scholarly journals Study the Effect of Enterocin produced by Enterococcus faecalisU36 Against Some Food Borne Pathogenic Bacteria

2010 ◽  
Vol 4 (1) ◽  
pp. 54-64
Author(s):  
NuhaJoseph Kandala ◽  
Ghazi M. Aziz
Keyword(s):  
Mode Of Action ◽  
Pathogenic Bacteria ◽  
Food Additives ◽  
Viable Count ◽  
Lytic Activity ◽  
Antimicrobial Proteins ◽  
Food Borne ◽  
Inhibitory Type ◽  
Tract Infections ◽  
Increased Activity

Enterocin U36 (ENT U36), is a bacteriocin produced by Enterococcus faecalisU36, strain isolated from urine samples have collected from patients suffering from urinary tract infections. The Bacteriocin is an antimicrobial proteins or peptides that inhibit growth of bacteria closely related to the producing organism. The results has been shown that ENT U36 active against Enterococcus faecalis S10 Lactococcuslactis,Lactobacillusfermentumand few other food borne gram positive pathogens bacteria including Listeria monocytogenes, Staphylococcus auraus,Bacillussubtilis and Streptococcusspp . The inhibitory type and mode of action of purified ENT U36 were tested against some isolates test bacteria which includedL.monocytogenes and E.coli It was observed that purified ENT U36 have bacteriostatic effect when the numbers of inhibited test bacteria increased in parallel with the increased activity of ENT U36 (unit/ml) . The treatment period also has its effect on reducing the numbers of test bacteria. The results showed that 400 unit/ml was enough to kill L.monocytogenes viable count of in 3.1 x105 cell/ml in 2 hours when treated with ENT U36, and E.coli in 3.7x105 cell/ml in 24 hour'. And when lytic activity of purified ENT U36 studied, it was observed that its mode of action was on cell membrane and did not show any lytic activity on the isolated cell walls of test bacteria or any lytic activity on DNA. This beneficial trait has led to utilization of purified enterocinas as food additives.

scholarly journals Chemical characterization and mode of action of Ligustrum lucidum flower essential oil against food-borne pathogenic bacteria

2016 ◽  
Vol 11 (1) ◽  
pp. 269 ◽  
Author(s):  
Vivek K. Bajpai ◽  
Siddhartha Singh ◽  
Archana Mehta
Keyword(s):  
Essential Oil ◽  
Mode Of Action ◽  
Pathogenic Bacteria ◽  
Membrane Integrity ◽  
Chemical Characterization ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Spectrometry Analysis ◽  
Ligustrum Lucidum ◽  
Food Borne

<p class="Abstract">Current research analyzes the chemical composition of <em>Ligustrum lucidum</em> flower essential oil obtained by the hydrodistillation, and examines its anti-microbial mode of action against food-borne pathogenic bacteria. Gas chromatography-mass spectrometry analysis of the oil resulted in the determination of 44 different compounds, representing 85.2% of the total oil. The oil (1 mg/disc) showed significant antibacterial effect as diameters of inhibition zones (14.6 ± 0.2 – 19.7 ± 0.3 mm), as well as minimum inhibitory and minimum bactericidal concentrations values (250–1000 and 250–2000 µg/mL), respectively. Based on the susceptibility, <em>L. lucidum</em> flower oil revealed its mode of action on membrane integrity as confirmed by increased release of extracellular ATP (2.5 and 2.2 pg/mL), leakage of potassium ions (950 and 900 mM/L), loss of 260-nm absorbing materials (4.2 and 3.9 optical density), and increase in relative electrical conductivity (10.6 and 9.8%) against <em>Staphylococcus aureus</em> KCTC-1621 (Gram-positive) and <em>Salmonella enterica</em> ATCC-4731 (Gram-negative), respectively.</p><p> </p>

scholarly journals Assessing the Molecular Targets and Mode of Action of Furanone C-30 on Pseudomonas aeruginosa Quorum Sensing

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1620
Author(s):  
Victor Markus ◽  
Karina Golberg ◽  
Kerem Teralı ◽  
Nazmi Ozer ◽  
Esti Kramarsky-Winter ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Quorum Sensing ◽  
Conformational Changes ◽  
Mode Of Action ◽  
Pathogenic Bacteria ◽  
Molecular Targets ◽  
Resistant Bacteria ◽  
Public Healthcare ◽  
C 30

Quorum sensing (QS), a sophisticated system of bacterial communication that depends on population density, is employed by many pathogenic bacteria to regulate virulence. In view of the current reality of antibiotic resistance, it is expected that interfering with QS can address bacterial pathogenicity without stimulating the incidence of resistance. Thus, harnessing QS inhibitors has been considered a promising approach to overriding bacterial infections and combating antibiotic resistance that has become a major threat to public healthcare around the globe. Pseudomonas aeruginosa is one of the most frequent multidrug-resistant bacteria that utilize QS to control virulence. Many natural compounds, including furanones, have demonstrated strong inhibitory effects on several pathogens via blocking or attenuating QS. While the natural furanones show no activity against P. aeruginosa, furanone C-30, a brominated derivative of natural furanone compounds, has been reported to be a potent inhibitor of the QS system of the notorious opportunistic pathogen. In the present study, we assess the molecular targets and mode of action of furanone C-30 on P. aeruginosa QS system. Our results suggest that furanone C-30 binds to LasR at the ligand-binding site but fails to establish interactions with the residues crucial for the protein’s productive conformational changes and folding, thus rendering the protein dysfunctional. We also show that furanone C-30 inhibits RhlR, independent of LasR, suggesting a complex mechanism for the agent beyond what is known to date.

scholarly journals Exploring the possibilities of infrared spectroscopy for urine sediment examination and detection of pathogenic bacteria in urinary tract infections

2020 ◽  
Vol 58 (10) ◽  
pp. 1759-1767
Author(s):  
Mieke Steenbeke ◽  
Sander De Bruyne ◽  
Jerina Boelens ◽  
Matthijs Oyaert ◽  
Griet Glorieux ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Pathogenic Bacteria ◽  
Agar Plate ◽  
Principal Component ◽  
Blood Agar Plate ◽  
Urine Sediment ◽  
Flight Mass Spectrometry ◽  
Tract Infections

AbstractObjectivesIn this study, the possibilities of Fourier-transformed infrared spectroscopy (FTIR) for analysis of urine sediments and for detection of bacteria causing urinary tract infections (UTIs) were investigated.MethodsDried urine specimens of control subjects and patients presenting with various nephrological and urological conditions were analysed using mid-infrared spectroscopy (4,000–400 cm−1). Urine samples from patients with a UTI were inoculated on a blood agar plate. After drying of the pure bacterial colonies, FTIR was applied and compared with the results obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Chemometric data analysis was used to classify the different species.ResultsDue to the typical molecular assignments of lipids, proteins, nucleic acids and carbohydrates, FTIR was able to identify bacteria and showed promising results in the detection of proteins, lipids, white and red blood cells, as well as in the identification of crystals. Principal component analysis (PCA) allowed to differentiate between Gram-negative and Gram-positive species and soft independent modelling of class analogy (SIMCA) revealed promising classification ratios between the different pathogens.ConclusionsFTIR can be considered as a supplementary method for urine sediment examination and for detection of pathogenic bacteria in UTI.

scholarly journals Evaluation of non-thermal effect of microwave radiation and its mode of action in bacterial cell inactivation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Priyanka Shaw ◽  
Naresh Kumar ◽  
Sohail Mumtaz ◽  
Jun Sup Lim ◽  
Jung Hyun Jang ◽  
...  
Keyword(s):  
Thermal Effect ◽  
Microwave Radiation ◽  
Bacterial Cell ◽  
Mode Of Action ◽  
Surface Damage ◽  
Peak Frequency ◽  
Viable Count ◽  
Bacterial Inactivation ◽  
Bacterial Strains ◽  
Log Reduction

AbstractA growing body of literature has recognized the non-thermal effect of pulsed microwave radiation (PMR) on bacterial systems. However, its mode of action in deactivating bacteria has not yet been extensively investigated. Nevertheless, it is highly important to advance the applications of PMR from simple to complex biological systems. In this study, we first optimized the conditions of the PMR device and we assessed the results by simulations, using ANSYS HFSS (High Frequency Structure Simulator) and a 3D particle-in-cell code for the electron behavior, to provide a better overview of the bacterial cell exposure to microwave radiation. To determine the sensitivity of PMR, Escherichia coli and Staphylococcus aureus cultures were exposed to PMR (pulse duration: 60 ns, peak frequency: 3.5 GHz) with power density of 17 kW/cm2 at the free space of sample position, which would induce electric field of 8.0 kV/cm inside the PBS solution of falcon tube in this experiment at 25 °C. At various discharges (D) of microwaves, the colony forming unit curves were analyzed. The highest ratios of viable count reductions were observed when the doses were increased from 20D to 80D, which resulted in an approximate 6 log reduction in E. coli and 4 log reduction in S. aureus. Moreover, scanning electron microscopy also revealed surface damage in both bacterial strains after PMR exposure. The bacterial inactivation was attributed to the deactivation of oxidation-regulating genes and DNA damage.

scholarly journals Transcriptome Analysis of the Cecal Tonsil of Jingxing Yellow Chickens Revealed the Mechanism of Differential Resistance to Salmonella

Genes ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 979 ◽  
Author(s):  
Fei Wang ◽  
Jin Zhang ◽  
Bo Zhu ◽  
Jie Wang ◽  
Qiao Wang ◽  
...  
Keyword(s):  
Immune Response ◽  
Pathogenic Bacteria ◽  
Molecular Mechanisms ◽  
Differential Resistance ◽  
Receptor Interaction ◽  
Salmonella Infection ◽  
Poultry Products ◽  
Food Borne ◽  
Cecal Tonsil ◽  
Iga Production

Salmonella is one of the most common food-borne pathogens. It can be transmitted between chickens, as well as to people by contaminated poultry products. In our study, we distinguished chickens with different resistances mainly based on bacterial loads. We compared the cecal tonsil transcriptomes between the susceptible and resistant chickens after Salmonella infection, aiming to identify the crucial genes participating in the antibacterial activity in the cecal tonsil. A total of 3214 differentially expressed genes (DEGs), including 2092 upregulated and 1122 downregulated genes, were identified between the two groups (fold change ≥ 2.0, padj < 0.05). Many DEGs were mainly involved in the regulation of two biological processes: crosstalk between the cecal tonsil epithelium and pathogenic bacteria, such as focal adhesion, extracellular-matrix–receptor interaction, and regulation of the actin cytoskeleton and host immune response including the cytokine–receptor interaction. In particular, the challenged resistant birds exhibited strong activation of the intestinal immune network for IgA production, which perhaps contributed to the resistance to Salmonella infection. These findings give insight into the mRNA profile of the cecal tonsil between the two groups after initial Salmonella stimulation, which may extend the known complexity of molecular mechanisms in chicken immune response to Salmonella.

scholarly journals Isolation and Characterization of Bacteriophage ZCSE6 against Salmonella spp.: Phage Application in Milk

Biologics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 164-176
Author(s):  
Abdallah S. Abdelsattar ◽  
Anan Safwat ◽  
Rana Nofal ◽  
Amera Elsayed ◽  
Salsabil Makky ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Raw Milk ◽  
Salmonella Spp ◽  
Isolation And Characterization ◽  
Food Borne ◽  
Wide Range ◽  
Almost All ◽  
And Control ◽  
Milk And Dairy Products

Food safety is very important in the food industry as most pathogenic bacteria can cause food-borne diseases and negatively affect public health. In the milk industry, contamination with Salmonella has always been a challenge, but the risks have dramatically increased as almost all bacteria now show resistance to a wide range of commercial antibiotics. This study aimed to isolate a bacteriophage to be used as a bactericidal agent against Salmonella in milk and dairy products. Here, phage ZCSE6 has been isolated from raw milk sample sand molecularly and chemically characterized. At different multiplicities of infection (MOIs) of 0.1, 0.01, and 0.001, the phage–Salmonella interaction was studied for 6 h at 37 °C and 24 h at 8 °C. In addition, ZCSE6 was tested against Salmonella contamination in milk to examine its lytic activity for 3 h at 37 °C. The results showed that ZCSE6 has a small genome size (<48.5 kbp) and belongs to the Siphovirus family. Phage ZCSE6 revealed a high thermal and pH stability at various conditions that mimic milk manufacturing and supply chain conditions. It also demonstrated a significant reduction in Salmonella concentration in media at various MOIs, with higher bacterial eradication at higher MOI. Moreover, it significantly reduced Salmonella growth (MOI 1) in milk, manifesting a 1000-fold decrease in bacteria concentration following 3 h incubation at 37 °C. The results highlighted the strong ability of ZCSE6 to kill Salmonella and control its growth in milk. Thus, ZCSE6 is recommended as a biocontrol agent in milk to limit bacterial growth and increase the milk shelf-life.

scholarly journals A Rapid and Sensitive Europium Nanoparticle-Based Lateral Flow Immunoassay Combined with Recombinase Polymerase Amplification for Simultaneous Detection of Three Food-Borne Pathogens

2021 ◽  
Vol 18 (9) ◽  
pp. 4574
Author(s):  
Kai Chen ◽  
Biao Ma ◽  
Jiali Li ◽  
Erjing Chen ◽  
Ying Xu ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Vibrio Parahaemolyticus ◽  
Pathogenic Bacteria ◽  
Simultaneous Detection ◽  
Lateral Flow ◽  
Recombinase Polymerase Amplification ◽  
Quantitative Detection ◽  
Bacterial Strains ◽  
Food Borne Pathogens ◽  
Food Borne

Food-borne pathogens have become an important public threat to human health. There are many kinds of pathogenic bacteria in food consumed daily. A rapid and sensitive testing method for multiple food-borne pathogens is essential. Europium nanoparticles (EuNPs) are used as fluorescent probes in lateral flow immunoassays (LFIAs) to improve sensitivity. Here, recombinase polymerase amplification (RPA) combined with fluorescent LFIA was established for the simultaneous and quantitative detection of Listeria monocytogenes, Vibrio parahaemolyticus, and Escherichia coliO157:H7. In this work, the entire experimental process could be completed in 20 min at 37 °C. The limits of detection (LODs) of EuNP-based LFIA–RPA were 9.0 colony-forming units (CFU)/mL for Listeria monocytogenes, 7.0 CFU/mL for Vibrio parahaemolyticus, and 4.0 CFU/mL for Escherichia coliO157:H7. No cross-reaction could be observed in 22 bacterial strains. The fluorescent LFIA–RPA assay exhibits high sensitivity and good specificity. Moreover, the average recovery of the three food-borne pathogens spiked in food samples was 90.9–114.2%. The experiments indicate the accuracy and reliability of the multiple fluorescent test strips. Our developed EuNP-based LFIA–RPA assay is a promising analytical tool for the rapid and simultaneous detection of multiple low concentrations of food-borne pathogens.

Urinary tract infections in febrile children: Changing spectra of pathogenic bacteria and antibiotic susceptibilities?

2018 ◽  
Vol 55 (6) ◽  
pp. 680-689
Author(s):  
Jus Rakhra ◽  
Gabrielle Williams ◽  
Ben J Marais ◽  
Jonathan C Craig ◽  
Hasantha Gunasekera
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Pathogenic Bacteria ◽  
Antibiotic Susceptibilities ◽  
Tract Infections

scholarly journals Development of Innovative Pediocin PA-1 by DNA Shuffling among Class IIa Bacteriocins

2007 ◽  
Vol 73 (16) ◽  
pp. 5292-5299 ◽  
Author(s):  
Tatsuya Tominaga ◽  
Yoshinori Hatakeyama
Keyword(s):  
Dairy Products ◽  
Dairy Product ◽  
Food Additives ◽  
Dna Shuffling ◽  
Activity Assay ◽  
Effective Version ◽  
Activity Screening ◽  
Leuconostoc Lactis ◽  
Enterocin A ◽  
Increased Activity

ABSTRACT Pediocin PA-1 is a member of the class IIa bacteriocins, which show antimicrobial effects against lactic acid bacteria. To develop an improved version of pediocin PA-1, reciprocal chimeras between pediocin PA-1 and enterocin A, another class IIa bacteriocin, were constructed. Chimera EP, which consisted of the C-terminal half of pediocin PA-1 fused to the N-terminal half of enterocin A, showed increased activity against a strain of Leuconostoc lactis isolated from a sour-spoiled dairy product. To develop an even more effective version of this chimera, a DNA-shuffling library was constructed, wherein four specific regions within the N-terminal half of pediocin PA-1 were shuffled with the corresponding sequences from 10 other class IIa bacteriocins. Activity screening indicated that 63 out of 280 shuffled mutants had antimicrobial activity. A colony overlay activity assay showed that one of the mutants (designated B1) produced a >7.8-mm growth inhibition circle on L. lactis, whereas the parent pediocin PA-1 did not produce any circle. Furthermore, the active shuffled mutants showed increased activity against various species of Lactobacillus, Pediococcus, and Carnobacterium. Sequence analysis revealed that the active mutants had novel N-terminal sequences; in active mutant B1, for example, the parental pediocin PA-1 sequence (KYYGNGVTCGKHSC) was changed to TKYYGNGVSCTKSGC. These new and improved DNA-shuffled bacteriocins could prove useful as food additives for inhibiting sour spoilage of dairy products.

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