Rakesh K.N et al. Journal of Biological & Scientific Opinion · Volume 1 (4). 2013 Available online through www.jbsoweb.com Research Article ANTICARIES ACTIVITY OF STREPTOMYCES SPECIES SRDP-TK-07 ISOLATED FROM A WESTERN GHAT SOIL OF TALAKAVERI, KARNATAKA, INDIA Rakesh K.N, Dileep N, Syed Junaid, Prashith Kekuda T.R* Department of Microbiology, S.R.N.M.N College of Applied Sciences, NES Campus, Shivamogga, Karnataka, India *Correspondence Abstract The present study aims at determining anti caries activity of a bioactive Streptomyces Prashith Kekuda T.R species SRDP-TK-07 isolated previously from a rhizosphere soil of Talakaveri, Karnataka, Department of Microbiology, S.R.N.M.N College of India. Efficacy of ethyl acetate extract of SRDP-TK-07 to inhibit seven cariogenic isolates Applied Sciences, NES Campus, Shivamogga, Karnataka, of Streptococcus mutans was tested by employing Agar well diffusion assay. The extract India was effective in inhibiting all seven isolates of S. mutans with zone of inhibition ranging 1.3 to2.9 cm. The isolate SRDP-TK-07 is found promising and can be used for the DOI: 10.7897/2321–6328.01409 development of inhibitory agents active against cariogenic bacteria. Article Received on: 25/10/13 Keywords: Talakaveri, Streptomyces, Dental caries, Streptococcus mutans, Agar well Accepted on: 30/11/13 diffusion INTRODUCTION Streptomyces species SRDP-TK-07 isolated previously from Dental caries is one among the common, pathological, most a rhizosphere soil collected at Talakaveri, India. The extract chronic and multi-factorial infectious diseases worldwide. In of the isolate SRDP-TK-07 was reported to possess a susceptible host, the disease occurs as a result of the antimicrobial and antioxidant activity in our previous study11. interaction of specific bacteria with constituents of a diet. Dietary carbohydrates are fermented into organic acids by the MATERIALS AND METHODS microbial community embedded in the bio film, the pH at Streptomyces species SRDP-TK-07 tooth surface drops below 5.5, demineralization proceeds The isolate SRDP-TK-07 was previously recovered from a faster and results in tooth decay. Several strains of oral rhizosphere soil of Talakaveri, India by Serial dilution streptococci are capable of initiating the formation of dental followed by plating on Starch Casein Nitrate (SCN) agar. The plaque and play an important role in the development of isolate was characterized as a species of Streptomyces based dental caries and periodontal disease in humans. Two α- on cultural and morphological studies11. haemolytic streptococci viz., Streptococcus mutans and S. sobrinus, are the potent cariogenics, however, other bacteria Fermentation and extraction notably lactobacilli and actinomyces may also be involved The protocols employed for bulk cultivation of the isolate the development of dental caries1-3. The recognition of the SRDP-TK-07 in SCN broth and extraction of the culture involvement of the microorganisms in dental caries has led to broth by solvent extraction (using ethyl acetate in separation the development of prevention and control measures for funnel) were as described in our previous study11. eliminating them or reducing their number in the oral cavity1. Actinomycetes are Gram positive, filamentous eubacteria Anti caries activity of ethyl acetate extract possessing high G+C content. Among actinomycetes, the Antibacterial activity of ethyl acetate extract was tested by genus Streptomyces is known to encompass the largest Agar well diffusion assay against 7 clinical isolates of number of species and varieties, found distributed in almost Streptococcus mutans (Sm-01 to Sm-07) isolated previously all ecological niches and differ in their morphology, from dental caries subjects. The test bacteria were inoculated physiology and biochemical characteristics. The members into sterile Brain heart infusion broth (Hi Media, Mumbai, belonging to Streptomyces are dominating in soil in terms of India) tubes and incubated overnight at 37oC. The broth number and the bioactive compounds they produce. These cultures were aseptically swabbed on sterile Brain heart organisms are being considered as fruitful sources of infusion agar (Hi Media, Mumbai, India) plates using sterile bioactive compounds having pharmaceutical and agricultural cotton swabs. Using a sterile cork borer, wells of 6 mm importance. They have provided 2/3rd of naturally occurring diameter were punched in the inoculated plates and 100 µl of antibiotics, such as tetracyclines, aminoglysides, macrolides ethyl acetate extract (5 mg/ml of 25 % dimethyl sufloxide etc., discovered so far4-10. Talakaveri, is the place that is [DMSO]), standard (Streptomycin, 1 mg/ml) and DMSO (25 generally considered to be the source of the river Kaveri. It is %) were transferred into respectively labeled wells. The located by Brahmagiri hill of the Western Ghats near plates were incubated aerobically at 37oC for 24 hours in Bhagamandala in Kodagu district, Karnataka, India 1276 m upright position and the zone of inhibition formed around the above sea level. The present study was undertaken to wells was measured using a ruler11. investigate anti caries activity of ethyl acetate extract from a Published by Moksha Publishing House. Website www.mokshaph.com · © All rights reserved. Page 327 Rakesh K.N et al. Journal of Biological & Scientific Opinion · Volume 1 (4). 2013 Statistical analysis CONCLUSION Antibacterial activity was done in triplicates and the results A marked inhibitory activity against cariogenic isolates of S. are mentioned as Mean ± Standard deviation. mutans by the ethyl acetate extract from Streptomyces species SRDP-TK-07 was observed in this study. The isolate can be a RESULTS potent source for the development of agents effective in the Table 1 shows the result of anti caries activity of ethyl acetate prevention and control of dental caries. Further studies on extract of SRDP-TK-07 against clinical isolates of S. mutans. purification of active components from the ethyl acetate It was observed that all the test bacteria were found to be extract and their bioactivity determinations are to be carried susceptible to ethyl acetate extract but to a varied extent (with out. zone of inhibition ranging 1.3 to 2.9 cm). Inhibition caused by reference antibiotic was higher than that of ethyl acetate ACKNOWLEDGEMENTS extract. DMSO was not inhibitory to clinical isolates. The authors express thanks to Head, Department of Microbiology, Principal, SRNMN College of Applied Sciences, Shivamogga for providing all the facilities to conduct work. Authors also express thanks to NES, Shivamogga Table 1: Anti cariogenic activity of ethyl acetate extract of SRDP-TK-07 for the moral support. Authors thank Dr. N. Mallikarjun, Associate Professor and Chairman, Dept. of Microbiology for providing the cultures of Zone of inhibition in cm Test bacteria cariogenic bacteria. SRDP-07 Streptomycin Sm-01 2.8 ± 0.1 3.3 ± 0.2 REFERENCES Sm-02 2.8 ± 0.3 3.3 ± 0.1 1. Tellez N, Tellez M, Perdomo M, Alvarado A, Gamboa F. Anticariogenic Sm-03 2.9 ± 0.1 3.9 ± 0.1 activity of the active fraction from Isertia laevis against S. mutans and S. Sm-04 2.2 ± 0.1 3.1 ± 0.2 sobrinus: Comparison of two extraction methods. 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