Bacteriophage Isolation from Denture Biofilm

Objective: this research evaluated if it is possible to isolate bacteriophages from dentures biofilm, and use it as an emergent way to control biofilm growing. Method: biofilm samples were collected from sixteen maxillary complete dentures in an aseptic zone by brushing their internal surfaces using a soft toothbrush. The biofilm suspensions obtained were added to standard strains (Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa) and the presence of lysis was evaluated. Results: bacteriophages were not isolated from the denture samples. Conclusion: this study presented an opportunity to invest in a new method to detect bacteriophages from mature biofilms of complete dentures. Descriptors: Denture, biofilm, bacteriophage.


INTRODUCTION
The science of biofilms has been a field of intense discussion in the scientific research since these communities were described.Despite being common, biofilm formation is a complex process involving several steps.Firstly, it is necessary the surface conditioning by macromolecules originating from surrounding fluid resulting in microbial adhesion.Microorganisms have an initial adhesion and begin to produce signaling molecules, developing and producing a matrix of extracellular polymeric substances (EPS) 1 .
The biofilm control has driven several studies in different areas of knowledge.There are physical-chemical methods for its removal 2 , antimicrobial photodynamic therapy 3 , induction of biofilm detachment 4 , degradation of EPS matrix 5 and quorum sensing inhibitors 6 .New investigations with the purpose of preventing biofilm formation had been reported through the development of non-adherent surfaces 7,8,9 and specifics bacterial inhibitors 10 .
Bacteriophages are viruses capable of limiting the bacterial overgrowth, without altering the local biological characteristics 11 .The potential applicability of bacteriophages to control biofilm growth has already related 12 .Over 20 years ago, clinical condition improvements of patients after using phage therapy in suppurative skin 13 and urinary infections 14 were reported.The therapeutic usage of bacteriophages in some European countries, such as Poland, is very usual and traditional, such as the Phage Therapy Unit, which develops research on phagotherapy 15 .Although the scientific literature is abundant in bacteriophage application to control infections and biofilms 16,17,18 , gaps still exist and should be investigated and understood.
In view of the pathogenic potential of the denture biofilm and its implication in the health and safety of patients, strategies involving the bacteriophages usage are promising.In this way, the objective of this study was to standardize the isolation of bacteriophages from mature biofilms of complete dentures.

RESULTS
Biofilm samples were collected from sixteen maxillary complete dentures.The denture wearers were 4 men and 12 women with age ranging from 55 to 75 years (age mean: 64.5 years old).
All the plates showed abundant bacteria growth after incubating.However, the samples of mature biofilms from complete dentures did not demonstrate any presence of bacteriophages.

DISCUSSION
The lack of phages described from denture mature biofilms encouraged us to try a method to isolate and characterize it, considering the hypothesis that bacteriophages can be found wherever their hosts are present.
Since there are about 700 bacterial species inhabiting the oral cavity, and many of them are able to form biofilms 20,21  Even if the isolation of phage from the oral cavity has been reported for a long time, the literature does not present a solid method in order to guide a research in a laboratory.Szafránski and cols 25 reviewed 94 articles about isolation and application of phage therapy against oral cavity bacteria and showed that few studies were carried out.In view of this, only a small fraction of the available phages was isolated and characterized.

CONCLUSION
This study presented an opportunity to invest in a new method to detect bacteriophages from mature biofilms of complete dentures.

Further
studies are required to explore the phage activity, focusing on multi-species biofilms, application in animal models and possibly combining with other antimicrobial agents.The use of phages as oral biofilm controller should be evaluated, aiming at the development of affordable drugs or therapeutic products available for oral health care.
, this study was submitted for appreciation of the Institutional Review Board School of 19nders and any age were eligible.Exclusion criteria were dentures that had been used for less than 01 year, as well as the relined, repaired, or fractured ones.About the biofilm presence, it was considered dentures that presented scores equal to or greater than 01 of biofilm visible in five predetermined areas according to the Additive Index19.Standard bacterial strains: Escherichia coli(ATCC 25922) -Ec, Enterococcus faecalis (ATCC 29212 -Ef, Streptococcus mutans (ATCC 25175) -Sm, Pseudomonas aeruginosa (ATCC 27853) -Pa and Staphylococcus aureus (ATCC 25923) -Sa were cultured in Tryptic Soy Broth (TSB) or Brain Heart Infusion Broth (BHI) -(HiMedia Laboratories Pvt.To collect the biofilm, each denture was placed inside a Petri plate in a class II type A1 biological safety cabinet (Pachane, Pa 400-ECO, Piracicaba, SP, Brazil).The dentures were rinsed Oliveira VC et al.Bacteriophage Isolation from Denture Biofilm Rev Pre Infec e Saúde.2017;3(2):34-