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Molecular Plant Pathology Nov 2019Pantoea agglomerans (Pa), a widespread commensal bacterium, has evolved into a host-specific gall-forming pathogen on gypsophila and beet by acquiring a plasmid...
Pantoea agglomerans (Pa), a widespread commensal bacterium, has evolved into a host-specific gall-forming pathogen on gypsophila and beet by acquiring a plasmid harbouring a type III secretion system (T3SS) and effectors (T3Es). Pantoea agglomerans pv. gypsophilae (Pag) elicits galls on gypsophila and a hypersensitive response on beet, whereas P. agglomerans pv. betae (Pab) elicits galls on beet and gypsophila. HsvG and HsvB are two paralogous T3Es present in both pathovars and act as host-specific transcription activators on gypsophila and beet, respectively. PthG and PseB are major T3Es that contribute to gall development of Pag and Pab, respectively. To establish the minimal combinations of T3Es that are sufficient to elicit gall symptoms, strains of the nonpathogenic bacteria Pseudomonas fluorescens 55, Pa 3-1, Pa 98 and Escherichia coli, transformed with pHIR11 harbouring a T3SS, and the phytopathogenic bacteria Erwinia amylovora, Dickeya solani and Xanthomonas campestris pv. campestris were transformed with the T3Es hsvG, hsvB, pthG and pseB, either individually or in pairs, and used to infect gypsophila and beet. Strikingly, all the tested nonpathogenic and phytopathogenic bacterial strains harbouring hsvG and pthG incited galls on gypsophila, whereas strains harbouring hsvB and pseB, with the exception of E. coli, incited galls on beet.
Topics: Bacterial Proteins; Bacterial Secretion Systems; Beta vulgaris; Host-Pathogen Interactions; Pantoea; Plant Tumors
PubMed: 31368647
DOI: 10.1111/mpp.12860 -
Microbiology Resource Announcements Jul 2021We present the complete genome sequence of Pantoea agglomerans ASB05 and three associated plasmids, generated using a combination of the Illumina and PacBio platforms....
We present the complete genome sequence of Pantoea agglomerans ASB05 and three associated plasmids, generated using a combination of the Illumina and PacBio platforms. ASB05 was isolated from fresh cherries purchased in Albany, CA, in 2016.
PubMed: 34323608
DOI: 10.1128/MRA.00501-21 -
Annals of Agricultural and... 2016Pantoea agglomerans, a Gram-negative bacterium developing in a variety of plants as epiphyte or endophyte is particularly common in grain and grain dust, and has been... (Review)
Review
Pantoea agglomerans: a mysterious bacterium of evil and good. Part II--Deleterious effects: Dust-borne endotoxins and allergens--focus on grain dust, other agricultural dusts and wood dust.
Pantoea agglomerans, a Gram-negative bacterium developing in a variety of plants as epiphyte or endophyte is particularly common in grain and grain dust, and has been identified by an interdisciplinary group from Lublin, eastern Poland, as a causative agent of work-related diseases associated with exposure to grain dust and other agricultural dusts. The concentration of P. agglomerans in grain as well as in the settled grain and flour dust was found to be high, ranging from 10(4)-10(8) CFU/g, while in the air polluted with grain or flour dust it ranged from 10(3)-10(5) CFU/m(3) and formed 73.2-96% of the total airborne Gram-negative bacteria. The concentration of P. agglomerans was also relatively high in the air of the facilities processing herbs and other plant materials, while it was lower in animal farms and in wood processing facilities. Pantoea agglomerans produces a biologically-potent endotoxin (cell wall lipopolysaccharide, LPS). The significant part of this endotoxin occurs in dusts in the form of virus-sized globular nanoparticles measuring 10-50 nm that could be described as the 'endotoxin super-macromolecules'. A highly significant relationship was found (R=0.804, P=0.000927) between the concentration of the viable P. agglomerans in the air of various agricultural and wood industry settings and the concentration of bacterial endotoxin in the air, as assessed by the Limulus test. Although this result may be interfered by the presence of endotoxin produced by other Gram-negative species, it unequivocally suggests the primary role of the P. agglomerans endotoxin as an adverse agent in the agricultural working environment, causing toxic pneumonitis (ODTS). Numerous experiments by the inhalation exposure of animals to various extracts of P. agglomerans strains isolated from grain dust, including endotoxin isolated with trichloroacetic acid (LPS-TCA), endotoxin nanoparticles isolated in sucrose gradient (VECN), and mixture of proteins and endotoxin obtained by extraction of bacterial mass in saline (CA-S), showed the ability of these extracts to evoke inflammatory and fibrotic changes in the lungs, to stimulate alveolar macrophages to produce superoxide anion (O2(-)), interleukin-1 (IL-1) and chemotactic factors for other macrophages and neutrophils, and to increase the pulmonary concentrations of toll-like receptors and chemokines. The most potent properties showed the CA-S which may be attributed to the allergenic properties of P. agglomerans proteins enhanced by the presence of the autologous endotoxin. The results of these experiments are in accord with the clinical studies which revealed a high reactivity of the agricultural and grain industry workers to allergenic extracts of P. agglomerans, and the presence in these populations of hypersensitivity pneumonitis and asthma cases caused by this bacterium. P. agglomerans has been also identified as a potential causative agent of allergic dermatitis in farmers and of allergic pulmonary disorders in cattle. In conclusion, similar to the cotton industry, also in the grain industry and in agriculture, Pantoea agglomerans should be regarded as one of the major causative agents of work-related diseases, caused by the adverse effects of protein allergens and endotoxin produced by this bacterium.
Topics: Agriculture; Allergens; Dust; Edible Grain; Endotoxins; Enterobacteriaceae Infections; Humans; Pantoea; Wood
PubMed: 27007514
DOI: 10.5604/12321966.1196848 -
Microorganisms May 2021Volatile organic compounds (VOCs) play an essential role in microbe-microbe and plant-microbe interactions. We investigated the interaction between two plant...
Volatile organic compounds (VOCs) play an essential role in microbe-microbe and plant-microbe interactions. We investigated the interaction between two plant growth-promoting rhizobacteria, and their interaction with tomato plants. VOCs produced by MVC 21 modulates the release of siderophores, the solubilisation of phosphate and potassium by () MVC 17. Moreover, VOCs produced by MVC 21 increased lateral root density (LRD), root and shoot dry weight of tomato seedlings. Among the VOCs released by MVC 21, only dimethyl disulfide (DMDS) showed effects similar to MVC 21 VOCs. Because of the effects on plants and bacterial cells, we investigated how MVC 21 VOCs might influence bacteria-plant interaction. Noteworthy, VOCs produced by MVC 21 boosted the ability of MVC 17 to increase LRD and root dry weight of tomato seedlings. These results could be explained by the positive effect of DMDS and MVC 21 VOCs on acid 3-indoleacetic production in MVC 17. Overall, our results clearly indicated that MVC 21 is able to establish a beneficial interaction with MVC 17 and tomato plants through the emission of DMDS.
PubMed: 34072820
DOI: 10.3390/microorganisms9061186 -
International Journal of Molecular... Jan 2023The bacterial genus comprises species found in a variety of different environmental sources. spp. are often recovered from plant material and are capable of both...
The bacterial genus comprises species found in a variety of different environmental sources. spp. are often recovered from plant material and are capable of both benefitting the plants and acting like phytopathogens. Some species of (including ) are considered opportunistic human pathogens capable of causing various infections in immunocompromised subjects. In this study, a strain of (identified by 16S rRNA gene sequencing) was isolated from a dead specimen of an unidentified Latvian grasshopper species. The retrieved strain of was then used as a host for the potential retrieval of phages from the same source material. After rounds of plaque purification and propagation, three high-titer lysates corresponding to putatively distinct phages were acquired. Transmission electron microscopy revealed that one of the phages was a myophage with an unusual morphology, while the two others were typical podophages. Whole-genome sequencing (WGS) was performed for each of these isolated phages. Genome de novo assembly and subsequent functional annotation confirmed that three different strictly lytic phages were isolated. Elaborate genomic characterization of the acquired phages was performed to elucidate their place within the so-far-uncovered phage diversity.
Topics: Humans; Bacteriophages; Pantoea; RNA, Ribosomal, 16S
PubMed: 36768143
DOI: 10.3390/ijms24031820 -
International Archives of Occupational... Aug 2022Gram-negative bacteria occur commonly in the inner tissues of stored coniferous and deciduous timber, showing a marked variation in numbers. The greatest maximal numbers... (Review)
Review
OCCURRENCE
Gram-negative bacteria occur commonly in the inner tissues of stored coniferous and deciduous timber, showing a marked variation in numbers. The greatest maximal numbers are found in the sapwood of coniferous timber. The common constituents of the Gram-negative biota are potentially pathogenic species of Enterobacteriaceae family of the genera Rahnella, Pantoea, Enterobacter, and Klebsiella. The air of wood-processing facilities is polluted with the wood-borne Gram-negative bacteria and produced by them endotoxin, as demonstrated worldwide by numerous studies.
EFFECTS
There are three potential pathways of the pathogenic impact of wood-borne Gram-negative bacteria on exposed woodworkers: allergic, immunotoxic, and infectious. Allergic impact has been underestimated for a long time with relation to Gram-negative bacteria. Hopefully, the recent demonstration of the first documented case of hypersensitivity pneumonitis (HP) in woodworkers caused by Pantoea agglomerans which developed in extremely large quantities in birch sapwood, would speed up finding of new wood-related cases of HP caused by Gram-negative bacteria. The second pathway is associated with endotoxin, exerting strong immunotoxic (excessively immunostimulative) action. It has been demonstrated that endotoxin is released into wood dust in the form of nano-sized microvesicles, by peeling off the outer membrane of bacteria. Endotoxin microvesicles are easily inhaled by humans together with dust because of small dimensions and aerodynamic shape. Afterwards, they cause a nonspecific activation of lung macrophages, which release numerous inflammatory mediators causing an inflammatory lung reaction, chest tightness, fever, gas exchange disorders, and bronchospasm, without radiographic changes. The resulting disease is known as "Organic Dust Toxic Syndrome" or "toxic pneumonitis." The potential third pathway of pathogenic impact is infection. The suspected species is Klebsiella pneumoniae that may occur commonly in wood dust; however, until now this pathway has not been confirmed.
CONCLUSION
Summarizing, Gram-negative bacteria-inhabiting timber should be considered, besides filamentous fungi and actinobacteria, as important risk factors of occupational disease in woodworkers that could be either HP with allergenic background or toxic pneumonitis elicited by endotoxin.
Topics: Bacteria; Dust; Endotoxins; Fungi; Gram-Negative Bacteria; Humans; Hypersensitivity; Occupational Exposure; Wood
PubMed: 35015109
DOI: 10.1007/s00420-021-01829-1 -
BMC Microbiology Sep 2009Pantoea agglomerans strains are among the most promising biocontrol agents for a variety of bacterial and fungal plant diseases, particularly fire blight of apple and... (Comparative Study)
Comparative Study
BACKGROUND
Pantoea agglomerans strains are among the most promising biocontrol agents for a variety of bacterial and fungal plant diseases, particularly fire blight of apple and pear. However, commercial registration of P. agglomerans biocontrol products is hampered because this species is currently listed as a biosafety level 2 (BL2) organism due to clinical reports as an opportunistic human pathogen. This study compares plant-origin and clinical strains in a search for discriminating genotypic/phenotypic markers using multi-locus phylogenetic analysis and fluorescent amplified fragment length polymorphisms (fAFLP) fingerprinting.
RESULTS
Majority of the clinical isolates from culture collections were found to be improperly designated as P. agglomerans after sequence analysis. The frequent taxonomic rearrangements underwent by the Enterobacter agglomerans/Erwinia herbicola complex may be a major problem in assessing clinical associations within P. agglomerans. In the P. agglomerans sensu stricto (in the stricter sense) group, there was no discrete clustering of clinical/biocontrol strains and no marker was identified that was uniquely associated to clinical strains. A putative biocontrol-specific fAFLP marker was identified only in biocontrol strains. The partial ORF located in this band corresponded to an ABC transporter that was found in all P. agglomerans strains.
CONCLUSION
Taxonomic mischaracterization was identified as a major problem with P. agglomerans, and current techniques removed a majority of clinical strains from this species. Although clear discrimination between P. agglomerans plant and clinical strains was not obtained with phylogenetic analysis, a single marker characteristic of biocontrol strains was identified which may be of use in strain biosafety determinations. In addition, the lack of Koch's postulate fulfilment, rare retention of clinical strains for subsequent confirmation, and the polymicrobial nature of P. agglomerans clinical reports should be considered in biosafety assessment of beneficial strains in this species.
Topics: Amplified Fragment Length Polymorphism Analysis; Cluster Analysis; DNA Fingerprinting; DNA Gyrase; DNA, Bacterial; Genes, Bacterial; Genetic Markers; Genotype; Gram-Negative Bacterial Infections; Humans; Pantoea; Phenotype; Phylogeny; Plant Diseases; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 19772624
DOI: 10.1186/1471-2180-9-204 -
Microorganisms Sep 2020Bacteriophages are viruses capable of recognizing with high specificity, propagating inside of, and destroying their bacterial hosts. The phage lytic life cycle makes...
Bacteriophages are viruses capable of recognizing with high specificity, propagating inside of, and destroying their bacterial hosts. The phage lytic life cycle makes phages attractive as tools to selectively kill pathogenic bacteria with minimal impact on the surrounding microbiome. To effectively harness the potential of phages in therapy, it is critical to understand the phage-host dynamics and how these interactions can change in complex populations. Our model examined the interactions between the plant pathogen , the antagonistic epiphyte , and the bacteriophages that infect and kill both species. strains are used as a phage carrier; their role is to deliver and propagate the bacteriophages on the plant surface prior to the arrival of the pathogen. Using liquid cultures, the populations of the pathogen, carrier, and phages were tracked over time with quantitative real-time PCR. The jumbo phage ϕEa35-70 synergized with both the ϕEa21-4 and ϕEa46-1-A1 and was most effective in combination at reducing growth over 24 h. Phage ϕEa35-70, however, also reduced the growth of . Phage cocktails of ϕEa21-4, ϕEa46-1-A1, and ϕEa35-70 at multiplicities of infections (MOIs) of 10, 1, and 0.01, respectively, no longer inhibited growth of . When this cocktail was grown with for 8 h prior to pathogen introduction, pathogen growth was reduced by over four log units over 24 h. These findings present a novel approach to study complex phage-host dynamics that can be exploited to create more effective phage-based therapies.
PubMed: 32971807
DOI: 10.3390/microorganisms8091449 -
Journal of Microbiology and... May 2021Levan is an industrially important, functional biopolymer with considerable applications in the food and pharmaceutical fields owing to its safety and biocompatibility....
Levan is an industrially important, functional biopolymer with considerable applications in the food and pharmaceutical fields owing to its safety and biocompatibility. Here, levan-type exopolysaccharide produced by Pantoea agglomerans ZMR7 was purified by cold ethanol precipitation and characterized using TLC, FTIR, H, and C NMR spectroscopy. The maximum production of levan (28.4 g/l) was achieved when sucrose and ammonium chloride were used as carbon and nitrogen sources, respectively, at 35°C and an initial pH of 8.0. Some biomedical applications of levan like antitumor, antiparasitic, and antioxidant activities were investigated in vitro. The results revealed the ability of levan at different concentrations to decrease the viability of rhabdomyosarcoma and breast cancer cells compared with untreated cancer cells. Levan appeared also to have high antiparasitic activity against the promastigote of . Furthermore, levan had strong DPPH radical scavenging (antioxidant) activity. These findings suggest that levan produced by ZMR7 can serve as a natural biopolymer candidate for the pharmaceutical and medical fields.
Topics: Antineoplastic Agents; Antioxidants; Antiparasitic Agents; Cell Line, Tumor; Cell Proliferation; Culture Media; Fructans; Humans; Leishmania tropica; Pantoea; Polysaccharides, Bacterial
PubMed: 33820887
DOI: 10.4014/jmb.2101.01025 -
Frontiers in Microbiology 2023The fermentative production of auxin/indole 3-acetate (IAA) using selected strains can be a promising approach to developing novel plant biostimulants for agriculture...
INTRODUCTION
The fermentative production of auxin/indole 3-acetate (IAA) using selected strains can be a promising approach to developing novel plant biostimulants for agriculture use.
METHODS
By integrating metabolomics and fermentation technologies, this study aimed to define the optimal culture conditions to obtain auxin/IAA-enriched plant postbiotics using strain C1. Metabolomics analysis allowed us to demonstrate that the production of a selected.
RESULTS AND DISCUSSION
Array of compounds with plant growth-promoting- (IAA and hypoxanthine) and biocontrol activity (NS-5, cyclohexanone, homo-L-arginine, methyl hexadecenoic acid, and indole-3-carbinol) can be stimulated by cultivating this strain on minimal saline medium amended with sucrose as a carbon source. We applied a three-level-two-factor central composite design (CCD) based response surface methodology (RSM) to explore the impact of the independent variables (rotation speed and medium liquid-to-flask volume ratio) on the production of IAA and IAA precursors. The ANOVA component of the CCD indicated that all the process-independent variables investigated significantly impacted the auxin/IAA production by train C1. The optimum values of variables were a rotation speed of 180 rpm and a medium liquid-to-flask volume ratio of 1:10. Using the CCD-RSM method, we obtained a maximum indole auxin production of 208.3 ± 0.4 mg IAA/L, which was a 40% increase compared to the growth conditions used in previous studies. Targeted metabolomics allowed us to demonstrate that the IAA product selectivity and the accumulation of the IAA precursor indole-3-pyruvic acid were significantly affected by the increase in the rotation speed and the aeration efficiency.
PubMed: 36970660
DOI: 10.3389/fmicb.2023.1022248