scholarly journals Optimization and Partial Characterization of a Putative Probiotic Bacterium Antagonistic to Vibrios in Shrimp Larval Rearing System

1970 ◽  
Vol 9 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Abdullah Sarker ◽  
Shafiqur Rahman ◽  
Shakila N Khan ◽  
M Niamul Naser
Keyword(s):  
Water Samples ◽  
Tween 80 ◽  
Antagonistic Activity ◽  
Probiotic Bacterium ◽  
Larval Rearing ◽  
Alkaline Ph ◽  
Optimum Activity ◽  
Cell Free Supernatant ◽  
Pathogenic Vibrios

Organic aquaculture utilizing probiotics for disease control and bioremediation has gained global acceptance in recent years. A preliminary study was conducted to isolate indigenous bacteria antagonistic to pathogenic vibrios as putative probiotics for shrimp hatcheries and grow-out systems. These efforts resulted in the isolation of a Gram-positive bacilli after screening thirty one water samples, collected from the coastal areas of the Bay of Bengal. This probiont, identified as Bacillus licheniformis exhibited vibriocidal activity in vitro against 60% of the Vibrio species isolated from the same water samples based on broad spectrum antagonistic and hydrolytic properties. In this study, we looked into the effects of pH, temperature, salinity, surfactants (Triton X114, Tween 80 and SDS) and EDTA on the vibriocidal property of the cell-free supernatant of the probiotic and observed that the antagonistic property was refractory to the surfactants used. The optimum activity of the cell-free supernatant was observed at 30°C, below and above which there was a marked decline in the inhibition. Neutral and alkaline pH ranges favored the antagonistic property while it was negligible at acidic ranges. The metal chelator EDTA nullified the antagonistic property at 0.01 mM concentration, the lowest tested, indicating the presence of a metal active group in the active fraction. The study suggests the potential of the selected bacterial isolate as a putative, antagonistic probiotic useful in the aquaculture systems of the tropics considering its broad antagonistic activity, higher activity in the neutral and alkaline pH and optimum activity at 30°C. Efforts are underway to purify and characterize the antagonistic compound in the cell-free supernatant. Key words: Probiotic; vibrios; Bacillus; shrimp; cell-free supernatant DOI: 10.3329/dujps.v9i1.7426 Dhaka Univ. J. Pharm. Sci. 9(1): 23-29 2010 (June)

scholarly journals The Roseobacter-group bacterium Phaeobacter as safe probiotic solution for aquaculture

2020 ◽  
Author(s):  
Eva C. Sonnenschein ◽  
Guillermo Jimenez ◽  
Mathieu Castex ◽  
Lone Gram
Keyword(s):  
Antibiotic Resistance Genes ◽  
Antagonistic Activity ◽  
Probiotic Bacterium ◽  
Live Feed ◽  
Current State ◽  
Virulent Phenotype ◽  
Algicidal Compounds ◽  
Pathogenic Vibrios ◽  
A Minor ◽  
Positive Effect

Phaeobacter inhibens has been assessed as a probiotic bacterium for application in aquaculture. Studies addressing the efficacy and safety indicate that P. inhibens maintains it antagonistic activity against pathogenic vibrios in aquaculture live cultures (live feed and fish egg/larvae), while having no or a positive effect on the host organisms, and a minor impact on the host microbiomes. While producing antibacterial and algicidal compounds, no study has so far found a virulent phenotype of P. inhibens cells against higher organisms. Additionally, an in silico search for antibiotic resistance genes using published genomes of representative strains did not raise concern regarding the risk for antimicrobial resistance. P. inhibens occurs naturally in aquaculture systems supporting its safe usage in this environment. Concluding, at the current state of knowledge, P. inhibens is a “safe-to-use” organism.

Effect of the endophytic plant growth promoting Enterobacter ludwigii EB4B on tomato growth

2020 ◽  
Vol 13 (2) ◽  
pp. 54-65 ◽  
Author(s):  
M.E.A. Bendaha ◽  
H.A. Belaouni
Keyword(s):  
Root Length ◽  
Biocontrol Agent ◽  
Growth Promotion ◽  
Dry Weight ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
Plant Growth Promoting ◽  
Enterobacter Ludwigii ◽  
Tomato Growth

SummaryThis study aims to develop a biocontrol agent against Fusarium oxysporum f.sp. radicis-lycopersici (FORL) in tomato. For this, a set of 23 bacterial endophytic isolates has been screened for their ability to inhibit in vitro the growth of FORL using the dual plate assay. Three isolates with the most sound antagonistic activity to FORL have been qualitatively screened for siderophore production, phosphates solubilization and indolic acetic acid (IAA) synthesis as growth promotion traits. Antagonistic values of the three candidates against FORL were respectively: 51.51 % (EB4B), 51.18 % (EB22K) and 41.40 % (EB2A). Based on 16S rRNA gene sequence analysis, the isolates EB4B and EB22K were closely related to Enterobacter ludwigii EN-119, while the strain EB2A has been assigned to Leclercia adecarboxylata NBRC 102595. The promotion of tomato growth has been assessed in vitro using the strains EB2A, EB4B and EB22K in presence of the phytopathogen FORL. The treatments with the selected isolates increased significantly the root length and dry weight. Best results were observed in isolate EB4B in terms of growth promotion in the absence of FORL, improving 326.60 % of the root length and 142.70 % of plant dry weight if compared with untreated controls. In the presence of FORL, the strain EB4B improved both root length (180.81 %) and plant dry weight (202.15 %). These results encourage further characterization of the observed beneficial effect of Enterobacter sp. EB4B for a possible use as biofertilizer and biocontrol agent against FORL.

Uji aktivitas antijamur ekstrak etanol Eleutherine americana Merr. terhadap Microsporum canis secara in vitro

2019 ◽  
Vol 5 (4A) ◽  
pp. 1497
Author(s):  
Buana Dewanti Wimpi ◽  
Diana Natalia ◽  
Effiana Effiana
Keyword(s):  
Tween 80 ◽  
Microsporum Canis ◽  
Eleutherine Americana

Latar Belakang: Dermatofitosis adalah suatu kondisi penyakit yang ditandai dengan infeksi pada jaringan berkeratin seperti epidermis, rambut dan kuku. Kondisi ini disebabkan oleh sekelompok jamur berfilamen terkait yang dikenal sebagai dermatofita. Bawang dayak (Eleutherine americana Merr.) merupakan tanaman berumbi merah yang mengandung senyawa bioaktif yang memiliki kemampuan menghambat pertumbuhan jamur golongan dermatofita. Metode: Umbi bawang dayak diekstraksi dengan metode maserasi menggunakan pelarut etanol 96%. Uji aktivitas antijamur menggunakan metode difusi cakram Kirby-Bauer dengan 5 variasi konsentrasi yaitu 60%, 30%, 15%, 7,5% dan 3,75%. Kontrol positif yang digunakan adalah itrakonazol 8 µg/disk sedangkan kontrol negatif yang digunakan adalah pelarut Tween 80 sebesar 10%. Hasil: Ekstrak umbi bawang dayak mengandung senyawa metabolit sekunder berupa saponin, kuinon, flavonoid, fenol, tanin, alkaloid, steroid dan triterpenoid. Uji aktivitas antijamur ekstrak etanol umbi bawang dayak dengan metode difusi cakram tidak membentuk zona hambat terhadap pertumbuhan Microsporum canis. Kesimpulan: Ekstrak etanol umbi bawang dayak tidak memiliki aktivitas antijamur terhadap pertumbuhan Microsporum canis.

PERILAKU DISOLUSI KETOPROFEN DAN INDOMETASIN FARNESIL TERSALUT GEL KITOSAN-GOM GUAR

2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Purwantiningsih Sugita ◽  
Bambang Srijanto ◽  
Budi Arifin ◽  
Fithri Amelia ◽  
Mahdi Mubarok
Keyword(s):  
Room Temperature ◽  
Guar Gum ◽  
Tween 80 ◽  
Chitosan Solution ◽  
In Vitro Dissolution ◽  
Dissolution Profile ◽  
Magnetic Stirrer ◽  
Dissolution Behaviour ◽  
Shrimp Shell Waste

Chitosan, a modification of shrimp-shell waste, has been utilized as microcapsule. However, it’s fragile gel property needs to be strengthened by adding glutaraldehyde (glu) and natural hydrocolloid guar gum (gg). This research’s purposes were to study dissolution behaviour of ketoprofen and infar through optimum chitosan-guar gum microcapsule. Into 228.6 mL of 1.75% (w/v) chitosan solution in 1% (v/v) acetic acid,38.1 mL of gg solution was added with concentration variation of 0.35, 0.55, and 0.75% (w/v) for ketoprofen microcapsules and 0.05, 0.19, and 0.33% (w/v) for infar microcapsules, and stirred with magnetic stirrer until homogenous. Afterwards, 7.62mL of glu was added slowly under stirring, with concentrations varied: 3, 3.5, and 4% (v/v) for ketoprofen microcapsules, and 4, 4.5, and 5% (v/v) for infar microcapsules. All mixtures were shaked for 20 minutes for homogenization. All mixtures wereshaked for 20 minutes for homogenization. Into each  microcapsule mixture for ketoprofen, a solution of 2 g of ketoprofen in 250 mL of 96% ethanol was added, whereas solution of 100 mg of in 250 mL of 96% ethanol was added into each microcapsule mixture for infar. Every mixture was then added with 5 mL of 2% Tween-80 and stirred with magnetic stirrer for an hour at room temperature. Everymixture was then added with 5 mL of 2% Tween-80 and stirred with magnetic stirrer for an hour at room temperature. Conversion of suspension into fine powders/granules (microcapsules) was done by using spray dryer. The data of [gg], [glu], and medicine’s content from each microcapsule were treated with Minitab 14 software to obtain optimum [gg] and [glu] for microencapsulation. The dissolution behaviour of optimum ketoprofen and infar microcapsules were investigated. The result of optimization by using Minitab Release 14 software showed that among the microcapsule compositions of [gg] and [glu] were 0.35% (w/v) and 3.75% (v/v), respectively, optimum to coat ketoprofen, whereas [gg] and [glu] of 0.05% (w/v) and4.00% (v/v), respectively, optimum to coat infar, at constant chitosan concentration (1.75% [w/v]). In vitro dissolution profile showed that chitosan-guar gum gel microcapsule was more resistant in intestinal pH condition (rather basic) compared with that in gastric pH (very acidic).

Investigating Non-Therapeutic Pharmaceutical Substances for Improving In-Vitro Efficacy of Clindamycin Phosphate Against MRSA and Staphylococcus Epidermidis

2020 ◽  
Vol 18 (2) ◽  
pp. 63-72
Author(s):  
Mohd Aftab Alam ◽  
Fahad I. Al-Jenoobi ◽  
Khaled A. Alzahrani ◽  
Mohammad H. Al-Agamy ◽  
Abdullah M. Al-Mohizea
Keyword(s):  
Fusidic Acid ◽  
Staphylococcus Epidermidis ◽  
Sorbic Acid ◽  
Tween 80 ◽  
Lauryl Sulfate ◽  
Individual Substance ◽  
Dependent Effect ◽  
Pharmaceutical Excipients ◽  
Active Substances

The aim of present study was to investigate the effect of pharmaceutical excipients and other active substances on antimicrobial efficacy of standard antibiotic against resistant and susceptible microorganisms. Pharmaceutical excipients (sodium lauryl sulfate [SLS], Tween-80, citric acid, NaOH, NaCl) and active substances (fusidic acid, sorbic acid) were investigated to check in-vitro efficacy and their effect on the efficacy of standard antibiotic. Clindamycin was selected as standard antibiotic. Clindamycin was found to be ineffective against methicillin-resistant Staphylococcus aureus (MRSA). Fusidic acid and SLS showed concentration dependent effect against MRSA. Other tested substances were also ineffective against MRSA, and also failed to improve the susceptibility of MRSA towards clindamycin. The clindamycin + fusidic acid (0.05 µg, 0.1 µg), and clindamycin + SLS (0.5 mg, 1 mg) showed concentration dependent effect on Staphylococcus epidermidis (S. epidermidis). Clindamycin combinations with fusidic acid or SLS showed better inhibition of S. epidermidis, than individual substance. At lower concentration of clindamycin (2 µg), the sorbic acid (25 µg) improves its effectiveness. SLS (0.5 mg, 1 mg) and clindamycin (4 µg, 10 µg) showed almost equal zone of inhibition against S. epidermidis, respectively. Present findings showed that certain pharmaceutical excipients (e.g. SLS) are effective against resistant and susceptible microbes, and suggested that more excipients should be screened for their antimicrobial potential and their ability to improve the efficacy of standard antibiotics.

Development and Optimization of Sustained Release Moxifloxacin Hydrochloride Loaded Nanoemulsion for Ophthalmic Drug Delivery: A 32 Factorial Design Approach

2020 ◽  
Vol 12 ◽  
Author(s):  
Sagar R. Pardeshi ◽  
Harshal A. Mistari ◽  
Rakhi S. Jain ◽  
Pankaj R. Pardeshi ◽  
Rahul L. Rajput ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Factorial Design ◽  
Water Solubility ◽  
Tween 80 ◽  
Drug Release Profile ◽  
Sustained Drug Release ◽  
Bacterial Conjunctivitis ◽  
Promising Alternative

Background: Moxifloxacin is a BCS class I drug used in the treatment of bacterial conjunctivitis and keratitis. Despite its high water solubility, it possesses limited bioavailability due to anatomical and physiological constraints associated with the eyes which required multiple administrations to achieve a therapeutic effect. Objective: In order to prolong drug release and to improve antibacterial efficacy for the treatment of bacterial keratitis and conjunctivitis, moxifloxacin loaded nanoemulsion was developed. Methods: The concentration of oil (oleic acid), surfactant (tween 80), and cosurfactant (propylene glycol) were optimized by employing a 3-level 2-factorial design of experiment for the development of nanoemulsion. The developed nanoemulsion was characterized by particle size distribution, viscosity, refractive index, pH, drug content and release, transmission electron microscopy (TEM), and antibacterial study. The compatibility of the drug with the excipients was accessed by Fourier transform infrared spectroscopy (FTIR). Result: The average globule size was found to be 198.20 nm. The TEM study reveals the globules were nearly spherical and are well distributed. In vitro drug release profile for nanoemulsion shown sustained drug release (60.12% at the end of 6 h) compared to drug solution, where complete drug released within 2 h. The antibacterial effectiveness of the drug-loaded nanoemulsion was improved against S. aureus compared with the marketed formulation. Conclusion: The formulated sustained release nanoemulsion could be a promising alternative to eye drop with improved patient compliance by minimizing dosing frequency with improved antibacterial activity.

scholarly journals In vitro and in vivo Evaluation of Ibuprofen Nanosuspensions for Enhanced Oral Bioavailability

2021 ◽  
Author(s):  
Mohsen Hedaya ◽  
Farzana Bandarkar ◽  
Aly Nada
Keyword(s):  
Particle Size ◽  
Tween 80 ◽  
Aqueous Solubility ◽  
In Vitro Dissolution ◽  
In Vivo Evaluation ◽  
Poorly Soluble ◽  
Extent Of Absorption ◽  
Better Than

Introduction: The objectives were to prepare, characterize and in vivo evaluate different ibuprofen (IBU) nanosuspensions prepared by ultra-homogenization, after oral administration to rabbits. Methods: The nanosuspensions produced by ultra-homogenization were tested and compared with a marketed IBU suspension for particle size, in vitro dissolution and in vivo absorption. Five groups of rabbits received orally 25 mg/kg of IBU nanosuspension, nanoparticles, unhomogenized suspension, marketed product and untreated suspension. A sixth group received 5 mg/kg IBU intravenously. Serial blood samples were obtained after IBU administration. Results: The formulated nanosuspensions showed significant decrease in particle size. Polyvinyl Pyrrolidone K30 (PP) was found to improve IBU aqueous solubility much better than the other tested polymers. Addition of Tween 80 (TW), in equal amount as PP (IBU: PP:TW, 1:2:2 w/w) resulted in much smaller particle size and better dissolution rate. The Cmax achieved were 14.8±1.64, 11.1±1.37, 9.01±0.761, 7.03±1.38 and 3.23±1.03 μg/ml and the tmax were 36±8.2, 39±8.2, 100±17.3, 112±15 and 105±17 min for the nanosuspension, nanoparticle, unhomogenized suspension, marketed IBU suspension and untreated IBU suspension in water, respectively. Bioavailability of the different formulations relative to the marketed suspension were the highest for nanosuspension> unhomogenized suspension> nanoparticles> untreated IBU suspension. Conclusion: IBU/PP/TW nanosuspensions showed enhanced in vitro dissolution as well as faster rate and higher extent of absorption as indicated from the higher Cmax, shorter tmax and larger AUC. The in vivo data supported the in vitro results. Nanosuspensions prepared by ultra-high-pressure-homogenization technique can be used as a good formulation strategy to enhance the rate and extent of absorption of poorly soluble drugs.

scholarly journals N-palmitoyl-D-glucosamine, A Natural Monosaccharide-Based Glycolipid, Inhibits TLR4 and Prevents LPS-Induced Inflammation and Neuropathic Pain in Mice

2021 ◽  
Vol 22 (3) ◽  
pp. 1491 ◽  
Author(s):  
Monica Iannotta ◽  
Carmela Belardo ◽  
Maria Consiglia Trotta ◽  
Fabio Arturo Iannotti ◽  
Rosa Maria Vitale ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Inflammatory Cytokines ◽  
Lipid A ◽  
Saturated Fatty Acids ◽  
Structural Similarity ◽  
Antagonistic Activity ◽  
Critical Function ◽  
Anti Inflammatory

Toll-like receptors (TLRs) are key receptors through which infectious and non-infectious challenges act with consequent activation of the inflammatory cascade that plays a critical function in various acute and chronic diseases, behaving as amplification and chronicization factors of the inflammatory response. Previous studies have shown that synthetic analogues of lipid A based on glucosamine with few chains of unsaturated and saturated fatty acids, bind MD-2 and inhibit TLR4 receptors. These synthetic compounds showed antagonistic activity against TLR4 activation in vitro by LPS, but little or no activity in vivo. This study aimed to show the potential use of N-palmitoyl-D-glucosamine (PGA), a bacterial molecule with structural similarity to the lipid A component of LPS, which could be useful for preventing LPS-induced tissue damage or even peripheral neuropathies. Molecular docking and molecular dynamics simulations showed that PGA stably binds MD-2 with a MD-2/(PGA)3 stoichiometry. Treatment with PGA resulted in the following effects: (i) it prevented the NF-kB activation in LPS stimulated RAW264.7 cells; (ii) it decreased LPS-induced keratitis and corneal pro-inflammatory cytokines, whilst increasing anti-inflammatory cytokines; (iii) it normalized LPS-induced miR-20a-5p and miR-106a-5p upregulation and increased miR-27a-3p levels in the inflamed corneas; (iv) it decreased allodynia in peripheral neuropathy induced by oxaliplatin or formalin, but not following spared nerve injury of the sciatic nerve (SNI); (v) it prevented the formalin- or oxaliplatin-induced myelino-axonal degeneration of sciatic nerve. SIGNIFICANCE STATEMENT We report that PGA acts as a TLR4 antagonist and this may be the basis of its potent anti-inflammatory activity. Being unique because of its potency and stability, as compared to other similar congeners, PGA can represent a tool for the optimization of new TLR4 modulating drugs directed against the cytokine storm and the chronization of inflammation.

scholarly journals Antagonistic activity of endophytic bacteria isolated from weed plant against stem end rot pathogen of pitaya in Vietnam

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
The Anh Luu ◽  
Quyet Tien Phi ◽  
Thi Thu Hang Nguyen ◽  
Mai Van Dinh ◽  
Bich Ngoc Pham ◽  
...  
Keyword(s):  
Endophytic Bacteria ◽  
Indole Acetic Acid ◽  
Pathogenic Fungi ◽  
Antagonistic Activity ◽  
Biofilm Production ◽  
Weed Plant ◽  
Seedling Biomass ◽  
Rot Disease ◽  
Positive Results

Abstract Background Fungal stem end rot disease of pitaya caused by Alternaria alternata is one of the most destructive diseases in Binh Thuan province, Vietnam. This study aimed to assess the antagonistic effects of some endophytic bacteria isolated from the weed plant (Echinochloa colonum) against A. alternata. Results A total of 19 endophytic bacteria were isolated and 5 of them presented in vitro antagonistic activity against A. alternata. Of five, strain EC80 significantly inhibited the pathogenic growth with a mean inhibition diameter of 11.88 ± 0.08 mm, while the other four (C79, EC83, EC90, and EC97) showed a weak inhibition. Interestingly, the combination of EC79 and EC80 reduced more biomass of pathogenic fungi than the single one did. EC79 showed positive results for amylase, indole acetic acid (IAA), and biofilm production, whereas EC80 presented positive capabilities for IAA and biofilm production and a negative one for amylase production. In addition, the combined filtrate of EC79 and EC80 presented non-antifungal activity on biocontrol tests in vitro, indicating that bacteria cells played a role in defending against the pathogen. Moreover, both isolates EC79 and EC80 significantly increased seedling biomass than the control. Conclusions The results suggest that those two strains in combination had the potential to be used as a biocontrol agent against A. alternata. More studies should be done in the future to evaluate their efficiency under the field conditions.

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