Intraspecies Variability Affects Heterotypic Biofilms of Porphyromonas gingivalis and Prevotella intermedia: Evidences of Strain-Dependence Biofilm Modulation by Physical Contact and by Released Soluble Factors

Abstract

It is well known that strain and virulence diversity exist within the population structure of Porphyromonas gingivalis. In the present study we investigate intra- and inter-species variability in biofilm formation of Porphyromonas gingivalis and partners Prevotella intermedia and Prevotella nigrescens. All strains tested showed similar hydrophobicity, except for P. gingivalis W83 which has roughly half of the hydrophobicity of P. gingivalis ATCC33277. An intraspecies variability in coaggregation of P. gingivalis with P. intermedia was also found. The association P. gingivalis W83/P. intermedia 17 produced the thickest biofilm and strain 17 was prevalent. In a two-compartment system P. gingivalis W83 stimulates an increase in biomass of strain 17 and the latter did not stimulate the growth of P. gingivalis W83. In addition, P. gingivalis W83 also stimulates the growth of P. intermedia ATCC25611 although strain W83 was prevalent in the association with P. intermedia ATCC25611. P. gingivalis ATCC33277 was prevalent in both associations with P. intermedia and both strains of P. intermedia stimulate the growth of P. gingivalis ATCC33277. FISH images also showed variability in biofilm structure. Thus, the outcome of the association P. gingivalis/P. intermedia seems to be strain-dependent, and both soluble factors and physical contact are relevant. The association P. gingivalis-P. nigrescens ATCC33563 produced larger biomass than each monotypic biofilm, and P. gingivalis was favored in consortia, while no differences were found in the two-compartment system. Therefore, in consortia P. gingivalis-P. nigrescens physical contact seems to favor P. gingivalis growth. The intraspecies variability found in our study suggests strain-dependence in ability of microorganisms to recognize molecules in other bacteria which may further elucidate the dysbiosis event during periodontitis development giving additional explanation for periodontal bacteria, such as P. gingivalis and P. intermedia, among others, to persist and establish chronic infections in the host.

Metatranscriptomic analysis of an in vitro biofilm model reveals strain-specific interactions among multiple bacterial species

“…The P. intermedia strain isolated from a diseased periodontal site exerts synergistic effects with P. gingivalis W83 but antagonistic effects with strain ATCC33277. Barbosa et al also reported that the outcome of the association between P. gingivalis and P. intermedia may be strain-dependent [37], which is consistent with our findings. It may explain why the keystone pathogen can be recovered from healthy sites but is not actively involved in disease.…”

Probiotics alter biofilm formation and the transcription of Porphyromonas gingivalis virulence-associated genes

“…P. gingivalis W83 is a capsulated/afimbriated highly virulent strain, whereas ATCC 33277 is a no capsulated/fimbriated less virulent strain [32,33]. These P. gingivalis strains also differ in relation to biofilm formation [34] and chromosomal transposable elements, which may alter their gene transcription [35], and physiology, such as their capacity to survive under oxidative stress [36], which altogether can contribute to explain differences on biofilm composition and transcription of virulence factors induced by probiotics.…”

Identification of New Factors Modulating Adhesion Abilities of the Pioneer Commensal Bacterium Streptococcus salivarius

“…Thus, S. salivarius JIM8777 appears to express both a cell surface adhesin and a carbohydrate receptor specific for the interaction with F. nucleatum . This may provide a partial explanation for the strain specificity of the co-aggregation reaction ( Weerkamp and McBride, 1980 ; Handley et al, 1987 ; Arzmi et al, 2015 ; Barbosa et al, 2015 ; Lima et al, 2017 ).…”