Negative Strains Research Articles

Essential oils from Elettaria cardamomum (L.) Maton grains and Cinnamomum verum J. Presl barks: Chemical examination and bioactivity studies

Context: Elettaria cardamomum (L.) Maton grains and Cinnamomum verum J. Presl barks are immensely consumed by Jordanian population as food flavoring and remedies in treating different disorders without awareness of their effect or dose toxicity. Aims: To evaluate the antibacterial, antioxidant and cytotoxic effects of essential oils (EOs) hydro-distilled from E. cardamomum grains and C. verum barks. Methods: Hydro-distillation was carried out using Clevenger apparatus; the EOs were analyzed using GC/MS, and their constituents were quantified using GC/FID. The antibacterial activity was determined by agar diffusion test and micro-broth dilution assay, while the antioxidant activity was evaluated by DPPH and ABTS scavenging assays. The cytotoxic activity was evaluated against the MDA-MB-231 breast cancer cell line. Results: E. cardamomum EO was most effective against Bacillus subtilis with MIC 3.75 µL/mL and exhibited antioxidant activity in DPPH assay with IC50 0.057 ±0.013 µL/mL (0.076 ±0.017 µL EO/µg Trolox®) but was ineffective in the ABTS test up to 5 µL/mL; 86.22% of its EO constituent are oxygenated monoterpenes with α-terpinyl acetate as the major component. Whilst C. verum EO was active against both tested Gram-positive and negative bacterial strains with MIC 1.25-5.00 µL/mL but was devoid of significant antioxidant activity up to 5 µL/mL; phenylpropanoids constituted 69.48% of its EO with E-cinnamaldehyde as the major component. Both EOs showed cytotoxic activity against the breast cancer cell line withIC50 0.14-0.46 µL/mL. Conclusions: The current results unveil the potential application of C. verum and E. cardamomum in complementary and alternative medicine as biosafe remedies besides their usage as flavoring and seasoning sources.

Development of enhanced electrochemical sensor and antimicrobial studies of ZnO NPs synthesized using green plant extract

The present investigation envisages for plant mediated synthesis of ZnO NPs (ZNPs) by green combustion route using eco-friendly LCL (Lantana Camara Leaf) Extract. The optical and structural characterizations of ZNPs was studied by spectral techniques; PXRD (Powder X-ray diffraction) study confirms the phase formation and crystalline nature of NPs with its average particle size found to be 35 ​nm The internal morphology of synthesized NPs comprises noticeable pores, voids and agglomeration obtained by SEM (Scanning Electron Microscopy) technique. TGA-DTA (Thermogravimetric-Differential Thermal Analysis) analysis reveals the changes in physico-chemical properties of ZNPs by the effect of temperature. The electrochemical reaction measurements of ZNPs-graphite paste electrode in a 3-electrode system using 1 ​M HCl solution was conducted by CV (Cyclic Voltametric) and EIS (Electrochemical Impedance Spectroscopy) techniques in the different scan rates 0.01–0.05 ​V/s. Further, the corrosion inhibition activities of ZNPs were examined on mild steel (MS) in 1 ​M HCl solution by electrochemical spectral studies (CV & EIS) and potentiodynamic polarization (PDP) measurements. The antimicrobial potential of ZNPs was discussed in detail in contrast to gram positive (Micrococcus luteus) and gram negative (P.auruginosa) bacterial strains by the zone of inhibition concept using disc diffusion technique.

Adhatoda vasica and Calotropis procera as a resource of novel chemical compounds, their biological bioluminescence assay, and investigation of morphological features of bacterial growth through advanced technologies.

This article reports the three principal groups of compounds for the first time from Adhatoda vasica and Calotropis procera plants species using nuclear magnetic resonance methods in which aliphatic, oxy heterocyclic, and tannins compounds were detected from these plants. The leaves of both species were subjected to testing tyrosinase inhibition and antioxidant activities. ATP bioluminescence use for indirect measurement of the amount of organic residue on the surface of the leaves that provide support to microbial growth. The distinguishing characteristics and intraoperative findings of bacterial diseases involved in treatments were conducted against the positive and negative microbial strains using a scanning electron microscope (SEM). The methanolic extracts of leaves of both species were applied to bacterial strains through broth microdilution method to determine the minimum inhabitation concentrations (MICs) for both species. It was concluded that both plants are a rich resource of bioactive compounds. Their extract may also be used to treat various bacterial diseases and in drug manufacturing. HIGHLIGHTS: New chemical compounds of oxy-heterocyclic, aliphatic, and tannins derivatives are isolated from herbal plants as a source of various drugs. 1 H NMR spectrum and 13 C NMR spectrum of each new derivate were calculated. NMR-spectral analysis of new compound of chemistry class was studied and further applied in various bacterial strains. Tyrosinase inhibition property of bacteria strains by application of active compounds on these strains. Agar overlay bioassays were used to evaluate intercellular morphological features of strains applied on extracts by electron microscope (SEM). a-Glucosidase inhibition assay determined with antioxidants activity through FRAP assay methods.

Evaluation of Anti Microbial Activity of -2-Pyridinealdazine

The main objective of this work was to prepare and to evaluate the antibacterial and anti fungal activity of 2-Pyridinealdazine.This azine is screened for its antimicrobial activity against both gram positive and gram negative bacterial and fungal strains like fungal strains Aspergillus flavus, Aspergillus niger, Fusarium oxysporum, Penicillium chrysogenum,Trichoderma viride. 2-Pyridinealdazine was found to be effective inhibitor of all pathogenic strains with the inhibition zone ranging from 10 to 30mm.

ĐỊNH DANH ĐẾN LOÀI MỘT SỐ CHỦNG MYCOBACTERIA BẰNG PHƯƠNG PHÁP GIẢI TRÌNH TỰ GEN

Objective: To discriminate and describe the prevalence between MTBC and NTM in the mycobacteria isolates at National Lung Hospital from the August of 2019 to the August of 2020, of which MPT64 cannot be detected by TBc ID. Methods: Identification mycobacteria isolates to the species level by analysis several target genes, including 16S rRNA, gyrB, rpoB, hsp65 and ITS. Results: Overall, there are 105 (100%) TBc ID negative strains, including 56 MTBC strains (53,3%) and 49 NTM strains (46,7%). Looking closely to species level identification, of all 56 MTBC strains, there are 55 M. tuberculosis strains (98,2%) and solely 1 M. bovis strains (1,8%). Within 49 NTM strains, the highest frequency is M. abscessus/ M. chelonae (27 strains- 55,1%), the second is MAC (8 strains- 16,3%) and other 13 NTM species take some small portions. Conclusion: Some strains of MTBC cannot be detected by TBc ID, including M. tuberculosis and M. bovis. The predominant NTM species related to pulmonary disease in Vietnam are M. abscessus/ M. chelonae and MAC. Keywords: Mycobacteria, MTBC, NTM, TBcID, sequencing

Green chemistry mediated facile synthesis of surface passivated ZnSe QDs and their cytotoxicity evaluation

Quantum Dots (QDs) of Zinc Selenide (ZnSe) are hereby presented as a promising bio-compatible antibacterial agent, which are designed and synthesized by adopting green chemistry principles. These synthesized ZnSe QDs have been found to be within quantum-confined range with excellent luminescence properties. These PVP capped ZnSe QDs are observed to be biocompatible (>80%) with mouse L929 fibroblastic and HeLa cell lines up to 72 h of post-treatment with a concentration range of 36 µg/ml and 24 µg/ml successively. These QDs are mildly lytic within the concentration range of 0.01–1 mg/ml for 4 h towards human erythrocytes. In vitro assessments prove their high killing capacity towards both gram-positive and gram negative strains of bacterial cells. Hence, these synthesized ZnSe QDs are expected to show immense utility in the domain of optoelectronics, targeted drug delivery, bio-imaging and antibacterial fouling without inducing toxicity to advanced organisms.

A Megabirnavirus Alleviates the Pathogenicity of Fusarium pseudograminearum to Wheat.

Fusarium pseudograminearum is a phytopathogen that causes wheat crown rot disease worldwide. Fusarium pseudograminearum megabirnavirus 1 (FpgMBV1) was isolated from the hypovirulent strain FC136-2A of F. pseudograminearum as a novel double-stranded RNA mycovirus belonging to the family Megabirnaviridae. Here we examined the effects of FpgMBV1 on colony morphology and pathogenicity of F. pseudograminearum. Through hyphal tip culture, we obtained virus-free progeny of strain FC136-2A, referred to as FC136-2A-V-. FpgMBV1 was transferred horizontally to another virus-free strain, WZ-8A-HygR-V-. The progeny obtained through horizontal transfer was referred to as WZ-8A-HygR-V+. Colony morphology was similar between the FpgMBV1-positive and -negative strains. The ability to penetrate cellophane invitro was lost, and pathogenicity on wheat plants was reduced significantly in the FpgMBV1-positive strains relative to the FpgMBV1-negative strains. Microscopic observations showed a 6-h delay in the formation of appressoria-like structures in FC136-2A relative to FC136-2A-V-. Mycelium extension was significantly longer in wheat coleoptiles infected by WZ-8A-HygR-V- than in that infected by WZ-8A-HygR-V+ at 12 and 20 h after inoculation (hai). In addition, expression of five genes that encode cell wall-degrading enzymes differed significantly between FpgMBV1-positive and -negative strains at 12 and 20 hai during early infection of wheat cells by conidia. This study provides evidence for the hypovirulence effect of FpgMBV1 on F. pseudograminearum and suggests that the underlying mechanism involves unsuccessful early infection and perhaps cell wall degradation.

Origin of Ferroelectric Domain Wall Alignment with Surface Trenches in Ultrathin Films.

Engraving trenches on the surfaces of ultrathin ferroelectric (FE) films and superlattices promises control over the orientation and direction of FE domain walls (DWs). Through exploiting the phenomenon of DW-surface trench (ST) parallel alignment, systems where DWs are known for becoming electrical conductors could now become useful nanocircuits using only standard lithographical techniques. Despite this clear application, the microscopic mechanism responsible for the alignment phenomenon has remained elusive. Using ultrathin PbTiO_{3} films as a model system, we explore this mechanism with large scale density functional theory simulations on as many as 5,136 atoms. Although we expect multiple contributing factors, we show that parallel DW-ST alignment can be well explained by this configuration giving rise to an arrangement of electric dipole moments which best restore polar continuity to the film. These moments preserve the polar texture of the pristine film, thus minimizing ST-induced depolarizing fields. Given the generality of this mechanism, we suggest that STs could be used to engineer other exotic polar textures in a variety of FE nanostructures as supported by the appearance of ST-induced polar cycloidal modulations in this Letter. Our simulations also support experimental observations of ST-induced negative strains which have been suggested to play a role in the alignment mechanism.

UV-light Photocatalytic Activity of Biocompatible Nanoparticles Provide Multiple Effects

Biocompatible silver (Ag) nanoparticles (NPs) were demonstrated using silver nitrate (AgNO3) and egg white extracted (EWE). Egg white mediated AgNPs were characterized and study its antimicrobial activity against human pathogenic bacteria (HPB), and under UV-light irradiation, photocatalytic degradation of methylene blue (MB) has been studied. Results showed that EWE-AgNPs act as remarkable antimicrobial agent against several Gram- Positive and Negative HPB strains. Maximal growth inhibition zone in Salmonella typhimurium (NCIM 2501) and a minimal inhibition zone in Bacillus subtilis (NCIM 2920) were observed at concentration of 80μg mL-1. High activity of photocatalytic degradation of methylene blue (MB) at about 94.67% was observed under UV-light irradiation when the reaction time was extended 30 min. The multi-functionality of EWE-AgNPs may be useful for many industrial applications such as catalysis to waste water treatment in near future. Copyright © VBRI Press.

HALOGEN FREE [HNMP]+CH3SO3 - IONIC LIQUID MEDIATED BIFUNCTIONALIZED NAPHTHOQUINONE-DIHYDROPYRIMIDIN-(1H)-ONE HYBRIDS AND EVALUATION OF ITS ANTIMICROBIAL POTENTIAL

An efficient halogen free ionic liquid (HFIL) N-methyl-2-pyrrolidonium methane sulfonate [HNMP]+[CH3SO3]- catalyzed Biginelli reaction is reported to synthesize naphthoquinone fused dihydropyrimidin-(1H)-ones (DHPM’s). Diversifying this naphthoquinone constituent provides an access to new and interesting DHPM’s for pharmacological profiling. A series of bifunctionalized naphthoquinone-dihydropyrimidin-(1H)-one conjugates (4a-4l) were synthesized and evaluated for their antimicrobial potential against selected bacterial and fungal pathogenic strains. The resulting naphthoquinone fused dihydropyrimidin-(1H)-one hybrids showed significant activities against all the tested Gram positive (Staphylococcus aureus, Bacillus subtilis) and Gram negative (Escherichia coli, Pseudomonas aeruginosa) bacterial pathogens and fungal strains of Aspergillus niger and Aspergillus flavus. Among the series, the DHPM conjugate 4k>4j>4e>4h samples exhibited highest activities against all the tested strains that proved to be important candidates in the drug development against various life threatening diseases. Presently, one-pot, three-component methodology have been developed for the synthesis of bifunctionalized naphthoquinone linked dihydropyrimidin-(1H)-one are being explored for bio-active asymmetric Biginelli scaffolds.

A sugarcane bagasse carbon-based composite material to decolor and reduce bacterial loads in waste water from textile industry

In present study, H3PO4–activated sugarcane bagasse carbon-based composite with Al(OH)3, was prepared and characterized by Brunauer-Emmett-Teller (BET), Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) techniques. The adsorptive decolorization of methylene blue (MB) and methyl violet (MV) contaminated water employing sugarcane (Saccharum officinarum L.) bagasse carbon/Al(OH)3 {SBC/Al(OH)3} composite was explored under varying operational conditions. The equilibrium data for MB and MV adsorption was best appropriated by Langmuir and Freundlich isotherm models, respectively with the maximum Langmuir adsorption capacity of 261 mg/g for MB and 125 mg/g for MV illustrating the monolayer adsorption of MB onto energetically homogeneous sites and multilayer adsorption of MV onto heterogeneous surface sites. The kinetics of both MB and MV adsorption process onto SBC/Al(OH)3 composite was consistent with pseudo-second order model. The thermodynamic parameters such as ∆H° (5–17 kJ/mol for MB; 20–17 kJ/mol for MV) and ∆S° (0.063–0.1 kJ/mol.K for MB; 0.095 −0.21 kJ/mol.K for MV), and –∆G° (6.1–11.3 kJ/mol for MB; 12.4–30.0 kJ/mol for MV) advocated respectively the endothermic, increased randomness at the SBC/Al(OH)3–MB or MV interface, and spontaneous and feasible adsorption process. The adsorbent was efficiently regenerated and had the potential to be used for five recycles with limited loss in efficacy. The SBC/Al(OH)3 exhibited consistently good antibacterial activity against gram–negative (K. pneumonia; E. coli; P. aeruginosa) bacterial strains with zone of inhibition between 8 and 18 mm compared to gram–positive, B. cereus (6–13 mm). The apparent superiority of SBC/Al(OH)3 over other adsorbents in terms of adsorption capacity, promising reusability, and potent antibacterial properties demonstrated that SBC/Al(OH)3 composite could be a sustainable, remarkably efficient and cost-effective adsorbent for aquatic pollution abatement.

Designing intimate porous Al2O3 decorated 2D CdO nano-heterojunction as enhanced white light driven photocatalyst and antibacterial agent

The mesoporous network of γ-Al2O3 ceramic support was coupled with the two dimensional (2D) hexagonal CdO nanoplates by ultrasonic assisted method. The fabricated photocatalyst was analyzed for its structural, morphological and optoelectrical properties by employing X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), photoluminescence, electron spin resonance (ESR) analysis and electrochemical impedance spectroscopy (EIS). The X-ray powder diffraction (XRD) result supports the good crystallinity of the fabricated nanohybrid with co-existence of pure phases of γ-Al2O3 and CdO nanoparticles (NPs). The nanohybrid was tailored to narrow down the bandgap to visible-light region. The bandgap energy obtained by UV–visible diffuse reflectance spectroscopy (DRS) for CdO/Al2O3 nanocomposite (NCs) was 2.95 eV. The Brunauer-Emmett-Teller (BET) surface area analysis shows porosity of material with high surface area. During photocatalysis, e- from CdO migrates to defect levels of Al2O3 that facilitated charge separation. The kinetic rate of degradation of methylene blue (MB) by NCs was 3.5 and 14 times higher than CdO and Al2O3 respectively. The performance was optimized and it showed good reusability. In addition, the multiple applications of the CdO/Al2O3 were evaluated by testing the bactericidal activity. The nanohybrid posed high growth inhibition activity towards both gram positive and negative bacterial strains. The maximum colour removal (97.3%) and high mineralization (87%) was verified by UV–visible and total organic carbon (TOC) measurements. This promotes the nanohybrid to act as a better candidate for environmental remediation and disinfectant applications.

Epidemiological characteristics of Streptococcus agalactiae in tilapia in China from 2006 to 2020

Group B Streptococcus (GBS) is the major causative pathogen of streptococcosis in tilapia, leading to a massive economic loss in the aquaculture industry worldwide. To date, the epidemiological characterization of tilapia GBS in China remains limited. Thus, the aim of this study was to determine the phenotype and genotype of GBS strains in tilapia in China from 2006 to 2020. A total of 678 GBS strains were isolated from farmed tilapia in the past decade. The CAMP reaction of GBS strains was investigated, and the cfb gene of the CAMP negative strains was sequenced and analysed. The genotypic distribution of these strains was determined by molecular serotyping, multi-locus sequence typing (MLST), virulence genotyping, and prophage genotyping. All GBS strains were divided into two serotypes (Ia and Ib), two sequence types (STs; ST7 and ST261), five virulence genotypes (V1–V5), and three prophage genotypes (P1-P3). A total of six genotypes (I–VI) were obtained based on serotyping, MLST, virulence genotyping, and prophage genotyping. Among them, strains in genotypes I, II, III, and IV were primarily prevalent from 2006 to 2015, and those in genotypes V and VI were the dominant epidemic strains from 2012 to 2020. Moreover, genotype VI strains showed a substantial population explosion from 2011 to 2020 and were mainly distributed in the geographically proximate provinces of Guangdong, Guangxi, Hainan, and Fujian. This is first report of tilapia Ia-GBS CAMP negative strains, and the strains were probably from the same hatchery. Genetic diversity in tilapia GBS strains has been high in China over the past decade, especially from 2010 to 2015. The genotypes of the tilapia GBS strains underwent obvious variation, and the prevalent strains in recent years have harboured more virulence-related genes. This study provides a better understanding of the epidemiology, pathogenesis, and evolutionary mechanism of tilapia GBS strains.

Mycochemical contents, Free-radical scavenging capacity and anti-microbial activity of wild edible mushroom from Algeria

Edible fungal species like desert truffles are often considered a healthy food source, contributing to high antioxidant and antimicrobial effects which have been used as functional foods for health promotion and disease prevention, and as treatments for a variety of diseases since antiquity. The use of desert truffles in traditional medicine has led to modern scientific investigation into their bioactive properties. This study is part of this perspective and consists of doing in a first time the determination of the nutritional value of Terfezia boudieri harvested from North-western of Algeria, Secondly, we have evalu-ated the antioxidant capacity using two complementary test systems, name-ly DPPH free radical scavenging and iron reduction (FRAP) , and finely the antimicrobial properties were screened against seventeen Gram positive and Gram negative pathogenic bacterial strains; and two strains of yeast using agar well diffusion method. The quantitative estimate of nutritional value shows that T. boudieri showed a preponderance of proteins and minerals with12.57 ± 0.13 and 15 ± 3g / 100g dry weight respectively; In addition, the methanolic extract of the ascocarps contains a high content of total phenols estimated at 44.68 ± 0.22 mg GAE / g, vitamin c and carotenoids are also present in large quantities. The methanolic extract has good capacity re-duction with iron. The free radical scavenging capacity DPPH is very inte-resting with an IC50 = 0.30 mg / ml; this last remains greater than the radical trapping capacity DPPH of ascorbic acid, whose IC50 = 0.08 mg / ml. Results of antimicrobial activity in particular against Gram (+) bacteria, the diameter of which varies from 10 ± 0.01 to 30 ± 0.57 mm where Bacillus subtilis ap-pears to be the most sensitive. On the other hand, they have moderate activ-ity against Gram (-) bacteria where Enterobacter cleacae, and Actinobacter baumannii, are the only Gram (-) bacteria that show hyper-sensitivity, our methanolic extract did not show anticandidal activity against Candida albi-cans. Therefore, the current results have demonstrated that this mushroom is nutritious and contain multiple antioxidants and has confirmed that desert truffle extracts have antimicrobial properties that are effective against com-mon pathogens that cause disease in humans, which can be further exploit-ed for clinical use.

Zinc(II) complexes of 3,5–dibromo–salicylaldehyde and α–diimines: Synthesis, characterization and in vitro and in silico biological profile

The synthesis of five neutral zinc(II) complexes of 3,5–dibromo–salicyladehyde (3,5–diBr–saloH) in the presence of nitrogen–donor co-ligands 2,2′–bipyridine (bipy), 1,10–phenanthroline (phen), 2,9–dimethyl–1,10–phenanthroline (neoc), or 2,2′–bipyridylamine (bipyam) was undertaken and complexes [Zn(3,5–diBr–salo)2(H2O)2] (1), [Zn(3,5–diBr–salo)2(bipy)] (2), [Zn(3,5–diBr–salo)2(phen)].3,5–diBr–saloΗ (3), [Zn(3,5–diBr–salo)2(neoc)] (4) and [Zn(3,5–diBr–salo)2(bipyam)] (5) were characterized by various techniques. The crystal structures of complexes 3 and 5 were determined by X–ray crystallography, revealing the co–existence of two different coordination modes of 3,5–diBr–salo− ligands. The new complexes show selective in vitro antibacterial activity against two Gram–positive and two Gram–negative bacterial strains. The complexes may scavenge 1,1–diphenyl–picrylhydrazyl and 2,2′–azinobis(3–ethylbenzothiazoline–6–sulfonic acid) radicals and reduce H2O2. The complexes may intercalate in–between the calf–thymus DNA–bases and have exhibited low–to–moderate ability to cleave supercoiled circular pBR322 plasmid DNA. The complexes may bind tightly and reversibly to bovine and human serum albumins. In order to explain the in vitro activity of the compounds, molecular docking studies were adopted on the crystal structure of calf-thymus DNA, human and bovine serum albumin, Escherichia coli and Staphylococcus aureus DNA–gyrase, 5–lipoxygenase, and 5–lipoxygenase activating protein. The employed in silico studies aimed to explore the ability of the compounds to bind to these target biomacromolecules, establishing a possible mechanism of action and were in accordance with the in vitro studies.

Synthesis and enhanced antibacterial using plant extracts with silver nanoparticles: Therapeutic application

This study evaluated the antimicrobial and therapeutic properties of plant extracts and silver nanoparticles. The silver nitrate nanoparticles developed from plant extracts like Tulsi (Ocimum tenuiflorum), Spearmint (Mentha spicata), Neem (Azadirachta indica) (TSNLs) leaves have shown strong applications as the agent for stabilizing the TSNLs extracts. The maximum amounts of volatile compounds are present in the Beta-Caryophyllene, Carvone and Phytol of Tulsi, Spearmint and Neem extracts. Optimal extract absorption of the TSNLs extracts was determined in 0.03 mol/L, individually, with 0.951% yield recorded. The TEM analysis of silver nitrate nanoparticles were done in an average diameter of 10 nm. A crystal magnitude of 12 nm was considered in the XRD investigation. In the TSNLs leaf extracts at 92.1667 ± 0.3626%, FTIR analysis showed no chemical connections with the covering element. Escherichia coliandStaphylococcus aureuswere employed to evaluate the antibacterial activities of the silver nanoparticles. In these samples, antimicrobial properties were evaluated in a gram negative and gram-positive microbes and fungal strains. The results showed that the nanoparticles made with TSNLs had produced quick natural control against pests and microbes, showing promising applications against pathogenic and spoilage microbes. The results also showed that these antimicrobial properties can be further improved through increasing the levels of the nanoparticle formulations.

Assessment of antimicrobial properties of a lectin isolated from <em>Amaranthus cruentus</em> Linn

Lectins are diverse class of proteins which have the ability to bind carbohydrates with considerable specificity and involved in many biological processes like host pathogen interactions, cell targeting, cell- cell communications, cancer metastasis and differentiation. Plants are rich sources of lectins that have great implications in medicinal and therapeutic applications. The antimicrobial property of a lectin isolated from Amaranthus cruentus Linn seeds has been explored in this study. ACL (Amaranthus cruentus Linn lectin) was isolated, purified and characterised by hemagglutination assay with human ABO blood groups and the molecular weight was determined by SDS PAGE. ACL was subjected to evaluation for inhibition of microbial growth by disc diffusion against human pathogenic Gram positive and Gram negative bacterial strains and some fungal strains. MIC and MBC were assessed. The effects of ACL on biofilm forming bacterial strains was assessed using crystal violet assay. The isolated and purified ACL have a molecular weight of 60 KDa. The Hemagglutination activity of ACL was inhibited by N-acetyl galactosamine. ACL exhibited both antibacterial and antifungal activities with considerable zones of inhibition. Biofilm mass reduction was observed in ACL treated bacteria. These findings indicate that ACL is having therapeutic applications with great importance in clinical microbiology.

Synthesis and antibacterial evaluation of new pyrido[3',2':4,5]thieno[3,2-d ]pyrimidin-4(3H)-one hybrids linked to different heteroarene units

A three-component protocol involving the reaction of 3-aminothieno[2,3-b]pyridine-2-carboxylate, Me2NCH(OMe)2 and heteroaryl (bis)amines in dioxane under microwave irradiation yielded a new series of pyrimidinones. The target hybrids were formed by an initial formamidine formation,Pyrazole-linked pyrimidinones displayed the best antibacterial activity against all the gram-positive and negative strains tested.

Synthesis of Manganese (Mn) doped Nickel oxide nano particles, its antibacterial activity

The present work deals with the synthesized Manganese (Mn) doped Nickel oxide nanoparticles. Using hydrothermal method, the Manganese (Mn) doped Nickel oxide nanoparticles were synthesized with the concentration ranges from 1 mol% to 2 mol%. The characterization done for the synthesized nanoparticles are X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), DSC spectroscopy and UV visible spectroscopy. The XRD reveals the amorphous nature with the size ranges from 60 nm to 20 nm. The chemical bonding nature and functional group analysis of the prepared material was confirmed by FTIR Spectroscopy. The optical behaviour of the Manganese (Mn) doped Nickel oxide nanoparticle was done using UV–Visible spectroscopy. The antibacterial activity of the prepared nanoparticles was done for both gram negative and gram-positive bacterial strains. The prepared nanoparticles have proven to be promising candidates to be utilized in drug delivery and food packaging applications.

Rapid and Accurate Antibiotic Susceptibility Determination of tet(X)-Positive E. coli Using RNA Biomarkers.

ABSTRACTThe emergence and prevalence of novel plasmid-mediated tigecycline resistance genes, namely, tet(X) and their variants, pose a serious threat to public health worldwide. Rapid and accurate antibiotic susceptibility testing (AST) that can simultaneously detect the genotype and phenotype of tet(X)-positive bacteria may contribute to the deployment of an effective antibiotic arsenal, mortality reduction, and a decrease in the use of broad-spectrum antimicrobial agents. However, current bacterial growth-based AST methods, such as broth microdilution, are time consuming and delay the prompt treatment of infectious diseases. Here, we developed a rapid RNA-based AST (RBAST) assay to effectively distinguish tet(X)-positive and -negative strains. RBAST works by detecting specific mRNA expression signatures in bacteria after short-term tigecycline exposure. As a proof of concept, a panel of clinical isolates was characterized successfully by using the RBAST method, with a 3-h assay time and 87.9% accuracy (95% confidence interval [CI], 71.8% to 96.6%). Altogether, our findings suggest that RNA signatures upon antibiotic exposure are promising biomarkers for the development of rapid AST, which could inform early antibiotic choices.IMPORTANCE Infections caused by multidrug-resistant (MDR) Gram-negative pathogens are an increasing threat to global health. Tigecycline is one of the last-resort antibiotics for the treatment of these complicated infections; however, the emergence of plasmid-encoded tigecycline resistance genes, namely, tet(X), severely diminishes its clinical efficacy. Currently, there is a lack of rapid and accurate antibiotic susceptibility testing (AST) for the detection of tet(X)-positive bacteria. In this study, we developed a rapid and robust RNA-based antibiotic susceptibility determination (RBAST) assay to effectively distinguish tet(X)-negative and -positive strains using specific RNA biomarkers in bacteria after tigecycline exposure. Using this RBAST method, we successfully characterized a set of clinical strains in 3 h. Our data indicate that the RBAST assay is useful for identifying tet(X)-positive Escherichia coli.