Ecotoxicological effects of erythromycin on a multispecies biofilm model, revealed by metagenomic and metabolomic approaches

Abstract In recent years, most biofilm studies have focused on fundamental investigations using multispecies biofilm models developed preferentially in simulated naturally occurring low-nutrient medium than in artificial nutrient-rich medium. Because biofilm development under low-nutrient growth media is slow, natural media are often supplemented with an additional carbon source to increase the rate of biofilm formation. However, there are knowledge gaps in interpreting the effects of such supplementation on the resulting biofilm in terms of structure and microbial community composition. We investigated the effects of supplementation of a simulated freshwater medium with sodium citrate on the resulting structure, bacterial community composition, and microbial network interactions of an early-stage multispecies biofilm model. Qualitative and quantitative analyses of acquired confocal laser scanning microscopy data confirmed that sodium citrate supplementation distinctly increased biofilm biomass. Sequencing data revealed that the microbial community structure of biofilms grown in sodium citrate-supplemented conditions was characterized with increased relative abundance and dominance of Proteobacteria compared with that of biofilms grown in sodium citrate-free conditions. Our findings suggest that the supplementation of a low-nutrient medium with a carbon source in experiments involving multispecies biofilms may lead to structural and compositional biases of the microbial community, causing changes in biofilm phenotype.

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Development and experimental evaluation of a steady-state, multispecies biofilm model

Biotechnology and Bioengineering ◽

10.1002/bit.260390906 ◽

1992 ◽

Vol 39 (9) ◽

pp. 914-922 ◽

Cited By ~ 136

Author(s):

Bruce E. Rittmann ◽

Jacques A. Manem

Keyword(s):

Steady State ◽

Experimental Evaluation ◽

Biofilm Model ◽

Multispecies Biofilm

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Effects of Antimicrobial Peptide GH12 on the Cariogenic Properties and Composition of a Cariogenic Multispecies Biofilm

Applied and Environmental Microbiology ◽

10.1128/aem.01423-18 ◽

2018 ◽

Vol 84 (24) ◽

Cited By ~ 10

Author(s):

Wentao Jiang ◽

Yufei Wang ◽

Junyuan Luo ◽

Xinwei Li ◽

Xuedong Zhou ◽

...

Keyword(s):

Dental Caries ◽

Antimicrobial Peptide ◽

Streptococcus Mutans ◽

Lactic Acid Production ◽

Minimal Bactericidal Concentration ◽

Content Type ◽

Biofilm Model ◽

Planktonic Bacteria ◽

Multispecies Biofilm ◽

Glucan Synthesis

ABSTRACTDental caries is a biofilm-mediated disease that occurs when acidogenic/aciduric bacteria obtain an ecological advantage over commensal species. In previous studies, the effects of the antimicrobial peptide GH12 on planktonic bacteria and monospecies biofilms were confirmed. The objectives of this study were to investigate the effects of GH12 on a cariogenic multispecies biofilm and to preliminarily explain the mechanism. In this biofilm model,Streptococcus mutansATCC 70061 was the representative of cariogenic bacteria, whileStreptococcus gordoniiATCC 35105 andStreptococcus sanguinisJCM 5708 were selected as healthy microbiota. The results showed that GH12 was more effective in suppressingS. mutansthan the other two species, with lower MIC and minimal bactericidal concentration (MBC) values among diverse type strains and clinical isolated strains. Therefore, GH12, at no more than 8 mg/liter, was used to selectively suppressS. mutansin the multispecies biofilm. GH12 at 4 mg/liter and 8 mg/liter reduced the cariogenic properties of the multispecies biofilm in biofilm formation, glucan synthesis, and lactic acid production. In addition, GH12 suppressedS. mutanswithin the multispecies biofilm and changed the bacterial composition. Furthermore, 8 mg/liter GH12 showed a selective bactericidal impact onS. mutans, and GH12 promoted hydrogen peroxide production inS. sanguinisandS. gordonii, which improved their ecological advantages. In conclusion, GH12 inhibited the cariogenic properties and changed the composition of the multispecies biofilm through a two-part mechanism by which GH12 directly suppressed the growth ofS. mutansas well as enhanced the ecological competitiveness ofS. sanguinisandS. gordonii.IMPORTANCEDental caries is one of the most prevalent chronic infectious diseases worldwide, with substantial economic and quality-of-life impacts.Streptococcus mutanshas been considered the principal pathogen of dental caries. To combat dental caries, an antimicrobial peptide, GH12, was designed, and its antibacterial effects on planktonicS. mutansand the monospecies biofilm were confirmed. As etiological concepts of dental caries evolved to include microecosystems, the homeostasis between pathogenic and commensal bacteria and a selective action on cariogenic virulence have increasingly become the focus. The novelty of this research was to study the effects of the antimicrobial peptides on a controlled cariogenic multispecies biofilm model. Notably, the role of an antimicrobial agent in regulating interspecific competition and composition shifts within this multispecies biofilm was investigated. With promising antibacterial and antibiofilm properties, the use of GH12 might be of importance in preventing and controlling caries and other dental infections.

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