Chemical composition and antibacterial and cytotoxic activities of Allium hirtifolium Boiss

The impact of probiotic cell-free metabolites in MDR Pseudomonas aeruginosa: antibacterial properties and effect on antibiotic resistance genes expression

There is a significant demand for novel antibacterial agents against multidrug-resistant (MDR) gram-negative bacteria. Recently, probiotics have been noted for their antibacterial properties against various pathogens. This study aimed to investigate the effects of probiotic cell-free supernatants on MDR Pseudomonas aeruginosa. Clinical isolates demonstrating the highest degree of antibiotic resistance were chosen, and the antibacterial effect of probiotic metabolites was evaluated using an agar-well diffusion assay. In addition, the effect of probiotics on the expression of resistance genes was evaluated using real-time PCR. The CFS was assessed using GC-MS to determine the antibacterial compounds. The supernatants inhibited the growth of the isolates (P < 0.0001); however, there was no noticeable difference in the effectiveness of the probiotics. In addition, the supernatants decreased the expression levels of mexD, mexB, mexF, and ampC, and an increase in oprD was observed in some groups. After the assessment of Lactobacillus acidophilus by GC-MS, antibacterial compounds, such as acetamide, nonadecane, 9-methyl, and tetradecane, were determined. Our findings showed that probiotic metabolites can effectively inhibit the growth of MDR P. aeruginosa. Gene expression analysis also revealed that the mechanism of antibacterial action was most likely related to the regulation of efflux pumps.

Chemical Composition Analysis of Atropa belladonna Grown in Iran and Evaluation of Antibacterial Properties of Extract-loaded Nanofibers

In the present work, the chemical composition of extract fractions of the Atropa belladonna plant growing in the north of Iran was investigated by HPTLC, HPLC, and GC-MS. Based on HPLC results, atropine, and scopolamine were found to be higher in the fruit and leaf extracts than in other parts of the plant. The comparative GC-MS analysis showed that diacetone alcohol, mesityl oxide, palmitic acid, and linoleic acid were the major bioactive components in the root, stem, leaf, and fruit extracts, respectively. Leaf extract showed the best antioxidant activity in the DPPH test. The antibacterial activity of fractional extracts was determined against Pseudomonas aeruginosa using the MIC method, and the fruit and leaf extracts exhibited the best antibacterial activities. The leaf extract was embedded into nanofibers by electrospinning technique, and its antibacterial activity was determined against Pseudomonas aeruginosa. The morphology and mechanical properties of the nanofibers were studied with SEM, contact angle, and tensile analysis, showing ultrafine fibers with uniform morphology.

Phytochemical Profiling of Allium subhirsutum L. Aqueous Extract with Antioxidant, Antimicrobial, Antibiofilm, and Anti-Quorum Sensing Properties: In Vitro and In Silico Studies

The present study was the first to evaluate the phytochemical composition, antioxidant, antimicrobial, antibiofilm, and anti-quorum sensing potential of Allium subhirsutum L. (hairy garlic) aqueous extract through in vitro and in silico studies. The phytochemical profile revealed the presence of saponins, terpenes, flavonols/flavonones, flavonoids, and fatty acids, particularly with flavonoids (231 ± 0.022 mg QE/g extract), tannins (159 ± 0.006 mg TAE/g extract), and phenols (4 ± 0.004 mg GAE/g extract). Gas chromatography–mass spectrometry (GC–MS) analysis identified 15 bioactive compounds, such as 5-hydroxymethylfurfural (37.04%), methyl methanethiolsulfonate (21.33%), furfural (7.64%), beta-D-glucopyranose, 1,6-anhydro- (6.17%), 1,6-anhydro-beta-D-glucofuranose (3.6%), trisulfide, di-2-propenyl (2.70%), and diallyl disulfide (1.93%). The extract was found to be non-toxic with 50% cytotoxic concentration higher than 30,000 µg/mL. The investigation of the antioxidant activity via DPPH (2, 2-diphenyl-1-picrylhydrazyl) and FRAP (IC₅₀ = 1 μg/mL), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid); IC₅₀ = 0.698 ± 0.107 μg/mL), and β-carotene (IC₅₀ = 0.811 ± 0.036 mg/mL) was assessed. Nevertheless, good antimicrobial potential against a diverse panel of microorganisms with bacteriostatic and fungistatic effect was observed. Quorum sensing inhibition effects were also assessed, and the data showed the ability of the extract to inhibit the production of violacein by the mutant C. violaceum strain in concentration-dependent manner. Similarly, the biofilm formation by all tested strains was inhibited at low concentrations. In silico pharmacokinetic and toxicological prediction indicated that, out of the sixteen identified compounds, fourteen showed promising drug ability and could be used as lead compounds for further development and drug design. Hence, these findings support the popular use of hairy garlic as a source of bioactive compounds with potential application for human health.

Efficacy of Dimethyl Trisulfide on the Suppression of Ring Rot Disease Caused by Botryosphaeria dothidea and Induction of Defense-Related Genes on Apple Fruits

Apple ring rot caused by Botryosphaeria dothidea is prevalent in main apple-producing areas in China, bringing substantial economic losses to the growers. In the present study, we demonstrated the inhibitory effect of dimethyl trisulfide (DT), one of the main activity components identified in Chinese leek (Allium tuberosum) volatile, on the apple ring rot on postharvest fruits. In in vitro experiment, 250 μL/L DT completely suppressed the mycelia growth of B. dothidea. In in vivo experiment, 15.63 μL/L DT showed 97% inhibition against the apple ring rot on postharvest fruit. In addition, the soluble sugar content, vitamin C content, and the soluble sugar/titratable acidity ratio of the DT-treated fruit were significantly higher than those of the control fruit. On this basis, we further explored the preliminary underlying mechanism. Microscopic observation revealed that DT seriously disrupted the normal morphology of B. dothidea. qRT-PCR determination showed the defense-related genes in DT-treated fruit were higher than those in the control fruit by 4.13–296.50 times, which showed that DT inhibited apple ring rot on postharvest fruit by suppressing the growth of B. dothidea, and inducing the defense-related genes in apple fruit. The findings of this study provided an efficient, safe, and environment-friendly alternative to control the apple ring rot on apple fruit.

Mooseer (Allium hirtifolium) boosts growth, general health status, and resistance of rainbow trout (Oncorhynchus mykiss) against Streptococcus iniae infection

In large-scale aquaculture, the fast growth rate of fish is positively influenced by feed additives such as medicinal plants. This is however; infectious disease may reduce fish growth and cause devastating economic loss. The present study investigated in vitro antibacterial efficacy of Mooseer (Allium hirtifolium) extract against Streptococcus iniae and its in vivo effects on growth, biochemical parameters, innate immunity of rainbow trout (Oncorhynchus mykiss). Therefore, six experimental diets were designed to include different levels of Mooseer from zero (as control), 5, 10, 15, 20, and 25 g per kg diet respectively referred to as M1 to M5. Results from the antibacterial evaluation showed that Mooseer extract inhibits S. iniae growth with MIC and MBC values of 128 and 256 μg ml^-1. Appreciable results were obtained in the groups supplemented with Mooseer. Mooseer enhanced growth performance, and modulated serum biochemical and immunological parameters (total protein, albumin, triglyceride, glucose, cortisol, cholesterol, lysozyme, Ig, ACH50, ALP, and protease activity), and liver enzymes (ALT, AST and ALP). The greatest effects were found for higher doses of Mooseer supplementation (M4 and M5). Meanwhile, results from the survival rate of fish challenged with S. iniae showed higher survival in M2 and M4 treatments. The present findings suggest the beneficial use of Mooseer in rainbow trout diet, with 20 g kg^-1 inclusion as the recommended dose.

Combined and Singular Effects of Ethanolic Extract of Persian Shallot (Allium hirtifolium Boiss) and Synbiotic Biomin®IMBO on Growth Performance, Serum- and Mucus-Immune Parameters and Antioxidant Defense in Zebrafish (Danio rerio)

Simple Summary

The present study investigated the effect of combined and singular ethanolic extract of Persian shallot and synbiotic Bomin^®IMBO in zebrafish. The aim of this study is to measure a range of parameters consisting of growth performance, serum and mucus immune parameters, and antioxidant defense. The results indicated that the measured parameters have a positive effect and hence we can suggest administration of these additives in zebrafish culture.

Abstract

This study was carried out to evaluate combined and singular effects of ethanolic extract of Persian shallot (Allium hirtifolium Boiss) and synbiotic Biomin^®IMBO on growth performance, innate immune responses, and antioxidant defense in zebrafish (Danio rerio). Fish with initial weight of 151.90 ± 0.31 mg were allocated in 21 10-L glass aquariums. The experimental groups were as follows: T1, control (without any supplementation); T2, 1% synbiotic; T3, 3% synbiotic; T4, 1% Persian shallot (as a medical plant); T5, 3% Persian shallot; T6, 1% Persian shallot and 1% synbiotic; T7, 3% Persian shallot and 3% synbiotic. At the end of the experiment (60 days), all treatments significantly showed higher final weight (FW), weight gain (WG), WG (%), and specific growth rate (SGR) compared with the fish fed on control diet. Furthermore, both synbiotic Biomin^®IMBO and Persian shallot significantly improved intestine immune parameters including lysozyme, alternative complement hemolytic activity (ACH50), total immunoglobulin (total Ig), and myeloperoxidase (MPO) of zebrafish compared to fish fed on control diet (p < 0.05). Also, in all experimental groups, hepatic catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR) activities significantly increased compared to the control group. Whereas, the highest MDA level was observed in the control group compared to the treatments (p < 0.05). Moreover, skin mucus immune parameters of zebrafish have been noticeably improved with synbiotic Biomin^®IMBO and Persian shallot compared to fish fed on the control diet (p < 0.05). The results indicate that synbiotic or Persian shallot supplemented diet could enhance the general health status of the zebrafish.

Can Leaves and Stems of Rubus idaeus L. Handle Candida albicans Biofilms?

Candida albicans is an opportunistic pathogen involved in many infections, especially linked to implanted medical devices. Its ability to form biofilms complicates the treatment of these infections as few molecules are active against sessile C. albicans. The aim of this study was to evaluate the potential of leaves, three-month-old and one-year-old stems of Rubus idaeus L. against C. albicans biofilm growth. Extractions with a polarity gradient were carried out on hydroacetonic extracts and followed by fractionation steps. The obtained extracts and fractions were tested for their anti-biofilm growth activity against C. albicans using XTT method. Compounds of active subfractions were identified by LC-MS. The hexane extracts from leaves and stems were the most active against the fungus with IC50 at 500 and 250 µg/mL. Their bioguided fractionation led to 4 subfractions with IC50 between 62.5 and 125 µg/mL. Most of the components identified in active subfractions were fatty acids and terpenoïds.

Chemical Characterization and Antibiofilm Activities of Bulbs and Leaves of Two Aglione (Allium ampeloprasum var. holmense Asch. et Graebn.) Landraces Grown in Southern Italy

The present study was carried out to determine some biochemical characteristics, in particular the total polyphenol content and the free radical scavenging activity, of the extracts recovered from bulbs and aerial parts (these last often considered as by-products) of two landraces of A. ampeloprasum var. holmense cultivated in Southern Italy. For the first time, the capacity of the extracts of these landraces to inhibit the formation of biofilm of different Gram-negative and Gram-positive bacteria and to affect the metabolism of the cells present within the bacterial biofilm was evaluated. All extracts exhibited an amount of total polyphenols not lower than 2.86 mg/g of dried product and revealed a noteworthy antioxidant activity, with EC₅₀ values not exceeding 4.95 mg. In both cases, the aerial parts extracts were more effective than the bulb extracts, which also showed a minor amount of total polyphenols. The extracts inhibited mainly the adhesive capability of Pseudomonas aeruginosa and Staphylococcus aureus, by 95.78% and 85.01%, respectively. The extracts demonstrated to inhibit also the metabolism of the bacterial cells reaching levels up to 90%. Finally, as assessed by the assays performed on the 24-h preformed biofilms, all the extracts were also capable to cause a reduction in bacterial biomass and to affect their metabolism.

Biochemical and Histological Evidence on the Protective Effects of Allium hirtifolium Boiss (Persian Shallot) as an Herbal Supplement in Cadmium-Induced Hepatotoxicity

MATERIALS AND METHODS

Thirty-six male Wistar rats were divided into six groups: groups 1, 2, and 3 received vehicle, Cd (100 mg/L/day by drinking water), and A. hirtifolium extract (200 mg/kg/day; orally), respectively. Groups 4, 5, and 6 were Cd groups which were treated with A. hirtifolium extract (50, 100, and 200 mg/kg/day, respectively). After 2 weeks, liver enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) and also oxidative stress biomarkers including lipid peroxidation (LPO), total antioxidant capacity (TAC), total thiol molecule (TTM), and the histopathological changes were determined using standard procedure.

RESULTS

The findings showed that Cd caused a remarkable rise in levels of serum hepatic enzymes such as ALT (P < 0.001), AST (P < 0.01) and ALP (P < 0.001) compared with the control group. In addition, Cd led to the decreasing of the levels of TTM (P < 0.001) and TAC (P < 0.001) and increasing of LPO (P < 0.001) in liver tissue in comparison with the control group. In this regard, remarkable vascular congestion, hepatocellular degeneration, and vacuolization were observed in hepatic tissue of Cd-treated rats. Following the administration of A. hirtifolium extract, a significant improvement was observed in the functional and oxidative stress indices of hepatic tissue alongside histopathologic changes.

CONCLUSION

The current study indicated that the A. hirtifolium extract might prevent hepatic oxidative injury by improving oxidant/antioxidant balance in rats exposed to Cd.

Needle in a haystack: Antibacterial activity-guided fractionation of a potato wound tissue extract

Erwinia carotovora is a major cause of potato tuber infection, which results in disastrous failures of this important food crop. There is currently no effective antibiotic treatment against E. carotovora. Recently we reported antibacterial assays of wound tissue extracts from four potato cultivars that exhibit a gradient of russeting character, finding the highest potency against this pathogen for a polar extract from the tissue formed immediately after wounding by an Atlantic cultivar. In the current investigation, antibacterial activity-guided fractions of this extract were analyzed by liquid chromatography-mass spectrometry (LC-MS) utilizing a quadrupole-time-of-flight (QTOF) mass spectrometer. The most active chemical compounds identified against E. carotovora were: 6-O-nonyl glucitol, Lyratol C, n-[2-(4-Hydroxyphenyl)] ethyldecanamide, α-chaconine and α-solanine. Interactions among the three compounds, ferulic acid, feruloyl putrescine, and α-chaconine, representing metabolite classes upregulated during initial stages of wound healing, were also evaluated, offering possible explanations for the burst in antibacterial activity after tuber wounding and a chemical rationale for the temporal resistance phenomenon.

Reduction in Acrylamide Formation in Potato Crisps: Application of Extract and Hydrocolloid-Based Coatings

ABSTRACT

Two different potato chip coatings-aqueous extracts including Zataria multiflora and Allium hirtifolium at concentrations of 1, 3, 5, and 7% and hydrocolloids individually or in combination-were used to decrease acrylamide content, and their effects on the characteristics of the product were then investigated. According to the results, the incorporation of hydrocolloids as the coating was more efficient in the reduction of acrylamide production than with the extracts. Also, the application of each extract and hydrocolloids individually can be considered a more efficient technique for acrylamide reduction than their mixture. In this regard, the economic aspects of the application of hydrocolloids in the coating of fried potato crisps can be evaluated.

HIGHLIGHTS

Shirazi balangu (Lallemantia royleana) seed mucilage: Chemical composition, molecular weight, biological activity and its evaluation as edible coating on beefs

In this study, Lallemantia royleana seed mucilage (LRSM) was extracted from whole seeds using hot-water extraction. The structural information (monosaccharide compositions and molecular weight analysis), chemical composition (moisture, protein, ash, fat and carbohydrate), biological activity (antimicrobial, total phenol content and antioxidant activity) and effect LRSM edible coating on population of microbial pathogens (total viable count (TVC), psychrotrophic bacteria, Escherichia coli, Staphylococcus aureus and fungi), chemical changes (thiobarbituric acid, peroxide value and pH) and sensory attributes (color, odor and total acceptability) of the beef slices at 4°C for 18days (0, 3, 6, 9, 12, 15 and 18) were determined. The LRSM had 76.74% carbohydrate, 3.86% protein, 9.92% ash and 9.48% moisture. LRSM is a high molecular weight (1.19×106Da) polysaccharide, composed of galactose (36.28%), arabinose (35.96%), rhamnose (15.18%), xylose (7.38%) and glucose (5.20%). The LRSM total phenolic content and antioxidant activity (IC50) were equal to 82.56±1.6μgGAE/mg and 528.54±0.35μg/ml, respectively. The results showed that, the beef shelf life based on TVC for samples control, LRSM, LRSM+1% AHEO, LRSM+1.5% AHEO, and LRSM+2% AHEO were 6, 9, 9, 12, and 15days, respectively. There was no significant difference between LRSM+1% AHEO and LRSM samples, but the TVC in first one had slight changes than LRSM. Compared to the control samples, LRSM extended the microbial shelf life, oxidative stability and sensorial acceptability of beef by 3, 6 and 6days, respectively.

Antibacterial and Antibiofilm Activities of Nonpolar Extracts of Allium stipitatum Regel. against Multidrug Resistant Bacteria

The present study assessed the in vitro antibacterial and antibiofilm potential of hexane (ASHE) and dichloromethane (ASDE) extracts of Allium stipitatum (Persian shallot) against planktonic cells and biofilm structures of clinically significant antibiotic resistant pathogens, with a special emphasis on methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and emerging pathogens, Acinetobacter baumannii and Stenotrophomonas maltophilia. Antibacterial activities were determined through disk diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), time-kill kinetics, and electron microscopy. Antibiofilm activity was assessed by XTT [2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide] reduction assay and by confocal laser scanning microscopy (CLSM). The zone of inhibition ranged from 13 to 33 mm, while the MICs and MBCs ranged from 16 to 1024 μg mL-1. Both ASHE and ASDE completely eradicated overnight cultures of the test microorganisms, including antibiotic resistant strains. Time-kill studies showed that the extracts were strongly bactericidal against planktonic cultures of S. aureus, MRSA, Acinetobacter baumannii, and S. maltophilia as early as 4 hours postinoculation (hpi). ASHE and ASDE were shown to inhibit preformed biofilms of the four biofilm phenotypes tested. Our results demonstrate the potential therapeutic application of ASHE and ASDE to inhibit the growth of gram-positive and gram-negative biofilms of clinical significance and warrant further investigation of the potential of A. stipitatum bulbs against biofilm-related drug resistance.

Antibacterial and Antifungal Activities of Spices

Infectious diseases caused by pathogens and food poisoning caused by spoilage microorganisms are threatening human health all over the world. The efficacies of some antimicrobial agents, which are currently used to extend shelf-life and increase the safety of food products in food industry and to inhibit disease-causing microorganisms in medicine, have been weakened by microbial resistance. Therefore, new antimicrobial agents that could overcome this resistance need to be discovered. Many spices-such as clove, oregano, thyme, cinnamon, and cumin-possessed significant antibacterial and antifungal activities against food spoilage bacteria like Bacillus subtilis and Pseudomonas fluorescens, pathogens like Staphylococcus aureus and Vibrio parahaemolyticus, harmful fungi like Aspergillus flavus, even antibiotic resistant microorganisms such as methicillin resistant Staphylococcus aureus. Therefore, spices have a great potential to be developed as new and safe antimicrobial agents. This review summarizes scientific studies on the antibacterial and antifungal activities of several spices and their derivatives.

Persian shallot, Allium hirtifolium Boiss, induced apoptosis in human hepatocellular carcinoma cells

This study investigated the potential of Persian shallot extract as an anticancer agent in HepG2 tumor cell line, an in vitro human hepatoma cancer model system. The inhibitory effect of Persian shallot on the growth of HepG2 cells was measured by MTT assay. To explore the underlying mechanism of cell growth inhibition of Persian shallot, the activity of Persian shallot in inducing apoptosis was investigated through the detection of annexin V signal by flow cytometry and expression of some apoptosis related genes such p21, p53, puma, caspase-8 family-Bcl-2 proteins like bid, bim, bcl-2 and bax were measured by real-time PCR in HepG2 cells. Persian shallot extract inhibited the growth of HepG2 cells in a dose-dependent manner. The IC₅₀ value (inhibiting cell growth by 50%) was 149 μg/ml. The results of real-time PCR revealed a significant up-regulation of bid, bim, caspase-8, puma, p53, p21 and bax genes and a significant downregulation of bcl-2 gene in HepG2 cells treated with Persian shallot extract significantly. Therefore, this is the first report on an increased expression of bid, bim, caspase-8, puma, p53, p21 and bax genes and down regulation of bcl-2 gene indicating that the Persian shallot extract possibly induced the process of cell death through the intrinsic and extrinsic apoptosis pathways and triggers the programmed cell death in HepG2 tumor cell lines by modulating the expression of pro-/anti-apoptotic genes. Furthermore, we showed that Persian shallot extract increased annexin V signal and expression, resulting in apoptotic cell death of HepG2 cells after 24 h treatment. Therefore, according to the results of this study, the Persian shallot extract could be considered as a potential candidate for production of drug for the prevention or treatment of human hepatoma.

Allium stipitatum Extract Exhibits In Vivo Antibacterial Activity against Methicillin-Resistant Staphylococcus aureus and Accelerates Burn Wound Healing in a Full-Thickness Murine Burn Model

The in vivo antibacterial and burn wound healing potency of Persian shallot bulbs (Allium stipitatum) were explored in a mice burn model infected with methicillin-resistant Staphylococcus aureus (MRSA). Hexane (ASHE) and dichloromethane (ASDE) extracts were tested. Female BALB/c mice were inflicted with third-degree thermal injury followed by infection with MRSA. ASHE and ASDE formulated with simple ointment base (SOB) at concentrations of 1%, 2%, and 5% (w/w) were topically applied to burn wounds twice a day for 20 days. Silver sulfadiazine (1%) served as drug positive control. Microbiological analysis was carried out on 1, 2, 3, 4, and 5 days postwounding (dpw) and histopathological analysis at the end of the experiment (20 dpw). Both ointments demonstrated strong antibacterial activity with complete elimination of MRSA at 48–72 h after infection. The rate of wound contraction was higher (95–100%) in mice groups treated with ASHE and ASDE ointments after 15 dpw. Histological analysis revealed significant increase (p < 0.05) in epithelialization and collagenation in treated groups. The ASHE and ASDE were found to be relatively noncytotoxic and safe to Vero cell line (383.4 μg mL⁻¹; 390.6 μg mL⁻¹), suggesting the extracts as safe topical antibacterial as well as promising alternatives in managing thermal injuries.

Protective effect of Polygonum orientale L. extracts against Clavibater michiganense subsp. sepedonicum, the causal agent of bacterial ring rot of potato

The Polygonum orientale L. extracts were investigated for antibacterial activity against Clavibater michiganense subsp. sepedonicum (Spieckermann & Kotthoff) Davis et al., the causal agent of a serious disease called bacterial ring rot of potato. The results showed that the leaf extracts of P. orientale had significantly (p<0.05) greater antibacterial activity against C. michiganense subsp. sepedonicum than root, stem, flower extracts in vitro. According to the results of single factor experiments and L(27)3(13) orthogonal experiments, optimum extraction conditions were A1B3C1, extraction time 6 h, temperature 80°C, solid to liquid ratio 1∶10 (g:mL). The highest (p<0.05) antibacterial activity was observed when pH was 5, excluding the effect of control. The extracts were stable under ultraviolet (UV). In vivo analysis revealed that 50 mg/mL of P. orientale leaf extracts was effective in controlling decay. Under field conditions, 50 mg/mL of P. orientale leaf extracts also improved growth parameters (whole plant length, shoot length, root length, plant fresh weight, shoot fresh weight, root fresh weight, dry weight, and number of leaves), in the 2010 and 2011 two growing seasons. Further solvent partition assays showed that the most active compounds were in the petroleum ether fractionation. Transmission electron microscopy (TEM) showed drastic ultrastructural changes caused by petroleum ether fractionation, including bacterial deformation, electron-dense particles, formation of vacuoles and lack of cytoplasmic materials. These results indicated that P. orientale extracts have strong antibacterial activity against C. michiganense subsp. sepedonicum and a promising effect in control of bacterial ring rot of potato disease.