scholarly journals Synthesis, characterization and antimicrobial activity of novel benzofuran- and thiophene-containing diketoxime derivatives

2017 ◽  
Vol 82 (4) ◽  
pp. 367-377 ◽  
Author(s):  
Demet Coskun ◽  
Seher Gur ◽  
Mehmet Coskun
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Salmonella Enterica ◽  
Good Activity ◽  
E Coli ◽  
Minimum Inhibitory Concentrations ◽  
Serovar Typhimurium ◽  
And Staphylococcus Aureus

The aim of this study was the preparation of 1,1?-(2,5-thiophenediyl) bis[1-(2-benzofuranyl)methanone] (2), the corresponding diketoxime (3), and the ether and ester derivatives (4a?e) of the diketoxime. These compounds were prepared in good yields. Minimum inhibitory concentrations (MIC) of the synthesized compounds 1?4 were determined against Salmonella enterica subsp. enterica serovar Typhimurium, Escherichia coli and Staphylococcus aureus. Among the synthesized compounds, 1 and 4e showed good activity against E. coli, S. enterica and S. aureus.

scholarly journals Evaluation preliminary phytochemistry and antimicrobial activity of extracts in Eugenia uniflora L. on Escherichia coli and Staphylococcus aureus

2021 ◽  
Vol 10 (13) ◽  
pp. e329101320579
Author(s):  
Alexandre Horácio Couto Bittencourt ◽  
Jaqueline Souza Machado ◽  
Mariana Garcia da Silva ◽  
Braz Antônio Pereira Cosenza
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Eugenia Uniflora ◽  
E Coli ◽  
And Staphylococcus Aureus

Devido ao aumento da resistência de patógenos humanos e animais aos medicamentos atuais, pesquisas por novos antimicrobianos têm sido incentivadas, principalmente por meio de plantas medicinais. Eugenia uniflora L., conhecida como pitangueira, é popularmente utilizada com diversas funções terapêuticas, justificando estudos nesta espécie. Assim, os objetivos deste estudo foram avaliar a atividade antibacteriana “in vitro” de extratos de folhas e cascas de Eugenia uniflora L. sobre Escherichia coli e Staphylococcus aureus. Para as etapas de triagem fitoquímica e microbiologia, foram utilizadas as metodologias usuais nessas áreas para obtenção dos extratos e avaliação da atividade antibacteriana com uso de controle positivo e negativo. Os resultados obtidos mostraram que no extrato das folhas foi verificada a presença de saponinas, flavonóides, alcalóides e taninos, enquanto na casca foram obtidos apenas saponinas e alcalóides. Os extratos da folha e da casca foram capazes de inibir o crescimento de Stapylococcus aureus apenas, promovendo halos de inibição de meio de 19,4 mm e 14,4 mm, respectivamente. As análises permitiram concluir que os extratos apresentam metabólitos secundários interessantes e de grande potencial antimicrobiano e que esses extratos foram capazes de inibir apenas as cepas de S. aureus, sendo resistentes às cepas de E. Coli.

Removal of pathogenic bacterial biofilms by combinations of oxidizing compounds

2015 ◽  
Vol 61 (5) ◽  
pp. 351-356 ◽  
Author(s):  
Gabriela María Olmedo ◽  
Mariana Grillo-Puertas ◽  
Luciana Cerioni ◽  
Viviana Andrea Rapisarda ◽  
Sabrina Inés Volentini
Keyword(s):  
Staphylococcus Aureus ◽  
Salmonella Enterica ◽  
Klebsiella Oxytoca ◽  
Fold Increase ◽  
Clinical Isolates ◽  
Bacterial Biofilms ◽  
Simultaneous Application ◽  
E Coli ◽  
Serovar Typhimurium ◽  
And Staphylococcus Aureus

Bacterial biofilms are commonly formed on medical devices and food processing surfaces. The antimicrobials used have limited efficacy against the biofilms; therefore, new strategies to prevent and remove these structures are needed. Here, the effectiveness of brief oxidative treatments, based on the combination of sodium hypochlorite (NaClO) and hydrogen peroxide (H2O2) in the presence of copper sulfate (CuSO4),were evaluated against bacterial laboratory strains and clinical isolates, both in planktonic and biofilm states. Simultaneous application of oxidants synergistically inactivated planktonic cells and prevented biofilm formation of laboratory Escherichia coli, Salmonella enterica serovar Typhimurium, Klebsiella pneumoniae, and Staphylococcus aureus strains, as well as clinical isolates of Salmonella enterica subsp. enterica, Klebsiella oxytoca, and uropathogenic E. coli. In addition, preformed biofilms of E. coli C, Salmonella Typhimurium, K. pneumoniae, and Salmonella enterica exposed to treatments were removed by applying 12 mg/L NaClO, 0.1 mmol/L CuSO4, and 350 mmol/L H2O2for 5 min. Klebsiella oxytoca and Staphylococcus aureus required a 5-fold increase in NaClO concentration, and the E. coli clinical isolate remained unremovable unless treatments were applied on biofilms formed within 24 h instead of 48 h. The application of treatments that last a few minutes using oxidizing compounds at low concentrations represents an interesting disinfection strategy against pathogens associated with medical and industrial settings.

Antimicrobial Activity of Hibiscus sabdariffa Aqueous Extracts against Escherichia coli O157:H7 and Staphylococcus aureus in a Microbiological Medium and Milk of Various Fat Concentrations

2014 ◽  
Vol 77 (2) ◽  
pp. 262-268 ◽  
Author(s):  
KRISTEN L. HIGGINBOTHAM ◽  
KELLIE P. BURRIS ◽  
SVETLANA ZIVANOVIC ◽  
P. MICHAEL DAVIDSON ◽  
C. NEAL STEWART
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Membrane Filtration ◽  
Anthocyanin Content ◽  
Escherichia Coli O157 ◽  
Hibiscus Sabdariffa ◽  
Aqueous Extracts ◽  
E Coli ◽  
And Staphylococcus Aureus

Hibiscus sabdariffa L. calyces are widely used in the preparation of beverages. The calyces contain compounds that exhibit antimicrobial activity, yet little research has been conducted on their possible use in food systems as antimicrobials. Aqueous extracts prepared from the brand “Mi Costenita” were sterilized by membrane filtration (0.22-μm pore size) or autoclaving (121°C, 30 min) and tested for antimicrobial activity against the foodborne pathogens Escherichia coli O157:H7 strains ATCC 43894 and Cider and Staphylococcus aureus strains SA113 and ATCC 27708 in a microbiological medium and ultrahigh-temperature-processed milk with various fat percentages. Extracts heated by autoclaving exhibited greater activity than did filtered extracts in a microbiological medium. Against E. coli, results of 20 mg/ml filtered extract were not different from those of the control, whereas autoclaved extracts reduced viable cells ca. 3 to 4 log CFU/ml. At 60 mg/ml, both extracts inactivated cells after 24 h. There were reduced populations of both strains of S. aureus (ca. 2.7 and 3 log CFU/ml, respectively) after 24 h of incubation in 40 mg/ml filtered extracts. When grown in autoclaved extracts at 40 mg/ml, both strains of S. aureus were inactivated after 9 h. Autoclaved extracts had decreased anthocyanin content (2.63 mg/liter) compared with filtered extracts (14.27 mg/liter), whereas the phenolic content (48.7 and 53.8 mg/g) remained similar for both treatments. Autoclaved extracts were then tested for activity in milk at various fat concentrations (skim [<0.5%], 1%, 2%, and whole [>3.25%]) against a 1:1 mixture of the two strains of E. coli O157:H7 and a 1:1 mixture of the two strains of S. aureus. Extracts at 40 mg/ml inactivated S. aureus after 168 h in skim and whole milk, and E. coli was inactivated after 96 h in 60 mg/ml extract in all fat levels. These findings show the potential use of Hibiscus extracts to prevent the growth of pathogens in foods and beverages.

scholarly journals Antimicrobial Activities of Ellagitannins against Clostridiales perfringens, Escherichia coli, Lactobacillus plantarum and Staphylococcus aureus

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3714
Author(s):  
Elina Puljula ◽  
Gemma Walton ◽  
Martin J. Woodward ◽  
Maarit Karonen
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Growth Inhibition ◽  
Lactobacillus Plantarum ◽  
Molecular Size ◽  
Antimicrobial Effects ◽  
E Coli ◽  
Inhibition Effect ◽  
And Staphylococcus Aureus

In this study, we tested the growth inhibition effect of 22 individual ellagitannins and of pentagalloylglucose on four bacterial species, i.e., Clostridiales perfringens, Escherichia coli, Lactobacillus plantarum and Staphylococcus aureus. All tested compounds showed antimicrobial effects against S. aureus, and almost all against E. coli and C. perfringens. For L. plantarum, no or very weak growth inhibition was detected. The level of inhibition was the greatest for S. aureus and the weakest for C. perfringens. For S. aureus, the molecular size or flexibility of ellagitannins did not show a clear relationship with their antimicrobial activity, even though rugosins E and D and pentagalloylglucose with four or five free galloyl groups had a stronger growth inhibition effect than the other ellagitannins with glucopyranose cores but with less free galloyl groups. Additionally, our results with S. aureus showed that the oligomeric linkage of ellagitannin might have an effect on its antimicrobial activity. For E. coli, the molecular size, but not the molecular flexibility, of ellagitannins seemed to be an important factor. For C. perfringens, both the molecular size and the flexibility of ellagitannin were important factors. In previous studies, corilagin was used as a model for ellagitannins, but our results showed that other ellagitannins are much more efficacious; therefore, the antimicrobial effects of ellagitannins could be more significant than previously thought.

scholarly journals Attachment and Colonization by Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium, and Staphylococcus aureus on Stone Fruit Surfaces and Survival through a Simulated Commercial Export Chain

2010 ◽  
Vol 73 (7) ◽  
pp. 1247-1256 ◽  
Author(s):  
STACEY COLLIGNON ◽  
LISE KORSTEN
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Stone Fruit ◽  
Escherichia Coli O157 ◽  
Infectious Dose ◽  
E Coli ◽  
Serovar Typhimurium ◽  
And Staphylococcus Aureus

The ability of the foodborne pathogens Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium, and Staphylococcus aureus to attach, colonize, and survive on stone fruit surfaces was investigated. Fifty microliters of bacterial suspension was spot inoculated onto the sterile intact fructoplane of whole peaches and plums. Minimum time required for initial adhesion and attachment was recorded for different surface contact times. Surface colonization patterns of the four pathogens and survival under simulated commercial export conditions also were evaluated. L. monocytogenes and Salmonella Typhimurium attached immediately to stone fruit surfaces. E. coli O157:H7 and S. aureus were visibly attached after 30 s and 1 h, respectively, of direct exposure. Holding freshly harvested stone fruit at 0.5°C to simulate cold storage conditions significantly lowered the titer of E. coli O157:H7 on plums and the titers of L. monocytogenes and Salmonella Typhimurium on stone fruit. E. coli O157:H7 and L. monocytogenes at a low inoculum level and S. aureus and Salmonella Typhimurium at high and low levels did not survive the simulated export chain conditions at titers that exceeded the minimum infectious dose. However, E. coli O157:H7 and L. monocytogenes were able to survive on stone fruit surfaces when inoculated at an artificially high level. In this case, the final titer at the end of the supply chain was higher than the infectious dose. In this laboratory experiment, E. coli O157:H7, L. monocytogenes, Salmonella Typhimurium, and S. aureus at potential natural contamination levels were unable to survive simulated export conditions.

scholarly journals Chemical constituents of Aspergillus sp EJC08 isolated as endophyte from Bauhinia guianensis and their antimicrobial activity

2013 ◽  
Vol 85 (4) ◽  
pp. 1247-1253 ◽  
Author(s):  
Eduardo A.A. Pinheiro ◽  
Josiwander M. Carvalho ◽  
Diellem C.P. dos Santos ◽  
Andre O. Feitosa ◽  
Patricia S.B. Marinho ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Chemical Constituents ◽  
2D Nmr ◽  
Good Activity ◽  
Ergosterol Peroxide ◽  
Aspergillus Sp ◽  
And Staphylococcus Aureus

The present work reports the isolation of five compounds from Aspergillus sp EJC08 isolated as endophytic from Bauhinia guianensis, a tipical plant of the Amazon. The compounds ergosterol (1), ergosterol peroxide (2), mevalolactone (3), monomethylsulochrin (4) and trypacidin A (5) were isolated by chromatographic procedures and identified by spectral methods of 1D and 2D NMR and MS. Compounds 3, 4 and 5 were tested against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus and showed good activity.

EFECTO INHIBITORIO DE EXTRACTOS DE Vitex mollis Kunth CONTRA BACTERIAS Y ESPECIES DE Fusarium DE IMPORTANCIA HUMANA Y AGRÍCOLA

2018 ◽  
Vol 41 (4) ◽  
pp. 353-363
Author(s):  
Alberto J. Valencia-Botin ◽  
Melesio Gutiérrez-Lomelí ◽  
Juan A. Morales-Del-Río ◽  
Pedro J. Guerrero-Medina ◽  
Miguel A. Robles-García ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Salmonella Enterica ◽  
Micrococcus Luteus ◽  
E Coli

Actualmente existe la necesidad de hacer frente al problema de la resistencia a los antibióticos y al uso indiscriminado de fungicidas químicos en la agricultura. El objetivo de este trabajo fue evaluar el efecto inhibitorio de extractos acuosos, metanólicos, acetónicos y hexánicos de hoja y tallo de Vitex mollis Kunth (Lamiaceae) contra diferentes bacterias (Escherichia coli, Micrococcus luteus, Salmonella enterica y Staphylococcus aureus) y especies del hongo Fusarium (F. verticillioides, F. oxysporum, F. tapsinum y F. oxysporum f.sp. lycopersici) de importancia en la salud y en la agricultura, así como determinar su composición química general. Se determinaron las concentraciones inhibitorias mínimas (CIM) de todos los extractos por la técnica de microdilución, excepto del hexánico, que no presentó inhibición en las bacterias estudiadas. S. enterica fue la bacteria que mostró mayor sensibilidad al extracto metanólico de tallo (CIM = 28 μg mL-1), le siguieron M. luteus (CIM = 32 μg mL-1), S. aureus (CIM = 75 μg mL-1) y E. coli (CIM = 80 μg mL- 1). Los extractos metanólicos y acuosos de tallo presentaron mayor porcentaje de inhibición contra los diferentes tipos de Fusarium evaluados por el método de dilución en agar. Los extractos de V. mollis inhibieron a F. verticillioides entre 62 y 91 % con 120 μg mL-1 de extracto. El orden de las especies de hongos inhibidas por los extractos fue: F. verticillioides > F. oxysporum > F. tapsinum > F. oxysporum f.sp. lycopersici. La composición química de las especies se determinó mediante pruebas para fenoles, taninos, flavonoides, triterpenos, alcaloides, cumarinas y saponinas. Ninguno de los extractos presentó alcaloides y saponinas. Los fenoles (37.1 mg EAG/g muestra seca) y flavonoides (26.8 mg EQ/g muestra seca) fueron los compuestos mayoritarios en los extractos metanólicos y acuosos. En conclusión, se requieren cantidades muy pequeñas de extracto para la inhibición de bacterias y de Fusarium; por lo tanto, V. mollis puede ser considerada una fuente de metabolitos para este fin y en la agricultura como control alternativo dentro de un manejo integrado de enfermedades.

Comparison of the Effects of Silver in Nanostructured and Ultrahigh Diluted Form on Growth and Volatile Compounds Produced by Escherichia coli and Staphylococcus aureus

2020 ◽  
Vol 10 (3) ◽  
pp. 316-329
Author(s):  
Fateme Mirzajani ◽  
Amin Hamidi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Life Cycles ◽  
Gas Chromatography Mass Spectrometry ◽  
Untreated Sample ◽  
E Coli ◽  
Volatile Metabolites ◽  
Octyl Acetate ◽  
Volatile Organic ◽  
And Staphylococcus Aureus

Introduction: In this project, the growth and volatile metabolites profiles of Escherichia coli (E. coli ) and Staphylococcus aureus were monitored under the influence of silver base chemical, nanoparticle and ultra-highly diluted compounds. Materials & Methods: The treatments were done for 12000 life cycles using silver nanoparticles (AgNPs) as well as ultra-highly diluted Argentum nitricum (Arg-n). Volatile organic metabolites analysis was performed using gas chromatography mass spectrometry (GC-MS). The results indicated that AgNPs treatment made the bacteria resistant and adapted to growth in the nanoparticle condition. The use of ultra-highly diluted Arg-n initially increased growth but it decreased later. Also, with the continuous usage of these materials, no more bacterial growth was observed. Results: The most important compounds produced by E. coli are Acetophenone, Octyl acetate, Styrene, 1,8-cineole, 4-t-butyl-2-(1-methyl-2-nitroethyl)cyclohexane, hexadecane and 2-Undecanol. The main compounds derived from S. aureus are Acetophenone,1,8-cineole, Benzaldehyde, 2-Hexan-1-ol, Tridecanol, Dimethyl Octenal and tetradecane. Acetophenone and 1,8-cineole were common and produced by both organisms. Conclusion: Based on the origin of the produced volatiles, main volatiles percentage of untreated sample is hydrocarbon (>50%), while bacteria treatments convert the ratio in to aldehydes, ketones and alcohols in the case of AgNPs, (>80%) and aldehydes, ketones and terpenes in the case of Arg-n (>70%).

TiO2 antifouling coating based on epoxy-modified tung oil waterborne resin

2021 ◽  
pp. 096739112110111
Author(s):  
Hailiang Hu ◽  
Minmin Chen ◽  
Mengye Cao
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Survival Rate ◽  
Light Irradiation ◽  
Fouling Resistance ◽  
Tung Oil ◽  
E Coli ◽  
Antifouling Coating ◽  
Waterborne Epoxy

The eco-friendly functionalized TiO2/polymer antifouling (AF) coating was successfully synthesized by dispersing TiO2 nanoparticles in waterborne epoxy-modified tung oil resin. The AF effectiveness of coating was evaluated toward Staphylococcus aureus ( S. aureus, ATCC6538), Escherichia coli ( E. coli, ATCC8739) and diatom ( Cyclotella sp., FACHB-1635). The nanoTiO2/polymer AF coating showed good antimicrobial activity both under the light and dark conditions by comparison with the pristine TiO2 nanoparticles and bulk polymer. Under light irradiation for 50 min, the AF coating showed only 8.4% and 8% survival rate for S. aureus and E. coli. In addition, The AF coatings exhibited favorable inhibition efficacy toward the growth and adhesion of Cyclotella sp., and the efficacy was enhanced with the increase of TiO2 content. It can be concluded that TiO2 nanoparticles endow the AF coatings with promoted fouling resistance properties.

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