title: In Vitro Effects of Polyphosphate against Prevotella intermedia in Planktonic Phase and Biofilm.
abstract: Polyphosphate (polyP) has gained a wide interest in the food industry due to its potential as a decontaminating agent. In this study, we examined the effect of sodium tripolyphosphate (polyP3; Na5P3O10) against planktonic and biofilm cells of Prevotella intermedia, a major oral pathogen. The MIC of polyP3 against P. intermedia ATCC 49046 determined by agar dilution method was 0.075%, while 0.05% polyP3 was bactericidal against P. intermedia in time-kill analysis performed using liquid medium. A crystal violet binding assay for the assessment of biofilm formation by P. intermedia showed that sub-MICs of polyP3 significantly decreased biofilm formation. Under the scanning electron microscope, decreased numbers of P. intermedia cells forming the biofilms were observed when the bacterial cells were incubated with 0.025% or higher concentrations of polyP3. Assessment of biofilm viability with LIVE/DEAD staining and viable cell count methods showed that 0.05% or higher concentrations of polyP3 significantly decreased the viability of the preformed biofilms in a concentration-dependent manner. The zone sizes of alpha-hemolysis formed on horse blood agar produced by P. intermedia were decreased in the presence of polyP3. The expression of the genes encoding hemolysins and the genes of the hemin uptake (hmu) locus was downregulated by polyP3. Collectively, our results show that polyP is an effective antimicrobial agent against P. intermedia in biofilms as well as planktonic phase, interfering with the process of hemin acquisition by the bacterium.
authors.affiliation: Department of Maxillofacial Biomedical Engineering, School of Dentistry, and Institute of Oral Biology, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Eun-Young
authors.initials: EY
authors.lastname: Jang
authors.affiliation: Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Minjung
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Mi Hee
authors.initials: MH
authors.lastname: Noh
authors.affiliation: Department of Maxillofacial Biomedical Engineering, School of Dentistry, and Institute of Oral Biology, Kyung Hee University, Seoul, Republic of Korea Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul, Republic of Korea prudence75@khu.ac.kr ljinyong@khu.ac.kr.
authors.forename: Ji-Hoi
authors.identifier: http://orcid.org/0000-0003-0286-5297
authors.initials: JH
authors.lastname: Moon
authors.affiliation: Department of Maxillofacial Biomedical Engineering, School of Dentistry, and Institute of Oral Biology, Kyung Hee University, Seoul, Republic of Korea prudence75@khu.ac.kr ljinyong@khu.ac.kr.
authors.forename: Jin-Yong
authors.initials: JY
authors.lastname: Lee
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016866:Bacteroidaceae Infections / Q000188:drug therapy*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D009055:Mouth / Q000382:microbiology; D010933:Plankton / Q000187:drug effects* / Q000254:growth & development; D011122:Polyphosphates / Q000494:pharmacology*; D018713:Prevotella intermedia / Q000187:drug effects* / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D011122:Polyphosphates; C005692:triphosphoric acid