Structural basis of pore formation in the mannose phosphotransferase system (man-PTS) by pediocin PA-1

2021 ◽  
Author(s):  
Liyan Zhu ◽  
Jianwei Zeng ◽  
Chang Wang ◽  
Jiawei Wang
Keyword(s):  
Antibacterial Activity ◽  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Severe Disease ◽  
Structural Basis ◽  
Target Cells ◽  
Bacterial Strains ◽  
Phosphotransferase System ◽  
Core Domain ◽  
Contaminated Food

Bacteriocins are ribosomally synthesized bacterial antimicrobial peptides that have a narrow spectrum of antibacterial activity against species closely related to the producers. Pediocin-like (or class IIa) bacteriocins (PLBs) exhibit antibacterial activity against several Gram-positive bacterial strains by forming pores in the cytoplasmic membrane of target cells with the specific receptor, the mannose phosphotransferase system (man-PTS). In this study, we report the cryo-electron microscopy structures of man-PTS from Listeria monocytogenes alone and its complex with pediocin PA-1, the first and most extensively studied representative PLB at a resolution of 3.12 Å and 2.45 Å, respectively. The structures revealed that the binding of pediocin PA-1 opens the Core domain of man-PTS away from its Vmotif domain, creating a pore through the cytoplasmic membranes of target cells. During this process, the N-terminal β-sheet region of pediocin PA-1 can specifically attach to the extracellular surface of the man-PTS Core domain, whereas the C-terminal half penetrates the membrane and cracks the man-PTS like a wedge. Thus, our findings shed light on a design of novel PLBs that can kill target pathogenic bacteria. Importance Listeria monocytogenes is a ubiquitous microorganism responsible for listeriosis, a rare but severe disease in humans who become infected by ingesting contaminated food products ( i.e. , dairy, meat, fish, and vegetables), which have a fatality rate of 33%. Pediocin PA-1 is an important commercial additive used in food production to inhibit Listeria species. The mannose phosphotransferase system (man-PTS) is responsible for the sensitivity of Listeria monocytogenes to pediocin PA-1. In this study, we report the cryo-EM structures of man-PTS from Listeria monocytogenes alone and its complex with pediocin PA-1 at a resolution of 3.12 Å and 2.45 Å, respectively. Our results facilitate the understanding of the mode of action of class IIa bacteriocins as an alternative to antibiotics.

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.

scholarly journals Alkaloid-Rich Crude Extracts, Fractions and Piperamide Alkaloids of Piper guineense Possess Promising Antibacterial Effects

Antibiotics ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 98 ◽  
Author(s):  
Eunice Mgbeahuruike ◽  
Pia Fyhrquist ◽  
Heikki Vuorela ◽  
Riitta Julkunen-Tiitto ◽  
Yvonne Holm
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Bacterial Resistance ◽  
Hot Water ◽  
Bacterial Strains ◽  
Inhibitory Effects ◽  
Piper Guineense ◽  
E Coli ◽  
Growth Inhibitory ◽  
Derivatives Of

Piper guineense is a food and medicinal plant commonly used to treat infectious diseases in West-African traditional medicine. In a bid to identify new antibacterial compounds due to bacterial resistance to antibiotics, twelve extracts of P. guineense fruits and leaves, obtained by sequential extraction, as well as the piperine and piperlongumine commercial compounds were evaluated for antibacterial activity against human pathogenic bacteria. HPLC-DAD and UHPLC/Q-TOF MS analysis were conducted to characterize and identify the compounds present in the extracts with promising antibacterial activity. The extracts, with the exception of the hot water decoctions and macerations, contained piperamide alkaloids as their main constituents. Piperine, dihydropiperine, piperylin, dihydropiperylin or piperlonguminine, dihydropiperlonguminine, wisanine, dihydrowisanine and derivatives of piperine and piperidine were identified in a hexane extract of the leaf. In addition, some new piperamide alkaloids were identified, such as a piperine and a piperidine alkaloid derivative and two unknown piperamide alkaloids. To the best of our knowledge, there are no piperamides reported in the literature with similar UVλ absorption maxima and masses. A piperamide alkaloid-rich hexane leaf extract recorded the lowest MIC of 19 µg/mL against Sarcina sp. and gave promising growth inhibitory effects against S. aureus and E. aerogenes as well, inhibiting the growth of both bacteria with a MIC of 78 µg/mL. Moreover, this is the first report of the antibacterial activity of P. guineense extracts against Sarcina sp. and E. aerogenes. Marked growth inhibition was also obtained for chloroform extracts of the leaves and fruits against P. aeruginosa with a MIC value of 78 µg/mL. Piperine and piperlongumine were active against E. aerogenes, S. aureus, E. coli, S. enterica, P. mirabilis and B. cereus with MIC values ranging from 39–1250 µg/mL. Notably, the water extracts, which were almost devoid of piperamide alkaloids, were not active against the bacterial strains. Our results demonstrate that P. guineense contains antibacterial alkaloids that could be relevant for the discovery of new natural antibiotics.

scholarly journals INVESTIGATION OF THE SYNERGISTIC ANTIBACTERIAL ACTION OF COPPER NANOPARTICLES ON CERTAIN ANTIBIOTICS AGAINST HUMAN PATHOGENS

2018 ◽  
Vol 10 (10) ◽  
pp. 83
Author(s):  
Selvarani Murugan
Keyword(s):  
Antibacterial Activity ◽  
Copper Nanoparticles ◽  
Pathogenic Bacteria ◽  
Color Change ◽  
Quantitative Information ◽  
Inorganic Nanoparticles ◽  
Diffusion Method ◽  
Human Pathogens ◽  
Bacterial Strains ◽  
Agar Disc

Objective: Resistance to antibacterial agents by pathogenic bacteria has emerged in recent years and is a major challenge for the healthcare industry. Copper nanoparticles (CuNPs) are known to be one of the multifunctional inorganic nanoparticles with effective antibacterial activity. Hence the present investigation has been focused on synthesizing and evaluating the bactericidal effect of copper nanoparticles.Methods: CuNPs were synthesized by reducing the aqueous solution of copper sulfate with sodium borohydride. The synthesized particles were characterized by x-ray diffractogram (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques to analyze size, morphology and quantitative information respectively. The antibacterial activity of CuNPs was examined by agar well diffusion method. Synergistic effect of CuNPs with broad-spectrum antibiotics was determined by the agar disc diffusion method.Results: Color change of reaction mixture from blue to dark brown indicated the formation of CuNPs. SEM image clearly demonstrated that the synthesized particles were spherical in shape and its size was found to be 17.85 nm. EDS report confirmed the presence of elemental copper in the resultant nanoparticles and its accounts for major proportion (96%) of the mass of nanoparticles. Bacterial effect of CuNPs revealed that Pseudomonas aeruginosa showed the highest antibacterial sensitivity (16.00±1.63 mm), whereas least susceptibility (9.67±0.47 mm) was noticed against Staphylococcus aureus. An enhanced antibacterial activity of commercial antibiotics was also noticed when it combined with CuNPS. A minimum zone of inhibition was increased from 0.67±0.47 mm to 10.66±0.24 mm when the nanoparticles and antibiotics were given together.Conclusion: It was observed that copper nanoparticles exhibited profound activity against all the tested bacterial strains which shows that CuNPs may serve as a better option for use in medicine in the future.

Phytochemical Screening, Antibacterial and Synergistic activity of Dittrichia Viscosa Extracts against Multi-Resistant Pathogenic Bacteria

2019 ◽  
Vol 2 (1) ◽  
pp. 01-06
Author(s):  
Rhazi Fouzia
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Antibacterial Effect ◽  
Synergistic Activity ◽  
Phytochemical Screening ◽  
Bacterial Strains ◽  
Dittrichia Viscosa ◽  
Study Results ◽  
Ethanolic Extracts

Study contextual: Faced with the global problem of antimicrobial resistance, and the use of traditional medicine for the research of antibacterial biomolecules. Aim: our work focused on the valorization of a medicinal plant Dittrichia viscosa which has many therapeutic and culinary virtues worldwide. Methods: To do this, a phytochemical screening of the leafy stems of the plant is carried out according to a set of physicochemical reactions, as well as an in vitro evaluation of the antibacterial activity, of the aqueous and ethanolic extracts against multi-resistant bacterial strains, by microdilution technique on microplates. An evaluation of the synergistic interaction between extracts and weakened antibiotics against pathogenic bacteria was also highlighted in this study. Results: The tests revealed the richness of Dittrichia viscosa species by tannins, flavonoids, saponosides, sterols and triterpenes. As for the antibacterial effect, the MICs range from 0.858±0.29 to 66.66 ± 0.00 mg / ml and the MBCs from 4.300 ± 1.01 to 11.610 ± 2.31 mg / ml is an interesting antibacterial activity. Regarding the combination of extracts with antibiotics tested, it revealed a synergistic action inducing an amplification of the antibacterial power of Penicillin, Imipenem and Erythromycin with a rate that reaches 471%. Conclusion: The results of this study show that the aqueous and ethanolic extracts of Dittrichia viscosa have interesting and promising antibacterial activity in the pharmaceutical, food and cosmetic industries.

scholarly journals Some endemic medicinal plants of Andamans with antimicrobial potential

2016 ◽  
Vol 1 (1) ◽  
pp. 10
Author(s):  
Asma Bibi ◽  
A. Thangamani ◽  
V. Venkatesalu
Keyword(s):  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Pathogenic Bacteria ◽  
Phytopathogenic Fungi ◽  
Gram Negative Bacteria ◽  
Andaman Islands ◽  
Bacterial Strains ◽  
Endemic Plant ◽  
Ethanol Extracts ◽  
Endemic Plant Species

The present study was aimed to determine the antimicrobial activity of some endemic plant species used in folkloric medicine by the inhabitants of Andaman Islands, India. The ethanol extracts prepared from the leaves of four plants viz; Alstonia kurzii, Tabernaemontana crispa, Mangifera andamanica and Vitex diversifolia were assessed for antibacterial activity against clinically isolated human pathogenic bacteria and antifungal activity against some phytopathogenic fungi. The ethanol extracts showed more inhibition towards Gram positive than Gram negative bacteria and the bacterial strains showed more susceptibility than the fungal strains tested. Among the plants, Vitex diversifolia exhibited the highest antibacterial activity and Mangifera andamanica showed the highest antifungal activity.

scholarly journals Extraction and Isolation of Compound from Roots of Kniphofia pumila, and Its Antibacterial Activities in Combination with Zinc Chloride

2020 ◽  
Vol 17 (7) ◽  
pp. 631-638
Author(s):  
Dele ABDISSA ◽  
Gezahegn FAYE ◽  
Melkamu FAYERA ◽  
Shiferaw DEMISSIE
Keyword(s):  
Antibacterial Activity ◽  
Crude Extract ◽  
Pathogenic Bacteria ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Spectroscopic Techniques ◽  
Bacterial Strains ◽  
Pure Compound ◽  
Standard Drug ◽  
Isolated Compound

Kniphofia pumila has been traditionally used for the treatment of different diseases in Oromiya regional state, western part of Ethiopia. Thus, the main objective of this study was to extract bioactive natural products from the roots of K. pumila and perform in vitro antibacterial activity tests against selected pathogens. Extraction of compound from the roots of K. pumila was carried out by maceration method at room temperature and its antibacterial activity was done using agar disc diffusion method. The crude extracts alone and along with ZnCl2 were tested against pathogenic bacteria Escherichia coli (ATCC 25722), Klebsiella pneumoniae subsp. pneumoniae (DSM 19613), Staphylococcus aureus (ATCC 25925) and Salmonella Typhimurium (ATCC 13311). Following its promising activity, the acetone crude extract that have shown better antibacterial activity was subjected to column chromatography for isolation of pure compound. Hence, one pure compound (GZ-1) was obtained from acetone crude extract. Meanwhile, the antibacterial activities of the isolated compound alone and in combination with ZnCl2 were also performed against all aforementioned bacterial strains. Then, isolated compound was characterized by using NMR spectroscopic techniques such as 1H-NMR, 13C-NMR and, 2D NMR, so as to establish its structure as 3’-acetyl-2’,6’-dihydroxy-4-methoxyphenyl-1,8-dihydroxy-3-methylanthraquinone, trivial name knipholone. Finally, GZ-1 was isolated from the roots of K. pumila and it was noted that the antibacterial activities of ZnCl2 in combination with crude extract as well as with isolated compound against E. coli (ATCC 25722), S. aureus (ATCC 25925) and S. Typhimurium (ATCC 13311) bacterial strains showed remarkable results which were greater than the antibacterial activity of the positive standard drug (gentamycin). To sum up, from the chromatographic isolation of roots acetone extract of K. pumila one pure compound (knipholone) was obtained. Its antibacterial activity was also evaluated in combination with ZnCl2 salt and alone.

scholarly journals STUDY CYTOTOXICITY, ANTIBACTERIAL ACTIVITY, AND COMPOSITIONS BY FT-IR AND GC-MS FOR ORGANIC EXTRACT OF WHITE IRAQI DESERT TRUFFLE TIRMANIA NIVEA

2020 ◽  
Vol 17 (36) ◽  
pp. 18-31
Author(s):  
Ahmad khadem HACHIM ◽  
Rashid Rahim HATEET ◽  
Tawfik Muhammad MUHSIN
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Cell Line ◽  
Pathogenic Bacteria ◽  
Inhibitory Concentration ◽  
Biological Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Bacterial Strains ◽  
Organic Extract

The purpose of the present work aimed at exploring the potential biochemical components and biological activities of an organic extract of the white truffle Tirmania nivea collected from the Iraqi desert, then test the organic extract against the Cytotoxicity on Human Larynx carcinoma cells and selected strains of pathogenic bacteria. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry GC/MSS were used to analyze mycochemical compositions. The antibacterial activity and Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) was investigated using a disk diffusion agar method. The truffle extract's cytotoxicity effect against the larynx cell line (Hep-2) was assessed by the MTT assay (in vitro). FTIR results provided the presence of phenol, carboxylic acid, and alkane's functional group, The GC-MS analysis of T. nivea disclose the existence of nineteen compounds that can contribute to the pharmaceutical properties of the truffle. As for antibacterial activity result, A growth inhibition activity of truffle extract at (18-40 mm inhibition zones) against the tested pathogenic bacterial strains was detected, which minimum inhibitory concentration values ranged from 3.12 to 6.25 mg/mL for Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) Respectively. The results of cytotoxicity shown that the organic truffle extract exhibited a high inhibitory rate (52.685%) against cell line (Hep-2) at a concentration of 1.56 ?g/mL. In this work, the results showed that the organic extracts of T. nivea are very promising as cancer cytotoxicity and antibacterial agent for future medical applications.

scholarly journals The antimicrobial activity of some medical plants against bacteria that cause urinary tract infection

2018 ◽  
Vol 28 (3) ◽  
pp. 72
Author(s):  
Nehia Hussein ◽  
Noor Ameer Hanon
Keyword(s):  
Urinary Tract Infection ◽  
Antibacterial Activity ◽  
Urinary Tract ◽  
Tract Infection ◽  
Plant Extracts ◽  
Pathogenic Bacteria ◽  
Resistant Bacteria ◽  
Aqueous Extracts ◽  
Bacterial Strains ◽  
Qualitative Detection

This study was done to evaluate the antibacterial activity of hot ethanolic and aqueous extracts of Syzygium aromatic (S.aromatic ) and Q.infectoria infectoria (gall) against pathogenic bacteria that cause urinary tract infection (UTI). Such as Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Qualitative detection of the active compounds of the plant extracts was done with chemical reagents. Also, the Qualitative detection of the active groups was further verified with (FTIR). The sensitivity of the UTI causing bacteria was examined against 12 different antibiotics. The results show that E.coli was the most resistant bacteria, resisting 8 from 12 antibiotics; P.aeruginosa resisted 5 from 12 antibiotics; while S.aureus showed resistance to 4 only. The antibacterial activity of the plant extracts was investigated by using four concentrations (40, 60, 80, 100 mg/ml) for each extract against two types of Gram negative bacteria (E.coli, P.aeruginosa), and one type of Gram-positive bacteria (S. aureus). The plant extracts showed different effects on the growth of all bacterial strains. The Minimum Inhibitory Concentration (MIC) and the Minimum bactericidal concentration (MBC) of the ethanolic extracts and aqueous extracts in the study were determined.The kill- time was determined also for each extract.The antioxidant activity of the plants in the study was investigated. Finally, the toxicity of the plant extracts was examined on human red blood cells.

In-vitro evaluation of cisplatin nanoparticles encompass natural polymer

2020 ◽  
Vol 3 (1) ◽  
pp. 1-6
Author(s):  
Bhavani J ◽  
Sunil Kumar Prajapati ◽  
Ravichandran S
Keyword(s):  
Antibacterial Activity ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
Research Work ◽  
Dilution Method ◽  
Bacterial Strains ◽  
Active Components ◽  
Synthetic Drugs

Opportunistic bacterial infections are common in the various parts of human body. In recent years bacterial species have shown resistance against a number of synthetic drugs. This study measured the antibacterial activity of bacterial strains against five common pathogenic bacteria related strains. Cup plate method and two fold serial dilution method were used to evaluated by antibacterial activity by the help of different bacterial related strains. The results revealed that Cisplatin (CIP) using natural as a polymer showed a minimum inhibitory concentration (MIC) at 250 mg/ml to 500 mg/ml of the broth against all bacterial strains. CIP using natural as a polymer was prepared different doses1000 μg/ml and 2000 μg/ ml and measured zone of inhibition dose dementedly reduced when compared to standard. The CIP using natural as a polymer exhibited strong anti-bacterial activity against five different species of bacteria and this may be attributed to various active components. Our research work has been indicated Nanoparticles containing CIP using natural as a polymer formulated for the enhanced anti-cancer activity through antimicrobial mechanism. 

scholarly journals Chemical Composition, Antioxidant Potential, and Antibacterial Activity of Essential Oil Cones of TunisianCupressus sempervirens

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Aicha Ben Nouri ◽  
Wissal Dhifi ◽  
Sana Bellili ◽  
Hanene Ghazghazi ◽  
Chedia Aouadhi ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Pathogenic Bacteria ◽  
Klebsiella Oxytoca ◽  
Inhibitory Effect ◽  
Major Constituent ◽  
Bacterial Strains ◽  
Cupressus Sempervirens ◽  
Antioxidant Power

The extraction yield of the essential oil (EO) extracted by hydrodistillation from the cones of TunisianCupressus sempervirensL. was of 0.518%. The chemical composition was analyzed by GC-MS. Results showed that this essential oil was mainly composed of monoterpene hydrocarbons (65%) withα-pinene as the major constituent (47.51%). Its antioxidant activity was ascertained by evaluating the total antioxidant capacity and also by evaluating its inhibitory effect against DPPH and ABTS radicals. In addition, it showed a strong antioxidant power against the DPPH (IC50= 151 µg/mL) and ABTS (IC50= 176.454 µg/mL) radicals scavenging. Moreover, its antibacterial activity was tested against different species of pathogenic bacteria (three Gram-positive and eight Gram-negative bacteria). The bacterial strains susceptible to the evaluated oil wereBacillus subtilis,Escherichia coli,Klebsiella oxytoca,Morganella morganii,Shigella, andVibrio cholerae.

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