The Antimicrobial Efficacy Of Plasma Activated Water Against Listeria and E. coli Is Modulated By Reactor Design And Water Composition

2021 ◽  
Author(s):  
Joanna G. Rothwell ◽  
David Alam ◽  
Dee A. Carter ◽  
Behdad Soltani ◽  
Robyn McConchie ◽  
...  
Keyword(s):  
Reactor Design ◽  
Antimicrobial Efficacy ◽  
E Coli ◽  
Water Composition ◽  
Plasma Activated Water

scholarly journals The Antimicrobial Efficacy Of Plasma Activated Water Is Modulated By Reactor Design And Water Composition

2021 ◽  
Author(s):  
Joanna G Rothwell ◽  
David Alam ◽  
Dee A Carter ◽  
Behdad Soltani ◽  
Robyn McConchie ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Tap Water ◽  
Fresh Produce ◽  
Critical Role ◽  
Reactive Species ◽  
Antimicrobial Efficacy ◽  
Model Organisms ◽  
Atmospheric Conditions ◽  
E Coli ◽  
Plasma Activated Water

Plasma activated water (PAW) contains a cocktail of reactive oxidative species and free radicals and has demonstrated efficacy as a sanitizer for fresh produce, however there is a need for further optimization. The antimicrobial efficacy of PAW produced by a bubble spark discharge (BSD) reactor and a dielectric barrier discharge-diffuser (DBDD) reactor operating at atmospheric conditions with air, discharge frequencies of 500, 1000 and 1500 Hz, and MilliQ and tap water, was investigated with model organisms Listeria innocua and Escherichia coli.  Optimal conditions were subsequently employed for pathogenic bacteria Listeria monocytogenes, E. coli and Salmonella enterica. PAW generated with the DBDD reactor decontaminated more than 6-log CFU of bacteria within 1 minute of treatment. The BSD-PAW, while attaining high CFU reduction was less effective, particularly for L. innocua. Analysis of physicochemical properties revealed BSD-PAW had a greater variety of reactive species than DBDD-PAW. Scavenger assays were employed to specifically sequester reactive species, including the short-lived superoxide (?O2-) radical that could not be directly measured in the PAW. This demonstrated a critical role of superoxide for the inactivation of both E. coli and L. innocua by DBDD-PAW, while in BSD-PAW it had a role in L. innocua inactivation only. Overall, this study demonstrates the potential of DBDD-PAW in fresh produce, where there is a need for sterilization while minimizing chemical inputs and residues and maintaining food quality. Highly effective PAW was generated using air as a processing gas and tap water, making this a feasible and cost-effective option.

scholarly journals Comparative Study on the Antimicrobial Efficacy of Methanolic Extract of Root, Callus and Fruit Extracts of Myxopyrum smilacifolium Blume

2014 ◽  
Vol 2 (4) ◽  
pp. 521-524
Author(s):  
RP Praveen ◽  
Ashalantha Nair
Keyword(s):  
Antimicrobial Activity ◽  
Methanolic Extract ◽  
Fungal Strain ◽  
Antimicrobial Efficacy ◽  
Bacterial Strains ◽  
E Coli ◽  
Root Extracts ◽  
Fruit Extracts ◽  
Root Callus ◽  
And Staphylococcus Aureus

The aim of the present study was to compare the antimicrobial efficacy of methanolic extract of root, callus and fruit of Myxopyrum smilacifolium Blume. Antimicrobial activity was tested using agar well diffusion with four bacterial strains viz: Escherechia coli, Enterococcus faecalis, Bacillus subtilis and Staphylococcus aureus of which E. coli alone was gram negative. The fungal strain employed was Candida albicans. Root extracts shown to be effective only against B. subtilis. Fruit extracts showed the maximum antimicrobial activity against all the microbial species considered for the current study except against S. aureus. Highlight of the present study was the antimicrobial activity of callus extracts. DOI: http://dx.doi.org/10.3126/ijasbt.v2i4.11362  Int J Appl Sci Biotechnol, Vol. 2(4): 521-524 

scholarly journals Antimicrobial efficacy of a new tri-antibiotic combination against resistant endodontic pathogens: An in-vitro study

2020 ◽  
Vol 23 (4) ◽  
pp. 8p ◽  
Author(s):  
Prasanna T. Dahake ◽  
Sudhindra M Baliga
Keyword(s):  
Root Canal ◽  
Pathogenic Bacteria ◽  
Culture Media ◽  
In Vitro Study ◽  
Vitro Study ◽  
New Combination ◽  
Antimicrobial Efficacy ◽  
E Coli ◽  
Background Removal

Background: Removal of all the pathogenic bacteria from the root canal system is of prime importance for the success of endodontic therapy. Objective: The study aimed to determine the antimicrobial efficacy of three antibiotics and their new combination against selected endodontic pathogens. Methods: In this in-vitro study, we used bacterial strains associated with the refractory endodontic condition and determined MIC and MBC of Clindamycin (C), Metronidazole (M), Doxycycline (D) as well as their combination CMD. We cultured Candida Albicans, Pseudomonas Aeruginosa, Escherichia Coli, Enterococcus Faecalis, Streptococcus Mutans, Bacillus Subtilis subsp. spizizenii, Actinomyces Actinomycetemcomitans on selective culture media. We analyzed the data using paired 't' test, one-way ANOVA, and Tuckey's HSD post hoc test. Results: Clindamycin inhibited the growth of C. Albicans (90%) and S. Mutans (90%) significantly and P. Aeruginosa, E. Coli, E. Faecalis, B. Subtilis, and A. Actinomycetemcomitans were resistant to it. Metronidazole did not inhibit any of the bacteria. Doxycycline inhibited C. Albicans (90%), P. Aeruginosa (90%), and S. Mutans (90%) significantly while E. Coli, E. Faecalis, B. Subtilis, and A. Actinomycetemcomitans were resistant to it. The combination of CMD inhibited all the microbes significantly. However, at bactericidal concentrations of CMD, E. Faecalis (p = 0.024), B. Subtilis (p = 0.021) and A. Actinomycetemcomitans (p = 0.041) were eliminated significantly, while C. Albicans (p = 0.164), P. Aeruginosa (p = 0.489), E. Coli (p = 0.106) and S. Mutans (p = 0.121) showed resistance. Conclusion: Combination CMD can be used against resistant endodontic pathogens to achieve predictable endodontic results.KEYWORDSAntimicrobial agents; Clindamycin; Doxycycline; Metronidazole; Root canal therapy.    

Cations Reduce Antimicrobial Efficacy of Lysozyme-Chelator Combinations

2004 ◽  
Vol 67 (2) ◽  
pp. 285-294 ◽  
Author(s):  
J. S. BOLAND ◽  
P. M. DAVIDSON ◽  
B. BRUCE ◽  
J. WEISS
Keyword(s):  
Mechanistic Model ◽  
Monovalent Cation ◽  
Antimicrobial Efficacy ◽  
Titration Calorimetry ◽  
Escherichia Coli O157 ◽  
Tetraacetic Acid ◽  
Mineral Salts ◽  
E Coli ◽  
Strain Type ◽  
Antimicrobial Effectiveness

Reduction of the antimicrobial efficacy of lysozyme-chelator combinations against two Escherichia coli O157:H7 strains on addition of mineral salts was studied. The objective of the study was to determine the effect of type and concentration of mono-, di-, and trivalent mineral salts on the antimicrobial effectiveness of lysozyme and various chelators against E. coli O157:H7. Seven salts (Al3+, Ca2+, Fe2+, Fe3+, K+, Mg2+, and Na+) at 1 to 10 mM were added to aqueous solutions of lysozyme and disodium ethylenediamine tetraacetic acid (EDTA), disodium pyrophosphate (DSPP), or pentasodium tripolyphosphate (PSTPP) at pH 6, 7, or 8 and applied to cultures of E. coli O157:H7 strains 932 and H1730. Inhibitory activity of lysozyme chelator combinations against both strains was completely lost after addition of ≥1 mM Ca2+ and Mg2+ at pH 7 and 8. At pH 6, antimicrobial activity of lysozyme-EDTA against both strains was retained in the presence of calcium or magnesium cations. DSPP-lysozyme inhibited strain H1730 at pH 6 despite the presence of Mg2+. Concentrations above 4 mM Fe2+ neutralized activity of all lysozyme-chelator combinations. Reversal of inhibition by lysozyme-chelator complexes by the monovalent Na+ and K+ ions depended on E. coli O157:H7 strain type. Neither monovalent cation reversed inhibition of strain 932. However, Na+ and K+ reversed lysozyme-chelator inhibition of strain H1730. The addition of ≥1 mM Fe3+ or Al3+ was effective in reversing inhibition of both strains by lysozyme and EDTA at pH 6, 7, and 8. Isothermal titration calorimetry was used to determine the amount of ion-speci c competitive binding of free cations by EDTA-lysozyme combinations. A mechanistic model for the antimicrobial functionality of chelator-lysozyme combinations is proposed.

scholarly journals Comparative antimicrobial efficacy study of different commercially available toothpaste in India: An in vitro study

2021 ◽  
pp. 122-131
Keyword(s):  
In Vitro Study ◽  
Chemotherapeutic Agents ◽  
Oral Bacteria ◽  
Oral Microbiome ◽  
Antimicrobial Efficacy ◽  
Bacteria Growth ◽  
E Coli ◽  
Test Organisms ◽  
Oral Pathogens

Antimicrobial chemotherapeutic agents have been recommended for lowering oral bacteria growth. The main purpose of this study is to examine the efficacy of different toothpaste formulations in providing complete oral cavity protection against oral pathogens. By using a modified well agar diffusion assay, twenty kinds of toothpaste were examined for antimicrobial efficacy against two oral pathogens: Streptococcus aureus and Escherichia coli. The examination indicated that the majority of the non-herbal dentifrices and combinations of herbal and chemical-based dentifrices chosen for the investigation were viable against both microbial strains, however, to differing degrees. TP1 and TP17 were found the best against E. coli and S. aureus, respectively, with 21.553 mm and 23.443 mm as the zone of inhibition. From the herbal dentifrices, TP15 was found to have significant effect on E. coli, followed by TP19 for S. aureus. Nevertheless, toothpaste TP15 and TP19 were not effective against S. aureus and E. coli, respectively. In correlation, the inhibition zones of every single other dentifrice were found to be less. Antimicrobial activity against test organisms was stronger in a sodium lauryl sulphate-based dental formulations, when combined with fluoride. A formulation including TP15 exhibited substantial activity against the tested bacterium E. coli among herbal dentifrices. Statistical analysis demonstrated that the effectiveness against Gram-negative bacteria was greater than against Gram-positive bacteria. Furthermore, herbal toothpaste can be incorporated with chemotherapeutic agents to enhance its effectiveness against pathogens present in the oral microbiome. This comparison aids in the identification of the toothpaste’s shortcomings and benefits over other formulations, widening the scope of more potent toothpaste products.

scholarly journals EFFECT OF BOILING AND MICROWAVE ASSISTED PROCESSING ON THE ANTIMICROBIAL EFFICACY OF VITAMIN–C IN EMBLICA OFFICINALIS

2020 ◽  
pp. 102-105
Author(s):  
PAYEL SUTRADHAR ◽  
SHALINI GHOSH ◽  
BINITA KUMARI ROY
Keyword(s):  
Vitamin C ◽  
Crude Extract ◽  
Active Form ◽  
Citrus Fruit ◽  
Inhibitory Effect ◽  
Antimicrobial Efficacy ◽  
Diffusion Method ◽  
Emblica Officinalis ◽  
E Coli ◽  
Microwave Assisted

Objective: The present work aimed to expand the awareness of restoring vitamin-C in its active form on different heat exposures. The effect of microwave-assisted processing and boiling of the aqueous crude extract of citrus fruit Emblica officinalis (amla) has been correlated with its antimicrobial efficacy against E. coli. Methods: The aqueous crude extract of dried amla pulp exposed to microwave radiation(600W,5 min) and boiling (5 min) were titrimetrically estimated for vitamin-C content by DCPIP-(2,6, Dinitrophenol indophenol) method and compared the same with the untreated sample. These three samples were studied for their effect on the growth pattern of E. coli turbidimetrically. The antimicrobial susceptibility test by agar cup well diffusion method was further followed to measure the zone of inhibitions (ZOI) for these three test extracts against E. coli. Results: The total estimated vitamin-C content was 26.76 mg/100g, 25.35 mg/100g and 21.12 mg/100g in the untreated extract (UTE), microwaved extract (MWE) and boiled extract (BE) respectively. At a higher concentration (0.8 mg/ml), the UTE showed a greater ZOI of 20 mm and a comparable ZOI of 18 mm for the MWE against E. coli. In addition, a reduced ZOI of 10 mm was recorded in case of the BE. At a lowest concentration (0.05 mg/ml), the UTE inhibited the growth with a least ZOI of 7 mm, whereas no inhibition zones were detected for MWE and BE at this concentration. Conclusion: The present investigation demonstrated the effect of boiling and microwave-assisted processing on the content of bioactive vitamin-C and its antimicrobial activity. The DCPIP method calculated a more vitamin-C retention in the MWE than the BE. As the boiling method destroyed the vitamin more rapidly, a higher growth rate of E. coli was measured in the presence of BE than the UTE and MWE. In addition, the antimicrobial assay also showed a least inhibitory effect against E. coli in the presence of the BE. A moderate inhibitory effect for MWE was also detected. Thus the present investigation proved that the boiling process destroys vitamin-C present in a food sample to a higher extent than the microwave-assisted processing.

scholarly journals Evaluating the Antimicrobial Properties of Commercial Hand Sanitizers

mSphere ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
M. Chojnacki ◽  
C. Dobrotka ◽  
R. Osborn ◽  
W. Johnson ◽  
M. Young ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Benzalkonium Chloride ◽  
Bacterial Pathogens ◽  
Antimicrobial Properties ◽  
World Health ◽  
Antimicrobial Efficacy ◽  
Content Type ◽  
E Coli ◽  
Antibacterial Performance ◽  
Antimicrobial Performance

ABSTRACT Hand sanitizers have been developed as a convenient means to decontaminate an individual’s hands of bacterial pathogens in situations in which soap and water are not available. Yet to our knowledge, no study has compared the antibacterial efficacy of a large collection of hand sanitizers. Using zone of growth inhibition and kill curve assays, we assessed the performance of 46 commercially available hand sanitizers that were obtained from national chain big-box stores, gasoline stations, pharmacies, and boutiques for antibacterial activity toward prototypical Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterial pathogens. Results revealed substantial variability in the efficacy of many sanitizers evaluated. Formulations following World Health Organization-recommended ingredients (80% ethanol or 75% isopropyl alcohol) or those including benzalkonium chloride as the active principal ingredient displayed excellent antibacterial activity, whereas others exhibited modest or poor activity in the assays performed. Results also revealed that E. coli was generally more susceptible to most sanitizers in comparison to S. aureus and that there was significant strain-to-strain variability in hand sanitizer antimicrobial efficacy regardless of the organism evaluated. Further, tests of a subset of hand sanitizers toward severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) revealed no direct correlation between antibacterial and antiviral performance, with all ethyl alcohol formulations performing equally well and displaying improved activity in comparison to benzalkonium chloride-containing sanitizer. Taken together, these results indicate that there is likely to be substantial variability in the antimicrobial performance of commercially available hand sanitizers, particularly toward bacterial pathogens, and a need to evaluate the efficacy of sanitizers under development. IMPORTANCE In response to the coronavirus disease 2019 (COVID-19) pandemic, hand hygiene has taken on a prominent role in efforts to mitigate SARS-CoV-2 transmission and infection, which has led to a radical increase in the number and types of hand sanitizers manufactured to meet public demand. To our knowledge, no studies have evaluated or compared the antimicrobial performance of hand sanitizers that are being produced under COVID-19 emergency authorization. Tests of 46 commercially available hand sanitizers purchased from national chain brick-and-mortar stores revealed considerable variability in their antibacterial performance toward two bacterial pathogens of immediate health care concern, S. aureus and E. coli. Expanded testing of a subset of hand sanitizers revealed no direct correlation between antibacterial performance of individual sanitizers and their activity toward SARS-CoV-2. These results indicate that as the pandemic subsides, there will be a need to validate the antimicrobial efficacy of sanitizers being produced.

scholarly journals Antimicrobial Activity and Prevention of Bacterial Biofilm Formation of Silver and Zinc Oxide Nanoparticle-Containing Polyester Surfaces at Various Concentrations for Use

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 442 ◽  
Author(s):  
Fabio Fontecha-Umaña ◽  
Abel Guillermo Ríos-Castillo ◽  
Carolina Ripolles-Avila ◽  
José Juan Rodríguez-Jerez
Keyword(s):  
Antimicrobial Activity ◽  
Zinc Oxide ◽  
Biofilm Formation ◽  
Antimicrobial Properties ◽  
Bacterial Biofilm ◽  
Antimicrobial Efficacy ◽  
Ag Nps ◽  
Zno Nps ◽  
E Coli ◽  
Food Contact Surfaces

Food contact surfaces are primary sources of bacterial contamination in food industry processes. With the objective of preventing bacterial adhesion and biofilm formation on surfaces, this study evaluated the antimicrobial activity of silver (Ag-NPs) and zinc oxide (ZnO-NPs) nanoparticle-containing polyester surfaces (concentration range from 400 ppm to 850 ppm) using two kinds of bacteria, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli), and the prevention of bacterial biofilm formation using the pathogen Listeria monocytogenes. The results of antimicrobial efficacy (reductions ≥ 2 log CFU/cm2) showed that at a concentration of 850 ppm, ZnO-NPs were effective against only E. coli (2.07 log CFU/cm2). However, a concentration of 400 ppm of Ag-NPs was effective against E. coli (4.90 log CFU/cm2) and S. aureus (3.84 log CFU/cm2). Furthermore, a combined concentration of 850 ppm Ag-NPs and 400 ppm ZnO-NPs showed high antimicrobial efficacy against E. coli (5.80 log CFU/cm2) and S. aureus (4.11 log CFU/cm2). The results also showed a high correlation between concentration levels and the bacterial activity of Ag–ZnO-NPs (R2 = 0.97 for S. aureus, and R2 = 0.99 for E. coli). They also showed that unlike individual action, the joint action of Ag-NPs and ZnO-NPs has high antimicrobial efficacy for both types of microorganisms. Moreover, Ag-NPs prevent the biofilm formation of L. monocytogenes in humid conditions of growth at concentrations of 500 ppm. Additional studies under different conditions are needed to test the durability of nanoparticle containing polyester surfaces with antimicrobial properties to optimize their use.

Temporal efficacy of antimicrobials against aerobic bacteria isolated from equine endometritis: an Italian retrospective analysis (2010–2017)

2019 ◽  
Vol 185 (19) ◽  
pp. 598-598 ◽  
Author(s):  
Lorenzo Pisello ◽  
Elisa Rampacci ◽  
Valentina Stefanetti ◽  
Francesca Beccati ◽  
Doreene Rose Hyatt ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Reproductive Tract ◽  
Antibiotic Use ◽  
Antimicrobial Efficacy ◽  
Aerobic Bacteria ◽  
Resistant Bacteria ◽  
E Coli ◽  
Aerobic Culture ◽  
Agar Disc ◽  
Susceptibility Patterns

This study aimed to describe bacteria isolated from the reproductive tract of mares and to identify changes in antimicrobial susceptibility patterns to those antibiotics commonly used for the treatment of equine endometritis. A total of 4122 equine uterine swabs were collected from mares suffering from reproductive tract disorders in the period 2010–2017. Aerobic culture and antimicrobial susceptibility testing using agar disc diffusion were performed on each sample. Aerobic bacteria were isolated from 3171 of 4122 (76.9 per cent) samples. The most frequently isolated microorganisms were Escherichia coli (885/3171, 27.9 per cent) and Streptococcus equi subspecies zooepidemicus (791/3171, 24.9 per cent), confirming previous findings from the literature. Antimicrobial susceptibility patterns of E coli, S equi subspecies zooepidemicus and Klebsiella pneumoniae changed over time. A statistically significant decrease in antimicrobial efficacy of cefquinome against E coli was observed over the years, as well as of ampicillin, cefquinome and penicillin against S equi subspecies zooepidemicus. The high frequency of resistant bacteria isolated in the present work proceeds in the same way as indicated by surveillance data on the huge antibiotic use in Italy. As a result, testing and monitoring programmes of antimicrobial efficacy are crucial to consciously using antibiotics and preserving their effectiveness both for veterinary and human medicine.

Sign in / Sign up

Export Citation Format

Share Document