Marine Bacterial Dextranases: Fundamentals and Applications.

Dextran, a renewable hydrophilic polysaccharide, is nontoxic, highly stable but intrinsically biodegradable. The α-1, 6 glycosidic bonds in dextran are attacked by dextranase (E.C. 3.2.1.11) which is an inducible enzyme. Dextranase finds many applications such as, in sugar industry, in the production of human plasma substitutes, and for the treatment and prevention of dental plaque. Currently, dextranases are obtained from terrestrial fungi which have longer duration for production but not very tolerant to environmental conditions and have safety concerns. Marine bacteria have been proposed as an alternative source of these enzymes and can provide prospects to overcome these issues. Indeed, marine bacterial dextranases are reportedly more effective and suitable for dental caries prevention and treatment. Here, we focused on properties of dextran, properties of dextran-hydrolyzing enzymes, particularly from marine sources and the biochemical features of these enzymes. Lastly the potential use of these marine bacterial dextranase to remove dental plaque has been discussed. The review covers dextranase-producing bacteria isolated from shrimp, fish, algae, sea slit, and sea water, as well as from macro- and micro fungi and other microorganisms. It is common knowledge that dextranase is used in the sugar industry; produced as a result of hydrolysis by dextranase and have prebiotic properties which influence the consistency and texture of food products. In medicine, dextranases are used to make blood substitutes. In addition, dextranase is used to produce low molecular weight dextran and cytotoxic dextran. Furthermore, dextranase is used to enhance antibiotic activity in endocarditis. It has been established that dextranase from marine bacteria is the most preferable for removing plaque, as it has a high enzymatic activity. This study lays the groundwork for the future design and development of different oral care products, based on enzymes derived from marine bacteria.

Enzymes in therapy of biofilm-related oral diseases.

Biofilm-related infections of the oral cavity, including dental caries and periodontitis, represent the most prevalent health problems. For years, the treatment thereof was largely based on antibacterial chemical agents. Recently, however, there has been growing interest in the application of more preventive and minimally invasive biotechnological methods. This review focuses on the potential applications of enzymes in the treatment and prevention of oral diseases. Dental plaque is a microbial community that develops on the tooth surface, embedded in a matrix of extracellular polymeric substances of bacterial and host origin. Both cariogenic microorganisms and the key components of oral biofilm matrix may be the targets of the enzymes. Oxidative salivary enzymes inhibit or limit the growth of oral pathogens, thereby supporting the natural host defense system; polysaccharide hydrolases (mutanases and dextranases) degrade important carbohydrate components of the biofilm matrix, whereas proteases disrupt bacterial adhesion to oral surfaces or affect cell-cell interactions. The efficiency of the enzymes in in vitro and in vivo studies, advantages and limitations, as well as future perspectives for improving the enzymatic strategy are discussed.

Chemical Plaque Control Strategies in the Prevention of Biofilm-associated Oral Diseases.

Dental plaque is a biofilm that forms naturally on the surfaces of exposed teeth and other areas of the oral cavity. It is the primary etiological factor for the most frequently occurring oral diseases, such as dental caries and periodontal diseases. Specific, nonspecific, and ecologic plaque hypothesis explains the causation of dental and associated diseases. Adequate control of biofilm accumulation on teeth has been the cornerstone of prevention of periodontitis and dental caries. Mechanical plaque control is the mainstay for prevention of oral diseases, but it requires patient cooperation and motivation; therefore, chemical plaque control agents act as useful adjuvants for achieving the desired results. Hence, it is imperative for the clinicians to update their knowledge in chemical antiplaque agents and other developments for the effective management of plaque biofilm-associated diseases. This article explores the critical analysis of various chemical plaque control strategies and the current trends in the control and prevention of dental plaque biofilm.

Characterization of a marine-derived dextranase and its application to the prevention of dental caries.

The dextranase added in current commercial dextranase-containing mouthwashes is largely from fungi. However, fungal dextranase has shown much higher optimum temperature than bacterial dextranase and relatively low activity when used in human oral cavities. Bacterial dextranase has been considered to be more effective and suitable for dental caries prevention. In this study, a dextranase (Dex410) from marine Arthrobacter sp. was purified and characterized. Dex410 is a 64-kDa endoglycosidase. The specific activity of Dex410 was 11.9 U/mg at optimum pH 5.5 and 45 °C. The main end-product of Dex410 was isomaltotriose, isomaltoteraose, and isomaltopentaose by hydrolyzing dextran T2000. In vitro studies showed that Dex410 effectively inhibited the Streptococcus mutans biofilm growth in coverage, biomass, and water-soluble glucan (WSG) by more than 80, 90, and 95 %, respectively. The animal experiment revealed that for short-term use (1.5 months), both Dex410 and the commercial mouthwash Biotene (Laclede Professional Products, Gardena, CA, USA) had a significant inhibitory effect on caries (p = 0.0008 and 0.0001, respectively), while for long-term use (3 months), only Dex410 showed significant inhibitory effect on dental caries (p = 0.005). The dextranase Dex410 from a marine-derived Arthrobacter sp. strain possessed the enzyme properties suitable to human oral environment and applicable to oral hygiene products.

Dextranase enzyme and Enterococcus faecium probiotic have anti-biofilm effects by reducing the count of bacteria in dental plaque in the oral cavity of dogs.

OBJECTIVE: Periodontal disease is a common clinical complication and has a negative impact on the quality of life and the welfare of companion dogs. Periodontal disease occurs when pathogenic bacteria are accumulated in the gingival sulcus, which favors biofilm formation. The oral health of dogs can be significantly compromised by dental plaque accumulation. Thus, this investigation demonstrates the effect of Enterococcus faecium probiotic, dextranase enzyme, and their combination on dental biofilm in the oral cavity of dogs. ANIMALS: The 30 dogs were referred to Polyclinic with no oral ulcers, severe periodontitis, and internal diseases. PROCEDURES: Dextranase enzyme, E faecium probiotic, and their combination were administered in the oral cavity of dogs. Microbiological samples were obtained from tooth surfaces and gums before and after intervention with the substances. Bacterial colonies were enumerated by using a colony counter. Also, Porphyromonas gingivalis hmuY gene expression was evaluated by reverse transcription quantitative real-time PCR analysis. RESULTS: The total colony count of the bacterial culture indicated that the dextranase enzyme, E faecium probiotic, and their combination significantly reduced the total bacteria count in the oral cavity. Moreover, in the reverse transcription quantitative real-time PCR analysis it was observed that using the combination of E faecium probiotic and dextranase enzyme decreases the hmuY gene expression of P gingivalis bacteria. CLINICAL RELEVANCE: The results clearly indicated that the dextranase enzyme and E faecium probiotic could be used as preventive agents to reduce oral biofilm in dogs. Furthermore, no side effects were observed while using these substances.

Enzymolysis of glomerular immune deposits in vivo with dextranase/protease ameliorates proteinuria, hematuria, and mesangial proliferation in murine experimental IgA nephropathy.

The therapeutic effects of saccharolytic and proteolytic enzymes were investigated in models of IgA nephropathy. Mesangial glomerulonephritis was induced in mice by intravenous injection of preformed soluble immune complexes of dextran sulfate and either IgA (J 558) or IgM (MOPC 104 E) anti-dextran MAb (passive model) or by immunization with DEAE dextran (active model). In the passive model, only 30-40% of dextranase-treated mice given IgA or IgM immune complexes had mesangial Ig or dextran deposits, compared with 100% of saline-treated controls (P less than 0.01). There was no significant difference in mice given only protease. In the active model, dextranase and protease separately each reduced glomerular dextran and C3 deposits, and hematuria (P less than 0.01). Dextranase also reduced the glomerular IgA deposits (20 vs. 100% of saline-treated mice) and the frequency and severity of mesangial matrix expansion (both P less than 0.02), but did not reduce the modest IgG or IgM codeposits. Protease reduced IgG and IgM deposits, proteinuria and mesangial hypercellularity compared with saline (P less than 0.02), but did not diminish IgA, and had no effect on mesangial matrix expansion. The combination of dextranase plus protease attenuated all components of glomerular injury as judged by clinical and pathological parameters, but inactivated dextranase plus inactivated protease had no effect on any parameter. We conclude that enzymatic digestion of antigen and antibody can reduce immune deposits, mesangial proliferation, proteinuria, and hematuria in experimental glomerulonephritis.

Enhanced intracellular stability and efficacy of PEG modified dextranase in the treatment of a model storage disorder.

A model for storage disorders was produced in the livers of mice by the administration of liposomally encapsulated FITC-dextran. Liposomally delivered dextranase was found to be more efficient in degrading the accumulated substrate as compared to the free enzyme. Dextranase was covalently modified with PEG, and liposomes were used as carriers for delivering the free and the modified enzyme to the liver at similar rates. The PEG-dextranase conjugate showed greater intracellular stability as compared to the native enzyme. Liposomally delivered PEG-dextranase, by virtue of its enhanced intracellular stability, could not only degrade the accumulated FITC-dextran, but could also prevent its further accumulation over a period of time. This enhanced intracellular stability of enzymes would be of importance in extending the catalytic life of therapeutically active enzymes and thereby improve their therapeutic potential for the treatment of intracellular storage disorders.

Comparison of dextranases for their possible use in eliminating dental plaque.

Dextranases produced by P lilacinum NRRL 896 and NRRL 895 and by P funiculosum NRRL 1768 were studied for their possible incorporation into a dental plaque elimination system. The following properties of the enzymes were compared: effect of the pH level on the activity and the stability of the enzymes on the acid side of the pH range; molecular weight; affinity to Sephadex G-25 which served as a model for insoluble dextran in plaques; and the extent of hydrolytic action on dextrans containing alpha-1,3, alpha-1,4 and alpha-1,6 bonds in various proportions. The enzyme of P funiculosum NRRL 1768 certainly has its limitations as a plaque-degrading enzyme, for example, diminished activity at a high pH level and lack of activity on alpha-1,3 bonds. However, from our studies, and from a survey of the relevant literature with respect to the aforementioned properties in other dextranases, the enzyme of P funiculosum NRRL 1768 emerges as a suitable choice for incorporation as dextranase, possibly together with other enzymes, into an enzymatic dental plaque elimination system.

Clinical studies of plaque control agents: an overview.

Dental plaque is massed packed bacterial cells which accumulate on the supra- and subgingival surfaces of the teeth as well as on the oral mucosa. The microorganisms of plaque have been shown to be associated with both dental caries and periodontal disease. This overview of clinical studies of plaque control agents reviews the properties and effects of chemical compounds which have demonstrated a potential for the control of plaque microorganisms. The search for clinically effective antiplaque agents has been stimulated by findings in laboratory and animal studies of plaque dynamics. Based upon these in vitro and in vivo experiments, chemotherapeutic agents such as antibiotics, antiseptics, enzymes, detergents, bacteriosides, antimetabolites, and oxidizing agents have been evaluated against human plaque microorganisms using the ultimate biological model -- man. Continued study of chemotherapeutic agents should be encouraged because many of these drugs have been shown to be safe for human use and may require only the development of a delivery system to potentiate their concentration in a specific local site. Use of these chemotherapeutic agents, which can be self-administered, becomes an attractive way of providing the public with a cost-effective method of preventing caries and periodontal disease.

[Hydrolysis of streptococcal polysaccharides by micromycete dextranases]. / Gidroliz polisakharidov streptokokkov dekstranazami mikromitsetov.

The effect of dextranase enzyme preparations obtained from Penicillium piscarium BIM G-102, Penicillium funiculosum, Aspergillus insuetus G-116 and Aspergillus ustus on polysaccharides synthesized by cariesogenic Streptococcus sanguis and Streptococcus mitis was being studied. According to the data obtained dextranases from P. piscarium, P. funiculosum and Asp. ustus can be considered as a promising anticarious agent.

Chemical inhibition of plaque.

Attempts to control plaque by chemical means using enzymes, antibiotics and antiseptics are reviewed. Enzymes such as mucinase, dehydrated pancreas, enzymes of fungal origin, dextranase and mutanase showed limited clinical success despite promising in vitro and animal studies. Side effects from the use of enzymes were observed. Many antibiotics have been used in attempts to control plaque and several have been successful. However, problems exist from the long-term use of such drugs which precludes their routine use as agents for controlling plaque. The biguanide chlorhexidine is the most widely used and investigated method of chemical plaque control. Many studies have been demonstrated that it will successfully control plaque. No toxic side effects have been reported from its long-term use but local side effects such as staining of the teeth do occur. The quaternary ammonium compounds have at present no advantages over the biguanides and require more frequent usage to achieve the same degree of plaque control as chlorhexidine.

Inhibition of rat dental caries by dextranase from a strain of Spicaria violacea.

Dextranase AD17 obtained from a culture liquor of a strain of Spicaria violacea was assessed for its ability to inhibit the development of dental caries in conventional Sprague-Dawley rats which had been infected with one of the Streptococcus mutans strains. MT6R (serotype c), OMZ 176R (d), or MT-703R (e). These experiments showed that caries was significantly inhibited when rats were given cariogenic diets No. 2000 and drinking water containing AD17 at a concentration of 10 units/g, as compared to control rats not given dextranase. The inhibitory effects of AD17 were more prominent in smooth surface caries than in total caries. AD17 had a tendency to retard both the establishment of inoculated S. mutans and plaque deposition on tooth surfaces. However, S. mutans could be implanted in the rat oral cavity after repeated inoculation of the bacteria, even in the presence of AD17. These results suggest that the anticaries activity of AD17 is due to not only inhibition of adherence of S. mutans cells on tooth surfaces but also to physiochemical changes of dental plaque formed under the enzymatic action of AD17. Preliminary histophatological examination showed that AD17 had no significant toxicity in rats.

A review of chemotherapeutic plaque control.

Of the plaque-control agents studied, it would appear that chlorhexidine is the most suitable agent to prevent plaque accumulation and the development of gingivitis. It also is attractive to speculate on the possibilities of a commercially available mouthwash. A trio of antibiotics--kanamycin, spiramycin, and vancomycin--may prove of value in the treatment of severe gingival and periodontal disease. The ultimate role of xylitol has yet to be determined. Regardless of the agent selected, access to the gingival sulcus region seems critical.