scholarly journals Antimicrobial Activity of Nisin and Lysozyme on Foodborne Pathogens Listeria Monocytogenes, Staphylococcus Aureus, Salmonella Typhimurium, and Escherichia Coli at Different pH

2018 ◽  
Author(s):  
Hamdollah Moshtaghi ◽  
Azadeh Rashidimehr ◽  
Behzad Shareghi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Inhibitory Concentration ◽  
Low Ph ◽  
Bacteria Growth ◽  
Microdilution Method ◽  
Natural Preservatives

Background: To prevent or inhibit the growth of pathogenic microorganisms and food spoilage factors, many studies have been done by using natural preservatives. The aim of study was to investigate the effect of different concentrations of lysozyme and Nisin on the growth rate and also to determine the minimum inhibitory concentration (MIC) and minimum bactericidal cocentratiin (MBC) of these combinations on the bacteria of Escherichia coli, Staphylococcus aureus, Salmonella typhimorium and Listeria monocytogenes. Methods: In this study, various concentrations of lysozyme and Nisin were set in form of alone concentration and in combination concentrations (0, 19.53, 39.06, 78.13, 156.25, 312.5, 625, 1250, 2500, 5000) in vitro conditions and 6 pH 5.5, 6, 6.5, 7, 7.5, and 8. Microdilution method at 24°C was done and the combined effect on bacteria growth was read by using ELISA reader. Results: The results showed that lysozyme was less effective on Escherichia coli and Nisin was less effective on Listeria monocytogenes. Moreover, combining lysozyme and Nisin at low pH decreased the MIC. Conclusions: The results of the study showed that the effect of combining lysozyme and Nisin on Staphylococcus aureus is above all other bacteria and at low pH reduces the MIC.

scholarly journals In vitro combined effect of oregano essential oil and caprylic acid against Salmonella serovars, Escherichia coli O157:H7, Staphylococcus aureus and Listeria monocytogenes

2011 ◽  
Vol 80 (4) ◽  
pp. 343-348 ◽  
Author(s):  
Radka Hulánková ◽  
Gabriela Bořilová
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Essential Oil ◽  
Foodborne Pathogens ◽  
Caprylic Acid ◽  
Oregano Essential Oil ◽  
Combined Application ◽  
Broth Microdilution Method

In vitro inhibition of foodborne pathogens via action of natural antimicrobials – caprylic acid (CA) and essential oil from Origanum vulgare L. (OEO) with high carvacrol content (72%) was evaluated. For 15 Salmonella strains the minimum inhibitory concentration (MIC) determined by broth microdilution method ranged between 3.67–4.33 μl·ml-1 for CA and between 0.48–0.57 μl·ml-1 for OEO. For 7 Listeria monocytogenes strains the MIC ranged between 2.17–2.83 μl·ml-1 for CA and between 0.52–0.58 μl·ml-1 for OEO. Type strains of Escherichia coli O157:H7 and Staphylococcus aureus were tested, too, with MIC of CA 3.60 μl·ml-1 and 3.20 μl·ml-1 and MIC of OEO 0.51 μl·ml-1 and 0.48 μl·ml-1, respectively. Furthermore, it was found that the MIC of CA can be decreased by even low addition (0.05%) of citric or acetic acid and to a lesser extent by lactic acid, whereas the MICs of OEO did not notably decrease. Combined application of CA and OEO determined by FIC index led only to an additive effect (0.5 ≤ FIC ≤ 1). Combination of natural additives OEO, CA and eventually acetic or citric acid seems to have the potential to be an effective mixture for inhibition of foodborne pathogens, predominantly Salmonella spp. and L. monocytogenes, even in only slightly acidic food.

POTENCIAL ANTIBACTERIANO IN VITRO E TOXICOLÓGICO IN VIVO DAS FOLHAS DO JAMBO VERMELHO (Syzygium malaccensis, Myrtaceae) FRENTE A ZEBRAFISH (D. rerio) ADULTO

2021 ◽  
Author(s):  
Fernando E. T. Cunha ◽  
Maria I. C. Ferreira ◽  
Rafael S. Cruz ◽  
Maria J. G. Ferreira ◽  
Clarissa M. Aquino ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Danio Rerio ◽  
Salmonella Enteritidis

Este trabalho reporta o potencial antibacteriano in vitro e toxicológico in vivo das folhas do jambo (Syzygium malaccense) frente a zebrafish (Danio rerio) adulto (ZFa). As folhas de jambo foram submetidas a desidratação (35 ± 2°C) por 24 horas, trituração e posterior extração de metabólitos por decocção, infusão e maceração com água destilada. Os extratos obtidos foram liofilizados e submetidos a análise de atividade antibacteriana in vitro frente a Gram-negativas (Escherichia coli ATCC 25922, Salmonella Enteritidis IAL 1132) e Gram-positivas (Listeria monocytogenes ATCC 19115 e Staphylococcus aureus ATCC 27664), bem como ao potencial toxicológico in vivo frente ao ZFa. O extrato obtido por infusão se mostrou mais promissor, pois apresentou concentração mínima bactericida (CMB) e concentração mínima inibitória (CMI) com maior potencial frente às gram- positivas (CMB - 6,25 e CMI - 6,25 mg/ml), bem como às gram-negativas (CMB - 25,0 e 3,125 e CMI - 3,125 mg/ml). Todos os extratos testados não se mostraram tóxicos frente ao zebrafish adulto e não alteraram o sistema locomotor dos mesmos. Desta forma, conclui-se que o extrato aquoso das folhas do jambo vermelho (Syzygium malaccense) obtido por infusão é seguro e pode ser utilizado como conservante natural com maior ação antibacteriana. Este trabalho nos conduz a novos estudos de isolamento e caracterização de princípios bioativos.

Rosemary and Tea Tree Essential Oils Exert Antibiofilm Activities In Vitro against Staphylococcus aureus and Escherichia coli

2020 ◽  
Vol 83 (7) ◽  
pp. 1261-1267
Author(s):  
TING LIU ◽  
JINGFAN WANG ◽  
XIAOMAN GONG ◽  
XIAOXIA WU ◽  
LIU LIU ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Biofilm Formation ◽  
Gas Chromatography Mass Spectrometry ◽  
Tea Tree ◽  
E Coli ◽  
Microdilution Method ◽  
Broth Microdilution Method

ABSTRACT The purpose of the present study was to determine the bioactive compounds in rosemary essential oil (REO) and tea tree essential oil (TEO) and to investigate their antibacterial and antibiofilm activities against Staphylococcus aureus and Escherichia coli in vitro. The MIC and MBC assays were performed to assess the antibacterial activity of these two EOs against S. aureus and E. coli with the broth microdilution method. A crystal violet assay was used to ascertain the effects of EOs on the biofilm formation of the test strains, and a tetrazolium bromide (MTT) assay was used to measure the level of inactivation of mature biofilms by EOs. Gas chromatography–mass spectrometry revealed 15 compounds in REO and 27 compounds in TEO, representing 97.78 and 98.13% of the total EO, respectively. Eucalyptol and α-pinene were found in high concentrations in REO, and the two major compounds in TEO were 4-terpineol and terpinolene. The MICs of REO for the two S. aureus and E. coli test strains were both 0.5 mg/mL, and the MICs of TEO for the two strains were both 0.25 mg/mL. Therefore, these EOs can significantly inhibit the formation of biofilms and induced morphological biofilm changes, as verified by scanning electron microscopy. Both EOs had destructive effects on the mature biofilm of the two test strains. TEO was more inhibitory than REO for biofilm formation by the two test strains. HIGHLIGHTS

scholarly journals Avaliação in vitro de atividade antimicrobiana de peptídeos anfipáticos derivados de proteínas do soro de leite

2018 ◽  
Vol 16 ◽  
pp. 1 ◽  
Author(s):  
Jessica Audrey Feijó Corrêa ◽  
Chibuike Udenigwe ◽  
Fernando Bittencourt Luciano
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Fusarium Graminearum ◽  
Aspergillus Parasiticus ◽  
Fusarium Verticillioides

O objetivo deste estudo foi avaliar, in vitro, a atividade antimicrobiana de peptídeos anfipáticos derivados de proteínas do soro de leite contra importantes microrganismos patogênicos e toxigênicos. Para isto, foram testados dois peptídeos de 16 e 6 aminoácidos, de sequências HQPHQPLPPTVMFPPQ e KIPAVF respectivamente, frente às bactérias Salmonella Typhimurium, Staphylococcus aureus, Listeria monocytogenes e Escherichia coli, e frente aos fungos Aspergillus parasiticus, Fusarium verticillioides e Fusarium graminearum. Buscou-se determinar as concentrações inibitórias mínimas (CIMs) dos dois peptídeos contra os microrganismos utilizando o método de microdiluição em placas de 96 poços. Foram testadas doses de até 5000 mg.L-1 de cada peptídeo, contudo, não foi possível determinar suas CIMs frente aos patógenos e contaminantes testados. Analisando trabalhos similares com peptídeos e/ou lisados proteicos de soro de leite, percebe-se uma variação muito grande entre os resultados. Isso demonstra a divergência de bioatividade de peptídeos com diferentes sequências, além das possíveis diferentes respostas celulares a estas moléculas, tais como metabolização e alterações não-letais. Assim, conclui-se que os peptídeos aqui testados não são bons candidatos para aplicação na indústria de alimentos. Doses mais elevadas dos peptídeos não foram testadas, pois inviabilizaria sua aplicação em alimentos devido ao alto custo de obtenção.

scholarly journals Evaluation of the antibacterial and modulatory activities of ethanolic excract of Calotropis procera (Aiton) W.T. Aiton against multiresistant bacterial strains

2021 ◽  
pp. 205-209
Author(s):  
Yuri Geraldo ◽  
Livia Leandro ◽  
Ana Raquel Silva ◽  
Fábia Campina ◽  
Ana Carolina Araújo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Inhibitory Concentration ◽  
Ethanolic Extract ◽  
Calotropis Procera ◽  
Subinhibitory Concentration ◽  
Bacterial Strains ◽  
Resistant Species ◽  
Microdilution Method

The objective of this study was to evaluate the antibacterial and modulatory activities of ethanolic extract of Calotropis procera (Aiton) W.T. Aiton against resistant species. By microdilution method, the minimum inhibitory concentration (MIC) of the extract and modulation of the subinhibitory concentration MIC/8 to norfloxacine, gentamicin and imipenem against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. There was obtained 512 μg/mL to Pseudomonas aeruginosa. To Staphylococcus aureus, modulation showed synergism to norfloxacin and gentamicin, with imipenem against Pseudomonas aeruginosa and gentamicin against Escherichia coli. Based on these results, more studies are needed to test the antibacterial activity of the extract. El objetivo de este estudio fue evaluar la actividad antibacteriana y moduladora del extracto etanólico de Calotropis procera (Aiton) W.T. Aiton contra cepas multirresistentes de bacterias. Por el método de microdilución, fueron definidas la concentración inhibidora mínima (MIC) del extracto y la modulación con la concentración inhibidora CIM / 8 del extracto con norfloxacina, gentamicina e imipenem contra Staphylococcus aureus, Escherichia coli y Pseudomonas aeruginosa. Se obtuvo 512 μg/mL para Pseudomonas aeruginosa. Se descubrió sinergismo en el caso de Staphylococcus aureus, en la modulación con norfloxacina y gentamicina, mientras que con imipenem frente a Pseudomonas aeruginosa y con gentamicina para Escherichia coli. Con base en estos resultados, se necesitan más estudios para probar la actividad antibacteriana del extracto.

Étude in vitro des propriétés antioxydante, antiproliférative et antimicrobienne de Salvia clandestina du Maroc

2019 ◽  
Author(s):  
A. Et-Touys ◽  
A. Bouyahya ◽  
I. Bourais ◽  
N. Dakka ◽  
Y. Bakri
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Staphyloccocus Aureus

L’objectif de cette étude vise l’évaluation in vitro de l’activité antioxydante, antiproliférative et antimicrobienne des extraits organiques Salvia clandestina du Maroc. L’effet antioxydant est estimé par le test de balayage du radical DPPH. L’activité antiproliférative est évaluée sur deux lignées cellulaires cancéreuses en utilisant le test MTT. L’activité antimicrobienne est évaluée contre Escherichia coli, Staphyloccocus aureus et Listeria monocytogenes. L’extrait d’hexane et de dichlorométhane ont montré des capacités antioxydantes à l’IC50 = 118,28 ± 2,108 et 191,36 ± 2,72 μg/ml, respectivement. Alors que l’extrait méthanolique a montré une remarquable activité antiproliférative contre la lignée RD (IC50 = 86,24 μg/ml). Concernant l’activité antimicrobienne, les extraits hexanique et méthanolique sont plus actifs, alors que Staphylococcus aureus s’est montré la plus sensible. Vu les résultats obtenus, Salvia clandestina pourrait être considérée comme une source importante de molécules bioactives. Cependant, d’autres investigations sont nécessaires regardant les principes actifs responsables des effets pharmacologiques obtenus ainsi que l’investigation de l’action antibactérienne et anticancéreuse.

scholarly journals IN VITRO AND IN SILICO ANTIBACTERIAL ACTIVITY OF 1.5-BIS (3’-ETHOXY-4’-HYDROXYPHENYL)-1-4-PENTADIENE-3-ONE

2018 ◽  
Vol 10 (5) ◽  
pp. 70
Author(s):  
Agus Purwanggana ◽  
Esti Mumpuni ◽  
Esti Mulatsari
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Staphylococcus Epidermidis ◽  
In Silico ◽  
Inhibitory Concentration ◽  
Inhibition Zone ◽  
Antibacterial Study

Objective: The main objective of this research were screened in vitro and in silico of 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one as potential antibacterial agents.Methods: The in vitro antibacterial study was carried against Staphylococcus aureus, Staphylococcus epidermidis (gram positive) and Escherichia coli, Salmonella thypi (gram negative) using broth dilution method to determine Minimum Inhibitory Concentration (MIC), disc diffusion method to determine the diameter of inhibition zone. In silico antibacterial study was carried using computational software Protein-Ligand ANT System (PLANTS), computational docking was carried using receptor with Protein Data Bank (PDB) file 3MZD. The structures were optimized prior docking using YASARA, and MarvinSketch. The results of antibacterial testing were compared to two positive control drugs i. e amoxicillin and cefadroxil.Results: In vitro evaluation showed that 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one has a better antibacterial activity than amoxicillin and cefadroxil with a Minimum Inhibitory Concentration (MIC) of 0.15 ppm and diameter of inhibition zone of 11.27±0.31, 11.35±0.39, 11.25±0.33, and 11.05±0.45 mm in Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Salmonella thypi, respectively. These results in line with in silico evaluation that showed 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one has more negative docking score than amoxicillin, cefadroxil, and cloxacillin acyl as a native ligand on the 3MZD receptor.Conclusion: This results obtained in this research work were 1,5-bis (3'-ethoxy-4'-hydroxyphenyl)-1,4-pentadiene-3-one compound potential as an antibacterial agent. 

Inhibition and Inactivation of Five Species of Foodborne Pathogens by Chitosan

1992 ◽  
Vol 55 (11) ◽  
pp. 916-919 ◽  
Author(s):  
GUANG-HUA WANG
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Acetic Acid ◽  
Listeria Monocytogenes ◽  
Salmonella Typhimurium ◽  
Yersinia Enterocolitica ◽  
Foodborne Pathogens ◽  
E Coli ◽  
No Inhibition

Inhibition and inactivation of five species of foodborne pathogens (Staphylococcus aureus, Escherichia coli, Yersinia enterocolitica, Listeria monocytogenes, and Salmonella typhimurium) by chitosan were studied. Nutrient broths were supplemented with 0, 0.5, 1.0, 1.5, 2.0, and 2.5% chitosan, adjusted to pH 6.5 or 5.5 with 2% acetic acid, and incubated at 30°C. The outgrowths of these bacteria were observed. At pH 6.5, in general, antibacterial activity of chitosan was relatively weak. The effectiveness of chitosan against S. aureus was greatest, followed by S. typhimurium, E. coli, and Y. enterocolitica. As the concentration of chitosan increased, the effectiveness of chitosan against these four species of pathogens also increased. No inhibition of L. monocytogenes by chitosan occurred. At pH 5.5, presence of chitosan inactivated these pathogens except that 0.5% chitosan did not affect the growth of S. typhimurium. Thus, the antibacterial activity of chitosan was stronger at pH 5.5 than at pH 6.5.

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