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Different morphological forms of Helicobacter pylori (gram-staining, light miscroscope, magnification  1000) a) mainly rod-like cells from a 18 h culture (Brucella broth, 37 C, b) mainly coccoid cells from a 60 h culture (Brucella broth, 37 C, micro- microaerobic environment); aerobic environment)
Source publication
Helicobacter pylori infections have been associated with the pathogenesis of a number of stomach and gastroduodenal diseases. In order to find alternative drugs for their treatment the search is increasingly focused on new antimicrobial products. However, no standardized methods are available to test the anti-Helicobacter pylori activity in particu...
Context in source publication
Context 1
... serum (FCS). The flask was cov- ered with a loosely fitted cap and incubated for 18 AE 2 h at 37 C under microaerophilic conditions. Before inoculation the bacterial cells were checked for their morphology by gram-staining and light microscopy at a final magnification of  1000. Cultures showing a high proportion of coc- coid cell shapes (see Fig. 2) were discarded. The inoculum was adjusted to a final cell count of approximately 5  10 5 cfu/ml, which was controlled by the spiral plating counting method (Spiral System Cincinnati, OH, USA). Determination of the MIC and MBC based on a modified broth micro- dilution method according to DIN 58940 part 8 and appendix 1 (1997). ...
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Background:
Increased prevalence of antibiotic resistance to Helicobacter pylori (H. pylori) infection worldwide has driven the search for a new therapeutic candidate. Recently, sitafloxacin, a novel 4-quinolone agent, has emerged as a new therapeutic option for H. pylori eradication, in Japan. However, data on its efficacy for H. pylori eradicati...
Citations
... Determination of the minimum inhibitory concentration (MIC) was assessed for nine the most active compounds (C4-C12) and for mangiferin against 7H. pylori strains including reference strains and clinical susceptible (57/16) and resistant (104/16, 3CML) MIC values was performed using the broth microdilution method in Brain Heart Infusion Broth (BHI Broth, Oxoid) supplemented with 5 % Fetal Bovine Serum (FBS, Sigma) following the CLSI recommendations with slight modifications [35,55]. Briefly, a serial two-fold dilution of tested compound as well as antibiotics (clarithromycin and metronidazole) was prepared in 24-well flat bottom titrate plates. ...
... It was also suggested that Tween 80 reduced binding of the lipophilic antibiotics to the plastic surface of the microtiter plate [41]. However, 0.5% of Tween 80 had inhibitory effect on Helicobacter pylori [81]. Nielsen et al. [78] noted a stimulating effect of Tween 80 itself on growth of Staphylococcus aureus and inhibitory effect to Pseudomonas fluorescens in concentration of 0.1%. ...
... Emulsification may be also achieved by sonication [43,53,81]. The method is often part of preparation of EOs' nanoemulsions. ...
... The method is often part of preparation of EOs' nanoemulsions. Ultrasound waves create local pressure and turbulences in the liquid leading to collapse of larger oil droplets and creation of multiple droplets with smaller diameter [81,83]. ...
Essential oils (EOs) have been gaining popularity in the past decades among researchers due to their potential to replace conventional chemicals used in the fight against pests, pathogenic and spoilage microbes and oxidation processes. EOs are complex mixtures with many chemical components the content of which depends on many factors – not just the plant genus, species or subspecies, but also chemotype, locality and climatic conditions, phase of vegetation, method of extraction and others. Due to this fact, there’s still much to study, with antimicrobial effect being one of the key properties of EOs. There are many methods that have been frequently engaged by researchers for in vitro evaluation; however, although the research has been going on for decades, an internationally accepted standard is still missing. Most of methods are based on time-proven standards used for testing of antibiotics. Due to the specific properties of EOs and their components, such as volatility and hydrophobicity, many modifications of these standard procedures have been adopted. The aim of this review is to describe the most common methods and their modifications for testing of antimicrobial properties of EOs and to point out the most controversial variables which can potentially affect results of the assays.
... Ferric ion reducing power of tested sample was determined using modified method [32]. Concisely, fresh FRAP reagent was set by adding TPTZ (10 mM prepared in 40 mM HCL) to acetate buffer (300 mM), and ferric chloride (20 mM) in specified ratio (10:1:1). ...
Background
Oral bacterial infections are difficult to treat due to emergence of resistance against antibiotic therapy. Essential oils are considered emerging alternate therapy against bacterial infections and biofilms. We investigated Citrus bergemia flower essential oil against oral pathogens.
Methods
The essential oil was analsyed using Gas Chromatography(GC–MS), in silico investigations, antioxidant, antimicrobial, antibiofilm and antiquorum sensing assays.
Results
Gas Chromatography analysis confirmed presence of 17 compounds including 1,6-Octadien-3-ol,3,7-dimethyl, 48.17%), l-limonene (22.03%) and p-menth-1-ol, 8-ol (7.31%) as major components. In silico analysis showed compliance of all tested major components with Lipinski’s rule, Bioavailability and antimicrobial activity using PASS (prediction of activity spectrum of substances). Molecular docking with transcriptional regulators 3QP5, 5OE3, 4B2O and 3Q3D revealed strong interaction of all tested compounds except 1,6-Octadien-3-ol,3,7-dimethyl. All tested compounds presented significant inhibition of DPPH (2,2-diphenyl-1-picrylhydrazyl) (IC50 0.65 mg/mL), H2O2 (hydrogen peroxide) (63.5%) and high FRAP (ferrous reducing antioxidant power) value (239.01 µg). In antimicrobial screening a significant activity (MIC 0.125 mg/mL) against Bacillus paramycoides and Bacillus chungangensis was observed. Likewise a strong antibiofilm (52.1 – 69.5%) and anti-QS (quorum sensing) (4–16 mm) activity was recorded in a dose dependent manner.
Conclusion
It was therefore concluded that C. bergemia essential oil posess strong antioxidant, antimicrobial and antibiofilm activities against tested oral pathogens.
... The minimum inhibitory concentration (MIC) was determined with modifications of a previous study [14]. In brief, SDB (100 µL) was added to the wells of a 96-well plate, followed by an equal volume of oral rinses in the first wells. ...
Objectives:
Oral healthcare professionals play a crucial role in guiding patients toward evidence-based choices among the many available oral rinses. In this study, we explored how specific oral rinse formulations affect the viability and modulate critical virulence traits of the opportunistic fungal pathogen Candida albicans.
Materials and methods:
We assessed the effects of these oral rinses on the production of germ tube, production of phospholipase and hemolysin, as well as biofilm formation.
Results:
We found that oral rinses containing cetylpyridinium chloride (CPC) and chlorhexidine (CHX) showed the greatest fungicidal activity with the lowest MFCs (0.38% and 0.78%, respectively). Oral rinses based on zinc chloride and sodium fluoride with Miswak bark extract (MIS) or essential oils (EO) had much lower fungicidal activity (8-16 times lower) compared to CHX and CPC. However, they had a significantly greater impact on the virulence traits of C. albicans. They reduced germ tube production by 86% - 89% (versus 42% for CHX and 29% for CPC), completely inhibited phospholipase and hemolysin production, and together with the CPC-based oral rinse, exerted the greatest reductions in biofilm formation across all tested concentrations. This was in contrast to both the controls and CHX, which had a minimal effect on biofilm formation.
Conclusion:
By inhibiting the virulence factors the oral rinse can have a crippling effect on C. albicans, weakening this opportunistic pathogen and hindering its potential to cause infection.
... Although scarce, there are also some data concerning mint EOs. Weseler et al. [20] showed that peppermint EO was active against H. pylori with an MIC value of 135.6 mg/L and an MBC of 542.2 mg/L. Reichling et al. [21] indicated that H. pylori was sensitive to the EO from M. spicata with MIC values ranging from 50-100 mg/L, whilst an M. arvensis EO had an MIC of 100 mg/L. ...
Helicobacter pylori infections are highly common amongst the global population. Such infections have been shown to be the cause of gastric ulcers and stomach carcinoma and, unfortunately, most cases are asymptomatic. Standard treatment requires antibiotics such as metronidazole or azithromycin to which many strains are now resistant. Mentha species have been used as a natural treatment for gastrointestinal diseases throughout history and essential oils (EOs) derived from these plants show promising results as potential antimicrobial agents. In this study, EOs obtained from the leaves and flowers of five cultivars of Mentha × piperita and M. spicata were examined by GC-MS. The investigated mints are representatives of four chemotypes: the menthol chemotype (M. × piperita ‘Multimentha’ and M. × piperita ‘Swiss’), the piperitenone oxide chemotype (M. × piperita ‘Almira’), the linalool chemotype (M. × piperita ‘Granada’), and the carvone chemotype (M. spicata ‘Moroccan’). The chemical composition of EOs from mint flowers and leaves was comparable with the exception of the Swiss cultivar. Menthol was the most abundant component in the leaves while menthone was highest in flowers. The H. pylori ATCC 43504 reference strain and 10 other H. pylori clinical strains were examined for their sensitivity to the EOs in addition to their major monoterpenoid components (menthol, menthone, carvone, dihydrocarvone, linalool, 1,8-cineole, and limonene). All tested mint EOs showed inhibitory activity against both the reference H. pylori ATCC 43504 strain (MIC 15.6–31.3 mg/L) and clinical H. pylori strains (MIC50/90 31.3–250 mg/L/62.5–500 mg/L). Among the reference monoterpenes, menthol (MIC50/90 7.8/31.3 mg/L) and carvone (MIC50/90 31.3/62.5 mg/L) had the highest anti-H. pylori activity, which also correlated with a higher activity of EOs containing these compounds (M. × piperita ‘Swiss’ and M. spicata ‘Moroccan’). A synergistic and additive interaction between the most active EOs/compounds and antibiotics possibly points to a new plant-based anti-H. pylori treatment.
... Antibacterial activity of compounds was performed by modified method (Weseler et al., 2005). An overnight bacterial culture (1.5 x10 7 CFU/mL) of about 50 lL was loaded in 96 micro well plates and then added 50 lL of test compounds were added. ...
Several types of microbial infections are caused by Acinetobacter baumanii that has developed resistance to antimicrobial agents. We therefore investigated the role of plant polyphenols against A. baumannii using in silico and in vitro models. The clinical strains of A. baumannii were investigated for determination of resistance pattern and resistance mechanisms including efflux pump, extended spectrum beta lactamase, phenotype detection of AmpC production, and Metallo-β-lactamase. The polyphenolic compounds were docked against transcription regulator BfmR (PDB ID 6BR7) and antimicrobial, antibiofilm, and anti-quorum sensing activities were performed. The antibiogram studies showed that all isolated strains were resistant. Strain A77 was positive in Metallo-β-lactamase production. Similarly, none of strains were producers of AmpC, however, A77, A76, A75 had active efflux pumps. Molecular docking studies confirmed a strong binding affinity of Rutin and Catechin towards transcription regulator 6BR7. A significant antimicrobial activity was recorded in case of quercetin and syringic acid (MIC 3.1 µg/mL) followed by vanillic acid and caffeic acid (MIC 12.5 µg/mL). All tested compounds presented a strong antibiofilm activity against A. baumanii strain A77 (65 to 90%). It was concluded that all tested polyphenols samples posess antimicrobial and antibiofilm activities, and hence they may be utilized to treat multidrug resistance A. baumannii infections.
... 63 The broth microdilution technique is reported to be accurate and easy to perform. 64 Although both culture-based tests have the disadvantage of being labor-and time-intensive in the laboratory, their greatest advantage is that they can reliably assess resistance to all antimicrobial agents present. ...
As the rate of discovery of drug-resistant Helicobacter pylori cases increases worldwide, the relevant societies have updated their guidelines for primary eradication regimens. A promising strategy against drug-resistant H. pylori is tailored therapy based on the results of an antibiotic susceptibility test; however, it is difficult to apply this strategy to all cases. Although culture-based antibiotic susceptibility tests can assess resistance to any antimicrobial agent, their greatest disadvantage is the time required to draw a conclusion. In contrast, molecular-based methods, such as polymerase chain reaction, can rapidly determine the presence of resistance, although a single test can only test for one type of antimicrobial agent. Additionally, the limited availability of facilities for molecular-based methods has hindered their widespread use. Therefore, low-cost, minimally invasive, simple, and effective primary regimens are needed. Several studies have compared the efficacy of the latest primary eradication regimens against that of tailored therapies, and their results have shaped guidelines. This article reviews the latest research on empirical and tailored treatments for H. pylori infections. Evidence for the superiority of tailored therapy over empirical therapy is still limited and varies by region and treatment regimen. A network meta-analysis comparing different empirical treatment regimens showed that vonoprazan triple therapy provides a superior eradication effect. Recently, favorable results towards vonoprazan dual therapy have been reported, as it reached eradication levels similar to those of vonoprazan triple therapy. Both vonoprazan dual therapy and tailored therapy based on antibiotic susceptibility tests could contribute to future treatment strategies.
... Determination of the minimum inhibitory and bactericidal concentrations of crude extract and supernatant of isolated strains were conducted based on the method used by Weseler et al (24) with some modifications. The serial dilutions (1.95 µg/mL to 1 mg/mL) were prepared from each of the crude extracts and supernatant of bacteria, separately. ...
... Studies assessing the antibacterial properties of PSMs include comparisons of the effects of different types of PSMs against different bacteria strains, see Table 2 . PSMs have also been reported to have antifungal properties against Candida albicans, Candida tropicalis and Candida parapsilosis [64][65][66][67][68][69][70] . In addition, PSMs inhibit proliferation of multidrug resistance pathogens [ 71 , 72 ]. ...
There is a global epidemic of non-healing wounds. Chronic inflammation, overexpression of pro-inflammatory cytokines, oxidative stress and bacterial infection are implicated in delayed wound healing. Natural extracts are a rich source of bioactive molecules called plant secondary metabolites (PSMs) that include terpenes and phenols. These molecules may facilitate wound healing through their antioxidant, anti-inflammatory, and antibacterial activity. After briefly outlining the process of wound healing and how it is compromised in chronic wounds, this review focuses on investigating how PSMs-based polymers may improve wound healing. Best methods for incorporating PSMs into wound dressings are reviewed and critically compared. The exiting body of literature strongly suggests that PSMs-based polymers incorporated into wound dressings could have clinical value in aiding wound healing.
Statement of significance
Chronic wounds develop by the persistence of inflammation, oxidative stress and infection. Chronic wounds affect the worldwide population, by reducing quality of life of patients with significant cost to healthcare systems. To help chronic wounds to heal and overcome this burden, materials with anti-inflammatory, antioxidant and antibacterial properties are required. Plant secondary metabolites (PSMs) are volatile materials that have all these properties. PSMs-based polymers can be fabricated by polymerization techniques. The present review provides an overview of the state-of-the-art of the wound healing mechanisms of PSMs. Current developments in the field of PSMs-based polymers are reviewed and their potential use as wound dressings is also covered.
... After development, HPTLC plates were dried at 105ºC and scanned densitometrically at 254 nm. 23 . Each extract was dissolved with DMSO (10% final volume) and diluted with Mueller Hinton Broth (OXOID) media to a final concentration of 10; 5; 2.5; 1.25; 0.625 and 0.3125 mg / ml. ...
In continuing the inventory and investigation of Sumatra lichen, a collection of five species from the genus Stereocaulon has been carried out. In metabolite profiling analysis, the four main compounds, i.e. atranorin, MOC, lobaric acid, and stictic acid, were rapidly isolated as marker compounds by chromatography methods from S. halei and S. montagneanum. Then, the extracts from each species were analyzed using HPTLC densitometry measured at five wavelengths of 220, 254, 280 320, and 365 nm. Atranorin and MOC are two compounds found in all five Stereocaulon species tested. Subsequently, atranorin quantification was done by densitometric scanning at 254 nm from the ethyl acetate extract of each Stereocaulon species. The highest atranorin concentration was detected from S. graminosum (325,498 mg/g extract) and equivalent to 0.065 mg/g dried whole thallus, while the lowest was from S. verruculigerum (23,356 mg/g extract) and 0.023 mg/g dried whole thallus. Furthermore, all extracts and main compounds resulting from the isolation were evaluated for their antibacterial activity by the microdilution method. Ethyl acetate and acetone extracts from S. massartianum (1) showed the highest antibacterial activity against E. faecalis (MIC = 1.25 mg/mL).
