Cyanobacterial biodiversity from different freshwater ponds of Thanjavur, Tamilnadu (India)

Cyanobacterial biodiversity from different freshwater ponds of Thanjavur, Tamilnadu (India). Studies on the cyanobacterial biodiversity of 5 different freshwater ponds in and around Thanjavur, Tamilnadu during summer month (June, 2004) has been made and compared their variations among five different ponds. In addition, certain physico-chemical parameters of pond waters such as dissolved oxygen, net productivity, pH, carbonate, bicarbonate, nitrate, nitrite, total phosphorus, inorganic phosphorus etc. were also analyzed and statistically compared with the cyanobacterial diversity. Totally 39 species of 20 genera of cyanobacteria were recorded in all 5 different ponds. Only 6 species of cyanobacteria were identified in Pond 1 (Dabeerkulam), where a massive bloom of Microcystis aeruginosa was recorded, which had a significant effect in reducing the other cyanobacterial population. As many as five species namely Aphanothece microscopica, Synechocystis aquatilis, Merismopedia glauca, Oscillatoria limnetica and O. subbrevis were common in all the ponds surveyed except in Pond 1.Biodiversidad de cianobacterias en diferentes charcas de agua dulce de Thanjavur, Tamilnadu (India). Se ha inventariado, y comparado entre sí, la biodiversidad de cianobacterias de 5 charcas de agua dulce de Thanjavur, Tamilnadu (India); el estudio se llevó a cabo en junio de 2004. En paralelo, también se determinaron los valores de ciertos parámetros físico-químicos que podrían explicar las variaciones en los valores de biodiversidad: oxígeno disuelto, productividad neta, pH, carbonato, bicarbonato, nitrato, nitrito, fósforo total, fósforo inorgánico, etc. Un total de 39 especies de 20 géneros de cianobacterias se identificaron entre las 5 charcas. En la charca 1 (Dabeerkulam) se detectaron 6 especies, pero cuando tuvo lugar una flor de agua de Microcystis aeruginosa las restantes especies apenas se pudieron detectar. Cinco especies (Aphanothece microscopica, Synechocystis aquatilis, Merismopedia glauca, Oscillatoria limnetica y O. subbrevis fueron comunes en todas las charcas con excepción de la número 1

IN SILICO PROBING OF ANTI-ARTHRITIC POTENTIAL OF TRADITIONALLY FERMENTED AYURVEDIC POLYHERBAL PRODUCT BALARISHTA REVEALS LUPEOL AND DESULPHOSINIGRIN AS EFFICIENT INTERACTING COMPONENTS WITH UREC

Objective: To assess the anti-arthritic properties of Balarishta, an Ayurvedic fermented poly herbal product used to combat the immunological disorder, Rheumatoid Arthritis which is an autoimmune disease triggered by Proteus urinary tract infection through in silico analysis and assay of antimicrobial activity. Methods: Antibacterial activity of Balarishta against Proteus mirabilis was assessed. Phytochemical analysis was performed by Gas Chromatography-Mass Spectroscopy. Urease interaction proteins were homology modeled based on template constraints and physicochemical parameters and stereo chemical nature of the proteins were analyzed. Rigid and flexible docking was done to study the hydrogen bond interaction patterns between active ingredients of Balarishta and urease interaction proteins. Results: In Balarishta, 42 bioactive metabolites were identified by Gas Chromatography-Mass Spectroscopy analysis. These metabolites were checked for strong binding affinities against urease subunits and urease accessory proteins of Proteus mirabilis in silico. ureC subunit exhibited high binding to the compound desulphosinigrin (-10.5217 Kcal/mol) followed by lupeol (-10.0308 Kcal/mol) with conserved residue interaction ranging from amino acid residues 308 – 327. Further, lupeol when bound to ureC had 4 hydrogen bonds as compared to desulphosinigrin with 6 hydrogen bonds. Free energy calculations based on flexible docking showed that lupeol had significant binding affinity for ureC with -9.2 Kcal/mol rather than -6.0 Kcal/mol for desulphosinigrin. Both binding has residue conservation - Cys 319, His 320 and His 321. The results corroborated with in vitro antibacterial activity. Conclusion: It is proposed that Balarishta would be efficient in arresting Rheumatoid Arthritis complicated urinary tract infections

Noncompetitive Chromogenic Lateral-Flow Immunoassay for Simultaneous Detection of Microcystins and Nodularin

Abstract: Cyanobacterial blooms cause local and global health issues by contaminating surface waters. Microcystins and nodularins are cyclic cyanobacterial peptide toxins comprising numerous natural variants. Most of them are potent hepatotoxins, tumor promoters, and at least microcystin-LR is possibly carcinogenic. In drinking water, the World Health Organization (WHO) recommended the provisional guideline value of 1 µg/L for microcystin-LR. For water used for recreational activity, the guidance values for microcystin concentration varies mostly between 4–25 µg/L in different countries. Current immunoassays or lateral flow strips for microcystin/nodularin are based on indirect competitive method, which are generally more prone to sample interference and sometimes hard to interpret compared to two-site immunoassays. Simple, sensitive, and easy to interpret user-friendly methods for first line screening of microcystin/nodularin near water sources are needed for assessment of water quality and safety. We describe the development of a two-site sandwich format lateral-flow assay for the rapid detection of microcystins and nodularin-R. A unique antibody fragment capable of broadly recognizing immunocomplexes consisting of a capture antibody bound to microcystins/nodularin-R was used to develop the simple lateral flow immunoassay. The assay can visually detect the major hepatotoxins (microcystin-LR, -dmLR, -RR, -dmRR, -YR, -LY, -LF -LW, and nodularin-R) at and below the concentration of 4 µg/L. The signal is directly proportional to the concentration of the respective toxin, and the use of alkaline phosphatase activity offers a cost efficient alternative by eliminating the need of toxin conjugates or other labeling system. The easy to interpret assay has the potential to serve as a microcystins/nodularin screening tool for those involved in water quality monitoring such as municipal authorities, researchers, as well as general public concerned of bathing water quality. Keywords: noncompetitive immunoassay; cyanotoxin; microcystin; nodularin; lateral flow</div

Methanolic Extract of Plectranthus tenuiflorus Attenuates Quorum Sensing Mediated Virulence and Biofilm Formation in Pseudomonas aeruginosa PAO1

Pseudomonas aeruginosa is an important opportunistic pathogen which causes bacterial keratitis, cyctic fibrosis and other hospital acquired infections. Its ability to form biofilm provides resistance to conventional antibiotics and further corroborates the global health concerns. The antibiotic resistance by P. aeruginosa is due to highly complex cellular signaling system called quorum sensing (QS). As QS controls bacterial pathogenicity and plays a crucial role in biofilm formation, it is a promising alternative target to combat the bacterial virulence. The present study aims to determine the inhibitory activity of Plectranthus tenuiflorus extract on QS and biofilm development in P. aeruginosa PAO1. The crude plant extract inhibited the production of pyocyanin, elastase, protease and chitinase by 71.96 ± 1.82, 38.74 ± 1.29, 30.84 ± 1.20 and 44.75 ± 1.40 % respectively at sub-MIC concentration of 500 µg/ml. The production of biofilm aggravating phenotypes such as exopolysaccharides, alginate and rhamnolipid were also significantly reduced. The biofilm inhibition capability of P. tenuiflorus was further supported by light microscopic and confocal laser scanning microscopic analysis. The phytochemicals such as phytol and mosloflavone were identified from the crude extract using gas chromatography–mass spectrometry (GC-MS). The role of these phytochemicals in down regulation of QS in P. aeruginosa was further confirmed by in silico studies targeting transcriptional receptors, LasR and RhlR of the QS regulatory network. The in vitro and docking studies suggest the anti QS potential of P. tenuiflorus in combating the bacterial pathogenesis