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Microorganisms Oct 2022Multifaceted microorganisms such as the bacterium colonize a wide range of habitats and can exhibit both beneficial and harmful behaviors, which provide new insights... (Review)
Review
Multifaceted microorganisms such as the bacterium colonize a wide range of habitats and can exhibit both beneficial and harmful behaviors, which provide new insights into microbial ecology. In the agricultural context, several strains of spp. can promote plant growth through direct or indirect mechanisms. Members of this genus contribute to plant growth mainly by increasing the supply of nitrogen, solubilizing ammonia and inorganic phosphate, and producing phytohormones (e.g., auxins). Several other studies have shown the potential of strains of spp. to induce systemic resistance and protection against pests and pathogenic microorganisms in cultivated plants. Strains of the species deserve attention as a pest and phytopathogen control agent. Several of them also possess a biotechnological potential for therapeutic purposes (e.g., immunomodulators) and are implicated in human infections. Thus, the differentiation between the harmful and beneficial strains of is mandatory to apply this bacterium safely as a biofertilizer or biocontroller. This review specifically evaluates the potential of the strain-associated features of for bioprospecting and agricultural applications through its biological versatility as well as clarifying its potential animal and human health risks from a genomic point of view.
PubMed: 36296348
DOI: 10.3390/microorganisms10102072 -
BMC Microbiology Nov 2023Inflammatory bowel disease (IBD) is a multifactorial chronic inflammatory disease resulting from dysregulation of the mucosal immune response and gut microbiota. Crohn's...
BACKGROUND
Inflammatory bowel disease (IBD) is a multifactorial chronic inflammatory disease resulting from dysregulation of the mucosal immune response and gut microbiota. Crohn's disease (CD) and ulcerative colitis (UC) are difficult to distinguish, and differential diagnosis is essential for establishing a long-term treatment plan for patients. Furthermore, the abundance of mucosal bacteria is associated with the severity of the disease. This study aimed to differentiate and diagnose these two diseases using the microbiome and identify specific biomarkers associated with disease activity.
RESULTS
Differences in the abundance and composition of the microbiome between IBD patients and healthy controls (HC) were observed. Compared to HC, the diversity of the gut microbiome in patients with IBD decreased; the diversity of the gut microbiome in patients with CD was significantly lower. Sixty-eight microbiota members (28 for CD and 40 for UC) associated with these diseases were identified. Additionally, as the disease progressed through different stages, the diversity of the bacteria decreased. The abundances of Alistipes shahii and Pseudodesulfovibrio aespoeensis were negatively correlated with the severity of CD, whereas the abundance of Polynucleobacter wianus was positively correlated. The severity of UC was negatively correlated with the abundance of A. shahii, Porphyromonas asaccharolytica and Akkermansia muciniphilla, while it was positively correlated with the abundance of Pantoea candidatus pantoea carbekii. A regularized logistic regression model was used for the differential diagnosis of the two diseases. The area under the curve (AUC) was used to examine the performance of the model. The model discriminated UC and CD at an AUC of 0.873 (train set), 0.778 (test set), and 0.633 (validation set) and an area under the precision-recall curve (PRAUC) of 0.888 (train set), 0.806 (test set), and 0.474 (validation set).
CONCLUSIONS
Based on fecal whole-metagenome shotgun (WMS) sequencing, CD and UC were diagnosed using a machine-learning predictive model. Microbiome biomarkers associated with disease activity (UC and CD) are also proposed.
Topics: Humans; Colitis, Ulcerative; Crohn Disease; Inflammatory Bowel Diseases; Gastrointestinal Microbiome; Bacteria; Biomarkers
PubMed: 37951857
DOI: 10.1186/s12866-023-03084-5 -
Cureus Feb 2021is a plant pathogen infrequently reported to cause opportunistic bloodstream infections. This gram-negative bacillus is a rare cause of hospital-acquired infections in... (Review)
Review
is a plant pathogen infrequently reported to cause opportunistic bloodstream infections. This gram-negative bacillus is a rare cause of hospital-acquired infections in newborn infants with high mortality. Since the creation of the new genus in 1989, the evidence base available to neonatal health care providers is limited. Most of the available literature consists of case reports and case series. This review aims to consolidate the current reported literature on Pantoea infections, focusing on newborn infants and the neonatal intensive care unit (NICU). Prematurity and the associated relative immunocompromised state are major risk factors for hospital-acquired infections due to in newborn infants. Recent advances in molecular biology have improved our understanding of the cross-kingdom pathogenesis exhibited by . Respiratory symptoms and association with central venous lines are the most common clinical presentation of bacteremia in newborn infants. Early institution of appropriate antibiotic therapy against this organism could be lifesaving. Therefore, it is critical for neonatologists to understand the clinical spectrum of infections in NICUs.
PubMed: 33643749
DOI: 10.7759/cureus.13103 -
Plants (Basel, Switzerland) Oct 2022Bacteria from the genus have been reported to be widely distributed in rice paddy environments with contradictory roles. Some strains promoted rice growth and protected... (Review)
Review
Bacteria from the genus have been reported to be widely distributed in rice paddy environments with contradictory roles. Some strains promoted rice growth and protected rice from pathogen infection or abiotic stress, but other strain exhibited virulence to rice, even causing severe rice disease. In order to effectively utilize in rice production, this paper analyzed the mechanisms underlying beneficial and harmful effects of on rice growth. The beneficial effect of on rice plants includes growth promotion, abiotic alleviation and disease inhibition. The growth promotion may be mainly attributed to nitrogen-fixation, phosphate solubilization, plant physiological change, the biosynthesis of siderophores, exopolysaccharides, 1-aminocyclopropane-1-carboxylic acid deaminase and phytohormones, including cytokinin, indole-3-acetic acid (IAA), auxins, abscisic acid and gibberellic acid, while the disease inhibition may be mainly due to the induced resistance, nutrient and spatial competition, as well as the production of a variety of antibiotics. The pathogenic mechanism of can be mainly attributed to bacterial motility, production of phytohormones such as IAA, quorum sensing-related signal molecules and a series of cell wall-degrading enzymes, while the pathogenicity-related genes of include genes encoding plasmids, such as the pPATH plasmid, the hypersensitive response and pathogenicity system, as well as various types of secretion systems, such as T3SS and T6SS. In addition, the existing scientific problems in this field were discussed and future research prospects were proposed.
PubMed: 36235474
DOI: 10.3390/plants11192608 -
EFSA Journal. European Food Safety... Mar 2023The EFSA Plant Health Panel performed a pest categorisation of , a Gram-negative bacterium belonging to the Erwiniaceae family. is a well-defined taxonomic unit;...
The EFSA Plant Health Panel performed a pest categorisation of , a Gram-negative bacterium belonging to the Erwiniaceae family. is a well-defined taxonomic unit; nonetheless, its pathogenic nature is not well defined and non-pathogenic populations are known to occupy several, very different environmental niches as saprophytes, or as plant growth promoting bacteria or biocontrol agents. It is also described as a clinical pathogen causing bacteraemia and sepsis or as a member of the gut microbiota of several insects. is the causal agent of different diseases affecting numerous crops: in particular, centre rot of onion, bacterial leaf blight and grain discoloration of rice, leaf spot disease of maize and eucalyptus blight/dieback. A few insect species have been described as vectors of , among them, and . This bacterium is present in several countries in Europe, Africa, Asia, North and South America, and Oceania from tropical and subtropical regions to temperate areas worldwide. has been reported from the EU territory, both as pathogen on rice and maize and as an environmental, non-pathogenic bacterium in rice marshes and poplar rhizosoil. It is not included in EU Commission Implementing Regulation 2019/2072. The pathogen can be detected on its host plants using direct isolation, or PCR-based methods. The main pathway for the entry of the pathogen into the EU territory is host plants for planting, including seeds. In the EU, there is a large availability of host plants, with onion, maize, rice and strawberry being the most important ones. Therefore, disease outbreaks are possible almost at any latitude, except in the most northern regions. is not expected to have frequent or consistent impact on crop production and is not expected to have any environmental impact. Phytosanitary measures are available to mitigate the further introduction and spread of the pathogen into the EU on some hosts. The pest does not satisfy the criteria, which are within the remit for EFSA to evaluate whether the pest meets the definition of a Union quarantine pest. is probably widely distributed in different ecosystems in the EU. It may impact some specific hosts such as onions while on other hosts such as rice it has been reported as a seed microbiota without causing any impact and can even be beneficial to plant growth. Hence, the pathogenic nature of is not fully established.
PubMed: 36895574
DOI: 10.2903/j.efsa.2023.7849 -
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 -
Frontiers in Microbiology 2022Plum bacterial shot-hole caused by (. ) is one of the primary bacterial diseases in plum tree planting areas, resulting in abnormal growth of plum trees and severe...
Plum bacterial shot-hole caused by (. ) is one of the primary bacterial diseases in plum tree planting areas, resulting in abnormal growth of plum trees and severe economic losses. Early diagnosis of . is crucial to effectively control plant diseases. In this study, loop-mediated isothermal amplification (LAMP) analysis for genome-specific gene sequences was developed for the specific detection of . . We designed the LAMP primers based on the gene of . The best reaction system was 0.2 μmol·L for outer primer F3/B3 and 1.6 μmol·L for inner primer FIP/BIP. The LAMP reaction was optimal at 65°C for 60 min based on the color change and gel electrophoresis. This technology distinguished from other control bacteria. The detection limit of the LAMP technology was 5 fg·μl genomic DNA of . , which is 1,000 times that of the traditional PCR detection method. The LAMP technology could effectively detect the DNA of from the infected leaves without symptoms after indoor inoculation. Furthermore, the LAMP technology was applied successfully to detect field samples, and the field control effect of 0.3% tetramycin after LAMP detection reached 82.51%, which was 7.90% higher than that of conventional control. The proposed LAMP detection technology in this study offers the advantages of ease of operation, visibility of results, rapidity, accuracy, and high sensitivity, making it suitable for the early diagnosis of plum bacteria shot-hole disease.
PubMed: 35694300
DOI: 10.3389/fmicb.2022.896567 -
Plant Disease May 2021Maize (Zea mays) is the second most cultivated grain crop in Ecuador, with growing significance as a source of fodder and food. During the rainy season (November and...
Maize (Zea mays) is the second most cultivated grain crop in Ecuador, with growing significance as a source of fodder and food. During the rainy season (November and December) of 2018 and 2019, a disease of maize that was not previously observed in Ecuador was found at commercial fields of Misqui Sara variety, at four parishes of canton Quito (Tumbaco, Pifo, Puembo, and Checa), province of Pichincha. Infected plants, at tassel initiation, displayed symptoms of localized chlorotic streaks on leaves that expanded with time, and around a month later turned necrotic. Severely affected plants wilted and died. Symptoms appeared in lower leaves first and were later observed in upper leaves as the disease progressed. Disease incidence was between 20 and 30% in the affected plantations, with around 30% of infected plants wilting and dying, resulting in 20-25% of yield losses. Upper leaves from ten symptomatic plants, five from Puembo and five from Checa, were collected randomly. Two 0.5 cm2 pieces of leaf from each plant were excised from the margins of the necrotic lesions, surface sterilized and macerated in 9 mL of sterile peptone water. The 10-3 dilutions were plated onto nutrient agar and incubated at 28°C for 24 hours. Yellow, mucoid colonies were isolated on nutrient agar. Three isolates from Puembo and two from Checa were selected for testing Koch´s postulates and further biochemical and molecular characterization. Isolates were Gram-negative rods, oxidase negative, catalase, indol and citrate positive. Fragments of the 16S, gyrB, and rpoB loci were amplified and sequenced using the 27F/1492R (Lane, D. J., 1991), UP-1/UP-2r (Yamamoto & Harayama, 1995), and rpoBCM81-F/rpoBCM32b-R (Brady, C., et al., 2008) primer pairs, respectively. All isolates presented identical sequences for the different loci, therefore only sequences from isolate FP191505 were deposited in GenBank (GenBank accession no. MW528428-MW528430). A search of homologous sequences using BLAST resulted in identities of 99.3, 99.7, and 100 % for 16S, gyrB, and rpoB, respectively, with sequences from Pantoea ananatis type specimen LGM 2665 (Brady, C., et al., 2008; Hauben, L., et al., 1998; GenBank accession nos NR_119362.1, EF988824.1 EF988996.1), indicating that our isolates belong to this species. Pathogenicity tests were performed by syringe infiltration of bacterial suspensions. Each one of the five characterized P. ananatis isolates was inoculated in four leaves (500 ul of 1 x 108 CFU mL-1 per leave) of three healthy maize plants. Negative control plants were infiltrated with sterile distilled water. Plants were incubated at 28-30°C and 60% relative humidity for 24 hours. Later, plants were maintained in a greenhouse with 27°C/21°C day/night temperatures and observed daily. After six weeks all bacteria-inoculated plants developed symptoms of chlorosis and necrosis while the control was symptomless. Bacteria were re-isolated from symptomatic leaves and identified as P. ananatis following the same methodologies used for the initial identification. To our knowledge, this is the first report of P. ananatis causing leaf spot of maize in Ecuador.
PubMed: 33970033
DOI: 10.1094/PDIS-02-21-0298-PDN -
Microbiome Dec 2022Plants and their associated microbiota constitute an assemblage of species known as holobionts. The plant seed microbiome plays an important role in nutrient uptake and...
BACKGROUND
Plants and their associated microbiota constitute an assemblage of species known as holobionts. The plant seed microbiome plays an important role in nutrient uptake and stress attenuation. However, the core vertically transmitted endophytes remain largely unexplored.
RESULTS
To gain valuable insights into the vertical transmission of rice seed core endophytes, we conducted a large-scale analysis of the microbiomes of two generations of six different rice varieties from five microhabitats (bulk soil, rhizosphere, root, stem, and seed) from four geographic locations. We showed that the microhabitat rather than the geographic location and rice variety was the primary driver of the rice microbiome assemblage. The diversity and network complexity of the rice-associated microbiome decreased steadily from far to near the roots, rice exterior to interior, and from belowground to aboveground niches. Remarkably, the microbiomes of the roots, stems, and seeds of the rice interior compartments were not greatly influenced by the external environment. The core bacterial endophytes of rice were primarily comprised of 14 amplicon sequence variants (ASVs), 10 of which, especially ASV_2 (Pantoea) and ASV_48 (Xanthomonas), were identified as potentially vertically transmitted taxa because they existed across generations, were rarely present in exterior rice microhabitats, and were frequently isolated from rice seeds. The genome sequences of Pantoea and Xanthomonas isolated from the parental and offspring seeds showed a high degree of average nucleotide and core protein identity, indicating vertical transmission of seed endophytes across generations. In silico prediction indicated that the seed endophytes Pantoea and Xanthomonas possessed streamlined genomes with short lengths, low-complexity metabolism, and various plant growth-promoting traits. We also found that all strains of Pantoea and Xanthomonas exhibited cellulase activity and produced indole-3-acetic acid. However, most strains exhibited insignificant antagonism to the major pathogens of rice, such as Magnaporthe oryzae and X. oryzae pv. oryzae.
CONCLUSION
Overall, our study revealed that microhabitats, rather than site-specific environmental factors or host varieties, shape the rice microbiome. We discovered the vertically transmitted profiles and keystone taxa of the rice microbiome, which led to the isolation of culturable seed endophytes and investigation of their potential roles in plant-microbiome interactions. Our results provide insights on vertically transmitted microbiota and suggest new avenues for improving plant fitness via the manipulation of seed-associated microbiomes. Video Abstract.
Topics: Oryza; Endophytes; Seeds
PubMed: 36482381
DOI: 10.1186/s40168-022-01422-9 -
Biomolecules May 2020The 8488 lipopolysaccharide (LPS) was isolated, purified and characterized by monosaccharide and fatty acid analysis. The O-polysaccharide and lipid A components of the...
The 8488 lipopolysaccharide (LPS) was isolated, purified and characterized by monosaccharide and fatty acid analysis. The O-polysaccharide and lipid A components of the LPS were separated by mild acid degradation. Lipid A was studied by electrospray ionization mass spectrometry (ESI-MS) and found to consist of hexa-, penta-, tetra- and tri-acylated species. Two-dimensional nuclear magnetic resonance (NMR) spectroscopy revealed the following structure of the O-polysaccharide repeating unit →3)-α-L-Rha(1→6)-α-D-Man(1→3)-α-L-Fuc-(1→3)-β-D-GlcNAc-(1→. The LPS showed a low level of toxicity, was not pyrogenic, and reduced the adhesiveness index of microorganisms to 2.12, which was twofold less than the control. LPS modified by complex compounds of germanium (IV) and tin (IV) were obtained. It was found that six LPS samples modified by Sn compounds and two LPS samples modified by Ge compounds lost their toxic activity when administered to mice in a dose of LD (105 µg/mice or 5 mg/kg). However, none of the modified LPS samples changed their serological activity in an Ouchterlony double immunodiffusion test in agar.
Topics: Animals; Germanium; Lethal Dose 50; Lipid A; Mice; O Antigens; Organometallic Compounds; Pantoea; Tin
PubMed: 32456025
DOI: 10.3390/biom10050804