scholarly journals Silver Nanoparticles Synthesized by Using the Endophytic Bacterium Pantoea ananatis are Promising Antimicrobial Agents against Multidrug Resistant Bacteria

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3220 ◽  
Author(s):  
Tahmina Monowar ◽  
Md. Rahman ◽  
Subhash Bhore ◽  
Gunasunderi Raju ◽  
Kathiresan Sathasivam

Antibiotic resistance is one of the most important global problems currently confronting the world. Different biomedical applications of silver nanoparticles (AgNPs) have indicated them to be promising antimicrobial agents. In the present study, extracellular extract of an endophytic bacterium, Pantoea ananatis, was used for synthesis of AgNPs. The synthesized AgNPs were characterized by UV–Vis spectroscopy, FTIR, transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), and Zeta potential. The antimicrobial potential of the AgNPs against pathogenic Staphylococcus aureus subsp. aureus (ATCC 11632), Bacillus cereus (ATCC 10876), Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 10145) and Candida albicans (ATCC 10231), and multidrug resistant (MDR) Streptococcus pneumoniae (ATCC 700677), Enterococcus faecium (ATCC 700221) Staphylococcus aureus (ATCC 33592) Escherichia coli (NCTC 13351) was investigated. The synthesized spherical-shaped AgNPs with a size range of 8.06 nm to 91.32 nm exhibited significant antimicrobial activity at 6 μg/disc concentration against Bacillus cereus (ATCC 10876) and Candida albicans (ATCC 10231) which were found to be resistant to conventional antibiotics. The synthesized AgNPs showed promising antibacterial efficiency at 10 µg/disc concentration against the MDR strains. The present study suggests that AgNPs synthesized by using the endophytic bacterium P. ananatis are promising antimicrobial agent.

2019 ◽  
Vol 9 (04) ◽  
pp. 678-681
Author(s):  
Ashraf S Hassan ◽  
Khawlah J Khalaf ◽  
Hamzia A Ajah

The present study demonstrates the effect of storage period on silver nanoparticles (AgNPs), which synthesized by Pseudomonas aeruginosa and their antibacterial activity. The result shows that the size of (AgNPs) which synthesis by Pseudomonas aeruginosa was 93.55nm after 4-72hour, and when storage about 2 years, we found that the size of AgNPs was stable and reduced to 69.0nm. Antibacterial activity against pathogenic microbes: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Serratia sp,Streptococcus sp , Klebsiella sp, Candida albicans was performed before and after storage and found that AgNPs have activity against this microbes.


2019 ◽  
Author(s):  
I. Sifi ◽  
M. Yousfi

L’activité antimicrobienne des huiles essentielles de galles de Pistacia atlantica récoltées dans trois régions (Aïn-Oussara, Laghouat et Kheneg) a été évaluée sur sept souches pathogènes (Escherichia coli, Bacillus cereus, Pseudomonas aeruginosa, Staphylococcus aureus, MRSA+, Salmonella typhi et Candida albicans), en utilisant les méthodes de diffusion sur gélose, de microdilution et celle de microatmosphère (seulement pour Candida albicans). Les huiles essentielles ont révélé un effet antimicrobien remarquable contre les micro-organismes testés, avec des valeurs de CMI et de CMB variant de 0,13 à 7,99 μl/ml et de 0,25 à 7,99 μl/ml, respectivement. Une activité importante a été observée pour les échantillons de la station Kheneg contre l’espèce Candida albicans avec une zone d’inhibition de 68 mm (50 μl). Ces résultats suggèrent que les huiles essentielles testées pour leur activité antimicrobienne peuvent être classées comme bactéricides.


Author(s):  
Rajanikanth Garapati ◽  
N. Ramesh

Objective: In vitro investigated the potential of methanol extracts of micro-propagated C. orchiodes in the antimicrobial property against the three gram-negative bacteria, two gram-positive and one fungal filament.Methods: The micro propagated callus methanol extract was examined against Escherichia coli, Proteus vulgaris, Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus and Candida albicans. The zone of inhibitions are determined at 10 mg/ml concentration of methanol extracts of callus on agar well plate and MIC against tested microorganism.Results: The highest antibacterial activity recorded in Staphylococcus aureus Bacillus cereus and followed by Candida albicans. Antibacterial activity of leaf extracts of A. reticulata was also significant against the tested microorganisms Escherichia coli, Salmonella typhi, Proteus vulgaris, Pseudomonas aeruginosa compared to ciprofloxacin.Conclusion: Based on the above observations, these extracts were further evaluated for their effect on microorganisms causing infections like typhoid fever, urinary tract infections, septicemia, toxic shock syndrome, skin infection, nosocomial infection, arthritis and diarrhoea. The results also suggest that these plants serve a therapeutic purpose in the treatment bacterial infections.


Medicina ◽  
2011 ◽  
Vol 47 (3) ◽  
pp. 24 ◽  
Author(s):  
Vilma Jurkštienė ◽  
Alvydas Pavilonis ◽  
Daiva Garšvienė ◽  
Algirdas Juozulynas ◽  
Laimutė Samsonienė ◽  
...  

The aim of the study was to determine antimicrobial activity of rhaponticum and shrubby cinquefoil extracts. Material and Methods. Ethanol extract from the leaves of rhaponticum (Rhaponticum carthamoides D.C. Iljin) and shrubby cinquefoil (Potentilla fruticosa L.) was produced at the Department of Food Technology, Kaunas University of Technology. The antimicrobial activity of the viscous extract or rhaponticum and shrubby cinquefoil was evaluated using standard microorganism cultures (bacteria Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 33499, Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis ATCC 12459, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 8035 and fungi Candida albicans ATCC 60193). The minimum inhibitory concentration (MIC) of the examined preparations was determined. Results. Both studied preparations – rhaponticum (Rhaponticum carthamoides D.C. Iljin) and shrubby cinquefoil (Potentilla fruticosa L.) – demonstrated similar antimicrobial activity. The highest sensitivity to the studied preparations was observed in microbes with eukaryotic cell structure: Candida albicans, which is a fungus, and a spore-forming prokaryotic bacterium, Bacillus cereus. The highest resistance was observed in Escherichia coli and Klebsiella pneumoniae. Conclusions. The studied preparations – viscous extracts of rhaponticum and shrubby cinquefoil – are substances with antimicrobial activity against gram-positive (Staphylococcus aureus and Enterococcus faecalis) and gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis) bacteria, spore-forming bacteria (Bacillus subtilis and Bacillus cereus), and fungi (Candida albicans).


2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Rodrigo Luiz Fabri ◽  
Paula Spagnol Da Cunha ◽  
Lara Melo Campos ◽  
Ari Sérgio de Oliveira Lemos ◽  
Elaine Soares Coimbra ◽  
...  

Este presente estudo teve como objetivo investigar o potencial antimicrobiano, leishmanicida e citotóxico do extrato em diclorometano das partes aéreas de Mitracarpus frigidus. Além de identificar as principais classes de metabólitos especiais desse extrato. Para realização dos ensaios biológicos foram testadas nove linhagens de microrganismos (Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium, Shigella sonnei, Klebsiella pneumoniae, Escherichia coli, Bacillus cereus, Candida albicans e Cryptococcus neoformans), duas espécies de Leishmanias (L. amazonensis e L. chagasi). A citotoxicidade foi testada frente ao microcrustáceo Artemia salina. Os resultados mostraram que o extrato em diclorometano apresentou expressiva atividades leishmanicida, frente a ambas formas promastigotas das espécies de Leishmanias, e antimicrobiana, principalmente contra B. cereus e C. neoformans. O ensaio de bioautografia identificou que as classes que possuem atividade antifúngica foram alcaloides e triterpenos. Os resultados apresentados abrem perspectivas para o futuro isolamento, purificação e identificação das substâncias bioativas de Mitracarpus frigidus que possam ser utilizadas no tratamento de infecções microbianas e leishmanioses.


2020 ◽  
Vol 24 (9) ◽  
pp. 1519-1522
Author(s):  
A. Banso ◽  
B.F. Banso ◽  
A.A. Koleola

As a result of the development of resistance of microorganisms to older antimicrobial agents there is need for a search for new agents, which are effective for the treatment of infections. The crude aqueous and alcoholic extr acts of Garcinia kola fruits were assayed against Staphylococcus aureus, Bacillus cereus, Escherichia coli and Klebsiella pneumoniae. The results revealed that the plant extracts possess inhibitory effect against the microorganisms tested. The minimum inhibitory concentration of the plant extracts ranged between 20mg/ml and 45mg/ml. There was a change in the antibacterial activity of the test extracts on variation of temperature. The results obtained may suggest that the plant extract is thermal stable and could serve as a source of industrial drugs useful in chemotherapy of some microbial infections. Keywords: Garcinia kola, microorganisms, inhibitory, chemotherapy, drug


2017 ◽  
Vol 5 (2) ◽  
Author(s):  
Camila Kunz Zamprogna ◽  
Chariane Werlang ◽  
Raquel Zeni Ternus

Organismos aquáticos são reconhecido como potenciais reservatórios de produtos naturais biativos. Neste contexto, cianobactérias tem surgido como uma fonte promissora destes compostos. O objetivo deste trabalho foi estudar características biológicas e potencial biotecnológico de metabólitos secundários de cianobactérias isoladas em ambientes hídricos da região oeste catarinense. As amostras foram coletadas em ambientes naturais, em zona urbana e zona rural. Os cultivos foram feitos em meio BG-11 e os testes de atividade antimicrobiana realizados pelo de teste de capacidade antimicrobiana por disco difusão. O ensaio foi realizado em Placa com Ágar Mueller  testando os isolados de cianobactérias frente a 5 micro-organismos (Bacillus cereus, Salmonella Typhimurium, Staphylococcus aureus, Escherichia coli, Candida albicans). Resultados de halos de inibição, variando de 7 a 14 mm foram obtidos para Staphylococcus aureus, indicando o potencial bioativo. 


2021 ◽  
Vol 4 (1) ◽  
pp. 40-42
Author(s):  
Hajarat Yusuf ◽  
Joshua Olu

The antimicrobial effect of aqueous extract of lemongrass (Cymbopogon citratus) on some isolated microorganisms under varying parameters was investigated. Aqueous extract of lemongrass was prepared and its antimicrobial effect was evaluated against isolated bacteria (Staphylococcus aureus, Escherichia coli and Bacillus cereus) and fungi (Aspergillus flavus and Candida albicans) at varying temperature (40, 60 and 800C) and concentration (10-1, 10-2, 10-4, 10-8 and 10-16 mol/L) of the lemongrass aqueous extract shows that the extract was resisted by Escherichia coli, Bacillus cereus, Aspergillus flavus and Candida albicans. The aqueous C. citratus was able to inhibit the growth of Staphylococcus aureus and this inhibition increases as the concentration of the aqueous extract increase irrespective of the temperature of extraction. The aqueous extract of C. citratus is a tremendous antimicrobial substance especially towards Staphylococcus aureus.


Author(s):  
Katarzyna Modrzejewska ◽  
Elżbieta Bogusławska-Wąs

Celem niniejszej pracy było określenie poziomu wybranych mikroorganizmów, porównanie zawartości polifenoli i antocyjanów oraz zdolności przeciwutleniającej napojów kombucha dostępnych w handlu detalicznym z napojem wytworzonym doświadczalnie metodą tradycyjną. Badania objęły 12 napojów komercyjnych oraz jeden uzyskany doświadczalnie, którego bazą była zielona herbata z 10-procentowym dodatkiem sacharozy. W badanych produktach oznaczono: liczbę bakterii Acetobacter sp., Gluconobacter sp., LAB i drożdży, pH, ogólną zawartość antocyjanów, ogólną zawartość polifenoli oraz aktywność przeciwutleniającą. Aktywność przeciwdrobnoustrojową napojów kombucha oceniono metodą dyfuzyjną, z zastosowaniem kolumienek, w stosunku do szczepów wzorcowych: Escherichia coli ATCC 35218, Listeria monocytogenes serotyp 1/2a (KMSiFŻC), Yersinia entercolitica (PCM 1919), Salmonella enteritidis (ATCC 130764), Bacillus cereus (PCM 2019), Enterococcus faecalis (ATTC 29212), Staphylococcus aureus (ATTC 25923), Saccharomyces cerevisiae (ŁOCK 14), Candida albicans (KMSiFŻC). Stwierdzono, że napoje deklarowane jako pasteryzowane (K7 - K12) były pozbawione mikroorganizmów z analizowanych grup. W pozostałych produktach komercyjnych dominującym mikroorganizmem były bakterie Acetobacter sp., których liczba zawierała się w przedziale 6 × 106 ÷ 1,1 × 107 jtk/ml. W napoju doświadczalnym wykazano drożdże w ilości 6,5 × 105 jtk/ml. Odczyn pH produktów był charakterystyczny i nie przekraczał 4,3. Zawartość antocyjanów we wszystkich napojach pochodzących z handlu wahała się między 0,2 ÷ 0,3 mg/dl, natomiast w próbie doświadczalnej było ich ponad dwa razy więcej. Zawartość polifenoli oraz zdolność przeciwutleniająca prób były zróżnicowane i nie stwierdzono ich korelacji z pochodzeniem produktu. Głównym czynnikiem warunkującym zdolność napojów kombucha do inhibicji bakterii potencjalnie chorobotwórczych dla człowieka jest obecność kwasów organicznych. Żaden z badanych napojów nie wykazywał antagonizmu w stosunku do testowanych drożdży.


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