Khảo sát tiềm năng kháng khuẩn từ cao chiết lá cây ổi (Psidium guajava l.)

2020 ◽  
Vol 14 (1) ◽  
pp. 84-94
Author(s):  
Dương Nhật Linh ◽  
Nguyễn Tấn Phát ◽  
Nguyễn Doãn Thanh Liêm ◽  
Trần Thị Á Ni ◽  
Nguyễn Thanh Duy ◽  
...  
Keyword(s):  
Vitamin C ◽  
13C Nmr ◽  
Psidium Guajava ◽  
Salmonella Typhi ◽  
E Coli

Ngày nay, cùng với sự phát triển của y học, các hợp chất từ thực vật giữ vai trò chính trong việc phát hiện và phát triển các dược phẩm mới, được xem như là một trong những nguồn thay thế lý tưởng vì mức độ an toàn, không hoặc ít phản ứng phụ và có nhiều đích tác động khác nhau lên tế bào vi khuẩn nên ít có nguy cơ gây ra sự kháng thuốc, trong đó Ổi (Psidium guajava L.) rất giàu các chất chống oxy hóa, vitamin C, kali và chất xơ. Nghiên cứu dược lý cho thấy dịch chiết các bộ phận của cây ổi đều có khả năng kháng khuẩn, làm săn se niêm mạc và cầm tiêu chảy. Trong kết quả nghiên cứu này, cao ethyl axetat từ lá cây ổi có khả năng kháng khuẩn và kháng cao nhất với MRSA (31,67 ± 1,52mm). Cao chiết ethyl axetat có tác động ức chế MRSA, E. coli và Salmonella typhi ở nồng độ ức chế tối thiểu (MIC) là 1/128 tương ứng nồng độ 1,5625mg/mL và có tác động ức chế P. aeruginosa ở giá trị MIC là 1/256 tương ứng nồng độ 0,78mg/mL. Kết hợp phương pháp sắc ký cột và sắc ký lớp mỏng, chúng tôi đã phân lập và tinh chế được hợp chất PG01 có khả năng kháng MRSA cao nhất. Dựa trên dữ liệu phổ 1H, 13C-NMR cho thấy cấu trúc của hợp chất có khả năng kháng khuẩn mạnh (PG01) được xác định là 3-β-hydroxylup-20(29)-ene. Kết quả của đề tài có thể sẽ mở ra một hướng phát triển mới cho ngành Dược trước những thách thức của tình hình vi khuẩn đề kháng kháng sinh hiện nay.

scholarly journals AKTIVITAS ANTIMIKROBA YOGURT BERBASIS AIR KELAPA MENGHAMBAT BAKTERI PATOGEN SECARA IN VITRO

1970 ◽  
Vol 17 (2) ◽  
Author(s):  
Lindawati S. A. ◽  
Haniyah Y. S. ◽  
Miwada I N. S. ◽  
Inggriati N. W. T. ◽  
Hartawan M. ◽  
...  
Keyword(s):  
Salmonella Typhi ◽  
Lactobacillus Bulgaricus ◽  
Plate Count ◽  
Klebsiella Pneumonia ◽  
E Coli ◽  
Total Plate Count

Yogurt merupakan minuman susu yang difermentasi dengan menggunakan bakteri asam laktat Lactobacillus bulgaricus dan Streptococcus thermophyllus sebagai starter. Tujuan penelitian untuk mengetahui kemampuan tertinggi dari yogurt berbasis air kelapa dalam menghambat pertumbuhan bakteri pathogen (Salmonella, Staphylococcus, Klebsiela pneumonia dan E.coli) secara in vitro. Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan empat perlakuan dan empat ulangan. Keempat perlakuan tersebut: Ko: susu skim 12%+air; K1: susu skim 12%+air kelapa gading; K2: susu skim 12%+kelapa gading bulan; K3: susu skim 12%+air kelapa hijau. Peubah yang diamati adalah aktivitas antimikroba yogurt terhadap bakteri pathogen (Salmonellatyphi, Staphylococcus, Klebsiella pneumonia dan E.coli), total plate count (TPC), total bakteri asam laktat dan E,coli. Hasil penelitian menunjukkan bahwa aktivitas antimikroba tertinggi diperoleh pada yogurt berbasis air kelapa bulan terhadap bakeri Salmonella typhi dan Staphylococcus masing-masing sebesar 0,21 dan 0,26 cm dengan total bakteri asam laktat1,1×107 cfu/mL sedangkan untuk Klebsiella pneumonia dan E.coli diperoleh pada yogurt berbasis air kelapa gading sebesar 0,38 dan 0,64 mm dengan total bakteri asam laktat 3,1×106 cfu/mL.Dari hasil penelitian dapat disimpulkan bahwa yogurt berbasis air kelapa gading, bulan, hijau dan tanpa air kelapa memiliki aktivitas antimikroba berspektrum luas (menghambat bakteri gram positif dan negatif).

scholarly journals Níveis de sensibilidade de enterobactérias, em particular Salmonella typhi, a rifamicina S.V.

1969 ◽  
Vol 3 (2) ◽  
pp. 87-93
Author(s):  
Ivone R. Suassuna ◽  
I. Suassuna ◽  
C. E. de V. Serpa
Keyword(s):  
Escherichia Coli ◽  
Proteus Mirabilis ◽  
Salmonella Typhi ◽  
E Coli

Em face à predominante eliminação biliar da rifamicina S.V. atingindo concentrações muitas vêzes superiores aos níveis séricos obtidos com as doses terapêuticas, e pelo possível interêsse dessa verificação para o tratamento dos portadores biliares crônicos de Salmonella typhi determinou-se a concentração mínima inibitória de 165 estirpes de enterobactérias, incluindo 77 amostras de S. typhi. Foi verificado que a maioria das cepas de Escherichia coli, Shigella e Proteus mirabilis correspondiam a uma concentração inibitória mínima entre 33 a 65 μg/ml. Entre 65 e 128 μg/ml foram determinadas as concetrações inibitórias mínimas da maioria das outras espécies de Proteus, de Providencia e de Klebsiella. Para Salmonella e Enterobacter o limite mínino de sensibilidade foi, em regra, igual ou superior a 128 μg/ml. Diferenças mais acentuadas de comportamento entre as enterobactérias foram observadas quanto à ação bactericida da rifamicidas S.V. De uma maneira geral, para E. coli e Shigella, as concentrações inibitórias mínimas já referidas. Para as espécies de Proteus e Providencia houve variação maior de comportamento, mas tendência a que o efeito bactericidas fôsse encontrado em concentrações que correspondiam a 4 vêzes as bacteriostáticas para as mesmas espécies. Finalmente, de modo pouco feliz para os propósitos visados, em Salmonella, com a inclusão de S. typhi, não foi atingido um efeito bactericida, com as mais altas concentrações usadas as quais corresponderam em média a 6 vêzes as concentrações bacteriostáticas para esse gênero.

scholarly journals Assessment of Gut Microbiota and Selected Blood Parameters in Weaned Piglets Following Supplementation with a Probiotic and Vitamin C

2020 ◽  
Vol 20 (1) ◽  
pp. 179-189
Author(s):  
Leszek Tymczyna ◽  
Beata Trawińska ◽  
Marta Kowaleczko ◽  
Anna Chmielowiec-Korzeniowska ◽  
Jerzy Lechowski
Keyword(s):  
Vitamin C ◽  
Gut Microbiota ◽  
Total Cholesterol ◽  
Hdl Cholesterol ◽  
Blood Parameters ◽  
Control Group ◽  
Weaned Piglets ◽  
E Coli ◽  
Experimental Group ◽  
Control Group Group

AbstractThe aim of the study was to assess the gut microbiota and selected haematological and biochemical blood parameters of weaned piglets following dietary supplementation with a probiotic and vitamin C. the piglets were divided into a control group (group C) and an experimental group (group E), with 30 piglets in each group. All animals received the same feed ad libitum. The animals in the control group (group C) received feed with no added probiotic and vitamin C. the piglets in the experimental group (group E) were given a supplement containing a probiotic (Bacillus cereus 1×109 CFU/kg) in the amount of 1.5 g/piglet/day and vitamin c in the amount of 300 mg/piglet/day. The supplement was administered for 28 days. The total numbers of bacteria of the family Enterobacteriaceae and of the genus Lactobacillus were determined in faeces. The erythrocyte count, haemoglobin level, haematocrit, leukocyte count, and percentages of neutrophils and lymphocytes were determined in the blood. The biochemical analysis concerned the concentration of triacylglycerols, total cholesterol, and LDL and HDL cholesterol. In group E a significant decrease (P<0.01) in the total number of Enterobacteriaceae bacteria was observed in the faeces of the piglets, accompanied by an increase in the number of lactobacilli relative to group C. E. coli was found to predominate over other microorganisms. Salmonella choleraesuis bacteria were present in the faeces of both groups before administration of the supplement, but were not found after its use. The supplement with probiotic and vitamin C caused a significant increase in the erythrocyte, haemoglobin and haematocrit levels in the blood of the piglets and a significant decrease in the concentration of triacylglycerols, total cholesterol and LDL cholesterol.

scholarly journals Fermentation and Extraction of Antibacterial Metabolite Using Streptomyces spp. Isolated from Taplejung, Nepal

2021 ◽  
Vol 26 (1) ◽  
pp. 8-15
Author(s):  
Shiv Nandan Sah ◽  
Ramesh Majhi ◽  
Sunil Regmi ◽  
Arjun Ghimire ◽  
Bhageshwor Biswas ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Salmonella Typhi ◽  
Soil Samples ◽  
E Coli ◽  
Primary Screening ◽  
Streptomyces Spp ◽  
Antibacterial Compound ◽  
Fermented Broth ◽  
Layer Chromatography ◽  
Mic Value

Realizing an increasing need for a novel antibiotic, this study was carried out to screen antibacterial metabolites producing actinomycetes from 15 soil samples collected from Taplejung. Antibacterial metabolites producing actinomycetes were confirmed by primary screening and secondary screening. Macroscopic, microscopic, and biochemical characteristics were used for presumptive identification of probable actinomycetes genera. The potential isolate was cultured in starch casein broth for production of possible antibacterial compound. The antibacterial compound was extracted from fermented broth using organic solvents like ethyl acetate, n-butanol, chloroform, dichloromethane, and methanol. Among 24 isolates, only one (T18) showed antibacterial activity against both Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli, Salmonella Typhi and Pseudomonas aeruginosa) test-bacteria. The isolate was considered as Streptomyces spp based on microscopy and various biochemical, and physiological characteristics. Extracted antibacterial metabolite showed antibacterial activity with a MIC value of 1.2 mg/mL against E. coli (ATCC 25922). The chromatogram in Thin Layer Chromatography showed only one spot exhibited by extract with Rf value 0.87 suggested that the isolate produced a compound that was completely different from the spot with Rf value 0.94 produced by gentamicin (standard). This study revealed the distribution of the potent antibacterial metabolite producing actinomycetes in the soils of Taplejung.

scholarly journals Comparative account of vitamin C contents, antioxidant properties and iron contents of minor fruits in Sri Lanka

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Hashini Imalsha Abeysuriya ◽  
Vajira P Bulugahapitiya ◽  
Loku Pullukkutige Jayatissa
Keyword(s):  
Sri Lanka ◽  
Vitamin C ◽  
Mangifera Indica ◽  
Antioxidant Properties ◽  
Dehydroascorbic Acid ◽  
Psidium Guajava ◽  
Sri Lankan ◽  
Antioxidant Power ◽  
Melastoma Malabathricum ◽  
Ic50 Values

Sri Lanka is a habitat of diverse fruit varieties; nevertheless 95% of them are underutilized by people due to unawareness of their nutritional values and health aspects, and hence become ‘minor fruits’. This study was aimed on revealing vitamin C, iron and antioxidant contents of 29 varieties of minor fruits (MFs) with the comparison of the same with three best commonly consumable fruits (CFs), namely Carica papaya, Mangifera indica and Psidium guajava. Ascorbic acid (Asc), dehydroascorbic acid (DAsc), vitamin C (TC), phenolic (TP), flavonoid (TF), iron (Fe) contents and antioxidant capacities (AOCs) of fruits were determined using standard methods. The results of mean Asc, DAsc, TC, TP, TF and Fe contents in 100 gm of MFs ranged from 3.1 to 121.5 mg, 1.2 to 70.7 mg, 6.6 to 136.1 mg, 24.9 to 1613.3 mg Gallic acid equivalent, 6.2 to 228.0 mg Quercetin equivalents and 0.2 to 4.9 mg respectively. DPPH and Ferric Reducing Antioxidant Power (FRAP) assays were used for AOCs and variation of IC50 values in a DPPH assay was 1.2 to 245.4 mg/ml whereas FRAP values ranged from 9.6 to 486.7 ?mol FeSO4/gm. Among the studied minor fruits, Melastoma malabathricum (Maha bovitiya/ Malabar melastome) is found as the best respect to all considered parameters. As a conclusion, it can be stated that, the Sri Lankan minor fruits are good alternatives to the common fruits as they are recognized as good source of vitamin C, iron and higher content of antioxidants. As an outcome, Sri Lankan minor fruits can be promoted as alternatives to common fruits and as source of revenue for national economy.

scholarly journals Bactericides Properties of Chitosan Metal Quantum Dots Microbial Pathogenicity Against E. coli, S. aureus, and S. Typhi

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Galo Cárdenas-Triviño ◽  
María J. Saludes-Betanzo ◽  
Luis Vergara-González
Keyword(s):  
Quantum Dots ◽  
Antibacterial Properties ◽  
Inhibition Zone ◽  
Bactericidal Effect ◽  
Salmonella Typhi ◽  
Disk Diffusion ◽  
Initial Inoculum ◽  
E Coli ◽  
Growth Inhibition Zone ◽  
Average Size

The nanotechnology is considered as a tool to overcome antibiotic-resistant infections. The aim of this study was to investigate the antibacterial properties of quantum dots (QDs) of Au, Ag, and Cu supported in chitosan against Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 29213), and Salmonella Typhi (ATCC 9993) strains. The QDs were synthesized by the method (Chemical Liquid Deposition, CLD) using 2-ethoxyethanol as solvent (1×10−3 M approximate dispersion concentration). Then, NPs supported in chitosan were synthesized by solvated metal atom dispersion (SMAD) in two concentrations, labelled [A] and [B] (0.05 and 0.1 g/L) for each metal with chitosan resulting in an average size of Au 10±2.0, Ag 6±1.3, and Cu 10±2.4 nm, respectively. Several other techniques were performed such as TEM, SEM/EDX, TGA, DSC, and FT-IR for characterizing QDs. The antibacterial assay was performed with 8 agents on cultures of E. coli, S. aureus, and S. Typhi by disk diffusion, broth macrodilution, and determining death curve to the most sensitive pathogen. The antibacterial effect of the nanoparticles was compared using the diameter of growth inhibition zone by agar disk diffusion and through the minimal inhibitory concentration (MIC) and minimal bactericide concentration (MBC) obtained by macrodilution in batch culture with an initial inoculum of 5×105 CFU/mL. The highest bactericidal effect was obtained with nanoparticles of Au, Ag, and Cu (0.1 g/L) with MIC and MBC of 200 and 400 mg/mL, respectively. The greatest bactericidal effect considering the three pathogens turned out to be Ag QDs (0.05 and 0.1 g/L). A bactericidal effect of metal nanoparticles is affected mainly by the electronegativity, the concentration of nanoparticles, and the bacterial age culture.

scholarly journals Gadolinium Complexes as Contrast Agent for Cellular NMR Spectroscopy

2020 ◽  
Vol 21 (11) ◽  
pp. 4042 ◽  
Author(s):  
Nat Sakol ◽  
Ayako Egawa ◽  
Toshimichi Fujiwara
Keyword(s):  
Nmr Spectroscopy ◽  
Contrast Agent ◽  
13C Nmr ◽  
Specific Binding ◽  
Nmr Relaxation ◽  
Cell Membrane Permeability ◽  
Resonance Spectroscopy ◽  
E Coli ◽  
Gadolinium Complexes ◽  
Cellular Components

Aqua Gd3+ and Gd-DOTA (gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacete) complexes were studied as a contrast agent in cellular NMR (nuclear magnetic resonance) spectroscopy for distinguishing between intracellular and extracellular spaces. The contrast agents for this purpose should provide strong paramagnetic relaxation enhancement and localize in the extracellular space without disturbing biological functions. Cell membrane permeability to Gd complexes was evaluated from the concentrations of gadolinium complexes in the inside and outside of E. coli cells measured by the 1H-NMR relaxation. The site-specific binding of the complexes to E. coli cells was also analyzed by high-resolution solid-state 13C-NMR. The aqua Gd3+ complex did not enhance T1 relaxation in proportion to the amount of added Gd3+. This Gd3+ concentration dependence and the 13C-NMR indicated that its strong cytotoxicity should be due to the binding of the paramagnetic ions to cellular components especially at the lipid membranes. In contrast, Gd-DOTA stayed in the solution states and enhanced relaxation in proportion to the added amount. This agent exhibited strong T1 contrast between the intra- and extracellular spaces by a factor of ten at high concentrations under which the cells were viable over a long experimental time of days. These properties make Gd-DOTA suitable for selectively contrasting the living cellular space in NMR spectroscopy primarily owing to its weak interaction with cellular components.

scholarly journals Ascorbic Acid Changes Growth of Food-Borne Pathogens in the Early Stage of Biofilm Formation

2020 ◽  
Vol 8 (4) ◽  
pp. 553
Author(s):  
Jana Przekwas ◽  
Natalia Wiktorczyk ◽  
Anna Budzyńska ◽  
Ewa Wałecka-Zacharska ◽  
Eugenia Gospodarek-Komkowska
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Food Industry ◽  
Early Stage ◽  
Food Additives ◽  
Bacterial Biofilm ◽  
Biofilm Inhibition ◽  
E Coli ◽  
Food Borne ◽  
The Impact

Since bacterial biofilm may contribute to the secondary contamination of food during the manufacturing/processing stage there is a need for new methods allowing its effective eradication. Application of food additives such as vitamin C already used in food industry as antioxidant food industry antioxidants may be a promising solution. The aim of this research was evaluation of the impact of vitamin C (ascorbic acid), in a range of concentrations 2.50 µg mL−1–25.0 mg mL−1, on biofilms of Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes strains isolated from food. The efficacy of ascorbic acid was assessed based on the reduction of optical density (λ = 595 nm). The greatest elimination of the biofilm was achieved at the concentration of vitamin C of 25.0 mg mL−1. The effect of the vitamin C on biofilm, however, was strain dependent. The concentration of 25.0 mg mL−1 reduced 93.4%, 74.9%, and 40.5% of E. coli, L. monocytogenes, and S. aureus number, respectively. For E. coli and S. aureus lower concentrations were ineffective. In turn, for L. monocytogenes the biofilm inhibition was observed even at the concentration of 0.25 mg mL−1. The addition of vitamin C may be helpful in the elimination of bacterial biofilms. Nonetheless, some concentrations can induce growth of the pathogens, posing risk for the consumers’ health.

Comparative evaluation of antibacterial efficacy of plants traditionally used as antidiarrheal against enteropathogenic Escherichia coli

2015 ◽  
Author(s):  
Ashish Srivastava ◽  
D. B. Mondal
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Curcuma Longa ◽  
Punica Granatum ◽  
Psidium Guajava ◽  
Antibacterial Efficacy ◽  
E Coli ◽  
Methanolic Extracts

The study was conducted to investigate the antibacterial efficacy against enteropathogenic E. coli of plants commonly used to treat calf-diarrhoea. Methanolic extracts of six plants (Aegle marmelos, Curcuma longa, Dalbergia sissoo, Mangifera indica, Psidium guajava and Punica granatum) were screened for their antibacterial property against enteropathogenic E. coli by standard disc diffusion method. Minimum inhibitory concentration (MIC) and of the extract exhibiting highest antibacterial activity was estimated by broth dilution method and minimum bactericidal concentration (MBC) was measured by streaking the contents of MIC tubes on nutrient agar plates. Among the six extracts tested, only extracts of Curcuma longa, Psidium guajava and Punica granatum exhibited antibacterial activity against E. coli. Out of these three, Punica granatum extract was found to be most effective with a mean inhibition zone of 14.67±0.577 mm followed by Psidium guajava (9.67±0.577 mm) and Curcuma longa (8.67±0.577 mm), produced by the disc containing 8.00 mg of respective extract. Minimum inhibitory concentration and minimum bactericidal concentration of the Punica granatum extract were estimated to be 02.00 mg/mL and 03.00 mg/mL respectively. These findings suggest that methanolic extracts of Curcuma longa, Psidium guajava and Punica granatum possess antibacterial activity against enteropathogenic E.coli

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