AUTHOR=Albaghdadi Shurooq Zakariya , Altaher Jenan Bader , Drobiova Hana , Bhardwaj Radhika G. , Karched Maribasappa 

TITLE=In vitro Characterization of Biofilm Formation in Prevotella Species

JOURNAL=Frontiers in Oral Health

VOLUME=2

YEAR=2021

URL=https://www.frontiersin.org/journals/oral-health/articles/10.3389/froh.2021.724194

DOI=10.3389/froh.2021.724194

ISSN=2673-4842

ABSTRACT=<p><bold>Background:</bold> Periodontitis, a chronic inflammatory oral infection is the outcome of disturbances in the homeostasis of the oral biofilm microbiota. A number of studies have found the occurrence of <italic>Prevotella</italic> species in elevated levels in periodontitis compared to healthy subjects. Even though different aspects of <italic>Prevotella</italic> as part of oral biofilm have been studied, <italic>in vitro</italic> biofilms formed by these species have not been characterized systematically. The objective of this study was to characterize biofilms formed by several <italic>Prevotella</italic> species and further to assess biofilm inhibition and detachment of preformed biofilms.</p><p><bold>Methods:</bold> Biofilms were grown in 24-well plates containing brucella broth in anaerobic conditions for 3 days, and were quantified using crystal violet staining. Images of SYTO 9 Green fluorescent stained biofilms were captured using confocal microscopy. Biofilm inhibition and detachment by proteinase and DNase I was tested. The biochemical characterization included quantification of proteins and DNA in the biofilms and biofilm-supernatants.</p><p><bold>Results:</bold><italic>Prevotella loescheii, Prevotella oralis</italic> and <italic>Prevotella nigrescens</italic> showed highest biofilm formation. <italic>P. nigrescens</italic> formed significantly higher amounts of biofilms than <italic>P. loescheii</italic> (<italic>P</italic> = 0.005) and <italic>P. oralis</italic> (<italic>P</italic> = 0.0013). Inhibition of biofilm formation was significant only in the case of <italic>P. oralis</italic> when treated with proteinase (<italic>P</italic> = 0.037), whereas with DNase I treatment, the inhibition was not significant (<italic>P</italic> = 0.531). Overall, proteinase was more effective in biofilm detachment than DNase I. Protein and DNA content were higher in biofilm than the supernatant with the highest amounts found in <italic>P. nigrescens</italic> biofilm and supernatants. <italic>P. oralis</italic> biofilms appeared to secrete large amounts of proteins extracellularly into the biofilm-supernatants.</p><p><bold>Conclusion:</bold> Significant differences among <italic>Prevotella</italic> species to form biofilms may imply their variable abilities to get integrated into oral biofilm communities. Of the species that were able to grow as biofilms, DNase I and proteinase inhibited the biofilm growth or were able to cause biofilm detachment.</p>