Search results for: antimicrobial potency
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 954

Search results for: antimicrobial potency

714 Structure-Based Drug Design of Daptomycin, Antimicrobial lipopeptide

Authors: Satya Eswari Jujjavarapu, Swast Dhagat

Abstract:

Contagious diseases enact severe public health problems and have upsetting consequences. The cyclic lipopeptides explained by bacteria Bacillus, Paenibacillus, Pseudomonas, Streptomyces, Serratia, Propionibacterium and fungus Fusarium are very critical in confining the pathogens. As the degree of drug resistance upsurges in unparalleled manner, the perseverance of searching novel cyclic lipopeptides is being professed. The intense study has shown the implication of these bioactive compounds extending beyond antibacterial and antifungal. Lipopeptides, composed of single units of peptide and fatty acyl moiety, show broad spectrum antimicrobial effects. Among the surplus of cyclic lipopeptides, only few have materialized as strong antibiotics. For their functional vigor, polymyxin, daptomycin, surfactin, iturin and bacillomycin have been integrated in mainstream healthcare. In our work daptomycin has been a major part of antimicrobial resource since the past decade. Daptomycin, a cyclic lipopeptide consists of 13-member amino acid with a decanoyl side-chain. This structure of daptomycin confers it the mechanism of action through which it forms pore in the bacterial cell membrane resulting in the death of cell. Daptomycin is produced by Streptococccus roseoporus and acts against Streptococcus pneumonia (PSRP), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The PDB structure and ligands of daptomycin are available online. The molecular docking studies of these ligands with the lipopeptides were performed and their docking score and glide energy were recorded.

Keywords: daptomycin, molecular docking, structure-based drug design, lipopeptide

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713 Evaluation of the Biological Activities of Chrysin as an Important Perspective in the Treatment of Infectious and Cancer Diseases

Authors: Sajjad Jafari, Reza Akbari

Abstract:

Background and Aim: Chrysin, a flavonoid compound found in medicinal plants, honey, and propolis, has potential biological activities that make it an important perspective in the treatment of infectious and cancer diseases. The aim of this review study is to evaluate the biological activities of chrysin in the treatment of infectious and cancer diseases. Material and Methods: The present study is a review study that searched reputable scientific databases such as PubMed, Google Scholar, Scopus, and Web of Science from 2000 to 2023 using keywords such as antimicrobial, antifungal, chrysin, anticancer, antioxidants, and infectious diseases. The researchers examined 25 articles to determine the biological activities of chrysin. Results: Chrysin has high inhibitory or lethal activities on gram-positive and gram-negative bacteria, including Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Enterococcus faeces. It also has anti-biofilm effects and antifungal effects on strains such as Aspergillus niger and Candida albicans. Chrysin also has anticancer effects on various cancers, including colorectal cancer, pancreatic cancer, breast cancer, and MCF-7 cancer, which have been confirmed in vitro and in vivo. Conclusion: Chrysin has the potential as an important therapeutic option in the treatment of infectious and cancer diseases. Its high antimicrobial and anticancer activities, combined with its low toxicity in nanoparticle form, make it a promising candidate for further clinical trials. The production of anti-microbial and anti-cancer drugs from natural substances, such as chrysin, is a valuable contribution to the field of medicine.

Keywords: chrysin, antimicrobial, anticancer, infectious diseases

Procedia PDF Downloads 80
712 Bioactive Secondary Metabolites from Culturable Unusual Actinomycetes from Solomon Islands Marine Sediments: Isolation and Characterisation of Bioactive Compounds

Authors: Ahilya Singh, Brad Carte, Ramesh Subramani, William Aalbersberg

Abstract:

A total of 37 actinomycete strains were purified from 25 Solomon Islands marine sediments using four different types of isolation media. Among them, 54% of the strains had obligate requirement of seawater for growth. The ethyl acetate extract of 100 ml fermentation product of each strain was screened for antimicrobial activity against multidrug resistant human pathogens and cytotoxic activity against brine shrimps. A total of 67% of the ethyl acetate extracts showed antimicrobial and/or cytotoxic activities. A strain F-1915 was selected for isolation and evaluation of bioactive compound(s) based on its bioactive properties and chemical profile analysis using the LC-MS. The strain F-1915 was identified to have 96% sequence similarity to Streptomyces violaceusniger on the basis of 16S rDNA sequences using BLAST analysis. The 16S rDNA revealed that the strain F-1915 is a new member of MAR4 clade of actinomycetes. The MAR4 clade is an interesting clade of actinomycetes known for the production of pharmaceutically important hybrid isoprenoid compounds. The ethyl acetate extract of the fermentation product of this strain was purified by silica gel column chromatography and afforded the isolation of one bioactive pure compound. Based on the 1D and 2D NMR spectral data of compound 1 it was identified as a new mono-brominated phenazinone, Marinophenazimycin A, a structure which has already been studied by external collaborators at Scripps Institution of Oceanography but is yet to be published. Compound 1 displayed significant antimicrobial activity against drug resistant human pathogens. The minimum inhibitory concentration (MIC) of compound 1 was against Methicillin Resistant Staphylococcus aureus (MRSA) was about 1.9 μg/ml and MIC recorded against Amphotericin Resistant Candida albicans (ARCA) was about 0.24 μg/ml. The bioactivity of compound 1 against ARCA was found to be better than the standard antifungal agent amphotericin B. Compound 1 however did not show any cytotoxic activity against brine shrimps.

Keywords: actinomycetes, antimicrobial activity, brominated phenazine, MAR4 clade, marine natural products, multidrug resistent, 1D and 2D NMR

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711 Design and Facile Synthesis of New Amino Acid Derivatives with Anti-Tumor and Antimicrobial Activities

Authors: Hoda Sabry Othman, Randa Helmy Swellem, Galal Abd El-Moein Nawwar

Abstract:

N-cyanoacetyl glycine is a reactive polyfunctional precursor for synthesis of new difficult accessible compounds including pyridones, thiazolopyridine and others. The key step of this protocol is the formation of different ylidines which underwent Michael addition with carbon nucleophiles affording various heterocyclic compounds. Selected compounds underwent pharmacological evaluation, in vitro against two cell lines; breast cell line (MCF-7),and liver cell line(HEPG2). Compounds 14, 15a and 16 showed IC50 values 8.93, 8.18 and 8.03 (µ/ml) respectively for breast cell line (MCF-7), while the standard drug (Tamoxifen) revealed IC50 8.31. With respect to the liver cell line (HEPG2), compounds 14 and 15a revealed IC50 18.4 and 13.6(µ/ml) respectively while the IC50 of the standard drug(5-Flurouracil) is 25(µ/ml). The antimicrobial activity was also screened and revealed that oxime 7 and ylidine 9f showed a broad-spectrum activity.

Keywords: antitumor, cyanoacetyl glycine, heterocycles, pyridones

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710 Application of Chitosan as a Natural Antimicrobial Compound in Stirred Yoghurt

Authors: Javad Hesari, Tahereh Donyatalab, Sodeif Azadmard Damirchi, Reza Rezaii Mokaram, Abbas Rafat

Abstract:

The main objective of this research was to increase shelf life of stirred yoghurt by adding chitosan as a naturally antimicrobial compound. Chitosan were added at different concentrations (0.1, 0.3 and 0.6%) to the stirred yoghurt. Samples were stored at refrigerator and room temperature for 3 weeks and tested with respect of microbial properties (counts of starter bacteria, mold and yeast, coliforms and E. coli). Starter bacteria and yeast counts in samples containing chitosan was significantly (p<0.05) lower than those in control samples and its antibacterial and anti-yeast effects increased with increasing concentration of chitosan. The lowest counts of starter bacteria and yeast were observed at samples whit 0.6% of chitosan. The Results showed Chitosan had a positive effect on increasing shelf life and controlling of yeasts and therefore can be used as a natural preservative in stirred yogurt.

Keywords: chitosan, natural preservative, stirred yoghurt, self-life

Procedia PDF Downloads 435
709 The Bacteriocin Produced by Lactic Acid Bacteria as an Antibacterial of Sub Clinic Mastitis on Dairy Cows

Authors: Nenny Harijani, Dhandy Koesoemo Wardhana

Abstract:

The aim of this study is to know the bacteriocin as antimicrobial activity produced by Lactic Acid Bacteria (LAB) as Antibacterial of Sub Clinic Mastitis on Dairy Cows. The antimicrobial is produced by LAB which isolates from cattle intestine can inhibit the growth Staphylococcus aureus, Steptocococcus agalactiae an Escherichia coli which were caused by dairy cattle subclinical mastitis. The failure of this bacteria growth was indicated by the formation of a clear zone surrounding the colonies on Brain Heart Infusion Agar plate. The bacteriocin was produced by Lactic Acid Bacteria (LAB) as antimicrobial, which could inhibit the growth of indicator bacteria Staphylococcus aureus, S.aglactiae and E.coli. This study was also developed bacteriocin to be used as a therapeutic of subclinical mastitis on dairy cows. The method used in this study was isolation, selection and identification of LAB using Mann Rogosa Sharp Medium, followed by characterization of the bacteriocin produced by LAB. The result of the study showed that bacteriocin isolated from beef cattle’s intestine could inhibit the growth Staphylococcus aureus, S. agalactiae, an Escherichia coli, which was indicated by clear zone surrounding the colonies on Brain Heart Infusion Agar plate. Characteristics of bacteriocin were heat-stable exposed to 80 0C for 30 minutes and 100 ⁰C for 15 minutes and inactivated by proteolytic enzymes such as trypsin. This approach has suggested the development of bacteriocin as a therapeutic agent for subclinical mastitis in dairy cattle.

Keywords: lactic acid bacteria, bacteriocin, staphylococcus aureus, S. agalactiae, E. coli, sub

Procedia PDF Downloads 105
708 Antibacterial Activity of Bacillus thuringiensis Activated Delta-endotoxins

Authors: R. Gounina-Allouane, N. Ouali, F. Z. Berrabah, A. Bentaleb

Abstract:

For a long time, the Gram-positive spore-forming bacteria Bacillus thuringiensis (Bt) has been widely used in biological control against devastating and disease vectors insects. This is due to the insecticidal activity of its crystalline parasporal inclusion (crystals) predominantly comprised of one or more proteins (Cry and Cyt proteins) also called δ-endotoxins, produced during sporulation. The shape and composition of Bt crystals vary among strains and crystalline proteins are extremely varied (more than 475 cry gene were discovered). The insecticidal activity of Bt crystals is very well studied, thus their insecticidal mode of action is well established, however, their antimicrobial effect is largely unknown. The lack of data on the antimicrobial effect of crystalline proteins of Bt and the need for searching new antimicrobial molecules encouraged us to carried out this study. The antibacterial effect of δ-endotoxines produced by two Bt stains; a strain isolated from soil at northern of Algeria (Bt 7.2.B), and a strain isolated from a bioinsecticide (Bacillus thuringiensis var aizawai), activated by proteolysis, was assayed on clinical bacterial strains and ATCC collection ones respectively. Gram positive and negative clinical bacterial strains (Escherichia coli, Klebsiella pneumonaie, Pseudomonas aeruginosa, Staphylococcus aureus) were sensitive to activated Bt 72B endotoxins. Similarly, bacterial strains from ATCC collection (Escherichia coli ATCC 25922, Pseudomonas aerugenosa ATCC 27853, Staphylococcus aureus ATCC 25923) were sensitive to activated B. thuringiensis var aizawai δ-endotoxines. The activated δ-endotoxins were separated by SDS-PAGE.

Keywords: Bacillus thuringiensis, crystals, cry proteins, δ-endotoxins, antibacterial activity

Procedia PDF Downloads 423
707 Mode of Action of Surface Bound Antimicrobial Peptides Melimine and Mel4 against Pseudomonas aeruginosa

Authors: Muhammad Yasir, Debarun Dutta, Mark Willcox

Abstract:

Biomaterial-associated infections are a multi-billion dollar burden globally. Antimicrobial peptide-based coatings may be able to prevent such infections. The aim of this study was to investigate the mechanism of action surface bound peptides (AMPs) against Pseudomonas aeruginosa 6294. Melimine and Mel4 were covalently attached to glass coverslips using azido-benzoic acid. Attachment was confirmed using X-ray photoelectron spectroscopy. P. aeruginosa was allowed to attach to AMP-coated glass for up to 6 hours. The effect of the surface-bound AMPs on bacterial cell membranes was evaluated using the dyes DiSC3-(5), Sytox green, SYTO 9 and propidium iodide with fluorescence microscopy. Release of cytoplasmic materials ATP and DNA/RNA were determined in the surrounding fluid. The amount of cell death was estimated by agar plate counts. The AMPs were successfully covalently bound to the glass as demonstrated by increases in %nitrogen of 3.6% (melimine) and 2.3% (Mel4) compared to controls. Immobilized peptides disrupted the cytoplasmic membrane potential of P. aeruginosa within 10 min. This was followed by the release of ATP after 2 h. Membrane permeabilization started at 3 h of contact with glass coated AMPs. There was a significant number of bacteria (59% for melimine; 36% for Mel-4) with damaged membranes after 4 h of contact. At the 6 h time point, release of DNA occurred with melimine releasing 2 times the amount of DNA/RNA than Mel4 surfaces (p < 0.05). Surface bound AMPs were able to disrupt cell membranes with subsequent release of cytoplasmic materials, and ultimately resulting in bacterial death.

Keywords: biomaterials, immobilized antimicrobial peptides, P. aeruginosa, mode of action

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706 A Review of the Run to Run (R to R) Control in the Manufacturing Processes

Authors: Khalil Aghapouramin, Mostafa Ranjbar

Abstract:

Run- to- Run (R2 R) control was developed in order to monitor and control different semiconductor manufacturing processes based upon the fundamental engineering frameworks. This technology allows rectification in the optimum direction. This control always had a significant potency in which was appeared in a variety of processes. The term run to run refers to the case where the act of control would take with the aim of getting batches of silicon wafers which produced in a manufacturing process. In the present work, a brief review about run-to-run control investigated which mainly is effective in the manufacturing process.

Keywords: Run-to-Run (R2R) control, manufacturing, process in engineering, manufacturing controls

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705 Improvement of Antibacterial Activity for Ceftazidime by Partially Purified Tannase from Penicillium expansum

Authors: Sahira N. Muslim, Alaa N. Mohammed, Saba Saadoon Khazaal, Batool Kadham Salman, Israa M. S. AL-Kadmy, Sraa N. Muslim, Ahmed S. Dwaish, Sawsan Mohammed Kareem, Sarah N. Aziz, Ruaa A. Jasim

Abstract:

Tannase has wide applications in food, beverage, brewing, cosmetics and chemical industries and one of the major applications of tannase is the production of gallic acid. Gallic acid is used for manufacturing of trimethoprim. In the present study, a local fungal strain of Penicillium expansum A4 isolated from spoilt apple samples gave the highest production level of tannase. Tannase was partially purified with a recovery yield of 92.52% and 6.32 fold of purification by precipitation using ammonium sulfate at 50% saturation. Tannase led to increased antimicrobial activity of ceftazidime against Pseudomonas aeruginosa and S. aureus and had a synergism effect at low concentrations of ceftazidime, and thus, tannase may be a useful adjuvant agent for the treatment of many bacterial infections in combination with ceftazidime.

Keywords: ceftazidime, Penicillium expansum, tannase, antimicrobial activity

Procedia PDF Downloads 698
704 Biosynthesis, Characterization and Interplay of Bacteriocin-nanoparticles to Combat Infectious Drug Resistant Pathogens

Authors: Asma Ansari, Afsheen Aman, Shah Ali Ul Qader

Abstract:

In the past few years, numerous concerns have been raised against increased bacterial resistance towards effective drugs and become a debated issue all over the world. With the emergence of drug resistant pathogens, the interaction of natural antimicrobial compounds and antibacterial nanoparticles has emerged as a potential candidate for combating infectious diseases. Microbial diversity in the biome provides an opportunity to screen new species which are capable of producing large number of antimicrobial compounds. Among these antimicrobial compounds, bacteriocins are highly specific and efficient antagonists. A combination of bacteriocin along with nanoparticles could prove to be more potent due to broadened antibacterial spectrum with possibly lower doses. In the current study, silver nanoparticles were synthesized through biological reduction using various isolated bacterial, fungal and yeast strains. Spectroscopy and scanning electron microscopy (SEM) was performed for the confirmation of nanoparticles. Bacteriocin was characterized and purified to homogeneity through gel permeation chromatography. The estimated molecular weight of bacteriocin was 10 kDa. Amino acid analysis and N-terminal sequencing revealed the novelty of the protein. Then antibacterial potential of silver nanoparticles and broad inhibitory spectrum bacteriocin was determined through agar well diffusion assay. These synthesized bacteriocin-Nanoparticles exhibit a good potential for clinical applications as compared to bacteriocin alone. This combination of bacteriocin with nanoparticles will be used as a new sort of biocide in the field of nano-proteomics. The advancement of nanoparticles-mediated drug delivery system will open a new age for rapid eradication of pathogens from biological systems.

Keywords: BAC-IB17, multidrug resistance, purification, silver nanoparticles

Procedia PDF Downloads 467
703 Antibacterial Activity of Bacillus thuringiensis Cristalline Parasporal Proteins

Authors: R. Gounina-Allouane, N. Ouali, F. Z. Berrabah, A. Bentaleb

Abstract:

For a long time, the Gram-positive spore-forming bacteria Bacillus thuringiensis (Bt) has been widely used in biological control against devastating and disease vectors insects. This is due to the insecticidal activity of its crystalline parasporal inclusion (crystals) predominantly comprised of one or more proteins (Cry and Cyt proteins) also called δ-endotoxins, produced during sporulation. The shape and composition of Bt crystals vary among strains and crystalline proteins are extremely varied (more than 475 cry gene were discovered). The insecticidal activity of Bt crystals is very well studied, thus their insecticidal mode of action is well established, however, their antimicrobial effect is largely unknown. The lack of data on the antimicrobial effect of crystalline proteins of Bt and the need for searching new antimicrobial molecules encouraged us to carried out this study. The antibacterial effect of δ-endotoxines produced by two Bt stains; a strain isolated from soil at northern of Algeria (Bt 7.2.B), and a strain isolated from a bioinsecticide (Bacillus thuringiensis var aizawai), activated by proteolysis, was assayed on clinical bacterial strains and ATCC collection ones respectively. Gram positive and negative clinical bacterial strains (Escherichia coli, Klebsiella pneumonaie, Pseudomonas aeruginosa, Staphylococcus aureus) were sensitive to activated Bt 72B endotoxins. Similarly, bacterial strains from ATCC collection (Escherichia coli ATCC 25922, Pseudomonas aerugenosa ATCC 27853, Staphylococcus aureus ATCC 25923) were sensitive to activated B. thuringiensis var aizawai δ-endotoxines. The activated δ-endotoxins were separated by SDS-PAGE.

Keywords: Bacillus thuringiensis, crystals, cry proteins, δ-endotoxins, antibacterial activity

Procedia PDF Downloads 409
702 Analyzing Antimicrobial Power of Cotula cinerea Essential Oil: Case of Western Algeria

Authors: A. Abdenbi, B. Dennai, B. Touati, M. Bouaaza, A. Saad

Abstract:

The essential oils of many plants have become popular in recent years and their bioactive principles have recently won several industry sectors, however their use as antibacterial and anti fungal agents has been reported. This study focuses on the physico chemical and phyto chemical with a study of the antimicrobial activity of essential oils of aromatic and medicinal plant of southwest Algeria, this essential oil was obtained by hydro-distillation of aerial parts of Cotula cinerea, belonging to the Asteraceae family, it is very extensive in the spring season in a region called Kenadza road, located 12km from Bechar. Variable anti fungal activity of the essential oil of Cotula cinerea (yield 2%) were revealed about four fungal strains, the minimum inhibitory concentrations of essential oils were determined by the method of dilution in agar. Significant fungal sensitivity of Penicillium sp with an inhibition of 32.3 mm area.

Keywords: Cotula cinerea, essential oil, physico- chemical analysis and phyto- chemical, anti fungal power

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701 Prevalence, Antimicrobial Susceptibility Pattern and Associated Risk Factors for Salmonella Species and Escherichia Coli from Raw Meat at Butchery Houses in Mekelle, Tigray, Northern Ethiopia

Authors: Haftay Abraha Tadesse, Dawit Gebreegziabiher Hagos, Atsebaha Gebrekidan Kahsay, Mahumd Abdulkader

Abstract:

Background: Salmonella species and Escherichia coli (E. coli) are important foodborne pathogens affecting humans and animals. They are among the most important causes of infection that are associated with the consumption of contaminated food. This study was aimed to determine the prevalence, antimicrobial susceptibility patterns and associated risk factors for Salmonella species and E. coli in raw meat from butchery houses of Mekelle, Northern Ethiopia. Method: A cross-sectional study was conducted from January to December 2019. Socio-demographic data and risk factors were collected using a predesigned questionnaire. Meat samples were collected aseptically from the butchery houses and transported using icebox to Mekelle University, College of Veterinary Sciences for the isolation and identification of Salmonella species and E. coli. Antimicrobial susceptibility patterns were determined using Kirby disc diffusion method. Data obtained were cleaned and entered into Statistical Package for the Social Sciences version 22 and logistic regression models with odds ratio were calculated. P-value < 0.05 was considered as statistically significant. Results: A total of 153 out of 384 (39.8%) of the meat specimens were found to be contaminated. The contamination of Salmonella species and E. coli were 15.6% (n=60) and 20.8%) (n=80), respectively. Mixed contamination (Salmonella species and E. coli) was observed in 13 (3.4 %) of the analyzed. Poor washing hands regularly (AOR = 8.37; 95% CI: 2.75-25.50) and not using gloves during meat handling (AOR=11. 28; 95% CI:(4.69 27.10) were associated with overall bacterial contamination. About 100% of the tested isolates were sensitive to ciprofloxacin, gentamicin, Co trimoxazole , sulphamethoxazole, ceftriaxone, and trimethoprim and ciprofloxacin, gentamicin, and norfloxacine of E. coli and Salmonella species, respectively, while the resistance of amoxyclav_amoxicillin and erythromycin were both isolated bacteria species. The overall multidrug resistance pattern for Salmonella and E. coli were 51.4% (n=19) and 31.8% (14), respectively. Conclusion: Of the 153 (153/384) contaminated raw meat, 60 (15.6%) and 80 (20.8%) were contaminated by Salmonella species and E. coli, respectively. Poor handwashing practice and not using glove during meat handling showed a significant association with bacterial contamination. Multidrug-resistant showed in Salmonella species, and E. coli were 19 (51.4%) and 14 (31.8%), respectively.

Keywords: antimicrobial susceptibility test, butchery houses, E. coli, raw meat, salmonella species

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700 Enhancement in Bactericidal Activity of Hydantoin Based Microsphere from Smooth to Rough

Authors: Rajani Kant Rai, Jayakrishnan Athipet

Abstract:

There have been several attempts to prepare polymers with antimicrobial properties by doping with various N-halamines. Hydantoins (Cyclic N-halamine) is of importance due to their stability rechargeable chloroamide function, broad-spectrum anti-microbial action and ability to prevent resistance to the organisms. Polymerizable hydantoins are synthesized by tethering vinyl moieties to 5,5,-dialkyl hydantoin sacrificing the imide hydrogen in the molecule thereby restricting the halogen capture only to the amide nitrogen that results in compromised antibacterial activity. In order to increase the activity of the antimicrobial polymer, we have developed a scheme to maximize the attachment of chlorine to the amide and the imide moieties of hydantoin. Vinyl hydantoin monomer, (Z)-5-(4-((3-methylbuta-1,3-dien-2-yl)oxy)benzylidene)imidazolidine-2,4-dione (MBBID) was synthesized and copolymerized with a commercially available monomer, methyl methacrylate, by free radical polymerization. The antimicrobial activity of hydantoin is strongly dependent on their surface area and hence their microbial activity increases when incorporated in microspheres or nanoparticles as compared to their bulk counterpart. In this regard, smooth and rough surface microsphere of the vinyl monomer (MBBID) with commercial monomer was synthesized. The oxidative chlorine content of the copolymer ranged from 1.5 to 2.45 %. Further, to demonstrate the water purification potential, the thin column was packed with smooth or rough microspheres and challenged with simulated contaminated water that exhibited 6 log kill (total kill) of the bacteria in 20 minutes of exposure with smooth (25 mg/ml) and rough microsphere (15.0 mg/ml).

Keywords: cyclic N-halamine, vinyl hydantoin monomer, rough surface microsphere, simulated contaminated water

Procedia PDF Downloads 119
699 Papain Immobilized Polyurethane Film as an Antimicrobial Food Package

Authors: M. Cynthya, V. Prabhawathi, D. Mukesh

Abstract:

Food contamination occurs during post process handling. This leads to spoilage and growth of pathogenic microorganisms in the food, thereby reducing its shelf life or spreading of food borne diseases. Several methods are tried and one of which is use of antimicrobial packaging. Here, papain, a protease enzyme, is covalently immobilized with the help of glutarldehyde on polyurethane and used as a food wrap to protect food from microbial contamination. Covalent immobilization of papain was achieved at a pH of 7.4; temperature of 4°C; glutaraldehyde concentration of 0.5%; incubation time of 24 h; and 50 mg of papain. The formation of -C=N- observed in the Fourier transform infrared spectrum confirmed the immobilization of the enzyme on the polymer. Immobilized enzyme retained higher activity than the native free enzyme. The efficacy of this was studied by wrapping it over S. aureus contaminated cottage cheese (paneer) and cheese and stored at a temperature of 4°C for 7 days. The modified film reduced the bacterial contamination by eight folds when compared to the bare film. FTIR also indicates reduction in lipids, sugars and proteins in the biofilm.

Keywords: cheese, papain, polyurethane, Staphylococcus aureus

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698 Fungal Diversity and Bioprospecting of Termite-Associated Fungi from Nothern-Western Ghats of India

Authors: Gajanan V. Mane, Rashmi More, Mahesh S. Sonawane, Tushar Lodha, Rohit Sharma

Abstract:

The diversity of fungi isolated from two different termite species viz., Odontoterms assmuthi and O. abesus was investigated by dilution- plate method, combined with morphological characteristics and sequencing of internal transcribed spacer region. In total, ninety-six fungi were isolated and purified, out of which 69 isolates were obtained from O. assmuthi belonging to 18 genera and 31 species, whereas 27 isolates were obtained from O. abesus belonging to 15 genera and 17 species. The fungal strains were screened for laccase, amylase, cellulase and pectinase enzymes production. Twenty-seven strains were positive for laccase, 59 strains were positive for amylase, 71 strains were positive for cellulase and 72 strains were positive for pectinase enzymes. The antimicrobial activities of the isolated fungi were tested by the dual plate culture method against standard pathogens. Bioactive secondary metabolites were identified by HPLC and LCMS. Four isolates viz., Penicillium goetzii MG 57, Epicoccum sp. MG 39, Penicillium tanzanicum MG 30, Aspergillus polyporicola MG 54, showed positive antimicrobial activity against standard pathogens, Streptococcus pneumonia MCC 2425, Staphylococcus aureus MCC 2408, Pseudomonas aeruginosa MCC 2080, Escherichia coli MCC 2412, Enterococcus faecalis MCC 2409, Klebsiella pneumonia MCC 2451, Micrococcus luteus MCC 2155 and Candida albicans MCC 1151. In conclusion, the study showed that the insect gut harbor fungal diversity, which is futuristic with biotechnological potential and could be a good source of enzymes and antibiotics.

Keywords: termites, fungi, its, enzyme, antimicrobial activity

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697 Comparative Study of Antimicrobial Activity of Bacteriocin Producing Lactic Acid Bacteria from Fermented Batter of Green Gram And Bengal Gram Against Food-Borne Pathogens

Authors: Bandi Aruna

Abstract:

The increase of multidrug-resistant pathogens and the restriction on the use of antibiotics due to its side effects have drawn attention to the search for possible alternatives. Bacteriocins are ribosomally synthesized antimicrobial peptides that are active against Gram-positive and Gram-negative bacteria. The bacteriocins from lactic acid bacteria represent an important application of these peptides as clinical drugs or as food biopreservatives. The present study describes the isolation of bacteriocin producing lactic acid bacteria (LAB) from fermented batter of green gram and bengal gram using Man, Rogosa and Sharpe (MRS) media. The bacteriocin produced by these organisms inhibited the growth of Staphylococcus aureus, Escherichia coli, Klebsiella species, Pseudomonas aeruginosa, The isolates G1, G2 were isolated from green gram; B1 and B2 were isolated from fermented bengal gram batter. G1 and G2 were identified as Lactobacillus casie and B1 and B2 were identified as Streptococcus species. Antimicrobial activity of the bacteriocin produced by these strains was studied by agar well diffusion method. Bacteriocins produced by the Lactobacillus casie and Streptococcus secies retained their antagonistic property at pH of 5 and pH of 7. Exposure of bacteriocin to UV light for 4 min showed antibacterial activity. The antagonistic property was observed even at 100°C demonstrating stability at higher temperatures of the bacteriocin. The bacteriocins were stable for a period of 15 days at 27°C. The bacteriocins of G1, G2, and B2 exhibited highest antagonistic activity at pH of 5 and B1 at pH of 7. Therefore, the bacteriocins of the isolates may find important application in controlling the food-borne pathogens.

Keywords: Keywords: Antibacterial activity, Lactic acid bacteria, Bacteriocin

Procedia PDF Downloads 373
696 Polymer Composites Of MOF-5 For Efficient and Sustained Delivery of Cephalexin and Metronidazole

Authors: Anoff Anim, Lila Mahmoud, Maria Katsikogianni, Sanjit Nayak

Abstract:

Sustained and controlled delivery of antimicrobial drugs have been largely studied recently using metal organic frameworks (MOFs)and different polymers. However, much attention has not been given to combining both MOFs and biodegradable polymers, which would be a good strategy in providing a sustained gradual release of the drugs. Herein, we report a comparative study of the sustained and controlled release of widely used antibacterial drugs, cephalexin and metronidazole, from zinc-based MOF-5 incorporated in biodegradable polycaprolactone (PCL) and poly-lactic glycolic acid (PLGA) membranes. Cephalexin and metronidazole were separately incorporated in MOF-5 post-synthetically, followed by their integration into biodegradable PLGA and PCL membranes. The pristine MOF-5 and the loaded MOFs were thoroughly characterized by FT-IR, SEM, TGA and PXRD. Drug release studies were carried out to assess the release rate of the drugs in PBS and distilled water for up to 48 hours using UV-Vis Spectroscopy. Four bacterial strains from both the Gram-positive and Gram-negative types, Staphylococus aureus, Staphylococuss epidermidis, Escherichia coli, Acinetobacter baumanii, were tested against the pristine MOF, pure drugs, loaded MOFs and the drug-loaded MOF-polymer composites. Metronidazole-loaded MOF-5 composite of PLGA (PLGA-Met@MOF-5) was found to show highest efficiency to inhibit the growth of S. epidermidis compared to the other bacteria strains while maintaining a sustained minimum inhibitory concentration (MIC). This study demonstrates that the combination of biodegradable MOF-polymer composites can provide an efficient platform for sustained and controlled release of antimicrobial drugs and can be a potential strategy to integrate them in biomedical devices.

Keywords: antimicrobial resistance, biodegradable polymers, cephalexin, drug release metronidazole, MOF-5, PCL, PLGA

Procedia PDF Downloads 103
695 Biodegradable Polymer Composites of MOF-5 for Efficient and Sustained Delivery of Cephalexin and Metronidazole

Authors: Anoff Anim, Lila A. M. Mahmoud, Maria Katsikogianni, Sanjit Nayak

Abstract:

Sustained and controlled delivery of antimicrobial drugs have been largely studied recently using metal organic frameworks (MOFs)and different polymers. However, much attention has not been given to combining both MOFs and biodegradable polymers, which would be a good strategy in providing a sustained gradual release of the drugs. Herein, we report a comparative study of the sustained and controlled release of widely used antibacterial drugs, cephalexin and metronidazole, from zinc-based MOF-5 incorporated in biodegradable polycaprolactone (PCL) and poly-lactic glycolic acid (PLGA) membranes. Cephalexin and metronidazole were separately incorporated in MOF-5 post-synthetically, followed by their integration into biodegradable PLGA and PCL membranes. The pristine MOF-5 and the loaded MOFs were thoroughly characterized by FT-IR, SEM, TGA and PXRD. Drug release studies were carried out to assess the release rate of the drugs in PBS and distilled water for up to 48 hours using UV-Vis Spectroscopy. Four bacterial strains from both the Gram-positive and Gram-negative types, Staphylococus aureus, Staphylococuss epidermidis, Escherichia coli, Acinetobacter baumanii, were tested against the pristine MOF, pure drugs, loaded MOFs and the drug-loaded MOF-polymer composites. Metronidazole-loaded MOF-5 composite of PLGA (PLGA-Met@MOF-5) was found to show highest efficiency to inhibit the growth of S. epidermidis compared to the other bacteria strains while maintaining a sustained minimum inhibitory concentration (MIC). This study demonstrates that the combination of biodegradable MOF-polymer composites can provide an efficient platform for sustained and controlled release of antimicrobial drugs and can be a potential strategy to integrate them in biomedical devices.

Keywords: antimicrobial resistance, biodegradable polymers, cephalexin, drug release metronidazole, MOF-5, PCL, PLGA

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694 Cocoa Stimulates the Production Bioactive Components of Lactobacillus Casei and Competitively Excludes Foodborne Pathogens

Authors: Mengfei Peng, Serajus Salaheen, Debabrata Biswas

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Lactobacillus casei found in the human intestine and mouth is commonly applied for dairy production. Recently, it was found that some byproducts produced by Lactobacillus exhibited antimicrobial activities against multiple bacteria. Meanwhile, introduction of prebiotic-like foods (e.g. cocoa) or probiotics or both of them as food supplements in human diets as well as in farm animal feeds is believed to be an effective ways in control/reduce the colonization of foodborne bacterial pathogens infection in the gut environment. We hypothesized that cocoa may stimulate the production antimicrobial components of Lactobacillus casei and may potentially inhibit/reduce the colonization and infection of foodborne bacterial pathogens in the gut. Mixed culture of L. casei (LC) with enterohemorrhagic E. coli EDL933 (EHEC), Salmonella Typhimurium LT2 (ST), or Listeria monocytogenes LM2 (LM) showed that LC could competitively exclude (100%) them within 72 h. Further, investigation of cell-free culture supernatant (CFCS) revealed that the antimicrobial effects of LC came from CFCS. CFCS of LC eliminated (100%) EHEC, ST, and LM within 72 h, and 2 h CFCS treatment increased the hydrophobicity of EHEC (5.10 folds), ST (8.48 folds), and LM (2.03 folds). In addition, LC cells exhibited more inhibitive effects than CFCS on cell adhesive and invasive activities of EHEC (52.14% & 90.45%), ST (66.89% & 93.83%), and LM (61.10% & 83.40%). Two clusters of poly-peptides in CFCS were identified by SDS-PAGE, the molecular weights of which are ≈5 KD and 40-45 KD. LC CFCS with overnight growth in the presence of 3% strengthened all of the antimicrobial activities (growth inhibition, outer membrane disruption, and cell infective ability reduction). Liquid chromatography/Mass spectrometry analysis detected 5 unique components in class of flavonoids in LC CFCS with overnight 3% cocoa supplement. Furthermore, qPCR results showed that CFCSs up-regulated the expression level of genes responsible for flagellin synthesis and motility, but down-regulated genes for specific binding and invasion-associated proteins synthesis. The stimulatory effects of cocoa in producing bioactive components of probiotics may aid prevention of foodborne illness caused by major foodborne enteric bacterial pathogens.

Keywords: foodborne pathogens, probiotics, prebiotics, pathogen exclusion

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693 Investigation of Electrospun Composites Nanofiber of Poly (Lactic Acid)/Hazelnut Shell Powder/Zinc Oxide

Authors: Ibrahim Sengor, Sumeyye Cesur, Ilyas Kartal, Faik Nuzhet Oktar, Nazmi Ekren, Ahmet Talat Inan, Oguzhan Gunduz

Abstract:

In recent years, many researchers focused on nano-size fiber production. Nanofibers have been studied due to their different and superior physical, chemical and mechanical properties. Poly (lactic acid) (PLA), is a type of biodegradable thermoplastic polyester derived from renewable sources used in biomedical owing to its biocompatibility and biodegradability. In addition, zinc oxide is an antibacterial material and hazelnut shell powder is a filling material. In this study, nanofibers were obtained by adding of different ratio Zinc oxide, (ZnO) and hazelnut shell powder at different concentration into Poly (lactic acid) (PLA) by using electrospinning method which is the most common method to obtain nanofibers. After dissolving the granulated polylactic acids in % 1,% 2,% 3 and% 4 with chloroform solvent, they are homogenized by adding tween and hazelnut shell powder at different ratios and then by electrospinning, nanofibers are obtained. Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimeter (DSC) and physical analysis such as density, electrical conductivity, surface tension, viscosity measurement and antimicrobial test were carried out after production process. The resulting structures of the nanofiber possess antimicrobial and antiseptic properties, which are attractive for biomedical applications. The resulting structures of the nanofiber possess antimicrobial, non toxic, self-cleaning and rigid properties, which are attractive for biomedical applications.

Keywords: electrospinning, hazelnut shell powder, nanofibers, poly (lactic acid), zinc oxide

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692 Evaluation of Antimicrobial and Anti-Inflammatory Activity of Doani Sidr Honey and Madecassoside against Propionibacterium Acnes

Authors: Hana Al-Baghaoi, Kumar Shiva Gubbiyappa, Mayuren Candasamy, Kiruthiga Perumal Vijayaraman

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Acne is a chronic inflammatory disease of the sebaceous glands characterized by areas of skin with seborrhea, comedones, papules, pustules, nodules, and possibly scarring. Propionibacterium acnes (P. acnes), plays a key role in the pathogenesis of acne. Their colonization and proliferation trigger the host’s inflammatory response leading to the production of pro-inflammatory cytokines such as interleukin-8 (IL-8) and tumour necrosis factor-α (TNF-α). The usage of honey and natural compounds to treat skin ailments has strong support in the current trend of drug discovery. The present study was carried out evaluate antimicrobial and anti-inflammatory potential of Doani Sidr honey and its fractions against P. acnes and to screen madecassoside alone and in combination with fractions of honey. The broth dilution method was used to assess the antibacterial activity. Also, ultra structural changes in cell morphology were studied before and after exposure to Sidr honey using transmission electron microscopy (TEM). The three non-toxic concentrations of the samples were investigated for suppression of cytokines IL 8 and TNF α by testing the cell supernatants in the co-culture of the human peripheral blood mononuclear cells (hPBMCs) heat killed P. acnes using enzyme immunoassay kits (ELISA). Results obtained was evaluated by statistical analysis using Graph Pad Prism 5 software. The Doani Sidr honey and polysaccharide fractions were able to inhibit the growth of P. acnes with a noteworthy minimum inhibitory concentration (MIC) value of 18% (w/v) and 29% (w/v), respectively. The proximity of MIC and MBC values indicates that Doani Sidr honey had bactericidal effect against P. acnes which is confirmed by TEM analysis. TEM images of P. acnes after treatment with Doani Sidr honey showed completely physical membrane damage and lysis of cells; whereas non honey treated cells (control) did not show any damage. In addition, Doani Sidr honey and its fractions significantly inhibited (> 90%) of secretion of pro-inflammatory cytokines like TNF α and IL 8 by hPBMCs pretreated with heat-killed P. acnes. However, no significant inhibition was detected for madecassoside at its highest concentration tested. Our results suggested that Doani Sidr honey possesses both antimicrobial and anti-inflammatory effects against P. acnes and can possibly be used as therapeutic agents for acne. Furthermore, polysaccharide fraction derived from Doani Sidr honey showed potent inhibitory effect toward P. acnes. Hence, we hypothesize that fraction prepared from Sidr honey might be contributing to the antimicrobial and anti-inflammatory activity. Therefore, this polysaccharide fraction of Doani Sidr honey needs to be further explored and characterized for various phytochemicals which are contributing to antimicrobial and anti-inflammatory properties.

Keywords: Doani sidr honey, Propionibacterium acnes, IL-8, TNF alpha

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691 Comparative Characteristics of Bacteriocins from Endemic Lactic Acid Bacteria

Authors: K. Karapetyan, F. Tkhruni, A. Aghajanyan, T. S. Balabekyan, L. Arstamyan

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Introduction: Globalization of the food supply has created the conditions favorable for the emergence and spread of food-borne and especially dangerous pathogens (EDP) in developing countries. The fresh-cut fruit and vegetable industry is searching for alternatives to replace chemical treatments with biopreservative approaches that ensure the safety of the processed foods product. Antimicrobial compounds of lactic acid bacteria (LAB) possess bactericidal or bacteriostatic activity against intestinal pathogens, spoilage organisms and food-borne pathogens such as Listeria monocytogenes, Staphylococcus aureus and Salmonella. Endemic strains of LAB were isolated. The strains, showing broad spectrum of antimicrobial activity against food spoiling microorganisms, were selected. The genotyping by 16S rRNA sequencing, GS-PCR, RAPD PCR methods showed that they were presented by Lactobacillus rhamnosus109, L.plantarum 65, L.plantarum 66 and Enterococcus faecium 64 species. LAB are deposited in "Microbial Depository Center" (MDC) SPC "Armbiotechnology". Methods: LAB strains were isolated from different dairy products from rural households from the highland regions of Armenia. Serially diluted samples were spread on MRS (Merck, Germany) and hydrolyzed milk agar (1,2 % w/v). Single colonies from each LAB were individually inoculated in liquid MRS medium and incubated at 37oC for 24 hours. Culture broth with biomass was centrifuged at 10,000 g during 20 min for obtaining of cell free culture broth (CFC). The antimicrobial substances from CFC broth were purified by the combination of adsorption-desorption and ion-exchange chromatography methods. Separation of bacteriocins was performed using a HPLC method on "Avex ODS" C18 column. Mass analysis of peptides recorded on the device API 4000 in the electron ionization mode. The spot-on-lawn method on the test culture plated in the solid medium was applied. The antimicrobial activity is expressed in arbitrary units (AU/ml). Results. Purification of CFC broth of LAB allowed to obtain partially purified antimicrobial preparations which contains bacteriocins with broad spectrum of antimicrobial activity. Investigation of their main biochemical properties shown, that inhibitory activity of preparations is partially reduced after treatment with proteinase K, trypsin, pepsin, suggesting a proteinaceous nature of bacteriocin-like substances containing in CFC broth. Preparations preserved their activity after heat treatment (50-121 oC, 20 min) and were stable in the pH range 3–8. The results of SDS PAAG electrophoresis show that L.plantarum 66 and Ent.faecium 64 strains have one bacteriocin (BCN) with maximal antimicrobial activity with approximate molecular weight 2.0-3.0 kDa. From L.rhamnosus 109 two BCNs were obtained. Mass spectral analysis indicates that these bacteriocins have peptide bonds and molecular weight of BCN 1 and BCN 2 are approximately 1.5 kDa and 700 Da. Discussion: Thus, our experimental data shown, that isolated endemic strains of LAB are able to produce bacteriocins with high and different inhibitory activity against broad spectrum of microorganisms of different taxonomic group, such as Salmonella sp., Esherichia coli, Bacillus sp., L.monocytogenes, Proteus mirabilis, Staph. aureus, Ps. aeruginosa. Obtained results proved the perspectives for use of endemic strains in the preservation of foodstuffs. Acknowledgments: This work was realized with financial support of the Project Global Initiatives for Preliferation Prevention (GIPP) T2- 298, ISTC A-1866.

Keywords: antimicrobial activity, bacteriocins, endemic strains, food safety

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690 Synthesis, Characterization and Biological Evaluation of Some Pyrazole Derivatives

Authors: Afifa Hafidh, Hedia Chaabane

Abstract:

This work mainly focused on the synthetic strategies and biological activities associated with pyrazoles. Pyrazole derivatives have been successfully synthesized by simple and facile method and studied for their antibacterial activity. These compounds were prepared from pyrazolic difunctional compounds as starting materials, by reaction with salicylic acid, paracetamol and thiosemicarbazide respectively. Structure of all the prepared compounds confirmation were proved using (FT-IR), (1H-NMR) and (13C-NMR) spectra in addition to melting points. The screening of the antimicrobial activity of the pyrazolic derivatives was examined against different microorganisms in the present study. They were screened for their antimicrobial activities against gram positive bacteria, gram negative bacteria and Candida albicans. The synthesized compounds were found to exhibit high antibacterial and antifungal efficiency against several tested bacterial strains, using agar diffusion method and filter paper disc-diffusion method. Ampicillin was used as positive control for all strains except Candida albicans for which Nystatin was used. The obtained results reveal that the antibacterial activity of some pyrazolic derivatives is comparable to that observed for the control samples (Ampicilin and Nystatin), suggesting a strong antibacterial activity. The analysis of these results shows that synthesized products react on the surfaces cell walls that are disrupted. When these products are in contact with the bacteria, they damage the membrane, leading to the perturbation of different cellular processes and then leakage of cytoplasm, resulting in the death of the cells. The results will be presented in details. The obtained products constitute effective antibacterial agents and important compounds for biological systems.

Keywords: salicylic acid, antimicrobial activities, antioxidant activity, paracetamol, pyrazole, thiosemicarbazide

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689 Chemical Life Cycle Alternative Assessment as a Green Chemical Substitution Framework: A Feasibility Study

Authors: Sami Ayad, Mengshan Lee

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The Sustainable Development Goals (SDGs) were designed to be the best possible blueprint to achieve peace, prosperity, and overall, a better and more sustainable future for the Earth and all its people, and such a blueprint is needed more than ever. The SDGs face many hurdles that will prevent them from becoming a reality, one of such hurdles, arguably, is the chemical pollution and unintended chemical impacts generated through the production of various goods and resources that we consume. Chemical Alternatives Assessment has proven to be a viable solution for chemical pollution management in terms of filtering out hazardous chemicals for a greener alternative. However, the current substitution practice lacks crucial quantitative datasets (exposures and life cycle impacts) to ensure no unintended trade-offs occur in the substitution process. A Chemical Life Cycle Alternative Assessment (CLiCAA) framework is proposed as a reliable and replicable alternative to Life Cycle Based Alternative Assessment (LCAA) as it integrates chemical molecular structure analysis and Chemical Life Cycle Collaborative (CLiCC) web-based tool to fill in data gaps that the former frameworks suffer from. The CLiCAA framework consists of a four filtering layers, the first two being mandatory, with the final two being optional assessment and data extrapolation steps. Each layer includes relevant impact categories of each chemical, ranging from human to environmental impacts, that will be assessed and aggregated into unique scores for overall comparable results, with little to no data. A feasibility study will demonstrate the efficiency and accuracy of CLiCAA whilst bridging both cancer potency and exposure limit data, hoping to provide the necessary categorical impact information for every firm possible, especially those disadvantaged in terms of research and resource management.

Keywords: chemical alternative assessment, LCA, LCAA, CLiCC, CLiCAA, chemical substitution framework, cancer potency data, chemical molecular structure analysis

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688 Innovative Textile Design Using in-situ Ag NPs incorporation into Natural Fabric Matrix

Authors: M. Rehan, H. Mashaly, H. Emam, A. Abou El-Kheir, S. Mowafi

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In this work, we will study a simple highly efficient technique to impart multi functional properties to different fabric substrates by in situ Ag NPs incorporation into fabric matrix. Ag NPs as a coloration and antimicrobial agent were prepared in situ incorporation into fabric matrix (Cotton and Wool) by using trisodium citrate as reducing and stabilizing agent. The Ag NPs treated fabric (Cotton and Wool) showed different color because of localized surface Plasmon resonance (LSPR) property of Ag NPs. The formation of Ag NPs was confirmed by UV/Vis spectra for the supernatant solutions and The Ag NPs treated fabric (Cotton and Wool) were characterized by scanning electron microscopy (SEM) and X-ray photo electron spectroscopy (XPS). The dependence of color properties characterized by colorimetric, fastness and antibacterial properties evaluated by Escherichia coli using counting method and the reaction parameters were studied. The results indicate that, the in situ Ag NPs incorporation into fabric matrix approach can simultaneously impart colorant and antimicrobial properties into different fabric substrates.

Keywords: Ag NPs, coloration, antibacterial, wool, cotton fabric

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687 Coagulase Negative Staphylococci: Phenotypic Characterization and Antimicrobial Susceptibility Pattern

Authors: Lok Bahadur Shrestha, Narayan Raj Bhattarai, Basudha Khanal

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Introduction: Coagulase-negative staphylococci (CoNS) are the normal commensal of human skin and mucous membranes. The study was carried out to study the prevalence of CoNS among clinical isolates, to characterize them up to species level and to compare the three conventional methods for detection of biofilm formation. Objectives: to characterize the clinically significant coagulase-negative staphylococci up to species level, to compare the three phenotypic methods for the detection of biofilm formation and to study the antimicrobial susceptibility pattern of the isolates. Methods: CoNS isolates were obtained from various clinical samples during the period of 1 year. Characterization up to species level was done using biochemical test and study of biofilm formation was done by tube adherence, congo red agar, and tissue culture plate method. Results: Among 71 CoNS isolates, seven species were identified. S. epidermidis was the most common species followed by S. saprophyticus, S. haemolyticus. Antimicrobial susceptibility pattern of CoNS documented resistance of 90% to ampicillin. Resistance to cefoxitin and ceftriaxone was observed in 55% of the isolates. We detected biofilm formation in 71.8% of isolates. The sensitivity of tube adherence method was 82% while that of congo red agar method was 78%. Conclusion: Among 71 CoNS isolated, S. epidermidis was the most common isolates followed by S. saprophyticus and S. haemolyticus. Biofilm formation was detected in 71.8% of the isolates. All of the methods were effective at detecting biofilm-producing CoNS strains. Biofilm former strains are more resistant to antibiotics as compared to biofilm non-formers.

Keywords: CoNS, congo red agar, bloodstream infections, foreign body-related infections, tissue culture plate

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686 Polypropylene Matrix Enriched With Silver Nanoparticles From Banana Peel Extract For Antimicrobial Control Of E. coli and S. epidermidis To Maintain Fresh Food

Authors: Michail Milas, Aikaterini Dafni Tegiou, Nickolas Rigopoulos, Eustathios Giaouris, Zaharias Loannou

Abstract:

Nanotechnology, a relatively new scientific field, addresses the manipulation of nanoscale materials and devices, which are governed by unique properties, and is applied in a wide range of industries, including food packaging. The incorporation of nanoparticles into polymer matrices used for food packaging is a field that is highly researched today. One such combination is silver nanoparticles with polypropylene. In the present study, the synthesis of the silver nanoparticles was carried out by a natural method. In particular, a ripe banana peel extract was used. This method is superior to others as it stands out for its environmental friendliness, high efficiency and low-cost requirement. In particular, a 1.75 mM AgNO₃ silver nitrate solution was used, as well as a BPE concentration of 1.7% v/v, an incubation period of 48 hours at 70°C and a pH of 4.3 and after its preparation, the polypropylene films were soaked in it. For the PP films, random PP spheres were melted at 170-190°C into molds with 0.8cm diameter. This polymer was chosen as it is suitable for plastic parts and reusable plastic containers of various types that are intended to come into contact with food without compromising its quality and safety. The antimicrobial test against Escherichia coli DFSNB1 and Staphylococcus epidermidis DFSNB4 was performed on the films. It appeared that the films with silver nanoparticles had a reduction, at least 100 times, compared to those without silver nanoparticles, in both strains. The limit of detection is the lower limit of the vertical error lines in the presence of nanoparticles, which is 3.11. The main reasons that led to the adsorption of nanoparticles are the porous nature of polypropylene and the adsorption capacity of nanoparticles on the surface of the films due to hydrophobic-hydrophilic forces. The most significant parameters that contributed to the results of the experiment include the following: the stage of ripening of the banana during the preparation of the plant extract, the temperature and residence time of the nanoparticle solution in the oven, the residence time of the polypropylene films in the nanoparticle solution, the number of nanoparticles inoculated on the films and, finally, the time these stayed in the refrigerator so that they could dry and be ready for antimicrobial treatment.

Keywords: antimicrobial control, banana peel extract, E. coli, natural synthesis, microbe, plant extract, polypropylene films, S.epidermidis, silver nano, random pp

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685 Design and Synthesis of Copper Doped Zeolite Composite for Antimicrobial Activity and Heavy Metal Removal from Waste Water

Authors: Feleke Terefe Fanta

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The existence of heavy metals and microbial contaminants in aquatic system of Akaki river basin, a sub city of Addis Ababa, has become a public concern as human population increases and land development continues. This is because effluents from chemical and pharmaceutical industries are directly discharged onto surrounding land, irrigation fields and surface water bodies. In the present study, we synthesised zeolites and copper- zeolite composite based adsorbent through cost effective and simple approach to mitigate the problem. The study presents determination of heavy metal content and microbial contamination level of waste water sample collected from Akaki river using zeolites and copper- doped zeolites as adsorbents. The synthesis of copper- zeolite X composite was carried out by ion exchange method of copper ions into zeolites frameworks. The optimum amount of copper ions loaded into the zeolites frameworks were studied using the pore size determination concept via iodine test. The copper- loaded zeolites were characterized by X-ray diffraction (XRD). The XRD analysis showed clear difference in phase purity of zeolite before and after copper ion exchange. The concentration of Cd, Cr, and Pb were determined in waste water sample using atomic absorption spectrophotometry. The mean concentrations of Cd, Cr, and Pb in untreated sample were 0.795, 0.654 and 0.7025 mg/L respectively. The concentration of Cd, Cr, and Pb decreased to 0.005, 0.052 and BDL mg/L for sample treated with bare zeolite X while a further decrease in concentration of Cd, Cr, and Pb (0.005, BDL and BDL) mg/L respectively was observed for the sample treated with copper- zeolite composite. The antimicrobial activity was investigated by exposing the total coliform to the Zeolite X and Copper-modified Zeolite X. Zeolite X and Copper-modified Zeolite X showed complete elimination of microbilas after 90 and 50 minutes contact time respectively. This demonstrates effectiveness of copper- zeolite composite as efficient disinfectant. To understand the mode of heavy metals removal and antimicrobial activity of the copper-loaded zeolites; the adsorbent dose, contact time, temperature was studied. Overall, the results obtained in this study showed high antimicrobial disinfection and heavy metal removal efficiencies of the synthesized adsorbent.

Keywords: waste water, copper doped zeolite x, adsorption heavy metal, disinfection

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