Shunmugiah Karutha Pandian

Alagappa University, Karaikudi, Tamil Nadu, India

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Publications (93)202.92 Total impact

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    Padmavathi Alwar Ramanujam · Bakkiyaraj Dhamodharan · Shunmugiah Karutha Pandian ·
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    ABSTRACT: Biofilms are complex aggregation of microbial cells which aid the indwelling cells to survive and flourish well in the hostile environments. Besides, biofilms act as multicellular entities and provide resistance toward antibiotics and other bactericidal agents which makes their eradication cumbersome. Biofilm-related infections are tough to treat in healthcare, and they are equally important in agriculture as they afflict the crop survival and productivity. It is indeed important to develop a biofilm control strategy to combat biofilm related infections in agriculture. In recent years, biosurfactants have been exploited as potential antibiofilm candidates to languish the vigor of biofilm formers by selectively eradicating the biofilms. Biosurfactants are the surface active metabolites produced by microbes and are proven to have multifarious role in many fields right from bioremediation to biomedical applications. Biosurfactants due to their surface modifying property, modulate the biofilm forming ability of pathogens which directly prevents microbial colonization and biofilm formation. This chapter summarizes the importance of antibiofilm agents and the role of biosurfactants in eradicating biofilms formed by disease causing pathogens.
    Bacterial metabolites in Sustainable Agroecosystem, 1 edited by Dinesh K. Maheshwari, 11/2015: chapter Significance of Biosurfactants as Antibiofilm Agents in Eradicating Phytopathogens; Springer International Publishing., ISBN: 978-3-319-24652-9
  • Sivasamy Sethupathy · Chari Nithya · Shunmugiah Karutha Pandian ·
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    ABSTRACT: The aim of this study was to evaluate the anti-biofilm and quorum sensing inhibitory (QSI) potential of tender coconut water (TCW) against Chromobacterium violaceum and Pseudomonas aeruginosa. TCW significantly inhibited the QS regulated violacein, virulence factors and biofilm production without affecting their growth. qRT-PCR analysis revealed the down-regulation of autoinducer synthase, transcriptional regulator and virulence genes. Mass-spectrometric analysis of a petroleum ether extract of the TCW hydrolyte revealed that 2-furaldehyde diethyl acetal (2FDA) and palmitic acid (PA) are the major compounds. In vitro bioassays confirmed the ability of 2FDA to inhibit the biofilm formation and virulence factors. In addition, the combination of PA with 2FDA resulted in potent inhibition of biofilm formation and virulence factors. The results obtained strongly suggest that TCW can be exploited as a base for designing a novel antipathogenic drug formulation to treat biofilm mediated infections caused by P. aeruginosa.
    Biofouling 11/2015; 31(9-10):721-733. DOI:10.1080/08927014.2015.1102897 · 3.42 Impact Factor

  • RSC Advances 10/2015; DOI:10.1039/C5RA11641D · 3.84 Impact Factor
  • Sivasamy Sethupathy · Balakrishnan Shanmuganathan · Pandima Devi Kasi · Shunmugiah Karutha Pandian ·

    Journal of Applied Phycology 10/2015; DOI:10.1007/s10811-015-0717-z · 2.56 Impact Factor
  • Chandran Sivasankar · Ayyappan Ponmalar · James P Bhaskar · Shunmugiah K Pandian ·
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    ABSTRACT: The genus Malassezia has recently attracted wide attention in medical microbiology and dermatology as a pathogen. They are lipophilic yeasts possessing high level of cell surface hydrophobicity (CSH). l-glutathione (GSH) is a ubiquitous antioxidant which offers protection against microbial infections. This study is intended to investigate the role of GSH as a potential anti-hydrophobicity agent against Malazessia spp. Microbial adherence to hydrocarbon assay was performed to assess the anti-hydrophobicity activity (AHA) of GSH against four Malassezia spp. The assay revealed that GSH at 400 μg ml(-1) concentration inhibited CSH, ranging from 84% to 95% in M. furfur, M. globosa, M. restricta and M. sympodialis without killing the cells. The AHA of GSH was corroborated by auto-aggregation assay and zeta-potential measurement, through which delayed cell aggregation was observed due to reduction in CSH level and not by modification in cell surface charge. In addition, colony-forming unit assay was performed in which 62-93% of CSH reduction was observed in Malassezia spp. tested. Furthermore, GSH treatment enhanced the sensitivity of Malassezia spp. towards human blood at the rate of 64-72%. The AHA was further confirmed through Fourier transform infrared analysis. Thus, this study portrays GSH as a prospective therapeutic alternative for Malassezia-mediated infections. © 2015 Blackwell Verlag GmbH.
    Mycoses 09/2015; 58(10). DOI:10.1111/myc.12370 · 2.24 Impact Factor
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    ABSTRACT: Candida albicans, an opportunistic pathogen, has been known to form hypoxic biofilms on medical devices which in turn confers resistance towards antifungals, resulting in subsequent therapeutic failures. Inclusion of anti-biofilm agents in the control of infections is a topic of current interest in developing potential anti-infectives. The in vitro anti-fungal and anti-biofilm efficacy of 2,4-di-tert-butyl phenol [DTBP] was evaluated in this study, which revealed the potential fungicidal action of DTBP at higher concentrations where fluconazole failed to act completely. DTBP also inhibited the production of hemolysins, phospholipases and secreted aspartyl proteinase which are the crucial virulence factors required for the invasion of C. albicans. Various anti-biofilm assays and morphological observations revealed the efficacy of DTBP in both inhibiting and disrupting biofilms of C. albicans. Inhibition of hyphal development, a key process that aids in initial adhesion of C. albicans, was observed, and this could be a mechanism for the anti-biofilm activity of DTBP.
    Biofouling 08/2015; 31(7):565-74. DOI:10.1080/08927014.2015.1077383 · 3.42 Impact Factor
  • Ganapathy Ashwinkumar Subramenium · Karuppiah Vijayakumar · Shunmugiah Karutha Pandian ·
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    ABSTRACT: The present study explores the efficacy of limonene, a cyclic terpene found in the rind of citrus fruits, for antibiofilm potential against species of the genus Streptococcus, which have been deeply studied worldwide owing to their multiple pathogenic efficacy. Limonene showed a concentration-dependent reduction in the biofilm formation of Streptococcus pyogenes (SF370), with minimal biofilm inhibitory concentration (MBIC) of 400 μg ml - 1. Limonene was found to possess about 75-95 % antibiofilm activity against all the pathogens tested, viz. Streptococcus pyogenes (SF370 and 5 clinical isolates), Streptococcus mutans (UA159) and Streptococcus mitis (ATCC 6249) at 400 μg ml - 1 concentration. Microscopic analysis of biofilm architecture revealed a quantitative breach in biofilm formation. Results of a surface-coating assay suggested that the possible mode of action of limonene could be by inhibiting bacterial adhesion to surfaces, thereby preventing the biofilm formation cascade. Susceptibility of limonene-treated Streptococcus pyogenes to healthy human blood goes in unison with gene expression studies in which the mga gene was found to be downregulated. Anti-cariogenic efficacy of limonene against Streptococcus mutans was confirmed, with inhibition of acid production and downregulation of the vicR gene. Downregulation of the covR, mga and vicR genes, which play a critical role in regulating surface-associated proteins in Streptococcus pyogenes and Streptococcus mutans, respectively, is yet further evidence to show that limonene targets surface-associated proteins. The results of physiological assays and gene expression studies clearly show that the surface-associated antagonistic mechanism of limonene also reduces surface-mediated virulence factors.
    Journal of Medical Microbiology 08/2015; 64(8):879-90. DOI:10.1099/jmm.0.000105 · 2.25 Impact Factor
  • Dharmaprakash Viszwapriya · Chairmandurai Aravindraja · Shunmugiah Karutha Pandian ·
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    ABSTRACT: Epibacterial communities of co-occurring eukaryotic hosts of Palk Bay origin (five seaweed species (Gracilaria sp, Padina sp, Enteromorpha sp, Sargassum sp, and Turbinaria sp) and one seagrass [Cymodaceae sp]) were analyzed for diversity and compared using 16S rRNA based Denaturant Gradient Gel Electrophoresis analysis. Diversity index revealed that Turbinaria sp hosts highest bacterial diversity while it was least in Gracilaria sp. The DGGE band profile showed that the epibacterial community differed considerably among the studied species. Statistical assessment using cluster analysis and Non-metric multidimensional scale analysis also authenticated the observed variability. Despite huge overlap, the composition of bacterial community structure differed significantly among the three closely related species namely Sargassum, Turbinaria and Padina. In addition, Enteromorpha and Sargassum, one being chlorophyta and the other phaeophyta showed about 80% similarity in bacterial composition. This differs from the general notion that epibacterial community composition will vary widely depending on the host phyla. The results extended the phenomenon of host specific epibacterial community irrespective of phylogeny and similarity in geographical location.
    Indian journal of experimental biology 06/2015; 53(6):417-23. · 0.84 Impact Factor
  • Shalini Ramesh · Shunmugiah Karutha Pandian ·
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    ABSTRACT: Serratia marcescens is an opportunistic turned obligate pathogen frequently associated with urinary tract infections (UTI) and are multidrug resistant at most instances. Quorum sensing (QS) system, a population dependent global regulatory system, controls the pathogenesis machinery of S. marcescens as it does in other pathogens. In the present study, methanol extract of a common herb and spice, Anethum graveolens (AGME) was assessed for its anti-QS potential against the clinical isolate of S. marcescens. AGME notably reduced the biofilm formation and QS dependent virulence factors production in a concentration dependent manner (64-1024 μg mL(-1)). The light and confocal microscopic images clearly evidenced the antibiofilm activity of AGME (256 μg mL(-1)) at its minimal biofilm inhibitory concentration (MBIC). Besides, in support of biochemical assays, the expression analysis of QS regulated genes fimC, bsmA and flhD which are crucial for initial adhesion and motility, confirmed their down regulation upon exposure to AGME. LC-MS analysis of AGME revealed 3-O- methyl ellagic acid (3-O-ME) as one of its active principles having nearly similar antibiofilm activity and a reduced inhibition of prodigiosin (27%) and protease (15%) compared to AGME (prodigiosin (47%) and protease (50%)). UFLC analysis revealed that 0.355 mg g(-1) of 3- O- ME was present in the AGME. AGME and the 3-O-ME significantly interfered the QS system of a QS model strain S. marcescens MG1 and its mutant S. marcescens MG44 which in turn corroborates the anti-QS mechanism of AGME. © FEMS 2015. All rights reserved. For permissions, please e-mail:
    FEMS Immunology & Medical Microbiology 05/2015; 73(6). DOI:10.1093/femspd/ftv038 · 3.08 Impact Factor
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    ABSTRACT: Background: Group A streptococcus (GAS, Streptococcus pyogenes), a multi-virulent, exclusive human pathogen responsible for various invasive and non-invasive diseases possesses biofilm forming phenomenon as one of its pathogenic armaments. Recently, antibiofilm agents have gained prime importance, since inhibiting the biofilm formation is expected to reduce development of antibiotic resistance and increase their susceptibility to the host immune cells. Principal findings: The current study demonstrates the antibiofilm activity of 3Furancarboxaldehyde (3FCA), a floral honey derived compound, against GAS biofilm, which was divulged using crystal violet assay, light microscopy, and confocal laser scanning microscopy. The report is extended to study its effect on various aspects of GAS (morphology, virulence, aggregation) at its minimal biofilm inhibitory concentration (132μg/ml). 3FCA was found to alter the growth pattern of GAS in solid and liquid medium and increased the rate of auto-aggregation. Electron microscopy unveiled the increase in extra polymeric substances around cell. Gene expression studies showed down-regulation of covR gene, which is speculated to be the prime target for the antibiofilm activity. Increased hyaluronic acid production and down regulation of srtB gene is attributed to the enhanced rate of auto-aggregation. The virulence genes (srv, mga, luxS and hasA) were also found to be over expressed, which was manifested with the increased susceptibility of the model organism Caenorhabditis elegans to 3FCA treated GAS. The toxicity of 3FCA was ruled out with no adverse effect on C. elegans. Significance: Though 3FCA possess antibiofilm activity against GAS, it was also found to increase the virulence of GAS. This study demonstrates that, covR mediated antibiofilm activity may increase the virulence of GAS. This also emphasizes the importance to analyse the acclimatization response and virulence of the pathogen in the presence of antibiofilm compounds prior to their clinical trials.
    PLoS ONE 05/2015; 10(5):e0127210. DOI:10.1371/journal.pone.0127210 · 3.23 Impact Factor
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    ABSTRACT: Emergence of extended antibiotic resistance among bacterial pathogens often leads to the failure of existing antibiotics to treat bacterial infections; therefore, there is an urgent need to look for novel alternative treatment measures. The aim of this study was to evaluate the anti-quorum sensing (QS) potential of Synechococcus sp., to prevent the onset of bacterial infections as an alternate to antibiotics. A total of 110 marine cyanobacterial strains were screened for their anti-QS activity against biomarker strain Chromobacterium violaceum (ATCC 12472) and aquatic bacterial pathogens Vibrio harveyi (MTCC 3438) and Vibrio vulnificus (MTCC 1145). Of the 110 strains tested, the extract of unicellular algae Synechococcus sp. (Q-25) exhibited the efficient reduction in the production of violacein pigment of C. violaceum to the level of 82 %, bioluminescence of V. harveyi to 91 % and protease in V. vulnificus to 63 %. In V. harveyi and V. vulnificus, it exhibited a significant reduction of 71 and 84 % in biofilm formation and 66 and 68%in EPS production, respectively, without any antibacterial activity. Confocal laser scanning microscopic and light microscopic analyses further confirmed that the Q-25 extract effectively prevented initial attachment as well as disrupting the architecture of mature biofilm, when compared to their untreated controls. In addition, the characterization of active principle by gas chromatography–mass spectrometry analysis confirmed the presence of stable bioactive compound hexadecanoic acid in the extract. Hence, this study clearly revealed the antibiofilm and QS inhibitory potential of the cyanobacterium, Synechococcus sp. Keywords Aquaculture . Vibriosis . Antibiotic resistance . Quorum sensing . Cyanobacteria . Hexadecanoic acid
    Journal of Applied Phycology 02/2015; DOI:10.1007/s10811-015-0554-0 · 2.56 Impact Factor
  • Ramesh Salini · Muthukrishnan Sindhulakshmi · Thirumaran Poongothai · Shunmugiah Karutha Pandian ·
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    ABSTRACT: Bacterial urinary tract infections (UTIs) are the most common nosocomial infections, accounting for about 40 % of all hospital-acquired infections. The bacterial spectrum of nosocomial UTIs is broad and the treatment of UTIs is becoming difficult owing to the emergence of drug resistance. Therefore, it is reasonable to investigate novel and alternative therapeutic strategies to treat UTIs. Since UTIs are caused by uropathogens with quorum sensing (QS)-dependent biofilm forming abilities, interruption of QS systems may be a novel approach to combat drug resistance. In the present study, a methanol extract (and hexane extract derived from it) of the medicinal plant Hyptis suaveolens (L.) were shown to have anti-QS activity against the biosensor strain Chromobacterium violaceum (ATCC 12472). Furthermore, the hexane extract of H. suaveolens (HEHS) inhibited biofilm formation by uropathogens such as Escherichia coli, Proteus vulgaris, Proteus mirabilis, Klebsiella pneumoniae and Serratia marcescens. HEHS promotes the loosening of biofilm architecture and strongly inhibits in vitro biofilm formation by uropathogens, which was more apparent from microscopic images. In addition to this, HEHS reduces the production of QS-dependent virulence factors like protease and hemolysin, along with motility. The partial purification and GC-MS analysis of the active fraction revealed the presence of several therapeutically important compounds which may synergistically act on the uropathogens and possibly reduce the QS-dependent phenotypes. These findings suggest HEHS as potential phytotherapeutic agent which can be employed to formulate protective strategies against biofilm linked infections caused by uropathogens.
    Antonie van Leeuwenhoek 02/2015; 107(4). DOI:10.1007/s10482-015-0402-x · 1.81 Impact Factor
  • Alwar Ramanujam Padmavathi · Murugesan Periyasamy · Shunmugiah Karutha Pandian ·
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    ABSTRACT: Extracellular polymeric substances (EPS) play crucial roles in biofilm formation and biocorrosion resulting in heavy economic loss in an industrial setup. Hence, in an attempt to develop an agent to control the EPS across the hosts, the ability of 2,4-Di-tert-butylphenol (DTBP), a potent antioxidant, to modify the EPS of Serratiamarcescens has been investigated in this study using biophysical methods. Protein, polysaccharides and eDNA components of EPS were inhibited significantly (p<0.05) upon exposure to DTBP. DTBP treatment reduced the crystallite size and crystallinity index of EPS and increased the dislocation density of crystallites without inducing stress, besides increasing the hydration of EPS which reduced its thermal stability. On the whole, this study highlights the efficacy of DTBP to modulate secreted EPS of S. marcescens which in turn could facilitate the disruption of biofilms besides favouring the diffusion of antimicrobials into the cell aggregates resulting eradication of persistent biofilms. Copyright © 2015 Elsevier Ltd. All rights reserved.
    Bioresource Technology 01/2015; 188. DOI:10.1016/j.biortech.2015.01.049 · 4.49 Impact Factor
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    Industrial Crops and Products 01/2015; 69:180-186. · 2.84 Impact Factor
  • Alwar Ramanujam Padmavathi · Shunmugiah Karutha Pandian ·
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    ABSTRACT: Coral Associated Bacteria (CAB) (N = 22) isolated from the mucus of the coral Acropora digitifera were screened for biosurfactants using classical screening methods; hemolysis test, lipase production, oil displacement, drop collapse test and emulsifying activity. Six CAB (U7, U9, U10, U13, U14, and U16) were found to produce biosurfactants and were identified by 16S ribosomal RNA gene sequencing as Providencia rettgeri, Psychrobacter sp., Bacillus flexus, Bacillus anthracis, Psychrobacter sp., and Bacillus pumilus respectively. Their cell surface hydrophobicity was determined by Microbial adhesion to hydrocarbon assay and the biosurfactants produced were extracted and characterized by Fourier Transform Infrared spectroscopy. Since the biosurfactants are known for their surface modifying capabilities, antibiofilm activity of positive isolates was evaluated against biofilm forming Pseudomonas aeruginosa ATCC10145. Stability of the active principle exhibiting antibiofilm activity was tested through various temperature treatments ranging from 60 to 100 °C and Proteinase K treatment. CAB isolates U7 and U9 exhibited stable antibiofilm activity even after exposure to higher temperatures which is promising for the development of novel antifouling agents for diverse industrial applications. Further, this is the first report on biosurfactant production by a coral symbiont.
    Indian Journal of Microbiology 12/2014; 54(4). DOI:10.1007/s12088-014-0474-8 · 0.90 Impact Factor
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    ABSTRACT: Group A Streptococci (GAS) are involved in a number of life threatening diseases and biofilm formation by these pathogens are considered as an important virulence determinant as it mediates antibiotic resistance among them. In the present study, we have explored the ability of (+)-usnic acid, a lichen secondary metabolite, as an antibiofilm agent against four serotypes of Streptococcus pyogenes causing pharyngitis. Usnic acid inhibited the biofilms of M serotypes M56, st38, M89 efficiently and the biofilm of M74 to a lesser extent. Confocal imaging of the treated samples showed that usnic acid reduced the biomass of the biofilms when compared to that of the control. Fourier Transfer Infrared (FT-IR) spectroscopy indicated that usnic acid reduced the cellular components (proteins and fatty acids) of the biofilms. Interestingly, the FT-IR spectrum further revealed that usnic acid probably acted upon the fatty acids of the biofilms as evident from the disappearance of a peak at 2,455-2,100 cm(-1) when compared to the control only in serotypes M56, st38 and M89 but not in M74. The present study shows, for the first time, that usnic acid can act as an effective antibiofilm agent against GAS.
    Antonie van Leeuwenhoek 11/2014; 107(1). DOI:10.1007/s10482-014-0324-z · 1.81 Impact Factor
  • Alwar Ramanujam Padmavathi · Bose Abinaya · Shunmugiah Karutha Pandian ·
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    ABSTRACT: Intercellular communication in bacteria (quorum sensing, QS) is an important phenomenon in disease dissemination and pathogenesis, which controls biofilm formation also. This study reports the anti-QS and anti-biofilm efficacy of seaweed Gracilaria gracilis associated Vibrio alginolyticus G16 against Serratia marcescens. Purification and mass spectrometric analysis revealed the active principle as phenol, 2,4-bis(1,1-dimethylethyl) [PD]. PD affected the QS regulated virulence factor production in S. marcescens and resulted in a significant (p < 0.05) reduction in biofilm (85%), protease (41.9%), haemolysin (69.9%), lipase (84.3%), prodigiosin (84.5%) and extracellular polysaccharide (84.62%) secretion without hampering growth, as evidenced by XTT [2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] assay. qPCR analysis confirmed the down-regulation of the fimA, fimC, flhD and bsmA genes involved in biofilm formation. Apart from biofilm inhibition and disruption, PD increased the susceptibility of S. marcescens to gentamicin when administered synergistically, which opens another avenue for combinatorial therapy where PD can be used to enhance the efficacy of conventional antibiotics.
    Biofouling 10/2014; 30(9):1111-22. DOI:10.1080/08927014.2014.972386 · 3.42 Impact Factor
  • Balu Jancy Kalpana · Shunmugiah Karutha Pandian ·
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    ABSTRACT: A halotolerant α-amylase having the ability of digesting the insoluble raw starches was characterized from Bacillus subtilis S8-18, a marine sediment isolate from Palk Bay region. The electrophoresis techniques unveiled that the α-amylase was indeed a monomer with a molecular weight of 57 kDa. The optimum temperature and pH for the enzyme activity were 60 °C and 6.0 respectively. The enzyme was highly stable for 24 h over a wide range of pH from 4.0 to 12.0 by showing 84-94% activity. Interestingly, by retaining 72% activity even after 24 h, the enzyme also showed tolerance towards 28% NaCl. The α-amylase retained a minimum of 93% residual activity in 1 mM concentration for the selected divalent metal ions. The enzyme was found to be chelator resistant as it remained unaffected by 1 mM of EDTA and exhibited 96% activity even at 5 mM concentration. Furthermore, though 1% SDS caused remarkable reduction (68%) in amylase activity, the enzyme showed tolerance towards other detergents (1% of Triton-X and Tween 80) with 85% activity. Additionally, the α-amylase enzyme is capable of hydrolyzing the insoluble raw starch substrates which was evident from the scanning electron microscopic (SEM) and spectrophotometric analyses.
    Journal of Basic Microbiology 08/2014; 54(8). DOI:10.1002/jobm.201200732 · 1.82 Impact Factor
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    ABSTRACT: The recognition of DNA by small molecules is of special importance in the design of new drugs. Many natural and synthetic compounds have the ability to interact with the minor groove of DNA. In the present study, identification of minor groove binding compounds was attained by the combined approach of pharmacophore modelling, virtual screening and molecular dynamics approach. Experimentally reported 32 minor groove binding compounds were used to develop the pharmacophore model. Based on the fitness score, best three pharmacophore hypotheses were selected and used as template for screening the compounds from drug bank database. This pharmacophore-based screening provides many compounds with the same pharmacological properties. All these compounds were subjected to four phases of docking protocols with combined Glide-quantum-polarized ligand docking approach. Molecular dynamics results indicated that selected compounds are more active and showed good interaction in the binding site of DNA. Based on the scoring parameters and energy values, the best compounds were selected, and antibacterial activity of these compounds was identified using in vitro antimicrobial techniques. Copyright © 2014 John Wiley & Sons, Ltd.
    Journal of Molecular Recognition 07/2014; 27(7). DOI:10.1002/jmr.2363 · 2.15 Impact Factor
  • Shanmugaraj Gowrishankar · Balan Poornima · Shunmugiah Karutha Pandian ·
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    ABSTRACT: Since Streptococcus mutans is the principal etiologic agent causing dental caries, by encompassing an array of unique virulence traits, emerging treatment strategies that specifically target the virulence of this pathogen may be promising as alternative approaches compared to conventional antibiotic therapy. In this perspective, we investigated chloroform extract of cell-free culture supernatant from mangrove rhizosphere bacterium Bacillus amyloliquefaciens (MMS-50) in terms of anticariogenic properties of S. mutans, without suppressing its viability. Crude chloroform extract of MMS-50 was subjected to column and high performance liquid chromatographic techniques to obtain the active fraction (AF), and MMS-50 AF was used for all further assays. GC–MS and FT-IR were carried out to identify the major components present in MMS-50 AF. Comparative gene expression analysis of some biofilm-forming and virulence genes (vicR, comDE, gtfC, and gbpB) was done by real-time PCR. Cyclo(L-leucyl-L-prolyl) was found to be the chief compound in MMS-50 AF responsible for bioactivity. The minimum and maximum inhibitory concentrations of MMS-50 AF against S. mutans were found to be 100 and 250 μg/mL, respectively. Anti-virulence assays performed using below-sub-MIC levels of MMS-50 AF (30 μg/mL) resulted in significant reduction in adherence (68%), acid production, acid tolerance, glucan synthesis (32%), biofilm formation (53.5%) and cell surface hydrophobicity, all devoid of affecting its viability. The micrographs of CLSM and SEM further confirmed the antibiofilm and anti-virulence efficacies of MMS-50 AF. Expression data showed significant reduction in expression of all studied virulence genes. Thus, the current study unveils the anticariogenic potential of cyclo(L-leucyl-L-prolyl) from B. amyloliquefaciens, as well as its suitability as a novel and alternative anticariogenic agent against dental caries.
    Research in Microbiology 05/2014; 165(4). DOI:10.1016/j.resmic.2014.03.004 · 2.71 Impact Factor