinocytes on a fibroblast-embedded collagenous matrix were used. Infections were carried out using Streptococcus oralis strain 34, in combination with a C. albicans wild-type strain, or pseudohyphal-forming mutant strains. Increased moisture promoted a homogeneous surface biofilm by C. albicans. Dual biofilms had a stratified structure, with streptococci growing in close contact with the mucosa and fungi growing on the bacterial surface. Under semidry conditions, Candida formed localized foci of dense growth, which promoted focal growth of streptococci in mixed biofilms. Candida biofilm biovolume was greater under moist conditions, albeit with minimal tissue invasion, compared with semidry conditions. Supplementing the infection medium with nutrients under semidry conditions intensified growth, biofilm biovolume and tissue invasion/damage, without changing biofilm structure. Under these conditions, the pseudohyphal mutants and S. oralis formed defective superficial biofilms, with most bacteria in contact with the epithelial surface, below a pseudohyphal mass, resembling biofilms growing in a moist environment. The presence of S. oralis promoted fungal invasion and tissue damage under all conditions. We conclude that moisture, nutrient availability, hyphal morphotype and the presence of commensal bacteria influence the architecture and virulence characteristics of mucosal fungal biofilms.

Prevalence of adapted swallowing in a population of school children.

Adapted swallowing (AS) and its effects on dentofacial balance are frequently observed in children with orofacial myofunctional alterations. The preliminary objective of this research was to identify the frequency of cases of adapted swallowing in a population of school children, and targeting early treatment to prevent morphofunctional alteration of the face and its consequences on dentofacial harmony. One hundred school children between seven and nine years old attending the Children and Adolescents' Supporting Program (PRODECAD) of the State University of Campinas (UNICAMP) Brazil were selected at random and examined. Orofacial myofunctional assessments were carried out through standardized protocol. Results indicated the prevalence of adapted swallowing associated with resting posture alterations of dentofacial structures and mastication with dentofacial disharmony was 57%. Adapted swallowing without alteration of dentofacial form was observed in 19% of cases, and 24% of cases had a swallowing pattern within normal limits. The high prevalence of alterations suggests the need for early professional intervention.