scholarly journals Antimicrobial Activity of Xoconostle Pears (Opuntia matudae) againstEscherichia coliO157:H7 in Laboratory Medium

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Saeed A. Hayek ◽  
Salam A. Ibrahim
Keyword(s):  
Antimicrobial Activity ◽  
Brain Heart Infusion ◽  
Inhibitory Effect ◽  
E Coli ◽  
Laboratory Medium ◽  
Safety Risks ◽  
Strain Dependent ◽  
Natural Means ◽  
Over Time ◽  
Pathogenic Contamination

The objective of this study was to investigate the antimicrobial activity of xoconostle pears (Opuntia matudae) againstEscherichia coliO157:H7. Xoconostle pears were sliced, blended, and centrifuged. The supernatant was then filtered using a 0.45 μm filter to obtain direct extract. Direct extract of xoconostle pears was tested against four strains ofE. coliO157:H7 in brain heart infusion (BHI) laboratory medium using growth over time and agar well diffusion assays. Our results showed that direct extract of xoconostle pears had a significant (P<0.05) inhibitory effect at 4, 6, and 8% (v/v) concentrations and complete inhibitory effect at 10% (v/v) during 8 h of incubation at 37°C. Minimum inhibitory volume (MIV) was 400 μL mL−1(v/v) and minimum lethal volume (MLV) was 650 μL mL−1(v/v). The inhibitory effect of xoconostle pears found to be concentration dependent and not strain dependent. Thus, xoconostle pears extract has the potential to inhibit the growth ofE. coliO157:H7 and could provide a natural means of controlling pathogenic contamination, thereby mitigating food safety risks.

scholarly journals Synthesis, Characterisation and Antimicrobial Potential of Novel N-Alkylated Pyrrole Derivatives of Chitosan

2021 ◽  
Vol 14 (4) ◽  
pp. 1730-1736
Author(s):  
Kalpana. P. R
Keyword(s):  
Antimicrobial Activity ◽  
Inhibitory Effect ◽  
Maximum Activity ◽  
Diffusion Method ◽  
Zone Of Inhibition ◽  
Pyrrole Derivatives ◽  
Structural Modifications ◽  
E Coli ◽  
Antimicrobial Potential ◽  
Derivatives Of

Chitosan, a cationic biopolymer is a major derivative of chitin. It is biocompatible, non-toxic and environ-friendly material and has broad spectrum antimicrobial activity. However, it is less effective in neutral or basic conditions due to its solubility only in acidic medium. Therefore, chemical modification with suitable groups is necessary to enhance the potency of chitosan. The present study was mainly conducted to explore the effect of structural modifications on antimicrobial potential of chitosan. N-Methyl, N-Ethyl and N-Propyl pyrrole were reacted with N-chloroacyl-6-O-triphenylmethylchitosan prepared by stepwise modification of chitosan to form N-Methyl, N-Ethyl and N-Propyl pyrrole derivatives of chitosan. Structural characterization of these pyrrole derivatives was done by IR, NMR, XRD, DSC and Elemental Analysis. The gram-negative bacterium Escherichia coli, gram-positive bacterium Staphylococcus aureus were selected for antibacterial activity and the fungus C. albicans was selected for antifungal activity by agar diffusion method and MIC method. Antimicrobial activity of the N-Methyl, N-Ethyl and N-Propyl pyrrole derivatives on E. coli, S. aureus and C. albicans showed an inhibitory effect on all the organisms. The potency of inhibition was found to be varied with the substitutions. The maximum activity was shown by N-pyrrolylpropylchitosan against E. coli (zone of inhibition 1.2±0.05cm, MIC 0.15±0.03mg/ml), S. aureus (zone of inhibition 1.4±0.03cm, MIC 0.15±0.01mg/ml), C. albicans (zone of inhibition 0.8±0.03cm, MIC 0.2±0.03mg/ml). The study also confirmed that all the three derivatives exhibited higher inhibition than that of chitosan against E. coli (zone of inhibition 0.7±0.03cm, MIC 0.09±0.02mg/ml), S. aureus (zone of inhibition 0.8±0.03cm, MIC 0.09±0.02mg/ml), C. albicans (zone of inhibition 0.6±0.03cm, MIC 0.09±0.03mg/ml). Results demonstrated that these three N-alkylpyrrole chitosan derivatives exhibited improved potency and hence can have the more applicability as antimicrobials.

scholarly journals Antimicrobial Activity of Lactic Acid Bacteria Starters against Acid Tolerant, Antibiotic Resistant, and Potentially Virulent E. coli Isolated from a Fermented Sorghum-Millet Beverage

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Stellah Byakika ◽  
Ivan Muzira Mukisa ◽  
Robert Mugabi ◽  
Charles Muyanja
Keyword(s):  
Antimicrobial Activity ◽  
Antibiotic Resistance ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Brain Heart Infusion ◽  
Antimicrobial Effect ◽  
Effective Control ◽  
Fermented Foods ◽  
E Coli ◽  
Acid Stable

Bacterial contamination of fermented foods is a serious global food safety challenge that requires effective control strategies. This study characterized presumptive E. coli isolated from Obushera, a traditional fermented cereal beverage from Uganda. Thereafter, the antimicrobial effect of lactic acid bacteria (LAB) previously isolated from Obushera, against the E. coli, was examined. The presumptive E. coli was incubated in brain heart infusion broth (pH = 3.6) at 25°C for 48 h. The most acid-stable strains were clustered using (GTG)5 rep-PCR fingerprinting and identified using 16S rRNA sequencing. E. coli was screened for Shiga toxins (Stx 1 and Stx 2) and Intimin (eae) virulence genes as well as antibiotic resistance. The spot-on-the-lawn method was used to evaluate antimicrobial activity. Eighteen isolates were acid stable and are identified as E. coli, Shigella, and Lysinibacillus. The Stx 2 gene and antibiotic resistance were detected in some E. coli isolates. The LAB were antagonistic against the E. coli. Lactic acid bacteria from traditional fermented foods can be applied in food processing to inhibit pathogens. Obushera lactic acid bacteria could be used to improve the safety of fermented foods.

Antimicrobial Properties of Pepsin-Digested Lactoferrin Added to Carrot Juice and Filtrates of Carrot Juice

2000 ◽  
Vol 63 (3) ◽  
pp. 376-380 ◽  
Author(s):  
PANITA CHANTAYSAKORN ◽  
R. L. RICHTER
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Properties ◽  
Skim Milk ◽  
Test Organism ◽  
Inhibitory Effect ◽  
Culture Collection ◽  
Carrot Juice ◽  
E Coli ◽  
Esherichia Coli ◽  
Organism Growth

The objective of this study was to determine the antimicrobial activity of pepsin-digested lactoferrin added to carrot juice and filtrates prepared from carrot juice. Lactoferrin isolated from raw skim milk was digested by pepsin for 4 h at pH 3. The digest of lactoferrin was lyophilized, and the antimicrobial activity of the digests was determined in peptone-yeast-glucose broth, carrot juice, permeate from carrot juice, and the dialysate of carrot juice permeate using Esherichia coli (American Type Culture Collection strain 35343) as the test organism. Growth of E. coli and the inhibitory effect of the peptide were greater in peptone-yeast-glucose broth at pH 7 than at pH 4. The peptic digest of lactoferrin did not have antimicrobial properties in carrot juice at concentrations of less than 10 mg/ml of juice. Carrot juice was filtered through a membrane with a molecular weight rejection of 10,000 or 500 Da, and the permeate was dialyzed against distilled water. Growth of E. coli was delayed in the filtrate by 5 mg but not by 1 mg of the peptic digest of lactoferrin per ml of filtrate. Bacterial counts of the control and experimental samples were not significantly different after 24 h of incubation. The peptic digest of lactoferrin at a concentration of 5 mg of digest per ml of dialysate was bacteriostatic toward E. coli after 24 h of incubation at 23°C. Dialysis of permeate caused a percentage reduction in cation concentration in the permeate ranging from 69.23% (Co) to 99.32% (Na). The antimicrobial activity of lactoferrin added to carrot juice was probably inhibited by cations.

scholarly journals An Investigation of Stability and Species and Strain-Level Specificity in Bacterial Volatilomes

2021 ◽  
Vol 12 ◽  
Author(s):  
Shane Fitzgerald ◽  
Linda Holland ◽  
Aoife Morrin
Keyword(s):  
Solid Phase ◽  
Brain Heart Infusion ◽  
Strain Level ◽  
Growth Media ◽  
E Coli ◽  
The Future ◽  
Degree Of Stability ◽  
The Stability ◽  
High Degree ◽  
Strain Dependent

Microbial volatilomics is a rapidly growing field of study and has shown great potential for applications in food, farming, and clinical sectors in the future. Due to the varying experimental methods and growth conditions employed in microbial volatilomic studies as well as strain-dependent volatilomic differences, there is limited knowledge regarding the stability of microbial volatilomes. Consequently, cross-study comparisons and validation of results and data can be challenging. In this study, we investigated the stability of the volatilomes of multiple strains of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli across three frequently used nutrient-rich growth media. Volatilomic stability was assessed based on media-, time- and strain-dependent variation across the examined bacterial volatilomes. Strain-level specificity of the observed volatilomes of E. coli and P. aeruginosa strains was further investigated by comparing the emission of selected compounds at varying stages of cell growth. Headspace solid phase microextraction (HS-SPME) sampling coupled with gas chromatography mass spectrometry (GC-MS) was used to analyze the volatilome of each strain. The whole volatilomes of the examined strains demonstrate a high degree of stability across the three examined growth media. At the compound-level, media dependent differences were observed particularly when comparing the volatilomes obtained in glucose-containing brain heart infusion (BHI) and tryptone soy broth (TSB) growth media with the volatilomes obtained in glucose-free Lysogeny broth (LB) media. These glucose-dependent volatilomic differences were primarily seen in the emission of primary metabolites such as alcohols, ketones, and acids. Strain-level differences in the emission of specific compounds in E. coli and P. aeruginosa samples were also observed across the media. These strain-level volatilomic differences were also observed across varying phases of growth of each strain, therefore confirming that these strains had varying core and accessory volatilomes. Our results demonstrate that, at the species-level, the examined bacteria have a core volatilome that exhibits a high-degree of stability across frequently-used growth media. Media-dependent differences in microbial volatilomes offer valuable insights into identifying the cellular origin of individual metabolites. The observed differences in the core and accessory volatilomes of the examined strains illustrate the complexity of microbial volatilomics as a study while also highlighting the need for more strain-level investigations to ultimately elucidate the whole volatilomic capabilities of microbial species in the future.

scholarly journals Evaluation of antimicrobial activity of magnesium oxide nanocomposite film in combination with ε-poly-L-lysine against Foodborne pathogens in vacuum packaged beef

2021 ◽  
Author(s):  
Masumeh Samadi ◽  
Seyed Shahram Shekarforoush ◽  
Hamid Reza Gheisari
Keyword(s):  
Antimicrobial Activity ◽  
Magnesium Oxide ◽  
Culture Media ◽  
Antimicrobial Effect ◽  
Inhibitory Effect ◽  
Melt Mixing ◽  
E Coli ◽  
Mgo Nanoparticle

Abstract Background: The aim of this study was to evaluate the antimicrobial activity of magnesium oxide nanocomposite (MgO NC) film based on Low-density polyethylene (LDPE) alone or in combination with three concentrations of ε-poly-L-lysine (500, 1000 and 2000 µg/ml) on Escherichia coli O157:H7 and Listeria monocytogenes in culture media and fresh beef. Methods: MgO NC film were prepared by melt mixing LDPE and MgO nanoparticle in the extruder. For in vitro antibacterial analysis, the MgO NC film alone or in combination with polylysine were evaluated in tryptic soy broth for 5 days at 37 °C. For in vivo analysis, beef samples were inoculated with the selected bacteria and packaged in MgO NC film under vacuum and stored at 4 °C and evaluated for up to 20 days. Results: Polylysine had an antibacterial effect against E. coli and L. monocytogenes in TSB. But MgO NC film had a bacteriostatic effect only against E. coli. MgO NC film inhibited the growth of E. coli on the surface of beef samples. Pollysine at concentrations of 500 µg/ml or more showed inhibitory activity against E. coli and L. monocytogenes in beef samples. No additional reduction was observed by combining the different concentrations of polylysine with MgO NC film.Conclusions: Polylysine at all concentrations had an inhibitory effect on E. coli and L. monocytogenes in the culture medium and beef. Although the migration of MgO nanoparticle from the film to beef was very low, but as it has little antimicrobial effect, it is not recommended as a suitable package for improving the safety of raw beef.

scholarly journals Antimicrobial Activity of Copper Alone and in Combination with Lactic Acid againstEscherichia coliO157:H7 in Laboratory Medium and on the Surface of Lettuce and Tomatoes

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Rabin Gyawali ◽  
Salam A. Ibrahim ◽  
Salma H. Abu Hasfa ◽  
Shahnaz Q. Smqadri ◽  
Yosef Haik
Keyword(s):  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Growth Inhibition ◽  
Combination Treatment ◽  
Bacterial Population ◽  
Effective Solution ◽  
E Coli ◽  
Laboratory Medium ◽  
Effect Of Copper ◽  
Significant Growth Inhibition

The objective of this study was to evaluate the effect of copper alone and in combination with lactic acid againstE. coliO157:H7 in laboratory medium and on the surface of lettuce and tomatoes. Four strains ofE. coliO157:H7 were individually inoculated into BHI broth containing different concentrations of copper (5, 10, 20, and 40 ppm, w/v), lactic acid (0.1 and 0.2%, v/v), and their combinations. After incubation, aliquots of 1 mL from each sample were withdrawn and plated on BHI agar to determine the bacterial population. Significant growth inhibition (P<0.05) was observed with a combination treatment of copper (40 ppm) and lactic acid (0.2%). The population ofE. coliO157:H7 was reduced by 3.93 and 3.39 log on the surface of lettuce and tomato samples, respectively, when treated with the same combination. This indicates that combination of copper and lactic acid could be used as an effective solution to inhibitE. coliO157:H7 on fresh produce.

scholarly journals Antimicrobial activity of novel 1-[(2,4-(di-tert-butylphenoxy))-3-dialkylamino-2-propanol] derivativesy

2021 ◽  
Vol 2 (3) ◽  
pp. 27-33
Author(s):  
Nina VRYNCHANU ◽  
Yurii KOROTKIJ ◽  
Nataliia HRYNCHUK ◽  
Irina BOIKO ◽  
Elena SMERTENKO ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
High Efficiency ◽  
Gentian Violet ◽  
Inhibitory Effect ◽  
Chronic Infections ◽  
E Coli ◽  
External Stresses ◽  
Antibacterial And Antifungal ◽  
New Compounds ◽  
Adsorption Desorption

Introduction. The microbial biofilm-forming ability is one of the major aspects of the emerging issue of antibiotic resistance, which makes them tolerant to antibiotics and host defense systems and other external stresses, thus contributing to persistent chronic infections. A series of relevant studies confirmed the high efficiency of aminopropanol derivatives as potential antibacterial and antifungal agents. This present study was aimed to evaluate the antimicrobial activity of new 1-[(2,4-(di-tert-butylphenoxy))-3-dialkylamino-2-propanol] derivatives on the planktonic bacterial/fungal cells and biofilms. Material and methods. The minimum inhibitory concentrations (MIC) of the new compounds were determined by a standard method, along with their effects on biofilms estimated via the gentian violet adsorption-desorption assay.Results. The КVM-219 compound showed the most pronounced effect on planktonic bacterial and fungal cells. The MIC values ranged between 0.78 μg/mL to 12.5 μg/mL, depending on the microbial strain. The KVM-316 compound exhibited the strongest inhibitory effect on biofilms, thus preventing their formation by S. aureus (96.1%), E. coli (57.2%), and P. aeruginosa (96.1%). Conclusions. The 15 newly synthesized 1-[(2,4-(di-tert-butylphenoxy))-3-dialkylamino-2-propanol] derivatives revealed marked antibacterial and antifungal effects on planktonic microorganisms. Most of these compounds showed a strain-specific inhibition of biofilm formation by at least 50% for S. aureus 222, E. coli 311, P. aeruginosa 449 and C. glabrata 404 strains.

scholarly journals Antibacterial Activity and Chemical Composition of Essential Oils from Some Galium (Rubiaceae) Species Against Pathogenic Bacteria

2017 ◽  
Vol 5 (11) ◽  
pp. 1330
Author(s):  
Filiz Yağız ◽  
Rifat Battaloğlu ◽  
Sedef İlk ◽  
Ahmet Savran
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Essential Oils ◽  
Pseudomonas Syringae ◽  
Pathogenic Bacteria ◽  
Inhibitory Effect ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Potent Inhibitory Effect

In this work, chemical composition and antimicrobial activity of the essential oils of Galium incanum, Galium dieckii ve Galium aladaghense were firstly reported. The essential oils were obtained from the all parts of the plant by hydrodistillation and analyzed by using GC-MS. Antimicrobial activity of synthezied essential oils was carried out against 5 pathogen bacteria Escherichia coli (E. coli) ATCC 25922, Staphylococcus aureus (S. aureus) ATCC 25923, Pseudomonas syringae pv. tomato (P. syringae) DC300, Salmonella enterica serotype Typhmurium (S. typhmurium) SL 1344 and Streptococcus mutans (S. mutans) ATCC 25175. According to the results, it was determined that isolated essential oils comprised of 61 compounds. Compounds of essential oils included that structure monoterpene (8.2%), monoterpenoid (14.75%) and sesquiterpene (14.75%). Unclassified compounds have been identified as other compounds. From the antimicrobial activity was observed that the isolated essential oil from Galium incanum, Galium dieckii ve Galium aladaghense exhibited a potent inhibitory effect against all gram negative and gram positive bacteria with diameter of inhibition zones ranging from 4.3 to 12.3 mm. Essential oil of Galium aladaghense indicated that high antimicrobial activity on all bacteria than Galium incanum and Galium dieckii.

scholarly journals Estudo da Atividade Antimicrobiana das Folhas de Jatrophacurcas L. frente ao Staphylococcus aureus e Escherichia coli/ Study of Antimicrobial Activity of Leave of Jatropha curcas L. against Staphylococcus aureus and Escherichia coli

1970 ◽  
Vol 3 (2) ◽  
pp. 18-24
Author(s):  
Amanda Venturini Arantes ◽  
Mariléia Chaves Andrade ◽  
Nilo César do Vale Baracho
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Jatropha Curcas ◽  
Inhibitory Effect ◽  
Minas Gerais ◽  
University Hospital ◽  
E Coli ◽  
Jatropha Curcas L ◽  
Mueller Hinton

Objetivos: O presente estudo investigou a atividade antimicrobiana do extrato obtido das folhas de Jatropha curcas L., frente às bactérias Staphylococcus aureus e Escherichia coli isoladas de pacientes de um Hospital Escola do sul de Minas Gerais. Metodologia: Foi realizado o teste da Microdiluição em placas de 96 poços. Colocou-se 50µl de Ágar Mueller Hinton em todos os poços, seguidos de 50µl do extrato da planta em diferentes concentrações (25 a 200 mg/mL) nas colunas apropriadas e em seguida, 10µl de cada cepa bacteriana na concentração de 0,5 de McFarland em solução salina estéril. Seguiu-se a incubação em estufa de 35ºC por 24h. Posteriormente, realizou-se a revelação pela adição de 20 µL de Cloreto de Trifenil Tetrezólico e análise dos resultados pela coloração. Em cada placa foi realizado um controle positivo e negativo. Resultados: Houve efeito inibitório do crescimento microbiano de S. aureus e E. coli perante extratos de Jatropha Curcas L. nas concentrações de 50mg a 200mg. Apenas na concentração de 25mg não houve efeito inibitório diante de E. coli e S. aureus. Conclusão: O extrato bruto de Jatropha curcas L. apresentou atividade inibitória do crescimento de colônias de Staphylococcus aureus e Escherichia coli isoladas de pacientes de um hospital escola do sul de Minas Gerais, nas concentrações 50, 75, 100, 125, 150, 175 e 200mg/ml.  Palavras-chave: Jatropha curcas L.; Antimicrobiano; Fitoterapia.    ABSTRACT Objectives: This study investigated the antimicrobial activity of the extract obtained from the leaves of Jatropha curcas L., on the bacteria Staphylococcus aureus and Escherichia coli isolated from patients at a university hospital in southern Minas Gerais. Methodology: The microdilution test was made in plates of 96 wells. An amount of 50mL of Mueller Hinton agar was placed into each well, followed by 50mL of plant extract in different concentrations (25-200 mg / ml) in the appropriate columns, and then 10ml of each bacterial strain at a concentration of 0.5 McFarland in sterile saline solution. This was followed by incubation in an oven at 35°C temperature for 24h. Then development was performed by adding 20 µl Chloride Triphenyl Tetrezólico and analysis of results for staining. In each plate it was made a positive and a negative control. Results: There was a microbial growth inhibitory effect of S. aureus and E. coli before extracts of Jatropha curcas L. at concentrations of 50mg to 200mg. That is, at the concentration of 25mg no inhibitory effect on E. coli and S. aureus. Conclusion: The crude extract of Jatropha curcas L. showed inhibitory activity against the growth of colonies of Staphylococcus aureus and Escherichia coli isolated from patients at a university hospital in southern Minas Gerais in the concentrations 50, 75, 100, 125, 150, 175 and 200mg/ml.  Keywords: Jatropha curcas L.; Antimicrobial; Phytotherapy.

scholarly journals Chemical Constitution and Antimicrobial Activity of Kombucha Fermented Beverage

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 5026
Author(s):  
Abdul-Raouf Al-Mohammadi ◽  
Ahmed A. Ismaiel ◽  
Rehab A. Ibrahim ◽  
Ahmed H. Moustafa ◽  
Azza Abou Abou Zeid ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Pathogenic Bacteria ◽  
Brain Heart Infusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Bioactive Metabolites ◽  
Symbiotic Association ◽  
Safe Alternative ◽  
E Coli ◽  
Heat Treated ◽  
Fermented Beverage

Kombucha is a traditional beverage of sweetened black tea fermented with a symbiotic association of acetic acid bacteria and yeasts. In this study, kombucha fermented beverage (KFB) appeared to include nine chemical groups (alcohols, acids, lactones, condensed heterocyclic compounds, antibiotics, esters, aldehydes, fatty acids, and alkaloids) of many bioactive metabolites, as elucidated by gas chromatography–mass spectrometry (GC-MS) and IR spectra. The fermented metabolic components of KFB seem collectively to act in a synergistic action giving rise to the antimicrobial activity. Four types of kombucha preparations (fermented, neutralized, heat-treated and unfermented) were demonstrated with respect to their antimicrobial activity against some pathogenic bacterial and fungal strains using agar well diffusion assay. KFB exerted the strongest antimicrobial activities when compared with neutralized and heat-treated kombucha beverages (NKB and HKB). Staphylococcus aureus ATCC6538 (S. aureus) and Escherichia coli ATCC11229 (E. coli) were the organisms most susceptible to the antimicrobial activity of kombucha beverage preparations. Finally, the KFB preparation showed remarkable inhibitory activity against S. aureus and E. coli bacteria in a brain heart infusion broth and in some Egyptian fruit juices (apple, guava, strawberry, and tomato). These data reveal that kombucha is not only a prophylactic agent, but also appears to be promising as a safe alternative biopreservative, offering protection against pathogenic bacteria and fungi.

Sign in / Sign up

Export Citation Format

Share Document