Strains Of Pathogenic Bacteria Research Articles

Synthesis of Titanium Oxide Nanoparticles Using Root Extract of Kniphofia foliosa as a Template, Characterization, and Its Application on Drug Resistance Bacteria

Biogenic methods of synthesis of nanoparticles (NPs) using plant extracts have been given a great attention due to its nontoxicity and environmental friendliness. In this study, TiO2 NPs were synthesized from titanium tetrabutoxide and extract of root of Kniphofia foliosa. NPs of TiO2 were biosynthesized at different volume compositions of titanium tetrabutoxide to the plant extract with a ratio of 1 : 2, 1 : 1, and 2 : 1, respectively. These green synthesized NPs of TiO2 were characterized by thermogravimetric analysis (TGA/DTA), X-ray diffraction (XRD), scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-Vis), and Fourier transform infrared (FTIR) spectroscopy. TGA/DTA analysis has confirmed that the synthesized NPs of TiO2 were stable above the temperature of 500°C. The sharp and intense peaks at 2θ values of 25.3, 38.0, 47.9, 53.2, 54.8862, 62.7, 70.2, and 75.0 have confirmed formation of crystalline NPs of TiO2 in the sample of 1 : 1 and 2 : 1 ratios, and less crystalline samples for TiO2 NPs prepared in a 1 : 2 ratio. Comparison between FT-IR absorption bands of the plant extract and that of calcined NPs of TiO2 confirmed the purity of synthesized nanomaterials, except unavoidable adsorption of moisture on the surface of TiO2 NPs in an open air. The antibacterial activity of biosynthesized TiO2 NPs and that of ethanolic root extract of Kniphofia foliosa was investigated via the disc diffusion method against human pathogen bacteria strains of Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, and Streptococcus pyogenes. Among the different ratios, TiO2 (1 : 1) NP shows better performance towards Gram-negative bacteria due to its smaller average crystalline size and uniform morphology observed in SEM image relative to the other two ratios of TiO2 NPs. Antibacterial activity of the ethanolic root extract of Kniphofia foliosa itself showed better performance towards Gram-negative bacteria than NPs of TiO2 that might be due to antibacterial activity of residue of ethanol left with the plant extract.

Chemical constituents of Clausena lenis

Phytochemical examination of Clausena lenis Drake (Rutaceae), collected in Thailand, led to the isolation of seven coumarins, four furoquinolines, two amides, and one flavonoid glycoside. Four of these compounds, one coumarine derivative named as gravelliferone A (3), two furoquinoline derivatives (kokusagenin A (8) and B (9)) and one amide, clausenalansamide H (13), are reported for the first time. Compound 3 was isolated from the root bark, compound 8 from the stem bark and compounds 9 and 13 from the leaves. The molecular structures of all isolated compounds were established by means of NMR experiments combined with mass spectrometry. Preliminary tests of the lipophilic stem bark extract against various human pathogenic bacteria strains revealed promising effects against Staphylococcus aureus ATCC 43300.

Green aqueous synthesis and antimicrobial evaluation of 3,5-disubstituted 1,2,4-triazoles

An eco-friendly and simple procedure was proposed for the synthesis of 3,5-disubstituted 1,2,4-triazoles by optimized reaction of benzamidine hydrochloride and various aryl hydrazides. H 2 O and K 2 CO 3 were applied as green and available solvent and base, respectively. The products were generated in good to high yields in one step and sufficient purity after a simple workup. The designed process is applicable to other organic syntheses especially from poorly water-soluble reactants such as hydrazines or hydrazides. Inhibitory activity of all prepared derivatives was evaluated against 10 pathogenic bacteria strains including both Gram-positive and Gram-negative, as well as 2 mold and 1 yeast strains. The prepared derivatives showed good antimicrobial activities. 1,2,4-Triazoles containing 2-hydroxynaphthalen-3-yl and 5-chlorothiophen-2-yl substituents at position 3 showed the best antifungal and antibacterial properties, respectively.

Antimicrobial activity of quinine derivatives against human pathogenic bacteria

Nowadays, the antimicrobial resistance is considered as one of the greatest concern facing human health, as many of bacterial strains had become resistant to available antibiotics. The misuse of antibiotics has potentially reduced the efficacy of drugs, concurrent with the increase of bacterial resistance to commercially available drugs. Therefore, the discovery of effective antimicrobial agents are desperately needed to overcome this epidemic, especially from traditional medical plants and their derivatives. Quinine is a natural alkaloid from the bark of the cinchona tree that has been used for years as an antimalarial drug. Various literatures also regarded an antibacterial effect of quinine against both Gram-positive and Gram-negative pathogenic microorganisms. With this vision, a series of some novel quinine derivatives were synthesized and their biological activities against pathogenic bacteria were assessed. This present study therefore attempted to examine the antimicrobial properties of quinine-derived compounds and their Minimal Inhibitory of Concentration (MIC) against common pathogenic bacteria strains, e.g. Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus substillis. Disk diffusion test was performed for screening of antimicrobial activity of quinine derivatives. The results were evaluated and compared with references drug streptomycin. It was found that quinine derivatives showed moderate antimicrobial activity as compared with quinine itself on tested pathogenic bacterial strains. Ester quinine propionate was found to give the highest antibacterial activity among other derivatives, with a range inhibition zone from 9 to 23.5 mm to bacteria strains, compared to streptomycin with a range of inhibition zone from 8 to 12 mm. Further studies are needed to assess the bactericidal mechanisms of those derivative compounds.

Distribution characteristics and risk factors of infectious pathogens after open limb fracture surgery

Objective To investigate the distribution characteristics and risk factors of infectious pathogens after open limb fracture surgery. Methods From January 2016 to December 2018, 180 patients with open limb fracture admitted to Hangzhou Hospital of Zhejiang Medical and Health Group were selected to observe the infection after operation.Pathogens were isolated and identified by automatic biological analyzer and bacterial identification system, and drug resistance test was carried out by K-B method.Multivariate logistic regression analysis was used to analyze the risk factors of infection after open limb fracture surgery. Results Among 180 cases of open limb fracture, 29 cases had postoperative infection, the infection rate was 16.11%.Among 29 cases of post-operative infection, 34 strains of pathogenic bacteria were isolated, including 19 strains of Gram-positive bacteria, 13 strains of Gram-negative bacteria and 2 strains of fungi.The resistance rate of Staphylococcus aureus to penicillin G was high, and the resistance rate was 80.00%.Univariate analysis showed that there were no statistically significant differences in gender, BMI, injury site, smoking history, hypertension and intraoperative bleeding between the two groups (χ2=0.252, 0.416, 0.734, 0.856, 0.572, all P>0.05). There were statistically significant differences in age, diabetes mellitus, operation time, hospitalization time, wound contamination and drainage tube placement time between the two groups (χ2=21.537, 9.664, 17.244, 15.459, 24.327, 19.804, all P 60 years old, diabetes mellitus, operation time>3h, hospitalization time>14d, wound contamination and drainage tube placement time>4d were independent risk factors for infection after open limb fracture surgery. Conclusion Postoperative infection rate of open limb fracture is high.Gram-positive bacteria are the main pathogenic bacteria.Postoperative infection is affected by many factors.In order to prevent postoperative infection, specific measures should be taken and antibiotics should be used reasonably in strict accordance with drug sensitivity test. Key words: Fractures, open; Extremities; Infection; Gram-positive bacteria; Gram-negative bacteria; Fungi; Risk factors

Tetra-(p-tolyl)antimony(III)-Containing Heteropolytungstates, [{(p-tolyl)SbIII}4(A-α-XW9O34)2]n- (X = P, As, or Ge): Synthesis, Structure, and Study of Antibacterial and Antitumor Activity.

We have synthesized and structurally characterized three tetra-(p-tolyl)antimony(III)-containing heteropolytungstates, [{(p-tolyl)SbIII}4(A-α-XW9O34)2]n- [X = PV (1-P), AsV (1-As), or GeIV (1-Ge)], in aqueous solution using conventional, one-pot procedures. The polyanions 1-P, 1-As, and 1-Ge were fully characterized in the solid state and in solution and were shown to be soluble and stable in aqueous medium at pH 7. Biological studies demonstrated that all three polyanions possess significant antibacterial and antitumor activities. The minimum inhibitory concentrations of 1-P, 1-As, and 1-Ge were determined against four kinds of bacteria, including the two pathogenic bacteria strains, Vibrio parahaemolyticus and Vibrio vulnificus. The three novel polyanions also showed high cytotoxic potency in the human cell lines A549 (non-small cell lung cancer), CH1/PA-1 (ovarian teratocarcinoma), and SW480 (colon carcinoma).

Study of prebiotic properties of selected banana species in Thailand.

Prebiotics are functional foods with health-promoting properties that are used in many developed countries. Thailand is one of the countries that produces many plants that should have prebiotic properties. In this study, we investigated the potential prebiotic effects of powders obtained from Saba, Pisang Awak Banana and Silver bluggoe in vitro in accordance with their physical, chemical and microbiological properties. These selected plants were found to demonstrate good water-/oil-binding properties. They contained chlorophyll, beta carotene and lycopene and showed good resistance to stomach and small-intestine enzymes. The selected plants were further used to evaluate prebiotic properties by supplementing as a carbon source in culturing broth for growing probiotic bacteria and pathogenetic bacteria. The increase in the number of probiotic bacteria during fermentation of these selected plants correlated with decreased pH. The growth of four strains of probiotic bacteria seemed to be promoted in MRS broth containing these selected plants, but no significant differences in the number of probiotic bacterial groups were detected in response to difference concentrations of all these selected plants. In addition, we noted that a decrease in the number of all four strains of pathogenic bacteria during fermentation of these selected plants correlated with a decreased pH. Moreover, the antimicrobial activity of selected plant prebiotics supported probiotic substance production to inhibit growth of pathogenic bacteria. In conclusion, we have shown that the addition of selected prebiotic plants, indicating that they should be used as a prebiotic food ingredient, represents a potential alternative to available commercial prebiotics.

Diorganotin(IV) complexes derived from N-terminal methylation of Triapine: synthesis, characterization and antibacterial activity evaluation

The reaction of diorganotin(IV) with ligands (HL1 = 3-aminopyridine-2-carbaldehyde N(4) methylthiosemicarbazone, HL2 = 3-aminopyridine-2-carbaldehyde N(4)-dimethylthiosemicarbazone) afforded two compounds [PhSn(L1)Cl2] (1) and [(Ph)2Sn(L2)Cl] (2), respectively. The compounds were characterized by elemental analysis, infrared spectrum, UV–vis spectrometry, and X-ray crystallography. The ligands and corresponding complexes were assayed for their in vitro pharmaceutical activity against different pathogenic strains of bacteria by disk diffusion method. The results demonstrate that 1–2 have remarkable antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). 1 exhibit higher antibacterial properties against S. aurenu (MIC = 0.00095 μg/mL) and E. coil (MIC = 0.0019 μg/mL). In the same experimental conditions, the two complexes display more potent activity relative to standard antibiotics Kanamycin and Ampicillin.

Effect of Antimicrobial Agents Extracted from American Cockroach Insect Periplaneta Americana L. on Some Species of Microbes

current study was conducted for the period of October 2017 until November 2018 to investigate the effect of antimicrobial material of American cockroach Periplaneta americana hemolymph against strains of pathogenic bacteria and yeast. The samples of adults American cockroach was collected and divided into three major groups, the first collected their haemolymph without injecting the cockroaches with bacteria (non-immunizator) the second collected their haemolymph after 12 hours of being injected with E. coli (immunizator 12h), and the third group after 24 hours of being injected with the same bacteria (immunizator 24h), then divide each totals above to two subgroups one by cooling centrifuge on 4ºC and the other by table centrifuge at room temperature (non-cooling). protein concentration had measured of all transactions and was the highest value is immunizator 12-hour by cooling centrifuges.

Synthesis, spectroscopic characterization, biological activity, DFT and molecular docking study of novel 4-hydroxycoumarine derivatives and corresponding palladium(II) complexes

In the present manuscript, palladium(II) complexes (C1, C2) with newly synthesized coumarine ligands 3-(1-((3-chlorophenyl)amino)ethylidene)-chroman-2,4-dione (L1) and 3-(1-((4-chlorophenyl)amino)ethylidene)-chroman-2,4-dione (L2) were prepared and structurally characterized by spectroscopic techniques (FT-IR, 1H NMR, 13C NMR) in combination with elemental analysis and theoretical methods (DFT). The structures of all compounds were fully optimized using the B3LYP-D3BJ theoretical method. Cytotoxic activity of investigated compounds was tested against two cells lines (human colorectal carcinoma, HCT-116, and human fibroblast lung MRC-5), while their antimicrobial activity was screened against nine strains of pathogenic bacteria, five mould species and two yeast species. Unfortunately, their cytotoxic and antibacterial activities were weak. Docking studies for all compounds with epidermal growth factor receptor (EGFR) were performed. It was found that hydrophobic interactions that include chlorine atom have somewhat lower values of the pairwise interaction energies compared to the purely hydrophobic interactions. In addition, it was found the chlorine atom in the para position contributes to the slightly higher binding free energy and lower values of constant of inhibition.

In vivo and in vitro antimicrobial activity of phytol, a diterpene molecule, isolated and characterized from Adhatoda vasica Nees. (Acanthaceae), to control severe bacterial disease of ornamental fish, Carassius auratus, caused by Bacillus licheniformis PKBMS16

Bacillus licheniformis, a pathogenic new strain of bacteria is considered as the main cause of high mortalities and economic losses among the ornamental fish farms of India. The present study aimed to investigate the anti-bacterial and Immunostimulant activity of three selected Indian medicinal plants, Allium sativum, Adhatoda vasica and Centella asiatica for treating Bacillus licheniformis PKBMS16 by subsequent experimental and clinical trials using different organic polar and non-polar solvents. The antimicrobial and Immunostimulant activity of methanolic crude extracts of Adhatoda vasica was fractions and active constituents was further characterized by chromatography and mass spectroscopy studies using FTIR, 1HNMR and 13c NMR to identify as well as to determine the nature of the pure compound which is phytol (C20H40O), a diterpene alcohol with a molecular weight of m/z 297. In order to study the in vivo anti-pathogenic influence of the biologically active compounds, phytol were incorporated to the artificial diets at the concentration of 2, 5 and 8 mg/kg and fed to the1.0 × 105 CFU/ml of Bacillus licheniformis PKBMS16 injected experimentally challenged ornamental goldfish Carassius auratus for twenty days. Phytol treated group significantly (P < 0.01 and P < 0.05) reduced the rate of fish mortality. After the termination of survivability assay the estimation of hemato-biochemical parameters have been performed and revealed the significant recovery of health condition on 20th days post treatment. Therefore, the present study concluded that the low toxicity along with high bioactivity and tolerance by lower vertebrate supports the potential of phytol as a new compound for inducing fish immunity.

Antimicrobial Potential of anaconda body fat oil (Eunectes murinus), in Santarém city, Pará state, Brazil

The use of natural substances from animals and plants has always been the subject of research, because it is made in a rustic way and through popular knowledge, built by everyday experiences and without scientific approval. The oil from the body fat of the snake - or better known as lard of anaconda, extracted from the anaconda snake (Eunectes murinus) is a product widely used in traditional communities and is marketed in markets for therapeutic purposes in several diseases. Because of the low cost and popular beliefs, many people use zootherapeutic means to treat themselves. Hence the importance of therapeutic proof of these products. Thus, the aim of this study was to verify whether the lard of anaconda made in the traditional way has antimicrobial potential in certain strains of pathogenic bacteria and fungi. For that, the evaluation of the lard’s antimicrobial potential was carried out using the disk diffusion method, adapted from the manual M7-A6 standardized by the Clinical and Laboratory Standards Institute, against the strains of S. aureus, E. coli, C. albicans and C. krusei. The observed results showed that there was no presence of bacterial or yeast growth inhibition halos, indicating that the anaconda lard oil did not inhibit the growth of fungi and bacteria in any of the strains used. Therefore, the present study allows us to conclude that the anaconda lard oil (Eunectes murinus), did not present any inhibitory antimicrobial potential, against the tested bacterial and fungal strains.

EVALUATION OF POLYPHENOLS CONTENT OF TWO WILD\\r\\nASTERACEAE FROM ARID CLIMATE AND SCREENING OF THEIR\\r\\nANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES

This study is performed to evaluate the antioxidant and the antimicrobial activities of Brocchia cinerea (Vis.) and Matricaria pubescens (Desf.). These species are very abundant after rain season in arid regions of Algeria. Aerial parts of these plants were subjected to extraction using solvents of different polarity, alone and/or mixed with water (70% methanol, ethyl acetate, n-butanol, 80% acetone, chloroform, and heated water to obtain similar traditional preparation). The antioxidant capacity was evaluated by means of DPPH radical scavenging activity and ferric reducing power (FRAP). The antimicrobial activity of the extracts was investigated by the solid medium diffusion method and serial dilution assays against pathogenic bacteria strains; Gram positive: Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212 and Gram negative: Pseudomonas aeruginosa ATCC 27853, Enterobacter cloacae ATCC 13047, Klebsiella pneumoniae ATCC 49619 and Escherichia coli ATCC 25922. As well as the fungi: Aspergillus niger and the yeast Candida albicans. The majority of the extracts have shown relatively, high antioxidant activity and variable antimicrobial effects against the tested bacteria and fungi. The results exhibited by Brocchia cinerea by means of its extract n-butanol (2204.021±0,042 μg EAAs/mg ext) showed it as the most metal reducer. The highest antiradical activity expressed by the lowest EC50 was noted by Matricaria pubescens ethyl acetate extract (0.110±0,003 mg/ml). Overall, the minimum inhibitory concentration (MIC) values for active extracts ranged between 0.125 and 1 mg/ml. Some resistances were also noted.

Dietary supplementation with avilamycin and Lactobacillus acidophilus effects growth performance and the expression of growth-related genes in broilers

Context The use of antibiotics in poultry production is appropriate; however, it brings a high risk of dissemination of antibiotic-resistant strains of pathogenic and non-pathogenic bacteria and their further transmission to humans via the food chain. Aims The effects of supplementation with Lactobacillus acidophilus (a probiotic) or avilamycin (an in-feed antibiotic growth promoter), on growth performance, digestibility, plasma lipid levels, and the expression of certain growth-related genes were investigated. Methods In total, 135 15-day-old broiler chicks were divided into three groups (n = 45): a control group and two treatment groups. Each treatment group was then further divided into three replicates (15 birds each). The control group was fed a basal diet; the second group received basal diet supplemented with avilamycin (0.1 g/kg); the third group received basal diet plus L. acidophilus (0.1 g/kg). Growth performance (bodyweight, feed intake and feed-conversion ratio) was measured. Digestibility and gene expression were measured at the end of the experiment. Key results Greatest bodyweight gain was achieved in the L. acidophilus-fed chicks, which were significantly (P &amp;lt; 0.05) heavier than the control chicks and the avilamycin-fed chicks. Addition of avilamycin or L. acidophilus to the diet also significantly improved feed efficiency (P &amp;lt; 0.05) compared with the control. Although the digestibility of dry matter, crude protein and crude fibre significantly improved in the two experimental groups compared with the control, ether extract was not affected. In addition, plasma total cholesterol, triglyceride and low-density-lipoprotein cholesterol levels were significantly (P &amp;lt; 0.05) decreased whereas plasma high-density-lipoprotein cholesterol was significantly (P &amp;lt; 0.05) increased in the L. acidophilus group compared with the control. Expression of the genes for growth hormone secretagogue receptor (GHSR), insulin-like growth factor 1 (IGF-1) and insulin-like growth factor 1 receptor (IGF1R) was remarkably upregulated in the skeletal muscles of the two experimental groups. Conclusions Supplementation with L. acidophilus (0.1 g/kg) in the broiler diet had positive effects on growth, feed intake, feed efficiency, digestibility, and plasma lipid levels of the broilers. Implications Lactobacillus acidophilus might be a more useful additive in broiler feed than antibiotic growth promoters such as avilamycin.

Comparative evaluation of different probiotic products on salivary Streptococcus mutans and Lactobacillus level in caries risk population.

Introduction:Dental caries is a multifactorial disease with the main causative organism being Streptococcus mutans and Lactobacillus spp. “Probiotics” are defined as living microorganisms, principally bacteria, which are safe for human consumption and when ingested in sufficient quantities, have beneficial effects on human health, beyond basic nutrition. These can be used to replace the pathogenic strains of bacteria with the nonpathogenic type in the oral cavity thus can help prevent dental caries.Aims:To evaluate and compare the role of probiotic milk and lozenges on S. mutans and Lactobacillus spp. count on patients who are exposed to probiotics continuously for 7 days.Materials and Methods:Sixty volunteers who were prone to caries were divided into three equal groups. Experimental groups were given probiotics daily for 7 days. In Group A, patients were given milk without any probiotics (control); in Group B, probiotic milk is given; and in Group C, probiotic lozenges are given. Saliva samples were assessed on the 1st day and after 7 days of intervention. The collected saliva samples were inoculated on the selected culture media and estimation was done by measuring the colony-forming unit.Statistical Analysis Used:Statistical analysis was performed using Student's paired t-test and multiple comparisons by Tukey's honest significant difference test.Results:There was a significant reduction in salivary S. mutans level in both experimental groups after 7 days (P < 0.05). However, there was no significant difference in Lactobacillus count before and after the intervention.Conclusions:Probiotics have a role in reducing salivary S. mutans count. Probiotics lozenges showed greater efficacy in reducing salivary S. mutans count than probiotic milk.

An Improved Protocol for the Expression and Purification of Tetracycline Monooxgenase: An Enzyme Involved in Antibiotic Resistance

Tetracyclines are an important group of antibiotics used in agricultural and clinical settings. They function by binding to the 30S subunit of the prokaryotic ribosome to effectively halt translation. The emergence of tetracycline resistant strains of pathogenic bacteria has threatened the continued use of the drug. One mechanism of tetracycline resistance is the degradation of the drug by the flavin dependent enzyme tetracycline monooxygenase (TetX). Only a limited number of studies of the enzyme have been conducted to date due to the limited amounts of pure protein that can be obtained from current protocols (~6 mg/L of cell culture). The current report describes the development of optimized expression and purification protocols to obtain larger amounts of pure, soluble enzyme suitable for detailed kinetic studies to deduce its chemical mechanism. During the initial phase of this work the pET22a+ plasmid with the gene encoding for TetX was used to transform either DH5α or Rosetta (DE3) pLysS Escherichia coli cells. Expression trials of these cell lines in which both the temperature and times of incubation with isopropyl β-D-1-thiogalactopyrandoside were then carried out. Of the conditions tested, optimal expression of TetX was found with a 20 h induction period at 30 °C using E. coli DH5α cells. Ammonium sulfate precipitation trials were then conducted where it was concluded that a 20 fold purification of the enzyme is achieved through treatment with 40% saturation of salt and collection of the supernatant after centrifugation. A nickel affinity chromatographic protocol was also developed, which purified the enzyme to high levels as judged by sodium dodecyl sulfate polyacrylamide gel electrophoresis and the specific activity of the purified sample. The expression and purification protocol developed here resulted in ~36 mg/L of cell culture, which is a 6-fold improvement over published protocols.

Acanthamoeba - pathogen and vector of highly pathogenic bacteria strains to healthy and immunocompromised individuals.

Acanthamoeba is a free-living protist pathogen, which is present in every place on Earth. 50 to 100 percent of the adult population has serum antibodies, specific for Acanthamoeba antigens. Acanthamoeba is an etiological agent of keratitis and encephalitis diagnosed in human. Acanthamoeba keratitis occurs in healthy persons and may lead to visual impairment and blindness, because corneal infection with this parasite fails to induce cell-mediated immune response due to the absence of resident antigen-presenting cells in the cornea. Systemic immunization with Acanthamoeba antigens induces Th1 cell-mediated immunity and serum IgG antibody, but do not prevent the development of keratitis. Immunization via mucosal surfaces stimulates IgA antibodies in tears and protects against the development of keratitis.Amoebae feed mainly on bacteria, fungi, and algae. By transferring intracellular bacteria, amoeba contributes to the spread of diseases dangerous to humans. Some microorganisms have evolved to become resistant to protist, since they are not internalized or able to survive, grow, and exit free-living protists after internalization. In many cases, the bacteria inside living amoebae survive longer, and multiply better, showing higher virulence. There is a hypothesis, which assumes that Acanthamoeba and symbiontic bacteria survive and multiply better in moist soil, rich in nitrogen compounds, particularly in the vicinity of the root systems of Alnus glutinosa, infected with nitrogen-fixing bacteria Frankia alni. Impact of soil environment created by nitrogen-fixing bacterium Frankia alni on specific relations between protists Acanthamoeba and highly pathogenic bacteria strains in Alnus glutinosa habitats in Poland continue to be established.

Synthesis and Antimicrobial Activity of Novel Piperidinyl Tetrahydrothieno[2,3-c]isoquinolines and Related Heterocycles.

A novel series of 1-amino-2-substituted-5-piperidinyl-6,7,8,9-tertahydrothieno[2,3-c]isoquinolines (4a–e) was synthesized upon treatment of 4-cyano-1-piperidinyl-5,6,7,8-tetrahydroisoquinline-3(2H)-thione (2) with α-halo carbonyl compounds such as chloroacetone, ethyl chloroacetate, 2-bromoacetophenone, chloroacetamide, and chloroacetanilide. Construction the pyrrolyl ring associated with the thienotetrahydroisoquinoline moiety was achieved by treatment of compounds 4a, b with 2,5-dimethoxytertahydrofuran in acetic acid. 1-Pyrrolyl-2-substituted-thieno[2,3-c]isoquinolines 5a and 5b which in turn were used as multipurpose precursors for synthesis of other new heterocycles. Assignments of the chemical structures of the respectively synthesized thienotetrahydroisoquinolines and their derivatives were established on the bases of elemental and spectral techniques (Fourier transform infrared, 1H NMR, 13C NMR, and mass spectroscopy). Furthermore, certain compounds were screened for their antimicrobial activity which revealed promising activities against various pathogenic strains of bacteria and fungi.

Effects of Development and Ripening Stage on Phytochemical Compositions, Antioxidant and Antibacterial Activities of Date Palm Fruits

Edible parts of two dates cultivars (Deguel ahmar and Tanslit) at four maturation stages khellal, besser, rutab and tamr were analyzed for their phytochemical composition (total phenolic, total flavonoid and condensed tannins contents) as well as antioxidant and antibacterial activities. The antioxidant activity evaluated in vitro using scavenging assays of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2′-azino-bis(3- ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical and ferric reducing power. Antibacterial activity of extracts were evaluated in vitro by the agar disk diffusion method against five pathogenic bacterias trains: Bacillus subtilis ATCC 6633, Enterococcus ATCC 3315, Staphylococcus aureus ATCC 43300, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 7320. Results suggested that the content of these phytochemicals are very important at khellal stage and then decreased during maturation followed by a decrease in the antioxidant activity.

Fe3O4-alginate nanocomposite hydrogel beads material: One-pot preparation, release kinetics and antibacterial activity

In this work, a new and easy process was developed to fabricate a Fe3O4-alginate (Fe3O4NPs-ALG) hydrogel nanocomposite magnetic beads material. This preparation way consists in crosslinking sodium alginate solution in a mixed iron chloride solution containing FeCl3 and FeCl2. All characterization techniques confirmed the formation of small Fe3O4 nanoparticles with an average size of 9 nm in the alginate biopolymer matrix, in which iron atoms were linked to carbonyl acetyl groups through a bidentate bridging coordination. Furthermore, the magnetic nanocomposite beads have negatively charged surface. The obtained material was loaded with amoxicillin (AMOX) and tested as drug delivery system in the biolysis serum (NaCl 0.9% of pH 7) and in the simulated gastric medium (pH 2.1). The results showed that a cumulative release rate of 81.49% was obtained after three days in the biolysis serum, while this release rate was about 11.65% only, after four days, in the simulated gastric medium. The kinetic release data fulfilled Korsmeyer-Peppas model and the Hixson-Crowell, respectively. Antibacterial test on drug-loaded nanocomposite beads showed high activity against three of pathogenic bacteria strains.