scholarly journals Growth and adhesion inhibition of pathogenic bacteria by live and heat-killed food-origin Lactobacillus strains or their supernatants

2021 ◽  
Author(s):  
Dorota Zielińska ◽  
Anna Łepecka ◽  
Aleksandra Ołdak ◽  
Ewa Długosz ◽  
Danuta Kołożyn-Krajewska
Keyword(s):  
Pathogenic Bacteria ◽  
Antimicrobial Properties ◽  
Pharmaceutical Products ◽  
Antagonistic Activity ◽  
Diffusion Method ◽  
Moderate Activity ◽  
E Coli ◽  
Probiotic Strains ◽  
Inhibition Zones ◽  
Spoilage Microorganisms

Abstract The study aimed to evaluate qualitatively and quantitatively the antimicrobial capacity of ten potential probiotic Lactobacillus strains against model enteropathogens and spoilage microorganisms. The probiotic strains (live and heat-killed forms) were also assessed for their ability to inhibit adhesion of selected pathogens to Caco-2 cells. The largest inhibition zones (the diffusion method) were connected with the usage of whole bacteria cultures (WBC), also high and moderate with cell free supernatant (CFS), and the lowest with cell free neutralized supernatant (CNS). The highest antagonistic activity of Lactobacillus strains was observed against L. monocytogenes strains, moderate activity against Salmonella, Shigella, E. coli, Pseudomonas and, the lowest against S.aureus, Bacillus, and Enterococcus. The inhibition of adhesion to Caco-2 cells was very high in the case of E. coli, Salmonella, and L. monocytogenes, and moderate in the case of S.aureus. On average, the inhibition effect was higher when pathogenic bacteria were treated by WBC, than heat-killed Lactobacillus. Although, in most samples, the effect was not significantly different (p>0.05). The strains Lb. brevis O24 and Lb. rhamnosus K3 showed the biggest overall antimicrobial properties, and were most effective in adherence inhibition of investigated indicator strains. These bacteria or their metabolites can be used for the production of various foods or pharmaceutical products.

scholarly journals Antagonistic effects of raffia sap with probiotics against pathogenic microorganisms

2020 ◽  
pp. 24-31
Author(s):  
Manga Joseph Arsene Mbarga ◽  
Steve Carly Zangue Desobgo ◽  
Léopold Ngoune Tatsadjieu ◽  
Nyasha Kavhiza ◽  
Louis Kalisa
Keyword(s):  
Mathematical Models ◽  
Incubation Time ◽  
Pathogenic Bacteria ◽  
Antagonistic Activity ◽  
Bifidobacterium Bifidum ◽  
Antagonistic Effect ◽  
Diffusion Method ◽  
Study Objective ◽  
E Coli ◽  
Zones Of Inhibition

Introduction. Probiotics are known for their beneficial properties. Numerous studies have been conducted to find advantages that probiotics can provide. This study aimed to evaluate the functional properties of raffia sap, a Cameroonian drink, fermented with probiotics by investigating its antagonistic activity against pathogenic bacteria. Study objects and methods. The study objective was raffia sap fermented by Lactobacillus fermentum and Bifidobacterium bifidum. Box-Behnken design with four factors (seeding rates of L. fermentum and B. bifidum, temperature, and incubation time) was used to generate mathematical models. The disc diffusion method was used to evaluate an antagonistic effect of the probiotics against four pathogenic bacteria (Escherichia coli, Listeria monocytogenes, Salmonella sp., and Bacillus cereus). An optimization of mathematical models of the inhibition diameters allowed to determine the optimal conditions of antagonistic effect. Results and discussion. The experimental data showed that zones of inhibition were 0‒21 mm for Salmonella sp., 0‒23 mm for E. coli, 0‒20 mm for L. monocytogenes, and 0‒22 mm for B. cereus. ANOVA results and the mathematical models obtained showed that L. fermentum was effective against B. cereus and B. bifidum against Salmonella sp., E. coli, and B. cereus. The optimization of the models revealed maximum zones of inhibition at the seeding rates of L. fermentum and B. bifidum of 2 and 10%, respectively, incubation time of 48 h, and temperature of 37°C. Conclusion. Raffia sap fermented by L. fermentum and B. bifidum demonstrated antagonistic effect against pathogenic bacteria such as E. coli, L. monocytogenes, Salmonella sp., and B. cereus.

Bioenhancing Effect of Cow Urine Distillate and Pepper Extract on Antibacterial Activity of Azadirachta Indica Leaves

1970 ◽  
Vol 9 (2) ◽  
pp. 3212-3214
Author(s):  
Pramod Dhakal ◽  
Ankit a Achary ◽  
Vedamurthy Joshi
Keyword(s):  
Antibacterial Activity ◽  
Azadirachta Indica ◽  
Pathogenic Bacteria ◽  
Ethanol Extract ◽  
Watery Diarrhea ◽  
Diffusion Method ◽  
E Coli ◽  
Drug Molecules ◽  
Cow Urine

Bioenhancers are drug facilitator which do not show the typical drug activity but in combination to enhance the activity of other molecule in several way including increase the bioavailability of drug across the membrane, potentiating the drug molecules by conformational interaction, acting as receptor for drug molecules and making target cell more receptive to drugs and promote and increase the bioactivity or bioavailability or the uptake of drugs in combination therapy. The objective of the present study was to evaluate the antibacterial and activity of combination in Azadirachta indica extract with cow urine distillate and pepper extract against common pathogenic bacteria, a causative agent of watery diarrhea. It has been found that Indian indigenous cow urine and its distillate also possess bioenhancing ability. Bioenhancing role of cow urine distillate (CUD) and pepper extract was investigated on antibacterial activity of ethanol extract of Azadirachta indica. Antibacterial activity of ethanol extract neem alone and in combination with CUD and pepper extract were determined the ATCC strains against Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and E-coli by cup plate diffusion method. Ethanol extract of neem has showed more effect on P. aeruginosa, E-coli than S. aureus and K. pneumonia with combination of CUD and pepper extract. CUD and pepper did not show any inhibition of test bacteria in low concentration. The antibacterial effect of combination of extract and CUD was higher than the inhibition caused by extract alone and is suggestive of the bioenhancing role of cow urine distillate and pepper. Moreover, inhibition of test bacteria was observed with less concentration of extract on combining with CUD

scholarly journals Physicochemical and Antimicrobial Properties of Cocoa Pod Husk Pectin Intended as a Versatile Pharmaceutical Excipient and Nutraceutical

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Ofosua Adi-Dako ◽  
Kwabena Ofori-Kwakye ◽  
Samuel Frimpong Manso ◽  
Mariam EL Boakye-Gyasi ◽  
Clement Sasu ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Antimicrobial Properties ◽  
Microbiological Quality ◽  
Elemental Content ◽  
Moderate Activity ◽  
Pharmaceutical Excipient ◽  
E Coli ◽  
Swelling Capacity ◽  
Weak Activity ◽  
Cocoa Pod Husk

The physicochemical and antimicrobial properties of cocoa pod husk (CPH) pectin intended as a versatile pharmaceutical excipient and nutraceutical were studied. Properties investigated include pH, moisture content, ash values, swelling index, viscosity, degree of esterification (DE), flow properties, SEM, FTIR, NMR, and elemental content. Antimicrobial screening and determination of MICs against test microorganisms were undertaken using agar diffusion and broth dilution methods, respectively. CPH pectin had a DE of 26.8% and exhibited good physicochemical properties. Pectin had good microbiological quality and exhibited pseudoplastic, shear thinning behaviour, and high swelling capacity in aqueous media. The DE, FTIR, and NMR results were similar to those of previous studies and supported highly acetylated low methoxy pectin. CPH pectin was found to be a rich source of minerals and has potential as a nutraceutical. Pectin showed dose-dependent moderate activity against gram positive and gram negative microorganisms but weak activity against Listeria spp. and A. niger. The MICs of pectin ranged from 0.5 to 4.0 mg/mL, with the highest activity against E. coli and S. aureus (MIC: 0.5–1.0 mg/mL) and the lowest activity against A. niger (MIC: 2.0–4.0 mg/mL). The study has demonstrated that CPH pectin possesses the requisite properties for use as a nutraceutical and functional pharmaceutical excipient.

scholarly journals Synthesis of Silver Nano Particles from Adansonia digitata Leaf Extract and Its Antimicrobial Properties

2020 ◽  
pp. 10-22
Author(s):  
A. O. Akintola ◽  
A. M. Azeez ◽  
B. D. Kehinde ◽  
I. C. Oladipo
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Aspergillus Niger ◽  
Pathogenic Bacteria ◽  
Leaf Extract ◽  
Biomedical Application ◽  
Nano Particles ◽  
Diffusion Method ◽  
Adansonia Digitata ◽  
Inhibition Zones

Silver nano particles (AgNPs) were green synthesized using Adansonia digitata leaf extract. The synthesized silver nano particles were characterized in terms of synthesis, size, shape, morphology and capping functionalities by UV-Visible Spectroscopy, Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Antimicrobial activity of the synthesized silver nano particles was investigated by well diffusion method. The antibacterial activity of the nano particle was studied against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeurigunosa, Salmonella typhi and Klebsiella pneumonae while the antifungal activity was studied against Candida albicans, Aspergillus niger, Penicillum notatum and Rhizopus stolomifer. The synthesized AgNPs was active against all the studied microorganisms. Staphylococcus aureus was the most susceptible bacterium (inhibition zones ranging from 12.00 to 28.00 mm, MIC: 30 µl, MBC: 50 µl) while Aspergillus niger was the most susceptible fungi (inhibition zones ranging from 10.00 to 18.00 mm, MIC: 90 µl, MFC: 120 µl. In conclusion the synthesized silver nanoparticles was found to have antimicrobial activity against the pathogenic bacteria and fungi tested and hence has a great potential in biomedical application for the treatment of microbial infections.

scholarly journals Study of Antimicrobial, Antioxidant and Cytotoxicity Properties of Selected Plant Extracts for Food Preservative Applications

2021 ◽  
pp. 95-111
Author(s):  
Tania Islam ◽  
Md Nazrul Islam ◽  
Wahidu Zzaman ◽  
Md Morsaline Billah
Keyword(s):  
Pathogenic Bacteria ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Antimicrobial Properties ◽  
In Vivo Studies ◽  
Diffusion Method ◽  
Plant Materials ◽  
Food Preservative

An attempt has been made to evaluate antimicrobial, antioxidant and cytotoxicity properties of extracts from onion (Allium cepa L.), garlic (Allium sativum), leaves of guava (Psidium guajava), papaya (Carica papaya), tea (Camellia sinensis), baen (Avicennia alba) and keora (Sonneratia apetala), respectively to apply as natural preservatives for tomatoes. The air-dried plant materials of the respective plant species were subjected to ethanol-methanol extraction, concentrated and stored at 4 °C before use. The extracts were dissolved in 95% ethanol for analysis of antioxidant and antimicrobial properties. Of the extracts tested, tea extracts showed the highest zone of inhibition against several pathogenic bacteria (E. coli 35.0±3.2 mm; P. aeruginosa 29.3±2.6 mm; S. typhi 28.4±2.1 mm and S. pyogenes 27.7±3.7 mm) using the disc diffusion method. In regard to DPPH free radical scavenging assay, keora and guava extracts showed the highest percentage of radical scavenging activity with the values of 89.64± 0.18 and 89.39± 0.88, respectively, which were in agreement with higher total antioxidant capacity (TAC) of these extracts obtained by the phosphomolybdenum method. Brine shrimp lethality bioassay for cytotoxicity assessment showed LC50 of 132.54 ± 18.99 µg/mL for the leaf extract of keora which was found to be most toxic among all studied extracts. The initial results indicated that the extracts could be used for food preservative applications based on the antimicrobial, antioxidant and cytotoxicity properties of the tested extracts. However, efficacy, stability and safety issues need to be addressed with both in vitro and in vivo studies.

scholarly journals Synthesis and Antimicrobial Activity of Piperine Analogues Containing 1,2,4-Triazole Ring

2019 ◽  
Vol 31 (5) ◽  
pp. 1077-1080
Author(s):  
Kottakki Naveen Kumar ◽  
Karteek Rao Amperayani ◽  
V. Ravi Sankar Ummdi ◽  
Uma Devi Parimi
Keyword(s):  
Antimicrobial Activity ◽  
Triazole Ring ◽  
Diffusion Method ◽  
Moderate Activity ◽  
Disc Diffusion ◽  
Disc Diffusion Method ◽  
Antibacterial Study ◽  
Gram Negative ◽  
E Coli ◽  
Micro Organisms

A series 1,2,4-triazole piperine analogues (TP1-TP6) were designed and synthesized. The structures were confirmed using 1H NMR and 13C NMR. Antibacterial study was done using Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative micro-organisms (E. coli and Pseudomonas aeruginosa) by disc diffusion method. Compound containing chloro substitution (TP6) showed the highest effect, while compound TP1, TP3, TP4, TP5 showed the moderate activity.

Antimicrobial Activity of Photoactive Cerium Doped Zinc Oxide

2020 ◽  
Vol 307 ◽  
pp. 217-222 ◽  
Author(s):  
Maishara Syazrinni Rooshde ◽  
Wan Rafizah Wan Abdullah ◽  
Amie Zaidah Amran ◽  
Noradhiha Farahin Ibrahim ◽  
Fazilah Ariffin ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Uv Light ◽  
Light Exposure ◽  
Antimicrobial Properties ◽  
Diffusion Method ◽  
Gram Positive ◽  
E Coli ◽  
Antifouling Agent ◽  
Doped Zno ◽  
Zno Powder

Biofouling and biofilms exist as ubiquitous, undesirable accumulation of flora and fauna upon a given substrate when being immersed into an aquatic medium. Therefore, a novel antifouling based materials with the incorporation of nanotechnology has been developed for the prevention of biofouling in its initial stage through photocatalytic treatment. This study investigated the antimicrobial properties of photoactive Cerium (Ce) doped ZnO powder and explores its potential properties for future antifouling application. ZnO nanoparticles was doped with 0.4 mol% Ce was synthesized through the combination of modified citrate gelation technique and solid state sintering. The successful preparation of Ce doped ZnO was confirmed by XRD and SEM. The antimicrobial activity of Ce doped ZnO against E. coli and S. aureus was determined through antibacterial susceptibility test by agar well diffusion method whilst its photocatalytic inactivation efficiency against selected bacteria was analysed through photodegradation testing under UV light irradiation. The findings demonstrated that the synthesized Ce doped ZnO powder exhibited antibacterial effect against Gram-positive bacteria (S. aureus) and excellent photocatalytic efficiency to inactivate both Gram-negative (E. coli) and Gram-positive (S. aureus). 2 g/L of Ce doped ZnO catalyzed the 100% disinfection of both bacteria in 180 min of UV light exposure. Thus, this proved that Ce doped ZnO powder has the potential as efficient antifouling agent.

scholarly journals Antimicrobial Activity of Cultivable Endophytic and Rhizosphere Fungi Associated with “Mile-a-Minute,” Mikania cordata (Asteraceae)

2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Pavithra L. Jayatilake ◽  
Helani Munasinghe
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antimicrobial Properties ◽  
Pharmaceutical Products ◽  
Diffusion Method ◽  
Molecular Characteristics ◽  
Disk Diffusion Method ◽  
Rhizosphere Fungi

Endophytic and rhizosphere fungi are understood to be aiding the host plant to overcome a range of biotic and abiotic stresses (nutrition depletion, droughts, etc.) hence, they remain to be reservoirs of plethora of natural products with immense use. Consequently, this investigation of endophytic and rhizosphere fungi isolated from Mikania cordata (a perennial vine that is well established in Sri Lanka) for their antimicrobial properties was performed with the aim of future derivation of potential beneficial pharmaceutical products. Leaves, twigs, and roots of M. cordata were utilized to isolate a total of 9 endophytic fungi out of which the highest amount (44%) accounted was from the twigs. A sample of the immediate layer of soil adhering to the root of M. cordata was utilized to isolate 15 rhizosphere fungi. Fusarium equiseti and Phoma medicaginis were endophytes that were identified based on colony and molecular characteristics. The broad spectrum of antimicrobial activity depicted by F. equiseti (MK517551) was found to be significantly greater (p≤0.05, inhibitory against Bacillus cereus ATCC 11778, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) than P. medicaginis (MK517550) (inhibitory against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) as assessed using the Kirby-Bauer disk diffusion method. Trichoderma virens and Trichoderma asperellum were rhizospere fungi that exhibited remarkable antimicrobial properties against the test pathogens chosen for the study. T. asperellum indicated significantly greater bioactivity against all four bacterial pathogens and Candida albicans ATCC 10231 under study. The ranges of minimum inhibitory concentrations (MICs) of the fungi depicting antimicrobial properties were determined. The results obtained suggest that F. equiseti, P. medicaginis, T. asperellum, and T. virens of M. cordata harness bioprospective values as natural drug candidates. This is the first report on isolation and evaluation of the antimicrobial properties of endophytic and rhizosphere fungi of Mikania cordata.

Inactivation of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella in Cranberry, Lemon, and Lime Juice Concentrates

2003 ◽  
Vol 66 (9) ◽  
pp. 1637-1641 ◽  
Author(s):  
MARA C. L. NOGUEIRA ◽  
OMAR A. OYARZÁBAL ◽  
DAVID E. GOMBAS
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Antimicrobial Properties ◽  
Escherichia Coli O157 ◽  
Bacterial Inactivation ◽  
Lime Juice ◽  
E Coli ◽  
Log Reduction ◽  
C 32

The production of thermally concentrated fruit juices uses temperatures high enough to achieve at least a 5-log reduction of pathogenic bacteria that can occur in raw juice. However, the transportation and storage of concentrates at low temperatures prior to final packaging is a common practice in the juice industry and introduces a potential risk for postconcentration contamination with pathogenic bacteria. The present study was undertaken to evaluate the likelihood of Escherichia coli O157: H7, Listeria monocytogenes and Salmonella surviving in cranberry, lemon, and lime juice concentrates at or above temperatures commonly used for transportation or storage of these concentrates. This study demonstrates that cranberry, lemon, and lime juice concentrates possess intrinsic antimicrobial properties that will eliminate these bacterial pathogens in the event of postconcentration recontamination. Bacterial inactivation was demonstrated under all conditions; at least 5-log Salmonella inactivation was consistently demonstrated at −23°C (−10°F), at least 5-log E. coli O157:H7 inactivation was consistently demonstrated at −11°C (12°F), and at least 5-log L. monocytogenes inactivation was consistently demonstrated at 0°C (32°F).

Investigation of the antimicrobial properties of nanoclay and chitosan based nanocomposite on the microbial characteristics of Gouda cheese

2020 ◽  
Author(s):  
Mojtaba Mohammadzadeh-Vazifeh ◽  
Seyed Masoud Hosseini ◽  
Ali Mohammadi ◽  
Mahdi Jahanfar ◽  
Hadi Maleki
Keyword(s):  
Antimicrobial Properties ◽  
Chitosan Film ◽  
Antimicrobial Effect ◽  
Diffusion Method ◽  
Salmonella Spp ◽  
E Coli ◽  
Microbial Characteristics ◽  
Gouda Cheese ◽  
Mold And Yeast ◽  
Coagulase Positive Staphylococcus

  Background and Objectives: In recent years, active packaging has been introduced as a new method to better preserve food. Chitosan and nanoclay have been used for preparation of an active nanocomposite with respect to their antimicrobial properties to investigate its effects on the microbial limitation in Gouda cheese. Materials and Methods: Nanoclay film, chitosan film, chitosan-based nanocomposites and nanoclay-based nanocompos- ites were prepared and their antimicrobial properties were evaluated to the microbial limitations of Gouda cheese con- sist of coliforms, Escherichia coli, Salmonella spp., coagulase-positive Staphylococcus, mold and yeast by agar diffusion method. Results: The results indicated, the best antimicrobial effect belonged to nanocomposite film with the composition of chitosan 3 wt% by adding nanoclay 1 wt%, which can prevent microbial characteristics of Gouda cheese. Conclusion: The chitosan and nanoclay nanocomposite had excellent antibacterial activity and performed well against microbial limitations (coliforms, E. coli, Salmonella spp., coagulase-positive Staphylococcus, mold and yeast) of Gouda cheese. Therefore, the nanocomposite may be possibly used as a surface coating in addition to Gouda cheese as well as sim- ilar cheeses and other food to enhance microbial characteristics and extend shelf life.

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