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Background: Chromobacterium violaceum (C. violaceum), a Gram-negative, facultative anaerobic, non-sporing coccobacillus has a quorum-sensing system consisting of CviI/CviR, a homologous gene. Quorum sensing (QS) is a mechanism of intercellular communication in bacteria that received substantial attention as an alternate strategy for combating bacterial resistance and the development of new anti-infective agents. Methods: DATA SET Information of photochemical from the natural source deposited as a machine readable format in PubChem database was utilized to retrieve the compound for the study. To study ligand - receptor interactions, docking paves way to accomplish the protein ligand interaction was docked through rigid docking CviR protein (PDB ID: 3QP5) was prepared and energy minimized to evaluate the best affinity among the complex. Results: The results showed that the Alpha.,2.Alpha.- Epoxy-1.Beta.- Methyl Cholesta-4,6- Dien-3-One had high affinity for CviR receptor protein and Alpha.,2.Alpha.- Epoxy-1.Beta.- Methyl Cholesta-4,6- Dien-3-One binds to the active site of CviR with binding energy of -9.6 kcal/mol. Conclusion: Overall study concluded that 1. Alpha., 2. Alpha.- Epoxy-1.Beta.-Methyl Cholesta-4,6-Dien-3-One with highest binding affinity for the CviR protein possessing strong inhibitory binding interaction. Hence, we concluded that 1.Alpha.,2.Alpha.-Epoxy-1.Beta.- Methyl Cholesta-4, 6-Dien-3-One good serves as potential an anti-quorum sensing molecule for treating C. violaceum infection.

Background: Pseudomonas aeruginosa is a Gram-negative opportunistic human pathogen that mainly infects immunocompromised individuals and patients with urinary tract infection and chronic infections of the respiratory pathways, including cystic fibrosis. Many quorum sensing (QS) controlled components such as bio surfactants and swarming motilities play an important role in the establishment of biofilms. Targeting these factors through anti-QS strategies prevent biofilm formation and treating infections. Coccinia indica commonly called little gourd is used to treat diabetes, wound, burn infections and has antioxidant, antibacterial and antitussive properties. Methods: The methanolic fruit extract of C. indica was prepared and screened for anti-QS and anti-biofilm formation activity. Pyocyanin inhibition, rhamnolipid, crystal violet staining assay tests was performed and the extract was observed under fluorescent microscope. Results: The results obtained are as follows - the fruit extract inhibits the pyocyanin at 58.13% and 42.27% at 0.5 mg/ml and 1.0 mg/ml, biofilm at 69.86% and 49.06% at 0.5 mg/ml and 1.0 mg/ml, inhibits rhamnolipid assay and under fluorescent microscope it is seen scattered whereas control produce biofilm matrix like appearance. Conclusion: Since less study has been made on the quorum sensing and biofilm activity of C.indica our study aimed to fulfil it and it was found that it exhibits good biofilm formation and thus can be used for treating infections.

Background: Acinetobacter baumannii was considered as a low priority pathogen earlier, and is been now reported as a priority pathogen causing nosocomial infections. Selection of natural compounds to target the organism is the need of the hour. Aim: This study is aimed to target the KpsM protein of A. baumannii with the bio-compounds from Azadirachta indica using in-silico docking analysis. Materials and Methods: KpsM protein was retrieved and optimisation of protein was done. After that optimization and ligand preparation was carried out. It was continued by molinspiration assessment of the molecular properties of selected compounds. It was followed by docking simulation and docking visualisation. Results: Out of the 7 compounds of Azadirachta indica, dihydro diisoeugenol is the best compound to act on the KpsM protein of Acinetobacter baumannii and a binding energy of -6.83Kcal/Mol. Conclusion: The findings of the study reports isoeugenol with more binding energy than other compounds towards the selected protein KpsM of Acinetobacter baumannii. However it requires further experimental studies to understand the mechanism of its actions and safety.

Introduction: Periodontal disease is an infection of the tissues that hold your teeth in place. It's typically caused by poor brushing and flossing habits that allow plaque, a sticky film of bacteria, to build up on the teeth and harden. Elimination of these pathogens from the site of infection remains a perplexing task, which demands the use of antibiotics. The emergence of drug resistant forms has spurred interest into identifying novel therapeutic targets against these pathogens. Aim: The present study employs virtual screening method to identify the protein network interaction of berberine with red complex pathogens. Materials and Methods: Computational tools were used to identify the targets, assess their functional role and virulence property. Further, the peptide epitopes present in the virulence factors were identified using the BepiPred tool. The subcellular location of the virulence proteins was also elucidated using PSORTb. Results: Berberine was found to target vital protein transporters such as TetR family transcriptional regulator and MerR family transcriptional regulator, which is known to play a crucial role in the survival of bacterial cells. Conclusion: Hence the present study provides preliminary data on the protein targets of berberine against red complex pathogens. However, in vitro studies using the compound is warranted to further confirm the efficacy of the compound.

Introduction: Opuntia ficus-indica is a well adapted cactus to extreme climatic environments. In the usual diet and food industry, it is an interesting source of food ingredients. In general, the protective role of prickly pears has been due to their antioxidant components, phenolic compounds, and some minor components present in the content of seed oil and seed protein and the oil from cactus pear seed has been found with high levels of unsaturated fatty acids ,with antioxidant and antimicrobial activity as well as cardioprotective, antithrombotic, anti-inflammatory, antiarrhythmic, hypolipidemic, and antihyperglycemic effect. Aim: To evaluate the in vitro antimicrobial activity of Opuntia ficus-indica seed oil against Streptococcus mutans. Materials and Methods: Broth microdilution assay was performed by following modifications: Brain heart infusion (BHI) broth was prepared and sterilise at 121c for 15lbs, the 100 microlitre of streptococcus mutans inoculated at freshly prepared broth and incubated at 37c for 24 hours. Then BHI broth prepared with sucrose and serial two fold dilution were done with 160microlitre broth and 40 microlitre prickly pear seed oil. Then 20 microlitre of culture was added. Column 11 contains BHI using sterile micro pipettes and the plates were incubated at 30 c for 18 hours. The growth of bacteria was visualised and lowest concentration with no visible growth was recorded as MIC. Results: This study results shows that, by broth microdilution method at concentration ranging from 10%-0.039% v/v, Opuntia ficus-indica seed oil potentially inhibits the growth of streptococcus mutans at the concentration of 0.03% (v/v). Conclusion: From the study, the results demonstrated that Opuntia ficus-indica seed oil shows noticeable antimicrobial activity against streptococcus mutans. Use of essential oils against oral pathogens can be an alternative to other antimicrobial agents which could be cheap and effective modules used in control of bacteria which are responsible for oral infections.

Introduction: Triclosan is considered to be an important ingredient in toothpastes and mouth rinses. Several studies have reported contradictory results regarding the antimicrobial effect of triclosan. Hence, the present in silico study intends to identify the potential targets of triclosan in two common dental pathogens Streptococcus mutans and Enterococcus faecalis. Aim: To identify the protein network interactions of triclosan in Streptococcus mutans and Enterococcus faecalis by virtual screening method. Materials and Methods: The STITCH v5.0 database was initially used for identifying drug-protein interactions followed by VICMPred and VirulentPred which was employed to identify functional class of the proteins and its virulence property. Finally, BepiPred v1.0 Linear Epitope Prediction tool was used to identify the potential epitopes of the virulent proteins. Results: Triclosan was found to interact with crucial proteins in S. mutans and E. faecalis which could contribute to severe forms of periodontitis and endodontic diseases. Conclusion: Taken together, the present study provides the preliminary data on the potential targets of triclosan in common dental pathogens. Further experimental validation is warranted to provide concrete evidence on the molecular targets of dental pathogens.

Background: Antimicrobial drug resistance is the major problem encountered world-wide. Novel therapeutic leads have been identified and are regularly tested for their activity against microbial pathogens. Aim: To identify the protein network interactions of triclosan in red complex pathogens. Materials and Methods: The present study follows an observational study design which aims to screen for the interaction of triclosan in red complex pathogens. The interaction was analyzed using the STITCH v.5 pipeline. The functional class of proteins identified were assessed using VICMPred and VirulentPred softwares. The microbial pathogens Treponema denticola ATCC 35405, Tannerella forsythia ATCC 43037, Porphyromonas gingivalis ATCC 33277 are the strains of red complex pathogens that are included in the present study. Results and Discussion: Several proteins were found to interact with triclosan. Among the protein interactions, interactions of triclosan with virulent proteins seems to have a greater impact. The NAD-dependent nucleotide-diphosphate-sugar epimerase [PGN_1370], Putative NAD dependent epimerase [PGN_1886], GDP-fucose synthetase [PGN_1079], Probable oxidoreductase [PGN_1360] of Porphyromonas gingivalis, Conserved hypothetical protein [TDE_2401], Epimerase/dehydratase family protein [TDE_1439] of Treponema denticola, NAD dependent epimerase/dehydratase family protein [BFO_2919], Hypothetical protein [BFO_1782], Nitroreductase family protein [BFO_1604] and Nitroreductase family protein [BFO_1516] Tannerella forsythia were found to be exhibit virulence nature. Conclusion: This study identifies the molecular targets of triclosan on red complex pathogens. As triclosan interacts with the red complex pathogens, in future it can be used as a primary medicine for periodontitis and some oral conditions.

Burkholderia pseudomallei is the causative agent for melioidosis. Because of its intracellular nature, the bacterium is capable of replicating within a plethora of eukaryotic cell lines. B. pseudomallei can remain dormant within host cells without symptoms for years, causing recrudescent infections. Here, we investigated the pathogenesis mechanism behind the suppression of T cell responses by B. pseudomallei . Peripheral blood mononuclear cells (1×106 cells/well) isolated by Ficoll Paque (Sigma-Aldrich) density gradient centrifugation were incubated with optimized concentrations of bacterial crude culture filtrate antigens (CFAs) (10 ug ml−1) and heat-killed bacteria [1 : 10 multiplicity of infection (m.o.i.)]. Following incubation, cells were investigated for surface expression of coinhibitory molecules by flow cytometry. We found that B. pseudomallei induced the upregulation of programmed death 1 (PD-1), a molecule responsible for T cell exhaustion, on T cells in vitro following exposure to crude CFAs of B. pseudomallei . This upregulation of PD-1 probably contributes to poor immune surveillance and disease pathogenesis.

Pseudomonas aeruginosa use small signaling molecules such as acyl homoserine lactones (AHLs), which play an important role in release virulence factors and toxin for further establishment of host infection. Thus, involving with the QS system would provide alternative ways of preventing the pathogenicity. In the present study, totally six medicinal plants (Terminalia bellerica, Celastrus paniculatus, Kingiodendron pinnatum, Schleichera oleosa, Melastoma malabathricum, Garcinia gummi-gutta) were screened for anti-QS activity using biomonitor strain of Chromobacterium violaceum CV12472. The primary screening of antimicrobial activity of all the plant extracts have inhibited the growth of tested bacterial species. Of these at the sub-minimum inhibitory concentration the methanol extract of T. bellerica (0.0625–0.5 mg/ml) has significantly inhibited violacein production (20.07–66.22%) in C. violaceum (CV12472). Consequently, the extract of T. bellerica has reduced the production of pyocyanin, exopolysaccharide and biofilm formation in P. aeruginosa strains. Fluorescence and scanning electron microscopy analysis confirmed the reduction of biofilm formation in P. aeruginosa strains when treated with T. bellerica. GC–MS analysis showed the active compounds inhibited the production of virulence factors of P. aeruginosa. The results suggest the possible use of this T. bellerica as an anti-QS and anti-biofilm agent to control Pseudomonas infection. Interference of QS provides an important means for the inhibition of bacterial virulence and thus aids in treatment strategies., Graphical abstract Image 1

The antibiofilm activity of Murraya koenigii essential oil (EO) against Pseudomonas aeruginosa PAO1 was investigated in this study. A decrease in the production of rhamnolipid, extracellular polymeric substance and swarming motility was observed by the EO treatment (0.3% v/v). The static microtitre plate assay revealed 80% reduction in biofilm formation by P. aeruginosa PAO1 on M. koenigii EO treatment. Fluorescence microscopy and scanning electron microscopy analyses confirmed the reduction of biofilm formation in P. aeruginosa PAO1 when treated with M. koenigii EO. Gas chromatography–mass spectrometry analysis of the EO revealed the presence of well-known antibiofilm agents such as spathulenol (5.85%), cinnamaldehyde (0.37%) and linalool (0.04%). Cinnamaldehyde has not been previously reported in M. koenigii EO. The potent antibiofilm properties of M. koenigii EO may be effectively exploited in food and pharmaceutical industries as well as in controlling Pseudomonas biofilms on indwelling medical devices.

The work investigates on the potential of ten mangrove species for absorption, accumulation and partitioning of trace metal(loid)s in individual plant tissues (leaves, bark and root/pneumatophore) at two study sites of Indian Sundarban Wetland. The metal(loid) concentration in host sediments and their geochemical characteristics were also considered. Mangrove sediments showed unique potential in many- fold increase for most metal(loid)s than plant tissues due to their inherent physicochemical properties. The ranges of concentration of trace metal(loid)s for As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn in plant tissue were 0.006-0.31, 0.02-2.97, 0.10-4.80, 0.13-6.49, 4.46-48.30, 9.2-938.1, 0.02-0.13, 9.8-1726, 11-5.41, 0.04-7.64, 3.81-52.20 μg g (-1)respectively. The bio- concentration factor (BCF) showed its maximum value (15.5) in Excoecaria agallocha for Cd, suggesting that it can be considered as a high-efficient plant for heavy metal bioaccumulation. Among all metals, Cd and Zn were highly bioaccumulated in E. agallocha (2.97 and 52.2 μg g (-1) respectively. Our findings suggest that the species may be classified as efficient metal trap for Cd in aerial parts, as indicated by higher metal accumulation in the leaves combined with BCF and translocation factor (TF) values.

The global emergence of antibiotic-resistant strains of Pseudomonas aeruginosa poses a major threat in both hospital environments and the community. P. aeruginosa is an opportunistic human pathogen, and it also infects a wide range of model organisms including the nematode Caenorhabditis elegans. Quorum sensing (QS) mediates cell-to-cell communication in bacteria and has an important role in regulating virulence genes, antibiotic resistance and biofilm formation, which are crucial for establishment of the infection. Expression of many virulence factors such as pyocyanin and proteases in P. aeruginosa is under the control of the QS system, and are mediated by small molecules such as acyl homoserine lactones. Thus, interfering with the QS system would provide alternative ways of controlling the pathogenicity. Murraya koenigii is a medicinal plant widely used in India. The present study investigated the in vivo inhibitory activity of M. koenigii essential oil (EO) on QS-controlled virulence factors of P. aeruginosa PAO1 using C. elegans. M. koenigii EO significantly inhibited the pyocyanin production and staphylolytic LasA activity of P. aeruginosa PAO1. As compared to the control group with 100 % killing of C. elegans, M. koenigii EO was able to rescue an average of 60 % of C. elegans from death due to the toxic effect of P. aeruginosa. Thus, the present study suggests the anti-QS potential of M. koenigii EO which therefore can be considered as a future therapeutic agent for management of P. aeruginosa-mediated infections.

The biosynthesis of silver nanoparticles (AgNps) has a wide range of applications, and here we develop a rapid synthesis using the leaf extract of Ipomea carnea. We demonstrated that 100 mL of a 1 mM silver nitrate solution was reduced to AgNps by 500 µL of I. carnea extract in 5 min and that one or more of the chemical constituents present in the extract acted as the reducing agent. Surface plasmon resonance peaks were observed from 410 to 440 nm for AgNps synthesised using the plant extract, and the peaks showed a characteristic blue shift with variation of pH from 2 to 8. Particle size analysis revealed the size of the AgNps to be from 30 to 130 nm, which was also confirmed by dynamic light scattering, atomic force microscopy and transmission electron microscopy. Additionally, the antibacterial effects of the AgNps were evaluated against selected human pathogens such as Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Klebsiella pneumoniae, Aeromonas hydrophila, Salmonella typhi, Proteus vulg...

Studies are presented on new types of anaerobic digesters in which chopped or dry crushed Ipomoea carnea was fed without any other pretreatment, in an attempt to develop commercially viable means of utilizing the otherwise very harmful plant. Two types of solid-feed anaerobic digesters (SFADs) were studied. The first type had a single vessel in which the bottom 35% portion was separated from the top portion by a perforated PVC disk. The weed was charged from the top and inoculated with anaerobically digested cowdung-water slurry. The fermentation of the weed in the reactor led to the formation of volatile fatty acids (VFAs) plus some biogas. The leachate, rich in the VFAs, was passed through the perforated PVC sheet and collected in the lower portion of the vessel. The other type of reactors had two vessels, the first one was fully charged with the weed and the second received the VFA leachate. With both types were attached upflow anaerobic filters (UAFs) which converted the leachate into combustible biogas consisting of approximately 70% methane. All SFADs developed very consistent performance in terms of biogas yield within 17 weeks of start. The two-compartment reactors yielded significantly more biogas than the single-compartment reactors of corresponding total volume, and the reactors with which anaerobic filters (AF) were attached yielded more biogas than the ones without AF. The best performing units generated 2.41m(3) of biogas per m(3) of digester volume, as compared to 0.1-0.2m(3) of biogas, m(-3)d(-1), obtainable with conventional digesters. This indicates the viability of this technology. The spent weed can be vermicomposted directly to obtain good soil-conditioner cum fertilizer; earthworm Eudrilus eugeniae produced 540mg vermicast per animal every day, achieving near total conversion of feed to vermicast in 20 days. The proposed systems, thus, makes it possible to accomplish total utilization of ipomoea.