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 After incubation, aliquots of 1 mL from each sample were withdrawn and plated on BHI agar to determine the bacterial population.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.

Growth Inhibition of Escherichia coli O157:H7 and Listeria monocytogenes by Carvacrol and Eugenol Encapsulated in Surfactant Micelles

2005 ◽  
Vol 68 (12) ◽  
pp. 2559-2566 ◽  
Author(s):  
SYLVIA GAYSINSKY ◽  
P. MICHAEL DAVIDSON ◽  
BARRY D. BRUCE ◽  
JOCHEN WEISS
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Essential Oil ◽  
Growth Inhibition ◽  
Surfactant Concentration ◽  
Escherichia Coli O157 ◽  
Surfactant Micelles ◽  
E Coli ◽  
Oil Components

Growth inhibition of four strains of Escherichia coli O157:H7 (H1730, F4546, 932, and E0019) and Listeria monocytogenes (Scott A, 101, 108, and 310) by essential oil components (carvacrol and eugenol) solubilized in nonionic surfactant micelles (Surfynol 465 and 485W) was investigated. Concentrations of encapsulated essential oil components ranged from 0.02 to 1.25% depending on compound, surfactant type, and surfactant concentration (0.5 to 5%). Eugenol encapsulated in Surfynol 485W micelles was most efficient in inhibiting growth of the pathogens; 1% Surfynol 485W and 0.15% eugenol was sufficient to inhibit growth of all strains of E. coli O157:H7 and three of four strains of L. monocytogenes (Scott A, 310, and 108). The fourth strain, L. monocytogenes 101, was inhibited by 2.5% Surfynol and 0.225% eugenol. One percent Surfynol 485W in combination with 0.025% carvacrol was effective in inhibiting three of four strains of E. coli O157:H7. Strain H1730 was the most resistant strain, requiring 0.3% carvacrol and 5% surfactant for complete inhibition. Growth inhibition of L. monocytogenes by combinations of carvacrol and Surfynol 465 ranged between 0.15 and 0.35% and 1 and 3.75%, respectively. Generally, the antimicrobial activity of Surfynol 465 in combination with eugenol was higher than that for the combination with carvacrol. The potent activity was attributed to increased solubility of essential oil components in the aqueous phase due to the presence of surfactants and improved interactions of antimicrobials with microorganisms.

scholarly journals Citric and Lactic Acid Effects on the Growth Inhibition of E. coli and S. typhymurium on Beef during Storage

2015 ◽  
Vol 31 (3) ◽  
pp. 183-190 ◽  
Author(s):  
Gultaj Hussain ◽  
◽  
Abdur Rahman ◽  
Tariq Hussain ◽  
Siraj Uddin ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Growth Inhibition ◽  
E Coli

scholarly journals In Vitro Antimicrobial Activity of an Experimental Dentifrice Based on Ricinus Communis

2014 ◽  
Vol 25 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Vanessa Maria Fagundes Leite ◽  
Juliana Barchelli Pinheiro ◽  
Marina Xavier Pisani ◽  
Evandro Watanabe ◽  
Raphael Freitas de Souza ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Growth Inhibition ◽  
Bacterial Growth ◽  
Ricinus Communis ◽  
Candida Spp ◽  
E Coli ◽  
Reflected Light ◽  
Bacterial Growth Inhibition ◽  
Post Hoc

This study evaluated the antimicrobial activity of a Ricinus communis-based experimental dentifrice for denture hygiene against the following standard strains: Staphylococcus aureus, Escherichia coli, Streptococcus mutans, Enterococcus faecalis, Candida albicans and Candida glabrata. The minimum inhibitory concentration (MIC) assay was performed with R. communis in pure oil at 2.5%. Only E. coli was not inhibited by R. communis, but the MIC (0.0781%) was effective against the other microorganisms. From these results it was determined the R. communis concentrations for experimental dentifrices, 1, 2, 5 and 10%, which were evaluated by the test-well diffusion in agar. The commercial dentifrices Colgate, Trihydral and Corega Brite were tested for comparative purposes. The diameter of the zones of bacterial growth inhibition produced around the wells was measured (in mm) with a rule under reflected light. Data were analyzed statistically by analysis of variance and Tukey's post-hoc test (α=0.05). Neither the commercial nor the experimental dentifrices were effective against E. coli. The experimental dentifrices containing R. communis at 2, 5 and 10% presented action against S. mutans, S. aureaus and E. faecallis. The experimental dentifrices showed no antimicrobial activity against Candida spp. and E. coli in any of the tested concentrations. Trihydral was the most effective. Comparing the experimental dentifrices, the product with 10% R. communis produced the largest zones of bacterial growth inhibition and had similar antimicrobial activity to the commercial dentifrices, except against S. aureus.

scholarly journals Strong Synergy between a Eukaryotic Antimicrobial Peptide and Bacteriocins from Lactic Acid Bacteria

2003 ◽  
Vol 69 (3) ◽  
pp. 1797-1799 ◽  
Author(s):  
Torben Lüders ◽  
Gunn Alice Birkemo ◽  
Gunnar Fimland ◽  
Jon Nissen-Meyer ◽  
Ingolf F. Nes
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Growth Inhibition ◽  
Specific Activity ◽  
Antimicrobial Effect ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Listeria Ivanovii ◽  
High Concentrations

ABSTRACT The antimicrobial effect obtained upon combining the prokaryotic antimicrobial peptides (AMPs; more commonly referred to as bacteriocins) pediocin PA-1, sakacin P, and curvacin A (all produced by lactic acid bacteria [LAB]) with the eukaryotic AMP pleurocidin (from fish) has been investigated. The three LAB AMPs alone were active against gram-positive Listeria ivanovii bacteria at nanomolar concentrations, whereas they were inactive against gram-negative Escherichia coli bacteria. Pleurocidin alone was active against both of these types of bacteria at micromolar concentrations. Little if any synergy between the LAB AMPs and pleurocidin against the gram-positive L. ivanovii strain was obtained. In contrast, the LAB AMPs and pleurocidin acted highly synergistically against the gram-negative E. coli strain. Nanomolar concentrations of LAB AMPs increased the growth inhibitory potency of pleurocidin by about fourfold. When micromolar concentrations of LAB AMPs were combined with 2 μg of pleurocidin/ml, 100% growth inhibition was attained, whereas pleurocidin alone at a concentration of 2 μg/ml gave no growth inhibition. Most noteworthy, when high concentrations (128 μg/ml) of pleurocidin in the absence of LAB AMPs were used over a long period of incubation (1 week), some growth of E. coli was observed, whereas 16 μg of pleurocidin/ml completely abolished growth in the presence of 64 to 128 ng of LAB AMPs/ml over the same period of time. The results clearly demonstrate that combining eukaryotic and prokaryotic AMPs can greatly increase the specific activity and broaden the target-cell range of these peptides.

scholarly journals Isolation of Bifidobacterium from Infant’s Feces and Its Antimicrobial Activity

2020 ◽  
Vol 2 ◽  
pp. 00002
Author(s):  
Dyah Fitri Kusharyati ◽  
Pancrasia Maria Hendrati ◽  
Dini Ryandini ◽  
Tsani Abu Manshur ◽  
Meilany Ariati Dewi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Lactic Acid ◽  
Gastrointestinal Tract ◽  
Lactic Acid Bacteria ◽  
Inhibition Activity ◽  
Antimicrobial Substance ◽  
Inhibitory Zone ◽  
E Coli

<p class="Abstract"><i>Bifidobacterium</i> is a group of Lactic Acid Bacteria (LAB) that commonly found in the gastrointestinal tract and vagina. LAB has many health benefits, such as produce an antimicrobial substance against a pathogen. This research aims to isolate <i>Bifidobacterium</i> from an infant’s feces and know its antimicrobial activity against <i>Escherichia coli</i> and <i>Candida albicans.</i> A total of 5 isolates <i>Bifidobacterium</i> spp. were isolated from the sample. <span lang="EN">The largest inhibitory activity against <i>E. coli</i> was shown by isolate Bb3F, with the inhibitory zone of 10.80 mm. While the largest inhibition activity against <i>C. albicans</i> was shown by isolate Bb1B and Bb3F with the inhibitory zone of 9.70 mm.</span><o:p></o:p></p>

scholarly journals In Vitro Probiotic Potential of Lactic Acid Bacteria Isolated from Aguamiel and Pulque and Antibacterial Activity Against Pathogens

2019 ◽  
Vol 9 (3) ◽  
pp. 601 ◽  
Author(s):  
Alicia Cervantes-Elizarrarás ◽  
Nelly Cruz-Cansino ◽  
Esther Ramírez-Moreno ◽  
Vicente Vega-Sánchez ◽  
Norma Velázquez-Guadarrama ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Helicobacter Pylori ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Eradication Therapy ◽  
Antimicrobial Effect ◽  
E Coli ◽  
Probiotic Potential ◽  
H Pylori

Probiotics can act as a natural barrier against several pathogens, such Helicobacter pylori, a bacterium linked to stomach cancer. The aim of the present study was to isolate and identify lactic acid bacteria (LAB) from pulque and aguamiel, and evaluate their probiotic potential and antimicrobial effect on Escherichia coli, Staphylococcus aureus, and Helicobacter pylori. Ten isolates were selected and evaluated for in vitro resistance to antibiotics and gastrointestinal conditions, and antimicrobial activity against E. coli and S. aureus and the effect on H. pylori strains. 16S rRNA identification was performed. Ten potential probiotic isolates were confirmed as belonging to the genera Lactobacillus and Pediococcus. All the strains were susceptible to clinical antibiotics, except to vancomycin. Sixty percent of the isolates exhibited antimicrobial activity against E. coli and S. aureus. The growth of H. pylori ATCC 43504 was suppressed by all the LAB, and the urease activity from all the H. pylori strains was inhibited, which may decrease its chances for survival in the stomach. The results suggest that LAB isolated from pulque and aguamiel could be an option to establish a harmless relationship between the host and H. pylori, helping in their eradication therapy.

scholarly journals Multi-Functional Potential of Presumptive Lactic Acid Bacteria Isolated from Chihuahua Cheese

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 276 ◽  
Author(s):  
María Georgina Venegas-Ortega ◽  
Adriana Carolina Flores-Gallegos ◽  
Cristóbal Noé Aguilar ◽  
Raúl Rodríguez-Herrera ◽  
José Luis Martínez-Hernández ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Growth Inhibition ◽  
Competitive Inhibition ◽  
Radical Scavenging ◽  
Inhibition Zone ◽  
Food Preservation ◽  
Agar Diffusion ◽  
Chihuahua Cheese

The multifunctional properties of autochthonous lactic acid bacteria can be of use for enhancing the sensorial properties of food, as well as in food preservation. An initial screening for antimicrobial, proteolytic, and lipolytic capacities was done in 214 presumptive lactic acid bacteria isolates obtained from Chihuahua cheese manufacturing and during a ripening period of nine months. The antimicrobial screening was done by spot-on-the-lawn tests, using Listeria monocytogenes and Escherichia coli as indicator microorganisms; proteolysis was tested in casein-peptone agar and lipolysis in Mann–Rogosa–Sharpe (MRS)-tributyrin agar. More than 90% of the isolates hydrolyzed the casein, but only 30% hydrolyzed tributyrin; the inhibition of L. monocytogenes in the spot-on-the-lawn assay was used to select 39 isolates that had a bigger inhibition zone (>11.15 mm ± 0.3) than the control (Nisin producer Lactococcus lactis BS-10 Chr Hansen). The selected isolates were grown in MRS to obtain the neutralized cell-free supernatants and verify their antimicrobial activity by agar diffusion and the percentage of growth inhibition techniques. The selected isolates were also growth in casein peptone broth, and the cell-free supernatants were used for the determination of antioxidant activity by the radical scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS) techniques. The results were analyzed to identify similarities by cluster analysis, based on their antimicrobial and antioxidant capacities. The isolates were arranged into six clusters; one cluster that included 12 isolates demonstrated L. monocytogenes (784–2811 mm2/mL AU by agar diffusion assay) and E. coli (41%–47% growth inhibition) antimicrobial activity. The isolates clustered in these groups also showed competitive inhibition of both radicals (11%–19% of DPPH and 50%–60% of ABTS). The isolates from cluster one were also identified by 16S rDNA amplification and were identified as Enterococcus faecium. Traditional products such as Chihuahua cheese can be a source or lactic acid bacteria with metabolic properties that can be used in food preparation and preservation.

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.

scholarly journals CHARACTERIZATION OF LACTIC ACID BACTERIA AND ANTIMICROBIAL ACTIVITY IN SUI WU’U FROM BAJAWA DISTRICT, NUSA TENGGARA TIMUR, INDONESIA

2020 ◽  
pp. 44-49
Author(s):  
ROSALINA YULIANA AYEN ◽  
ENDANG KUSDIYANTINI ◽  
SRI PUJIYANTO
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
16S Rrna ◽  
Diffusion Method ◽  
E Coli ◽  
Query Cover

Objective: This research aimed to isolate, determine the characteristics of lactic acid bacteria (LAB) of Sui Wu’u from Bajawa, Nusa Tenggara Timur and identify LAB using 16S rRNA potential as antimicrobial activity against pathogenic bacteria. Methods: Sui Wu’u which has been stored for 6 months was obtained from Bajawa district, inoculated on de Man Rogosa-Sharpe Agar (Merck) + 0.5% CaCO3, purification of LAB, characterization of selected isolates, biochemical test, tolerance test for pH, viability to test temperature, and content NaCl, determination of antimicrobial action by the agar well disk diffusion method using antibiotic (Amoxicillin) as a control and as indicator bacteria (Staphylococcus aureus and Escherichia coli) and isolation of genomic 16S rRNA; molecular identification. Results: Based on research results obtained five isolates of LAB, Gram staining the LAB isolated from Sui Wu’u showed that the isolated bacteria (bacilli and coccus) are Gram-positive, catalase-negative and the isolates have tolerance of viability at temperatures of 10°C, 45°C, and 50°C and to salinitas of 4% and 6.5%. The inhibitory zone LAB isolates (2PKT) against E. coli bacteria (20 mm) and S. aureus (12 mm), and (2PKB) against E. coli bacteria (17 mm) and S. aureus (10 mm). The two selected isolates were identified as Lactobacillus fermentum strain HB bacteria with 100% identification value and 98.93% query cover and L. fermentum strain HT with 100% identification value and 99.23% query cover. Conclusion: L. fermentum from Sui Wu’u has antibacterial activity against Staphylococcus aureus and Escherichia coli.

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