The activity of silver against Escherichia coli biofilm is increased by a lipopeptide biosurfactant

2010 ◽  
Vol 56 (3) ◽  
pp. 272-278 ◽  
Author(s):  
Fabrizio Rivardo ◽  
Maria Giovanna Martinotti ◽  
Raymond Joseph Turner ◽  
Howard Ceri

Biological contamination of surfaces, both in industry and in health care, plays an important role as a potential vector of disease transmission. Metals have been described to be effective antibiofilm agents, and the efficacy of silver ions as a disinfectant has been known for centuries. The activity of AgNO3 combined with the lipopeptide biosurfactant V9T14 has been studied against a preformed Escherichia coli biofilm on the Calgary Biofilm Device. Results indicated that the activity of silver can be synergistically enhanced by the presence of V9T14, both allowing for a reduction in the quantity of silver used and for greater antimicrobial activity. The concentration of silver needed to obtain this reduction in the silver–biosurfactant solution was from 129- to 258-fold less than the concentration of silver alone. To our knowledge, this is the first time that a synergistic interaction between a lipopeptide biosurfactant and silver has been observed.

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ping-Chung Kuo ◽  
Guo-Feng Chen ◽  
Mei-Lin Yang ◽  
Ya-Hua Lin ◽  
Chi-Chung Peng

Lignans and phenylethanoid glycosides purified fromForsythia suspensawere reported to display various bioactivities in the previous literature, including the antimicrobial activity. Therefore, the present research is aimed to purify and identify the chemical constituents of the methanol extracts of fruits ofF. suspensa. The methanol extracts of fruits ofF. suspensawere fractionated and further purified with the assistance of column chromatography to afford totally thirty-four compounds. Among these isolates, 3β-acetoxy-20α-hydroxyursan-28-oic acid (1) was reported from the natural sources for the first time. Some of the purified principles were subjected to the antimicrobial activity examinations againstEscherichia colito explore new natural lead compounds.


Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4118 ◽  
Author(s):  
Noha Fathallah ◽  
Marwa M. Raafat ◽  
Marwa Y. Issa ◽  
Marwa M. Abdel-Aziz ◽  
Mokhtar Bishr ◽  
...  

Ammi majus L.; Family Apiaceae; is a plant indigenous to Egypt. Its fruits contain bioactive compounds such as furanocoumarins and flavonoids of important biological activities. An endophytic fungus was isolated from the fruits and identified as Aspergillus amstelodami (MK215708) by morphology, microscopical characterization, and molecular identification. To our knowledge this is the first time an endophytic fungus has been isolated from the fruits. The antimicrobial activity of the Ammi majus ethanol fruits extract (AME) and fungal ethyl acetate extract (FEA) were investigated, where the FEA showed higher antimicrobial activity, against all the tested standard strains. Phytochemical investigation of the FEA extract yielded five prenylated benzaldehyde derivative compounds isolated for the first time from this species: Dihydroauroglaucin (1), tetrahydroauroglaucin (2), 2-(3,6-dihydroxyhepta-1,4-dien-1-yl)-3,6-dihydroxy-5-(dimethylallyl)benzaldehyde (3), isotetrahydroauroglaucin )4), and flavoglaucin (5). Structure elucidation was carried out using (1H- and 13C-NMR). Fractions and the major isolated compound 1 were evaluated for their antimicrobial and antibiofilm activity. Compound 1 showed high antimicrobial activity against Escherichia coli with minimum inhibitory concentration (MIC) = 1.95 µg/mL, Streptococcus mutans (MIC = 1.95 µg/mL), and Staphylococcus aureus (MIC = 3.9 µg/mL). It exhibited high antibiofilm activity with minimum biofilm inhibitory concentration (MBIC) = 7.81 µg/mL against Staphylococcus aureus and Escherichia coli biofilms and MBIC = 15.63 µg/mL against Streptococcus mutans and Candida albicans and moderate activity (MBIC = 31.25 µg/mL) against Pseudomonas aeruginosa biofilm. This reveals that dihydroauroglaucin, a prenylated benzaldehyde derivative, has a broad spectrum antimicrobial activity. In conclusion, it was observed that the MICs of the FEA are much lower than that of the AME against all susceptible strains, confirming that the antimicrobial activity of Ammi majus may be due to the ability of its endophytic fungi to produce effective secondary metabolites.


2011 ◽  
Vol 322 ◽  
pp. 160-163
Author(s):  
Yin Lu ◽  
Hong Chen

A medicinal wild kiwi in China, Actinidia valvata Dunn, has been well known for its activities against leprosy and cancers. The compositions and the antimicrobial activity of its leaf oil were reported for the first time. The oil obtained by hydrodistillation and analyzed by GC and GC-MS, was characterized by the high content of monoterpenes. Linalool (48.14%) is the major component identified, followed by 1,2-dimethyl-lindoline (7.94%), linolenic acid methylester (6.57%) and (E)-phytol (5.29%). The antimicrobial activity of the oil was evaluated against four bacterial and three fungal species. The results showed that it exhibited a mild antibacterial activity against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), a significant activity against Gram-negative bacteria (Escherichia coli), and no activity on Pseudomonas aeruginosa. The test fungi were more sensitive to the oil, with a MIC range of 0.78~1.56 μL/mL than bacteria in the range which were significantly higher from 0.78 to 25.50 μL/mL.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Semih Kurban ◽  
Nahide Gulsah Deniz ◽  
Cigdem Sayil ◽  
Mustafa Ozyurek ◽  
Kubilay Guclu ◽  
...  

A series of new 1,4-naphtho- and benzoquinone derivatives possessing N-, S-, O-substituted groups which has not been reported yet has been synthesized from 2,3-dichloro-1,4-naphthoquinone 1 and 2,3,5,6-tetrachlorocyclohexa-2,5-diene-1,4-dione 15 involving a Michael addition. In the synthesized compounds, antimicrobial activity at low concentrations against Escherichia coli B-906, Staphylococcus aureus 209-P, and Mycobacterium luteum B-917 bacteria and Candida tenuis VKM Y-70 and Aspergillus niger F-1119 fungi in comparison with controls was identified. 2-Chloro-3-((2-(piperidin-1-yl)ethyl)amino)naphthalene-1,4-dione 3g and 2,5-dichloro-3-ethoxy-6-((2,4,6-trifluorophenyl)amino)cyclohexa-2,5-diene-1,4-dione 17 were the most potent, with a minimum inhibitory concentration value of 15.6 μg/mL against test-culture M. luteum and S. aureus, respectively. Furthermore, in this work, a catalase activity of benzo- and naphthoquinone derivatives was examined for the first time. The catalase activity of benzo- and naphthoquinone derivatives was determined, showing that compound 3g had significant inhibition activity for catalase enzyme.


2010 ◽  
Vol 53 (3) ◽  
pp. 629-632 ◽  
Author(s):  
Henrique Pereira Ramos ◽  
Glaucia Hollander Braun ◽  
Mônica Tallarico Pupo ◽  
Suraia Said

Papulaspora immersa and Arthrinium state of Apiospora montagnei Sacc. were isolated from the roots of Smallanthus sonchifolius (yacón). The crude extracts from their cultures inhibited the growth of Staphylococcus aureus, Kocuria rhizophila, Pseudomonas aeruginosa and Escherichia coli. The more relevant results were observed in the ethyl acetate extract from P immersa against P aeruginosa (90 µg/mL) and ethyl acetate extract from Arthrinium state of A montagnei Sacc. against P aeruginosa (160 µg/mL). The two endophytic fungi isolated from yacón roots as well as their antimicrobial activity detected in the crude extracts cultures were being reported for the first time.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4966
Author(s):  
Santanu Kumar Padhi ◽  
Nicoletta Baglieri ◽  
Valentina Bonino ◽  
Angelo Agostino ◽  
Lorenza Operti ◽  
...  

We report for the first time on the antimicrobial activity of MgB2 powders produced via the Reactive Liquid Infiltration (RLI) process. Samples with MgB2 wt.% ranging from 2% to 99% were obtained and characterized, observing different levels of grain aggregation and of impurity phases. Their antimicrobial activity was tested against Staphylococcus aureus ATCC BAA 1026, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. A general correlation is observed between the antibacterial activity and the MgB2 wt.%, but the sample microstructure also appears to be very important. RLI-MgB2 powders show better performances compared to commercial powders against microbial strains in the planktonic form, and their activity against biofilms is also very similar.


Marine Drugs ◽  
2019 ◽  
Vol 17 (8) ◽  
pp. 472 ◽  
Author(s):  
Germana Esposito ◽  
Linh H. Mai ◽  
Arlette Longeon ◽  
Alfonso Mangoni ◽  
Emilie Durieu ◽  
...  

Thirteen nitrogen-containing molecules (1a/1b and 2–12) were isolated from the Indonesian sponge Acanthostrongylophora ingens, highlighting the richness of this organism as a source of alkaloids. Their structures were elucidated using one- and two-dimensional NMR spectroscopy and HR-ESI-MS, while the stereochemistry of the diketopiperazines was established using Marfey’s method. All compounds were screened in our standard bioactivity assays, including antibacterial, antikinases, and amyloid β-42 assays. The most interesting bioactivity result was obtained with the known acanthocyclamine A (3), which revealed for the first time a specific Escherichia coli antimicrobial activity and an inhibitory effect on amyloid β-42 production induced by aftin-5 and no cytotoxicity at the dose of 26 µM. These results highlight the potentiality of a bipiperidine scaffold as a promising skeleton for preventing or reducing the production of amyloid β-42, a key player in the initiation of Alzheimer’s disease.


2010 ◽  
Vol 2 (2) ◽  
pp. 397-402 ◽  
Author(s):  
R. Badoni ◽  
D. K. Semwal ◽  
U. Rawat

Methyl esters of fatty acid obtained from Celtis australis fruits were subjected to GC-MS in order to determine the identity and concentration of its constituents. Methyl oleate (25.7%), methyl palmitate (22.2%), methyl tricosanoate (13.3%), methyl lineolate (7.8%), methyl dotriacentanoate (2.6%) and methyl 14-acetylhydroxypalmitate (2.1%) were the major constituents out of total characterized composition (95.455%) of fatty acid. The ethanolic extract of fruits was used for evaluating its antimicrobial activity against Staphylococcus aureus, Pseudomonas auroginosa, Escherichia coli and Bacillus subtilis. The extract showed significant results against P. auroginosa and E. coli.  The antimicrobial activity and fatty acid analysis of C. australis of fatty acid fruits has been carried out for the first time. Keywords: Celtis australis; Ulmaceae; methyl oleate; methyl tricosanoate; Pseudomonas auroginosa; Escherichia coli. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i2.4056                J. Sci. Res. 2 (2), 397-402 (2010) 


Planta Medica ◽  
2013 ◽  
Vol 79 (05) ◽  
Author(s):  
ADC Abergas ◽  
MCQ Aleria ◽  
ZJS Alimagno ◽  
KNC Batac ◽  
AFM De Lara ◽  
...  

Author(s):  
О.В. Шамова ◽  
М.С. Жаркова ◽  
П.М. Копейкин ◽  
Д.С. Орлов ◽  
Е.А. Корнева

Антимикробные пептиды (АМП) системы врожденного иммунитета - соединения, играющие важную роль в патогенезе инфекционных заболеваний, так как обладают свойством инактивировать широкий спектр патогенных бактерий, обеспечивая противомикробную защиту живых организмов. В настоящее время АМП рассматриваются как потенциальные соединения-корректоры инфекционной патологии, вызываемой антибиотикорезистентными бактериями (АБР). Цель данной работы состояла в изученим механизмов антибактериального действия трех пептидов, принадлежащих к семейству бактенецинов - ChBac3.4, ChBac5 и mini-ChBac7.5Nb. Эти химически синтезированные пептиды являются аналогами природных пролин-богатых АМП, обнаруженных в лейкоцитах домашней козы Capra hircus и проявляющих высокую антимикробную активность, в том числе и в отношении грамотрицательных АБР. Методы. Минимальные ингибирующие и минимальные бактерицидные концентрации пептидов (МИК и МБК) определяли методом серийных разведений в жидкой питательной среде с последующим высевом на плотную питательную среду. Эффекты пептидов на проницаемость цитоплазматической мембраны бактерий для хромогенного маркера исследовали с использованием генетически модифицированного штамма Escherichia coli ML35p. Действие бактенецинов на метаболическую активность бактерий изучали с применением маркера резазурина. Результаты. Показано, что все исследованные пептиды проявляют высокую антимикробную активность в отношении Escherichia coli ML35p и антибиотикоустойчивых штаммов Escherichia coli ESBL и Acinetobacter baumannii in vitro, но их действие на бактериальные клетки разное. Использован комплекс методик, позволяющих наблюдать в режиме реального времени динамику действия бактенецинов в различных концентрациях (включая их МИК и МБК) на барьерную функцию цитоплазматической мембраны и на интенсивность метаболизма бактериальных клеток, что дало возможность выявить различия в характере воздействия бактенецинов, отличающихся по структуре молекулы, на исследуемые микроорганизмы. Установлено, что действие каждого из трех исследованных бактенецинов в бактерицидных концентрациях отличается по эффективности нарушения целостности бактериальных мембран и в скорости подавления метаболизма клеток. Заключение. Полученная информация дополнит существующие фундаментальные представления о механизмах действия пролин-богатых пептидов врожденного иммунитета, а также послужит основой для биотехнологических исследований, направленных на разработку на базе этих соединений новых антибиотических препаратов для коррекции инфекционных заболеваний, вызываемых АБР и являющимися причинами тяжелых внутрибольничных инфекций. Antimicrobial peptides (AMPs) of the innate immunity are compounds that play an important role in pathogenesis of infectious diseases due to their ability to inactivate a broad array of pathogenic bacteria, thereby providing anti-microbial host defense. AMPs are currently considered promising compounds for treatment of infectious diseases caused by antibiotic-resistant bacteria. The aim of this study was to investigate molecular mechanisms of the antibacterial action of three peptides from the bactenecin family, ChBac3.4, ChBac5, and mini-ChBac7.5Nb. These chemically synthesized peptides are analogues of natural proline-rich AMPs previously discovered by the authors of the present study in leukocytes of the domestic goat, Capra hircus. These peptides exhibit a high antimicrobial activity, in particular, against antibiotic-resistant gram-negative bacteria. Methods. Minimum inhibitory and minimum bactericidal concentrations of the peptides (MIC and MBC) were determined using the broth microdilution assay followed by subculturing on agar plates. Effects of the AMPs on bacterial cytoplasmic membrane permeability for a chromogenic marker were explored using a genetically modified strain, Escherichia coli ML35p. The effect of bactenecins on bacterial metabolic activity was studied using a resazurin marker. Results. All the studied peptides showed a high in vitro antimicrobial activity against Escherichia coli ML35p and antibiotic-resistant strains, Escherichia coli ESBL and Acinetobacter baumannii, but differed in features of their action on bacterial cells. The used combination of techniques allowed the real-time monitoring of effects of bactenecin at different concentrations (including their MIC and MBC) on the cell membrane barrier function and metabolic activity of bacteria. The differences in effects of these three structurally different bactenecins on the studied microorganisms implied that these peptides at bactericidal concentrations differed in their capability for disintegrating bacterial cell membranes and rate of inhibiting bacterial metabolism. Conclusion. The obtained information will supplement the existing basic concepts on mechanisms involved in effects of proline-rich peptides of the innate immunity. This information will also stimulate biotechnological research aimed at development of new antibiotics for treatment of infectious diseases, such as severe in-hospital infections, caused by antibiotic-resistant strains.


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