Nano-metals forming bacteria in Egypt. I. Synthesis, characterization and effect on some phytopathogenic bacteria in vitro

AbstractBacterial metal reducers were isolated from water samples collected from harsh condition locations in Egypt. Four selected isolates were identified as Enterococcus thailandicus, Pseudomonas putida, Marinobacter hydrocarbonoclasticus, and P. geniculata for Copper (Cu), Iron (Fe), Cobalt (Co) and Zinc (Zn) Nanoparticles (NPs) production sequentially. Nitrate reductase enzyme was assayed for bacterial isolates which demonstrated that P. putida, and M. hydrocarbonoclasticus have the maximum enzyme production. The produced NPs were characterized by using XRD, TEM, UV–VIS spectroscopy. Magnetic properties for all selected metals NPs were measured using Vibrating Sample Magnetometer (VSM) and demonstrated that FeNPs recorded the highest magnetization value. The antibacterial activity of selected metals NPs was tested against some phytopathogenic bacteria causing the following diseases: soft rot (Pectobacterium carotovorum, Enterobacter cloacae), blackleg (Pectobacterium atrosepticum and Dickeya solani), brown rot (Ralstonia solanacearum), fire blight (Erwinia amylovora) and crown gall (Agrobacterium tumefaciens). All metals NPs showed an antagonistic effect against the tested isolates, particularly, FeNPs showed the highest antibacterial activity followed by CuNPs, and ZnNPs. Due to the small size, high reactivity, and large surface area of biologically synthesized NPs, they are used as a good disinfector, and can be considered as a new and alternative approach to traditional disease management methods.

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Mutual influence of selenium nanoparticles and FGF2-STAB® on biocompatible properties of collagen/chitosan 3D scaffolds: in vitro and ex ovo evaluation

Journal of Nanobiotechnology ◽

10.1186/s12951-021-00849-w ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Johana Muchová ◽

Vanessa Hearnden ◽

Lenka Michlovská ◽

Lucie Vištejnová ◽

Anna Zavaďáková ◽

...

Keyword(s):

Antibacterial Activity ◽

Metabolic Activity ◽

Mutual Influence ◽

Chorioallantoic Membrane ◽

Antagonistic Effect ◽

Dermal Fibroblasts ◽

Selenium Nanoparticles ◽

Freeze Dried ◽

Chitosan Scaffolds

AbstractIn a biological system, nanoparticles (NPs) may interact with biomolecules. Specifically, the adsorption of proteins on the nanoparticle surface may influence both the nanoparticles' and proteins' overall bio-reactivity. Nevertheless, our knowledge of the biocompatibility and risk of exposure to nanomaterials is limited. Here, in vitro and ex ovo biocompatibility of naturally based crosslinked freeze-dried 3D porous collagen/chitosan scaffolds, modified with thermostable fibroblast growth factor 2 (FGF2-STAB®), to enhance healing and selenium nanoparticles (SeNPs) to provide antibacterial activity, were evaluated. Biocompatibility and cytotoxicity were tested in vitro using normal human dermal fibroblasts (NHDF) with scaffolds and SeNPs and FGF2-STAB® solutions. Metabolic activity assays indicated an antagonistic effect of SeNPs and FGF2-STAB® at high concentrations of SeNPs. The half-maximal inhibitory concentration (IC50) of SeNPs for NHDF was 18.9 µg/ml and IC80 was 5.6 µg/ml. The angiogenic properties of the scaffolds were monitored ex ovo using a chick chorioallantoic membrane (CAM) assay and the cytotoxicity of SeNPs over IC80 value was confirmed. Furthermore, the positive effect of FGF2-STAB® at very low concentrations (0.01 µg/ml) on NHDF metabolic activity was observed. Based on detailed in vitro testing, the optimal concentrations of additives in the scaffolds were determined, specifically 1 µg/ml of FGF2-STAB® and 1 µg/ml of SeNPs. The scaffolds were further subjected to antimicrobial tests, where an increase in selenium concentration in the collagen/chitosan scaffolds increased the antibacterial activity. This work highlights the antimicrobial ability and biocompatibility of newly developed crosslinked collagen/chitosan scaffolds involving FGF2-STAB® and SeNPs. Moreover, we suggest that these sponges could be used as scaffolds for growing cells in systems with low mechanical loading in tissue engineering, especially in dermis replacement, where neovascularization is a crucial parameter for successful skin regeneration. Due to their antimicrobial properties, these scaffolds are also highly promising for tissue replacement requiring the prevention of infection.

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Modulatory Effects of Caffeine and Pentoxifylline on Aromatic Antibiotics: A Role for Hetero-Complex Formation

Molecules ◽

10.3390/molecules26123628 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3628

Author(s):

Anna Woziwodzka ◽

Marta Krychowiak-Maśnicka ◽

Grzegorz Gołuński ◽

Anna Felberg ◽

Agnieszka Borowik ◽

...

Keyword(s):

Antibacterial Activity ◽

Drug Repurposing ◽

Activity Level ◽

Titration Calorimetry ◽

Human Pathogens ◽

Neighborhood Association ◽

Treatment Regimens ◽

Vis Spectroscopy ◽

Antibiotic Interactions

Antimicrobial resistance is a major healthcare threat globally. Xanthines, including caffeine and pentoxifylline, are attractive candidates for drug repurposing, given their well-established safety and pharmacological profiles. This study aimed to analyze potential interactions between xanthines and aromatic antibiotics (i.e., tetracycline and ciprofloxacin), and their impact on antibiotic antibacterial activity. UV-vis spectroscopy, statistical-thermodynamical modeling, and isothermal titration calorimetry were used to quantitatively evaluate xanthine-antibiotic interactions. The antibacterial profiles of xanthines, and xanthine-antibiotic mixtures, towards important human pathogens Staphylococcus aureus, Enterococcus faecium, Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, and Enterobacter cloacae were examined. Caffeine and pentoxifylline directly interact with ciprofloxacin and tetracycline, with neighborhood association constant values of 15.8–45.6 M−1 and enthalpy change values up to −4 kJ·M−1. Caffeine, used in mixtures with tested antibiotics, enhanced their antibacterial activity in most pathogens tested. However, antagonistic effects of caffeine were also observed, but only with ciprofloxacin toward Gram-positive pathogens. Xanthines interact with aromatic antibiotics at the molecular and in vitro antibacterial activity level. Given considerable exposure to caffeine and pentoxifylline, these interactions might be relevant for the effectiveness of antibacterial pharmacotherapy, and may help to identify optimal treatment regimens in the era of multidrug resistance.

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Isolation, Characterization, and Identification of Biological Control Agent for Potato Soft Rot in Bangladesh

The Scientific World JOURNAL ◽

10.1100/2012/723293 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 8

Author(s):

M. M. Rahman ◽

M. E. Ali ◽

A. A. Khan ◽

A. M. Akanda ◽

Md. Kamal Uddin ◽

...

Keyword(s):

Biological Control ◽

Biological Control Agent ◽

Erwinia Carotovora ◽

Soft Rot ◽

Control Agent ◽

Antagonistic Activity ◽

Antagonistic Effect ◽

Antagonistic Bacteria ◽

And Storage

A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacteriumErwinia carotovorasubsp.carotovora(Ecc) were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was testedin vitroagainst the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited thein vitrogrowth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genusBacillusand the isolate E-45 asLactobacillussp. The stronger antagonistic activity against Ecc P-138 was found in E-65in vitroscreening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5%) antagonistic effect of E-65 was observed in the Granola and the lowest (32.7%) of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers.

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Bioactivity of Selected Phenolic Acids and Hexane Extracts from Bougainvilla spectabilis and Citharexylum spinosum on the Growth of Pectobacterium carotovorum and Dickeya solani Bacteria: An Opportunity to Save the Environment

Processes ◽

10.3390/pr8040482 ◽

2020 ◽

Vol 8 (4) ◽

pp. 482 ◽

Cited By ~ 1

Author(s):

Nader A. Ashmawy ◽

Said I. Behiry ◽

Asma A. Al-Huqail ◽

Hayssam M. Ali ◽

Mohamed Z. M. Salem

Keyword(s):

Phenolic Acids ◽

Tannic Acid ◽

Defense Mechanisms ◽

Pathogenic Bacteria ◽

Soft Rot ◽

Inhibition Zone ◽

Pectobacterium Carotovorum ◽

Bacterial Isolates ◽

Dickeya Solani

Phenolic acids and natural extracts, as ecofriendly environmental agents, can be used as bio bactericides against the growth of plant pathogenic bacteria. In this study, isolation trails from infected potato tubers and stems that showed soft rot symptoms in fields revealed two soft rot bacterial isolates and were initially identified through morphological, physiological, and pathogenicity tests. The molecular characterization of these isolates via PCR, based on the 16S rRNA region, was carried out by an analysis of the DNA sequence via BLAST and Genbank, and showed that the soft rot bacterial isolates belong to Pectobacterium carotovorum subsp. carotovorum (PCC1) and Dickeya solani (Ds1). The in vitro results of the tested phenolic acids against the cultured bacterial isolates proved that concentrations of 800, 1600, and 3200 μg/mL were the most effective. Ferulic acid was the potent suppressive phenolic acid tested against the Ds1 isolate, with an inhibition zone ranging from 6.00 to 25.75 mm at different concentrations (25–3200 μg/mL), but had no effect until reaching a concentration of 100 μg/mL in the PCC1 isolate, followed by tannic acid, which ranged from 7.00 to 25.50 mm. On the other hand, tannic acid resulted in a significant decrease in the growth rate of the PCC1 isolate with a mean of 9.11 mm. Chlorogenic acid was not as effective as the rest of the phenolic acids compared with the control. The n-hexane oily extract (HeOE) from Bougainvillea spectabilis bark showed the highest activity against PCC1 and Ds1, with inhibition zone values of 12 and 12.33 mm, respectively, at a concentration of 4000 μg/mL; while the HeOE from Citharexylum spinosum wood showed less activity. In the GC/MS analysis, nonanal, an oily liquid compound, was found ata percentage of 38.28%, followed by cis-2-nonenal (9.75%), which are the main compounds in B. spectabilis bark HeOE, and 2-undecenal (22.39%), trans-2-decenal (18.74%), and oleic acid (10.85%) were found, which are the main compounds in C. spinosum wood HeOE. In conclusion, the phenolic acids and plant HeOEs seem to raise the resistance of potato plants, improving their defense mechanisms against soft rot bacterial pathogens.

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The Iturin-like Lipopeptides Are Essential Components in the Biological Control Arsenal of Bacillus subtilis Against Bacterial Diseases of Cucurbits

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-06-11-0162 ◽

2011 ◽

Vol 24 (12) ◽

pp. 1540-1552 ◽

Cited By ~ 74

Author(s):

Houda Zeriouh ◽

Diego Romero ◽

Laura García-Gutiérrez ◽

Francisco M. Cazorla ◽

Antonio de Vicente ◽

...

Keyword(s):

Biological Control ◽

Antibacterial Activity ◽

Bacillus Subtilis ◽

Xanthomonas Campestris ◽

Soft Rot ◽

Bacterial Diseases ◽

Chromatography Analysis ◽

Essential Components ◽

Bacillus Spp

The antibacterial potential of four strains of Bacillus subtilis, UMAF6614, UMAF6619, UMAF6639, and UMAF8561, previously selected on the basis of their antifungal activity and efficacy against cucurbit powdery mildew, was examined. Among these strains, UMAF6614 and UMAF6639 showed the highest antibacterial activity in vitro, especially against Xanthomonas campestris pv. cucurbitae and Pectobacterium carotovorum subsp. carotovorum. These strains produced the three families of lipopeptide antibiotics known in Bacillus spp.: surfactins, iturins, and fengycins. Using thin-layer chromatography analysis and direct bioautography, the antibacterial activity could be associated with iturin lipopeptides. This result was confirmed by mutagenesis analysis using lipopeptide-defective mutants. The antibacterial activity was practically abolished in iturin-deficient mutants, whereas the fengycin mutants retained certain inhibitory capabilities. Analyses by fluorescence and transmission electron microscopy revealed the cytotoxic effect of these compounds at the bacterial plasma membrane level. Finally, biological control assays on detached melon leaves demonstrated the ability of UMAF6614 and UMAF6639 to suppress bacterial leaf spot and soft rot; accordingly, the biocontrol activity was practically abolished in mutants deficient in iturin biosynthesis. Taken together, our results highlight the potential of these B. subtilis strains as biocontrol agents against fungal and bacterial diseases of cucurbits and the versatility of iturins as antifungal and antibacterial compounds.

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Modulatory Effects of Caffeine and Pentoxifylline on Aromatic Antibiotics: A Role for Heterocomplex Formation

10.21203/rs.3.rs-138878/v1 ◽

2021 ◽

Author(s):

Anna Woziwodzka ◽

Marta Krychowiak-Maśnicka ◽

Grzegorz Gołuński ◽

Anna Felberg ◽

Agnieszka Borowik ◽

...

Keyword(s):

Antibacterial Activity ◽

Drug Repurposing ◽

Activity Level ◽

Titration Calorimetry ◽

Human Pathogens ◽

Neighborhood Association ◽

Treatment Regimens ◽

Vis Spectroscopy ◽

Antibiotic Interactions

Abstract Antimicrobial resistance is a major healthcare threat globally. Xanthines, including caffeine and pentoxifylline, are attractive candidates for drug repurposing, given their well-established safety and pharmacological profiles. This study aimed to analyze potential interactions between xanthines and aromatic antibiotics (i.e., tetracycline and ciprofloxacin), and their impact on antibacterial activity. UV-vis spectroscopy, statistical-thermodynamical modeling, and isothermal titration calorimetry were used to quantitatively evaluate xanthine-antibiotic interactions. The antibacterial profiles of xanthines and xanthine-antibiotic mixtures towards important human pathogens Staphylococcus aureus, Enterococcus faecium, Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, and Enterobacter cloacae were examined. Caffeine and pentoxifylline directly interact with ciprofloxacin and tetracycline, with neighborhood association constant values of 15.8–45.6 M− 1 and enthalpy change values up to -4 kJ M− 1. Caffeine showed antibacterial activity (minimum inhibitory concentration, 4–8 mg/mL) toward Gram-negative bacteria. Caffeine enhanced the antibacterial activity of the tested antibiotics in most pathogens tested. Antagonistic effects of caffeine were observed only with ciprofloxacin toward Gram-positive pathogens. Xanthines interact with aromatic antibiotics at the molecular and in vitro antibacterial activity level. Given considerable exposure to caffeine and pentoxifylline, these interactions are relevant for the effectiveness of antibacterial pharmacotherapy, and may help to identify optimal treatment regimens in the era of multidrug resistance.

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Diploid Potato Germplasm with Resistance to Dickeya solani

Potato Research ◽

10.1007/s11540-020-09482-w ◽

2020 ◽

Author(s):

Renata Lebecka ◽

Iwona Wasilewicz-Flis ◽

Dariusz Mańkowski

Keyword(s):

Yield Loss ◽

Potato Cultivar ◽

Optimal Growth ◽

Soft Rot ◽

Unreduced Gametes ◽

Optimal Growth Temperature ◽

Potato Germplasm ◽

Dickeya Solani ◽

And Storage

AbstractPotato growers suffer losses due to potato soft rot and blackleg caused by pectinolytic bacteria of different species. These bacteria cause yield loss during cultivation and storage, and can be transmitted to the next generations through seed tubers. The prevalence of Pectobacterium atrosepticum has decreased over the last 20 years in Europe in favour of Dickeya solani and P. carotovorum subsp. brasiliense. Twenty-six diploid interspecific Solanum hybrids, previously selected for tuber resistance to P. atrosepticum, were screened for resistance to a highly aggressive D. solani strain in terms of tuber and blackleg reaction. The bacterial strain used for inoculation was characterised by a relatively high optimal growth temperature in vitro, ranging from 33 to 35 °C. Twenty-four diploid clones did not differ in terms of tuber reaction to inoculation with this strain of bacteria in comparison with the clone USA 249, which is the somatic hybrid of S. brevidens (+) S. tuberosum with proven resistance to Pectobacterium. Seventeen clones performed significantly better in terms of blackleg resistance than the resistant potato cultivar Glada. Eleven of the selected diploids produced unreduced gametes, which allows their use in improving the resistance of tetraploid potatoes to diseases caused by bacteria of both Pectobacterium and Dickeya.

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Characterization of a New Bacteriocin, Carocin D, from Pectobacterium carotovorum subsp. carotovorum Pcc21

Applied and Environmental Microbiology ◽

10.1128/aem.03103-09 ◽

2010 ◽

Vol 76 (22) ◽

pp. 7541-7549 ◽

Cited By ~ 28

Author(s):

Eunjung Roh ◽

Tae-Ho Park ◽

Myung-il Kim ◽

Seungdon Lee ◽

Sangryeol Ryu ◽

...

Keyword(s):

Amino Acids ◽

Antibacterial Activity ◽

Biological Control Agent ◽

Soft Rot ◽

Control Agent ◽

Indicator Strain ◽

Amino Acid Sequences ◽

Pectobacterium Carotovorum ◽

N Terminus

ABSTRACT Two different bacteriocins, carotovoricin and carocin S1, had been found in Pectobacterium carotovorum subsp. carotovorum, which causes soft-rot disease in diverse plants. Previously, we reported that the particular strain Pcc21, producing only one high-molecular-weight bacteriocin, carried a new antibacterial activity against the indicator strain Pcc3. Here, we report that this new antibacterial activity is due to a new bacteriocin produced by strain Pcc21 and named carocin D. Carocin D is encoded by the caroDK gene located in the genomic DNA together with the caroDI gene, which seems to encode an immunity protein. N-terminal amino acid sequences of purified carocin D were determined by Edman degradation. In comparison with the primary translation product of caroDK, it was found that 8 amino acids are missing at the N terminus. This finding proved that carocin D is synthesized as a precursor peptide and that 8 amino acids are removed from its N terminus during maturation. Carocin D has two putative translocation domains; the N-terminal and C-terminal domains are homologous to those of Escherichia coli colicin E3 and Pseudomonas aeruginosa S-type pyocin, respectively. When caroDK and caroDI genes were transformed into carocin D-sensitive bacteria such as Pcc3, the bacteria became resistant to this bacteriocin. Carocin D has one putative DNase domain at the extreme C terminus and showed DNase activity in vitro. This bacteriocin had slight tolerance to heat but not to proteases. The caroDK gene was present in only 5 of 54 strains of P. carotovorum subsp. carotovorum. These results indicate that carocin D is a third bacteriocin found in P. carotovorum subsp. carotovorum, and this bacteriocin can be readily expressed in carocin D-sensitive nonpathogenic bacteria, which may have high potential as a biological control agent in the field.

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Antibacterial Activity of Coptis chinensis Extract Against Pectobacterium carotovorum subsp. carotovorum

International Journal of Phytopathology ◽

10.33687/phytopath.005.02.1159 ◽

2016 ◽

Vol 5 (2) ◽

pp. 61-66

Author(s):

Stephen Kironji Githeng'u ◽

Samuel Nyalala ◽

Liu Gaoqiong

Keyword(s):

Antibacterial Activity ◽

Crop Protection ◽

In Vitro Study ◽

Soft Rot ◽

Pectobacterium Carotovorum ◽

Streptomycin Sulphate ◽

Coptis Chinensis ◽

Calla Lily ◽

Carotovorum Subsp

Soft rot of Zantedeschia, caused by Pectobacterium carotovorum subsp. carotovorum (Pcc), has caused a significant worldwide threat to calla lily production. Hence, in order to effectively manage the disease, an intensive management programme aimed at adequte suppression of the pathogen is paramount. In order to investigate the antibacterial effect of a Coptis chinensis extract product against the soft rot- causing bacterium, an in vitro study was set up. Bacterial isolate were obtained from rotting calla lily tubers and maintained in Nutrient Broth under refrigeration. Sterile petri plates containing 15 ml of Nutrient agar were prepared and aseptically inoculated with 0.1 ml an overnight grown culture of a standardized Pectobacterium carotovorum subsp. carotovorum inoculum containing about 1x 108 cfu/ml. The inoculum was spread evenly over the whole surface of the plates. After solidification, 1 ml of the different concentrations of C. chinensis (1, 10, 25, 50 and 100%) were placed individually at the centre of the inoculated petri plates. Positive check was maintained using Streptomycin sulphate (100ppm) and a negative check using sterile distilled water. Eight replicates were maintained for each treatment and the experiment was repeated twice. Results indicated that the lower concentrations of C. chinensis did not cause any inhibition against Pcc. On the other hand, 100% C. chinensis made an inhibition zone comparable to that streptomycin sulphate. Our results demonstrated that C. chinensis has antibacterial activity and therefore feasible for use in crop protection against soft rots caused by Pectobacterium carotovorum subsp. carotovorum.

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