Agar Diffusion Assay Research Articles

Suitability of starch/carvacrol nanofibers as biopreservatives for minimizing the fungal spoilage of bread

The objective of this study was to evaluate the in vitro susceptibility of fungi to starch/carvacrol nanofibers produced by electrospinning. The nanofibers were incorporated into bread dough or used in the development of active packages to minimize bread spoilage. In agar diffusion and micro-atmosphere assays, the nanofibers with 30 % or 40 % carvacrol presented inhibition zones with low growth and were effective inhibiting both the fungi evaluated in this work. The MICs for nanofibers with 30 % carvacrol were 0.098 and 9.8 mg/mL against Penicillium sp. and Aspergillus flavus, respectively; for the 40 % nanofibers, the MIC was 19.6 mg/mL against Aspergillus flavus. As for MFC, only the 30 % nanofibers exerted fungicidal effect. The treatments administered directly to the bread dough had low colony-forming unit. For bioactive packages, nonwovens with 30 % carvacrol were effective in preventing bread spoilage. Thus, nanofibers are a good alternative to chemical additives or bioactive packages in food industry.

Antibacterial activity of honeys from Amazonian stingless bees of Melipona spp. and its effects on bacterial cell morphology.

Stingless bee honey has great therapeutic potential, especially as an antimicrobial agent. In the present study, we evaluated the in vitro antibacterial potential of honey from Melipona spp. with occurrence in Rio Branco-AC and Xapuri-AC from the Amazonian region. Samples were collected from the species Melipona eburnea, Melipona grandis, Melipona flavolineata and Melipona seminigra. The antibacterial activity of the honey samples was tested against standard Gram-positive and Gram-negative bacteria and two strains isolated from bovine mastitis. In the agar diffusion assay, we observed antibacterial activity for the four honeys against the tested strains. The honey from M. flavolineata showed a minimmum inhibitory concentration (MIC) lower than 3.12% (v/v). The minimum bactericidal concentration values were larger than the MIC for most of the microorganisms tested. Scanning electron microscopy (SEM) showed the damaging effect of the honey of M. flavolineata on Staphylococcus aureus cells, as well as its inhibitory effect on cell division. The results of the present study demonstrate that the honey from stingless bees possesses in vitro antimicrobial activity against pathogenic bacteria. The effects observed by SEM show that honey from the Amazonian stingless bee M. flavolineata has promising therapeutic potential as a future antimicrobial agent. © 2020 Society of Chemical Industry.

Antimicrobial activity of Baccharis dracunculifolia DC and its synergistic interaction with nisin against food-related bacteria.

The antimicrobial activities of Baccharis dracunculifolia DC essential oil (EO) and hydroalcoholic extract (HE) were evaluated. The EO showed broad antimicrobial activity and its synergistic combination with nisin was tested. Major components of EO were nerolidol, beta-pinene and D-limonene, while artepillin C, rutin and cafeic acid were major phenolics of HE. EO and HE were tested by agar diffusion assay against several strains of bacteria and yeasts, and mixed cultures of bacterial strains. The EO presented the largest spectrum of antimicrobial activity inhibiting all Gram-positive bacteria tested. Yeasts were not inhibited. The effect of EO against mixtures of sensitive and non-sensitive bacteria was tested on milk agar, being the inhibitory effect only observed on mixtures containing susceptible strains. The combination of EO and nisin at ½ MIC was evaluated on the growth curve of Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes and Salmonella Enteritidis during 24h at 37°C. The combination EO-nisin was effective and no viable counts of B. cereus, L. monocytogenes and S.Enteritidis was observed, while the individual antimicrobials caused no inhibition. The counts of S. aureus were about 4 log CFU/mL lower in comparison with EO or nisin alone. B. dracunculifolia DC may be a potential source of natural antimicrobials, and its synergistic effect with nisin would reduce the working concentration, minimizing the organoleptic effects associated with this plant antimicrobial.

Colistin and Isavuconazole Interact Synergistically In Vitro against Aspergillus nidulans and Aspergillus niger.

The in vitro interactions of isavuconazole in combination with colistin were evaluated against 55 clinical Aspergillus species isolates belonging to the five most important species (Aspergillus flavus, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus niger, and Aspergillus terreus) responsible for human aspergillosis by a microdilution checkerboard technique based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) reference method for antifungal susceptibility testing. Selected isolates (A. nidulans, n = 10; A. niger, n = 15) were additionally evaluated by an agar diffusion assay using isavuconazole gradient concentration strips with or without colistin incorporated Roswell Parc Memorial Institute (RPMI) agar. Interpretation of the checkerboard results was done by the fractional inhibitory concentration index. Using the checkerboard method, combination isavuconazole–colistin was synergistic for 100% of the 15 A. nidulans isolates and for 60% of the 20 A. niger isolates. No interactions were found for any of the other isolates. By agar diffusion assay, minimal inhibitory concentrations (MICs) in combination decreased compared to isavuconazole alone for 92% of the isolates. No interactions were found for any A. nidulans isolates, but synergy was observed for 40% of the A. niger isolates. A poor essential agreement of EUCAST and gradient concentration strip MICs at ± 2 log2 dilutions with 0% was obtained. Antagonistic interactions were never observed regardless of the technique used.

Antimicrobial activity of Satureja Khuzestanica Jamzad and Satureja bachtiarica Bunge essential oils against Shigella flexneri and Escherichia coli in table cream containing Lactobacillus plantarum LU5.

The essential oils (EOs) from Marzeh khuzestani (Satureja Khuzestanica Jamzad) and Marzeh bakhtiari (Satureja bachtiarica Bunge) were analyzed and their antibacterial activities on Shigella flexneri and Escherichia coli in probiotic table cream containing Lactobacillus plantarum LU5 were evaluated. Carvacrol (86.5%) was the main component of Marzeh khuzestani, but thymol (33.5%), carvacrol (14.2%), borneol (13.4%), and linalool (11.5%) were the major constituents of Marzeh Bakhtiari EOs. Marzeh khuzestani exhibited the highest antibacterial/bactericidal activity on the tested bacteria. EOs combination showed no interaction on the L. plantarum but a synergism effect to inhibit the pathogen strains observed. Agar diffusion assay showed the highest inhibitory effect on S. flexneri (32.7mm), E. coli (28.4mm), and L. plantarum (24.7mm) for the combination 2:1 Marzeh khuzestani:Marzeh Bakhtiari (p≤.05). The antibacterial activity of mixture of EOs in creams was evaluated and the sample contained of 1%k+1%b showed the highest antibacterial activity after day 10 of storage (by lowering the number of E. coli, S. flexneri, and L. plantarum to 2.3, 1.9, and 1.4 log CFU/g compared to control sample). Overall acceptability of creams slightly decreased by the increase in EOs addition and the highest acceptability score of 7.9 observed for the sample contained 0.5%k+0.5%b EOs. However, all treatments exhibited a high acceptance level that it confirms that the addition of EOs mixture had no effect on the sensorial attributes of the creams. The combination of tested EOs can be used as an antimicrobial agent in probiotic food products containing L. plantarum.

Antimicrobial Effect of Natural Berry Juices on Common Oral Pathogenic Bacteria.

(1) Background: Antimicrobial agents such as chlorhexidine (CHX) are commonly used in oral plaque control. However, sometimes those agents lack antimicrobial efficiency or cause undesired side effects. To identify alternative anti-infective agents, the present study investigated the antibacterial activity of all-fruit juices derived from blackcurrant, redcurrant, cranberry and raspberry on common oral pathogenic gram-positive and gram-negative bacteria (Streptococcus mutans, Streptococcus gordonii, Streptococcus sobrinus, Actinomyces naeslundii, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Enterococcus faecalis). (2) Methods: Antibacterial efficiency was evaluated by agar diffusion assay and in direct contact with bacteria in planktonic culture. Furthermore, cytotoxicity on human gingival fibroblasts was determined. (3) Results: Blackcurrant juice was most efficient at suppressing bacteria; followed by the activity of redcurrant and cranberry juice. Raspberry juice only suppressed P. gingivalis significantly. Only high-concentrated blackcurrant juice showed minimal cytotoxic effects which were significantly less compared to the action of CHX. (4) Conclusion: Extracts from natural berry juices might be used for safe and efficient suppression of oral pathogenic bacterial species.

Effect of Rosemary (Rosmarinus officinalis) and Sage (Salvia officinalis) Essential Oils on Disease Resistance against Aeromonas sobria in Goldfish (Carassius auratus)

In this study, the chemical composition and the antibacterial properties against Aeromonas sobria of the essential oils of rosemary and sage in gold fish were evaluated in vitro and in vivo for the first time. The major constituents were eucalyptol (26.36 %) and camphor (29.17 %) for rosemary essential oil and eucalyptol (27.08 %), thujone (20.52 %) and camphor (16.99 %) for sage oil. In vitro antibacterial effects of essential oils against A. sobria were detected by agar diffusion assay. The in vitro antibacterial effect of rosemary (20±2.82 mm) and sage (18.5±2.12 mm) essential oils (1000 µl ml-1) were determined to be strong against A. sobria (p˂0.05). The effects of the essential oils on the disease resistance of goldfish were also investigated. Fish (5±0.15 g) were fed with different concentrations (0, 1.0 and 3.0 ml kg-1) of each essential oil for 45 days. After feeding, the fish were challenged with A. sobria. Dietary administration of sage essential oil (1.0 and 3.0 ml kg-1) and rosemary oil (3 ml kg-1 ) resulted in a significant reduction in mortality due to A. sobria compared to control fish. Our results suggest that these plant oils could provide an alternative for A. sobria infection control in aquaculture.

Anti-bacterial, anti-scavenging and cytotoxic activity of garden cress polysaccharides.

Plants polysaccharides are an infinite stock of drug composites with varying pharmacological and biological activities. The present investigation aimed to examine the antibacterial, anti-scavenging and cytotoxic potential of garden cress (GC) polysaccharides. The antibacterial effects vs Escherichia coli and as well as Staphylococcus aureus of GC polysaccharides were examined by means of agar diffusion assay, minimum inhibitory concentration (MIC), outer and inner cell membrane permeability. Antioxidant potential of the GC polysaccharides were performed by free radical DPPH scavenging, superoxide anion scavenging, hydroxyl radical scavenging, reducing power potential assay, and hydrogen peroxide method. Cytotoxicity potential of GC polysaccharides were evaluated by MTT assay in human cervical (HeLa) and liver carcinoma (HepG2) cell lines. The findings showed that GC polysaccharides MIC were 1.06 and 0.56 mg mL−1 against E. coli and S. aureus, respectively. Compared to the standard inhibitor, the GC polysaccharides showed essential inhibitor assays in a very dose dependent approach, and notable actions to scavenge reactive oxygen species (ROS) are also due to the large quantities of hydrophilic polyphenols. The IC50 values of all tested parameters were measured against standard ascorbic acid antioxidant agent. The GC polysaccharides diminish the cell viability percentage of HeLa and HepG2 in a concentration dependent manner. GC polysaccharides at a dose of 500 µg ml−1 exhibited higher anti-tumor activity in both HeLa (65.33 ± 3.75%) and HepG2 (60.33 ± 3.48%). The findings obtained in this study indicate that GC polysaccharides has antibacterial and has a possible source of natural antioxidant and also has cytotoxic effect on different carcinoma cell lines.

3D printed antimicrobial PLA constructs functionalised with zinc- coated halloysite nanotubes-Ag-chitosan oligosaccharide lactate

ABSTRACT S. aureus and S. epidermidis are the most common bacteria responsible for causing implant infections. We propose that 3D-printed antimicrobial biomedical devices are a rational solution for the prevention of infection. 3D printed polylactic acid (PLA) constructs were alkali-treated to increase hydrophilicity and functionalized using a suspension of Zinc/HNTs-Ag-Chitosan Oligosaccharide Lactate (ZnHNTs-Ag-COS). PLA constructs were analyzed using scanning electron microscopy and Fourier-transform infrared spectroscopy (FTIR). The antimicrobial potential was assessed using agar diffusion and biofilm assays. The surface of 3D printed PLA constructs were chemically modified to increase hydrophilicity and suspensions of COS-ZnHNTs-Ag were adsorbed on the construct surface. Surface adsorption of ZnHNTs-Ag-COS on PLA printed constructs was determined to be a function of relative pore size. Morphological surface characterization confirmed the presence of the suspension coatings on the constructs, and FTIR analysis confirmed the presence of COS-ZnHNTs-Ag coatings. Growth inhibition studies validated the antimicrobial properties of PLA constructs.

Epidemiology of Bacterial Contamination of Inert Hospital Surfaces and Equipment in Critical and Non-critical Care Units: A Brazilian Study

Aims: The hospital environment is an important reservoir of microorganisms, including multidrug-resistant pathogens, which can cause in-patient contamination and healthcare-related infections. The objective of this study was to describe the epidemiology of bacterial contamination (contaminated sites, pathogen species and their antimicrobial susceptibility, and identifying of multidrug-resistant microorganisms - MDR) of inert hospital surfaces and medical equipment in two public hospitals in Northern Brazil.
 Methods: This was a cross-sectional study with 243 samples (n = 208, from Hospital A; and n = 35, from Hospital B) collected by friction with humidified swabs from inert surfaces and equipment. Sequentially the samples were cultivated and bacterial species were identified by culture-based methods and tested for their susceptibility through agar diffusion assay according to the Clinical and Laboratory Standards Institute (CLSI).
 Results: Most inert surfaces and equipment analyzed presented bacterial contamination (95.5%). Staphylococcus aureus was the main pathogen of clinical significance detected both in Hospital A (61.8%) and B (68.6%). Hospital A showed higher rates of isolated MDR bacteria than Hospital B, especially in the Adult Intensive Care Unit, which included methicillin-resistant Staphylococcus aureus (MRSA) (52.7%), Enterobacteria resistant to 4th generation cephalosporins (19.4%), and multidrug-resistant Pseudomonas aeruginosa (2.8%).
 Conclusion: The failures in the control of bacterial contamination of inert surfaces and equipment in the two hospitals analyzed reinforce the need for a revised protocol for cleaning and disinfection of the inert surfaces and equipment, and for regulation of antibiotic dispensing, mainly in the AICU of Hospital A, which was found to be a reservoir of MDR pathogens.

Effect of Piper betle extract on anti-candidal activity, gelation time, and surface hardness of a short-term soft lining material.

The purpose of this study was to evaluate anti-candidal activity, gelation time, and surface hardness of a short-term soft lining material incorporated with varying concentrations of Piper betle extract (0.25 to 20% w/w). Agar-diffusion assay was conducted to evaluate an inhibitory effect against Candida albicans. The gelation time was assessed and surface hardness was measured at 2 h and 7 days by Shore AO durometer. A soft liner containing at least 5% w/w of P. betle extract was observed the inhibitory effect against C. albicans. An increasing of P. betle concentrations provided larger inhibition zone. Incorporating 5% w/w of P. betle extract into the soft liner did not significantly alter its gelation time and surface hardness (ANOVA; p>0.05). The optimum composition at 5% w/w of P. betle extract can be used as an additive in the soft liner to provide the anti-candidal activity without significantly affect these two main properties.

Re-thinking Metronidazole: Anti-microbial Synergism of Hexane Extracts of Garcinia kola and Aframomum melegueta

Aims: This research evaluates knowledge, attitudes, and practice with regard to food poisoning treatment. It compares the antimicrobial effects of Garcinia kola (Gk) and Aframomum melegueta (Am) seeds with Metronidazole and Gentamicin as standards.
 Study Design: A survey with questionnaires was carried out among community Pharmacists in Lagos, Nigeria on drug of choice for suspected food poisoning and the responses analyzed. Hexane extracts of Gk and Am seeds were used on selected microbials that cause food poisoning.
 Place and Duration of Study: Department of Pharmacognosy; Phytochemistry Laboratory and Department of Pharmaceutics and Pharmaceutical Technology; Pharmaceutical Microbiology Laboratory, Faculty of Pharmacy. University of Lagos.
 Methodology: Agar diffusion assays were carried out using and using Gk and Am with Metronidazole and Gentamicin as controls. Gas chromatography and Mass spectroscopy of the extracts was also carried out to ascertain the possible active phytocomponents.
 Results: Our discovery on knowledge showed that 98.6% of the interviewed Pharmacists use Metronidazole for food poisoning treatment. 41.7% of the respondents prescribe Ciprofloxacin while 66.7% prescribed Tetracycline as adjunct medications. Gk and Am exerted powerful anti-microbial effects in a dose dependent manner. Gk on S. typhi showed 1.4-1.7 cm zone of inhibition (zi) at 200mg/ml and with E. coli, 1.2 cm at same concentration. Am with S. typhi showed1.2-1.8 cm and E. coli 1.5 cm zi at same concentration too, much better than Gk. Their mixture for the synergistic experiments had 2.0-2.2 cm and E. coli, 2.4 cm zi at 200 mg/ml, the best performance of the extracts as anti-infective agents against food poisoning. 19 compounds were discovered through GC/MS in Gk and 31 in Am. They each exerted more antimicrobial effects than Metronidazole and their mixture used for synergistic experiments compared favorably with Gentamicin.
 Conclusion: Hexane extracts of Gk and Am are good alternatives for the treatment of food poisoning. The study encourages further drug discovery research in order to ascertain the particular bioactive compounds in the extracts responsible for their powerful antimicrobial actions. Metronidazole is not the drug of choice for food poisoning management.

In-vitro Assessment of Biological Properties of Lipids Isolated from Gonads of Stomopneustes variolaris

Lipid fractions of gonads present in sea urchins serves as a source of bioactive agents with potent pharmaceutical properties. The present study reports the in-vitro biological effects of lipids isolated from gonads of sea urchin: Stomopneustes variolaris collected from the East coast of India. The extracted lipids were characterized by spectroscopic techniques such as GCMS and FTIR and tested for in-vitro biological effects. GCMS analysis of the lipid extract detected high levels of hexa triacontane (17.023 %), tetratetracontane (15.913%), and octacosane (15.628%) and low concentrations of oleic acid (2.206%) and sulfurous acid, pentadecy 2-propyl ester (1.744%). FTIR analysis identified rich composition of functional groups present in the lipids such as 3418.93 cm-1 (hydroxyl), 2921.08cm-1 and 2854.81 cm-1 (alkane), 2660.69 cm-1 (carboxylic acid), 1596.11 cm-1 (amine), 1291.76 cm-1 (aromatic amine). The lipid fraction evaluated by agar diffusion assay measured in terms of zone of inhibition showed bactericidal effects against gram-positive bacteria: Streptococcus aureus (30 mm); Pseudomonas aeruginosa (28.5 mm) and gram-negative bacteria: Escherichia coli (29.5 mm); Klebsiella pneumonia (27.5 mm) and Vibrio cholera (28 mm) respectively. The lipid fraction also showed an effective anti-fungal effect against C.albicans (25 mm). Further, the lipid fractions showed good radical scavenging effect against total phenolic, flavonoid content (15.12 mg GAE/g and 32.72 mg QE/g), and hydrogen peroxide radicals (IC50- 48.28mg/ml) confirming its anti-oxidant potential. Based on the observed results, it was identified that the lipid fraction of gonads of Stomopneustes variolaris demonstrated various biological effects such as bactericidal, anti-fungal and radical scavenging activities which could have a great scope in the formulation of biopharmaceutical agents.

Growth Inhibitory Effects of Antimicrobial Natural Products against Cariogenic and Health-Associated Oral Bacterial Species.

This study investigated whether selected natural products could specifically target the growth of a caries-associated bacterial species (Streptococcus mutans) without affecting the viability of a health-associated oral commensal bacterial species (Streptococcus sanguinis). Agar diffusion assays were used to screen the natural products for bacterial-growth inhibitory effects and the diameters of the inhibitory zones for the two bacterial species compared. The minimum inhibitory concentrations (MIC) of the natural products that showed growth inhibitory effects were determined using the broth microdilution method. Except for the berry extracts (cranberry, wild blueberry, and strawberry), all the other selected natural products (peppermint, ginger, cinnamon, rosemary, liquorice, xanthorrrhizol, tt-farnesol, guaijaverin, and macelignan) exhibited varying degrees of bacterial growth inhibition. The MIC values ranged from as low as 4 µg/ml for xanthorrrhizol to 1000 µg/ml for guaijaverin. All the growth inhibitory natural agents tested showed similar inhibition for both S. mutans and S. sanguinis. Although several natural products exerted significant antibacterial effects, none had selective inhibitory action on the growth of S. mutans.

Bactericidal Activity Study of ZrO2-Ag2O Nanoparticles.

In view of the continuous resistance to antibacterial agents by bacteria and the existing problems of silver nanoparticles as an antibacterial agent, this study reports on the synthesis of pure zirconium oxide, silver oxide, and ZrO2-Ag2O nanoparticles by sol-gel method. The nanoparticles were analyzed and tested for their antibacterial activity against gram-positive bacteria of Bacillus subtilis, Streptococcus mutans, Staphylococcus aureus, and gram-negative of Escherichia coli, Pseudomonas aeruginosa, and Klebsiella oxytoca. X-ray diffraction showed the monoclinic ZrO2, cubic Ag2O, and peaks corresponding to ZrO2 and Ag2O in their mixed samples. Scanning electron microscopy showed spherically shaped nanoparticles while dynamic light scattering analysis showed ZrO2 (76 nm), Ag2O (50 nm), and ZrO2-Ag2O samples between 14 and 42 nm. The Fourier Transformed Infrared spectroscopy spectra of ZrO2 gave bands at 480 cm−1 to 750 cm−1 (M-O stretching) with Ag2O at 580 cm−1, while ZrO2-Ag2O samples showed bands at 760 cm−1. The screening by agar diffusion assay revealed a pronounced increase in the antibacterial activity of ZrO2-Ag2O against all the tested bacteria when compared with the pure ZrO2 and Ag2O. The improved antibacterial activity of ZrO2-Ag2O largely results from the chemical stability conferred on it by the ZrO2 as observed from the zeta potential measurement.

Evaluation of Medicinal Plants Extract against Biofilm Formation in Pseudomonas aeruginosa

The antibacterial and biofilm inhibitory activity of leaf extracts of Ocimum gratissimum, Moringa oleifera, Hibiscus sabdariffa, Azadirachta indica and seed extract of Garcinia kola against clinical isolates of Pseudomonas aeruginosa were evaluated using the agar diffusion and crystal violet assay methods. The ethanol extracts of O. gratissimum and H. sabdariffa exhibited significant antibacterial activity against the P. aeruginosa with diameter zones of inhibition of 25 mm and 30mm with minimum inhibitory concentrations (MIC) of 0.16 mg/ml and 0.18 mg/ml respectively. While the ethanol extracts of A. indica, M. oleifera and G. kola showed no antibacterial effect against the test organism. However, all five plants extract inhibited the formation of biofilm with optical density (OD) values reduction from 0.168 to 0.160 for O. gratissimum, 0.170 to 0.151 for H. sabdariffa, 0.140 to 0.138 for A. indica, 0.145 to 0.137 for M. oleifera and 0.135 to 0.130 for G. kola. Out of five plants extract tested, H. sabdariffa exhibited the best growth and biofilm inhibition activity of P. aeruginosa. The results of this study indicate that various concentrations of the plants extract particularly H. sabdariffa, may provide an alternative to control biofilm-related infections caused by P. aeruginosa.

574 To assess the antifungal activity of Jublia® under real-world conditions

Onychomycosis affects up to 8% of the population and is most commonly caused by Trichophyton rubrum (T. rubrum) and Trichophyton mentagrophytes (T. mentagrophytes). Systemic antifungals provide higher rates of clearance compared to topical antifungals, but are associated with potentially serious side effects and drug-drug interactions. Efinaconazole, a triazole antifungal, is approved by the FDA as a 10% nail solution (Jublia®) for the treatment of distal and lateral subungual onychomycosis. Efinaconazole’s activity has been demonstrated using agar diffusion assays (ADAs) centered on cadaveric nail clippings; however, it has not been studied under real-world conditions that may provide a more accurate approximation of its true effectiveness.

Antibacterial potential assessment of Nalca (Gunnera tinctoria Mol.) ethanolic extracts

Nalca is an edible rhubarb-type plant from the southern of Chile; with studies focussing on petiole chemical and biological properties. This work evaluated for the first time the antibacterial capacities of three organs of nalca against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Petiole (P), root (R) and flower (F) ethanolic extracts at three different concentrations (25, 50, 100 mg/mL) were evaluated by means of agar diffusion assay and MIC. The result showed that antibacterial activities are bacteria and concentration dependent, with root having the highest antimicrobial activity of the organs plant studied. Compared to commercial antibiotics, nalca extracts show promising control over Ps. aeruginosa. The main polyphenolics of the extracts were identified by UPLC–MS/MS, observing for the first time caffeic, coumaric and gallic acids presence in all samples, with quercetin and rutin determined in petiole and flower extracts only. Our results contribute to better understanding of nalca attributes as potential source of antibacterial compounds to be used in nutraceutical, cosmetic and food industry.

Vagococcus salmoninarum’a karşı bazı uçucu yağların antibakteriyel aktivitesi

In this study, essential oils of thyme (Origanum vulgare), St. John's Wort (Hypericum perforatum), rosemary (Rosmarinus officinalis), ginger (Zingiber officinale), clove (Eugenia caryophyllata), peppermint (Menta piperita), lavandula (Lavandula hybrida) and black cumin (Nigella sativa) were screened for its chemical composition and in vitro antibacterial activity against Vagococcus salmoninarum. The composition of oils were analysed using GC/MS. Antibacterial effects of essential oils against V. salmoninarum were detected by agar diffusion and tube dilution assays. Thyme (125 μL ml-1 MIC) and clove (500 μL ml-1 MIC) essential oils were shown to possess strong antibacterial activity against V. salmoninarum. The main components of effective essential oils were carvacrol (63.57 %) and eugenol (85.99%), respectively. As a result, these two plant species that tested against V. salmoninarum which is causative agent of vagococcosis can be used as an antibacterial agent. For this purpose, in vivo antibacterial activities against vagococcosis of thyme and clove essential oils should be explored in the further studies.

Gastroprotective effect of phytoncide extract from Pinus koraiensis pinecone in Helicobacter pylori infection

For centuries, herbs have been used by traditional therapists around the world to treat gastrointestinal tract disorders, such as gastritis. We hypothesized that the anti-Helicobacter pylori properties of phytoncide, which is extracted from pinecone waste, would facilitate use as a natural gastroprotective product to treat gastrointestinal tract disorders. Thus, we investigated in vitro antibacterial efficacy against H. pylori by agar diffusion assay. To determine the gastroprotective properties of phytoncide, we conducted hematoxylin and eosin staining, performed assays for the detection of the cytotoxin gene, and evaluated pro-inflammatory cytokine expression in H. pylori-infected C57BL/6 mice. Phytoncide significantly inhibited the survival of H. pylori in the gastrointestinal system of C57BL/6 mice. Reduction of gastric severity in H. pylori-infected mice was associated with reductions in the expression levels of pro-inflammatory cytokines in the gastric mucosa, and of the cytotoxin CagA gene in phytoncide treated groups (P < 0.05 and P < 0.01). In conclusion, phytoncide significantly inhibited the growth of H. pylori in gastro tissue, possibly due to the abundant α-pinene present in the phytoncide as detected by HPLC analysis. Further studies are needed to validate our findings, but we suggest that phytoncide has the potential to be used as a natural ingredient in anti-H. pylori products.