Overexpression of mqsR in Xylella fastidiosa Leads to a Priming Effect of Cells to Copper Stress Tolerance

Copper-based compounds are widely used in agriculture as a chemical strategy to limit the spread of multiple plant diseases; however, the continuous use of this heavy metal has caused environmental damage as well as the development of copper-resistant strains. Thus, it is important to understand how the bacterial phytopathogens evolve to manage with this metal in the field. The MqsRA Toxin–Antitoxin system has been recently described for its function in biofilm formation and copper tolerance in Xylella fastidiosa, a plant-pathogen bacterium responsible for economic damage in several crops worldwide. Here we identified differentially regulated genes by X. fastidiosa MqsRA by assessing changes in global gene expression with and without copper. Results show that mqsR overexpression led to changes in the pattern of cell aggregation, culminating in a global phenotypic heterogeneity, indicative of persister cell formation. This phenotype was also observed in wild-type cells but only in the presence of copper. This suggests that MqsR regulates genes that alter cell behavior in order to prime them to respond to copper stress, which is supported by RNA-Seq analysis. To increase cellular tolerance, proteolysis and efflux pumps and regulator related to multidrug resistance are induced in the presence of copper, in an MqsR-independent response. In this study we show a network of genes modulated by MqsR that is associated with induction of persistence in X. fastidiosa. Persistence in plant-pathogenic bacteria is an important genetic tolerance mechanism still neglected for management of phytopathogens in agriculture, for which this work expands the current knowledge and opens new perspectives for studies aiming for a more efficient control in the field.

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Impact of Xylella fastidiosa subspecies pauca in European olives

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1912206117 ◽

2020 ◽

Vol 117 (17) ◽

pp. 9250-9259 ◽

Cited By ~ 17

Author(s):

Kevin Schneider ◽

Wopke van der Werf ◽

Martina Cendoya ◽

Monique Mourits ◽

Juan A. Navas-Cortés ◽

...

Keyword(s):

Xylella Fastidiosa ◽

Plant Diseases ◽

Disease Spread ◽

Economic Damage ◽

Climatic Suitability ◽

Case Scenario ◽

Worst Case ◽

Ongoing Research ◽

Phytosanitary Measures ◽

The Impact

Xylella fastidiosa is the causal agent of plant diseases that cause massive economic damage. In 2013, a strain of the bacterium was, for the first time, detected in the European territory (Italy), causing the Olive Quick Decline Syndrome. We simulate future spread of the disease based on climatic-suitability modeling and radial expansion of the invaded territory. An economic model is developed to compute impact based on discounted foregone profits and losses in investment. The model projects impact for Italy, Greece, and Spain, as these countries account for around 95% of the European olive oil production. Climatic suitability modeling indicates that, depending on the suitability threshold, 95.5 to 98.9%, 99.2 to 99.8%, and 84.6 to 99.1% of the national areas of production fall into suitable territory in Italy, Greece, and Spain, respectively. For Italy, across the considered rates of radial range expansion the potential economic impact over 50 y ranges from 1.9 billion to 5.2 billion Euros for the economic worst-case scenario, in which production ceases after orchards die off. If replanting with resistant varieties is feasible, the impact ranges from 0.6 billion to 1.6 billion Euros. Depending on whether replanting is feasible, between 0.5 billion and 1.3 billion Euros can be saved over the course of 50 y if disease spread is reduced from 5.18 to 1.1 km per year. The analysis stresses the necessity to strengthen the ongoing research on cultivar resistance traits and application of phytosanitary measures, including vector control and inoculum suppression, by removing host plants.

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Innovation and Application of the Type III Secretion System Inhibitors in Plant Pathogenic Bacteria

Microorganisms ◽

10.3390/microorganisms8121956 ◽

2020 ◽

Vol 8 (12) ◽

pp. 1956

Author(s):

Xiaochen Yuan ◽

Manda Yu ◽

Ching-Hong Yang

Keyword(s):

Type Iii Secretion ◽

Pathogenic Bacteria ◽

Plant Pathogens ◽

Current Knowledge ◽

Type Iii Secretion System ◽

Transcriptional Regulators ◽

Secretion System ◽

Plant Diseases ◽

Host Cells ◽

Type Iii

Many Gram-negative pathogenic bacteria rely on a functional type III secretion system (T3SS), which injects multiple effector proteins into eukaryotic host cells, for their pathogenicity. Genetic studies conducted in different host-microbe pathosystems often revealed a sophisticated regulatory mechanism of their T3SSs, suggesting that the expression of T3SS is tightly controlled and constantly monitored by bacteria in response to the ever-changing host environment. Therefore, it is critical to understand the regulation of T3SS in pathogenic bacteria for successful disease management. This review focuses on a model plant pathogen, Dickeyadadantii, and summarizes the current knowledge of its T3SS regulation. We highlight the roles of several T3SS regulators that were recently discovered, including the transcriptional regulators: FlhDC, RpoS, and SlyA; the post-transcriptional regulators: PNPase, Hfq with its dependent sRNA ArcZ, and the RsmA/B system; and the bacterial second messenger cyclic-di-GMP (c-di-GMP). Homologs of these regulatory components have also been characterized in almost all major bacterial plant pathogens like Erwiniaamylovora, Pseudomonassyringae, Pectobacterium spp., Xanthomonas spp., and Ralstonia spp. The second half of this review shifts focus to an in-depth discussion of the innovation and development of T3SS inhibitors, small molecules that inhibit T3SSs, in the field of plant pathology. This includes T3SS inhibitors that are derived from plant phenolic compounds, plant coumarins, and salicylidene acylhydrazides. We also discuss their modes of action in bacteria and application for controlling plant diseases.

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The Epidemiology of Xylella fastidiosa; A Perspective on Current Knowledge and Framework to Investigate Plant Host–Vector–Pathogen Interactions

Phytopathology ◽

10.1094/phyto-07-18-0239-fi ◽

2019 ◽

Vol 109 (2) ◽

pp. 200-209 ◽

Cited By ~ 2

Author(s):

Michael Jeger ◽

Claude Bragard

Keyword(s):

Plant Pathogen ◽

Current Knowledge ◽

Xylella Fastidiosa ◽

Plant Diseases ◽

Model Framework ◽

Plant Host ◽

Wide Range ◽

Epidemic Development ◽

Host Infection ◽

And Behavior

Insect-transmitted plant diseases caused by viruses, phytoplasmas, and bacteria share many features in common regardless of the causal agent. This perspective aims to show how a model framework, developed originally for plant virus diseases, can be modified for the case of diseases incited by Xylella fastidiosa. In particular, the model framework enables the specification of a simple but quite general invasion criterion defined in terms of key plant, pathogen, and vector parameters and, importantly, their interactions, which determine whether or not an incursion or isolated outbreak of a pathogen will lead to establishment, persistence, and subsequent epidemic development. Hence, this approach is applicable to the wide range of X. fastidiosa-incited diseases that have recently emerged in southern Europe, each with differing host plant, pathogen subspecies, and vector identities. Of particular importance are parameters relating to vector abundance and activity, transmission characteristics, and behavior in relation to preferences for host infection status. Some gaps in knowledge with regard to the developing situation in Europe are noted.

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Insects as vectors of foodborne pathogenic bacteria

Terrestrial Arthropod Reviews ◽

10.1163/187498311x543989 ◽

2011 ◽

Vol 4 (1) ◽

pp. 5-16 ◽

Cited By ~ 21

Author(s):

Jeffrey Blazar ◽

Marc Allard ◽

E. Kurt Lienau

Keyword(s):

Food Safety ◽

Foodborne Pathogens ◽

Pathogenic Bacteria ◽

Current Knowledge ◽

Disease Outbreaks ◽

House Fly ◽

American Cockroach ◽

Health Concern ◽

Foodborne Disease ◽

Salmonella Spp

AbstractFood safety is an important consideration worldwide. To maintain and improve our current knowledge of foodborne disease outbreaks, we must understand some of the more imminent issues related to food safety. A variety of agents are responsible for transmitting the estimated 76 million cases of illnesses caused by foodborne pathogens every year. This review explores why insects pose a serious health concern, in terms of worldwide food safety initiatives, by looking at evidence in published <abs>Food safety is an important consideration worldwide. To maintain and improve our current knowledge of foodborne disease outbreaks, we must understand some of the more imminent issues related to food safety. A variety of agents are responsible for transmitting the estimated 76 million cases of illnesses caused by foodborne pathogens every year. This review explores why insects pose a serious health concern, in terms of worldwide food safety initiatives, by looking at evidence in published literature. We highlight at least eleven different species of insects, including the lesser mealworm, Alphitobius diaperinus (Panzer); secondary screwworm, Cochliomyia macellaria (Fabricius); synanthropic flies [flesh fly, Sarcophaga carnaria (L.); house fly, Musca domestica (L.); fruit fly, Drosophila melanogaster (Meigen); and stable fly, Stomoxys calcitrans (L.)], American cockroach, Periplaneta americana (L.); German cockroach, Blatella germanica (L.); Oriental cockroach, Blatta orientalis (L.); Pacific beetle cockroach, Diploptera punctata (Eschscholtz); and Speckled feeder cockroach, Nauphoeta cinerea (Olivier), which act as vectors for Salmonella spp. or Escherichia coli and illustrate how these insects are successful vectors of foodborne disease outbreaks. We propose that insects be considered as one of the latest issues in food safety initiatives. Not only are some insects extremely important contributors to diseases, but now we suggest that more research into insects as potential carriers of E. coli and Salmonella spp., and therefore as contributing to foodborne disease outbreaks, is granted.

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How to Train Your Phage: The Recent Efforts in Phage Training

Biologics ◽

10.3390/biologics1020005 ◽

2021 ◽

Vol 1 (2) ◽

pp. 70-88

Author(s):

Abdallah Abdelsattar ◽

Alyaa Dawooud ◽

Nouran Rezk ◽

Salsabil Makky ◽

Anan Safwat ◽

...

Keyword(s):

Host Range ◽

Pathogenic Bacteria ◽

Bacterial Resistance ◽

Phage Therapy ◽

Current Knowledge ◽

Lytic Replication ◽

Resistant Bacteria ◽

Infection Cycles ◽

Different Strains ◽

Specific Species

Control of pathogenic bacteria by deliberate application of predatory phages has potential as a powerful therapy against antibiotic-resistant bacteria. The key advantages of phage biocontrol over antibacterial chemotherapy are: (1) an ability to self-propagate inside host bacteria, (2) targeted predation of specific species or strains of bacteria, (3) adaptive molecular machinery to overcome resistance in target bacteria. However, realizing the potential of phage biocontrol is dependent on harnessing or adapting these responses, as many phage species switch between lytic infection cycles (resulting in lysis) and lysogenic infection cycles (resulting in genomic integration) that increase the likelihood of survival of the phage in response to external stress or host depletion. Similarly, host range will need to be optimized to make phage therapy medically viable whilst avoiding the potential for deleteriously disturbing the commensal microbiota. Phage training is a new approach to produce efficient phages by capitalizing on the evolved response of wild-type phages to bacterial resistance. Here we will review recent studies reporting successful trials of training different strains of phages to switch into lytic replication mode, overcome bacterial resistance, and increase their host range. This review will also highlight the current knowledge of phage training and future implications in phage applications and phage therapy and summarize the recent pipeline of the magistral preparation to produce a customized phage for clinical trials and medical applications.

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Controlled spatial organization of bacterial clusters reveals cell filamentation is vital for Xylella fastidiosa biofilm formation

10.1101/2021.01.08.425936 ◽

2021 ◽

Author(s):

Silambarasan Anbumani ◽

Aldeliane M. da Silva ◽

Eduarda R. Fischer ◽

Mariana de Souza e Silva ◽

Antonio A.G. von Zuben ◽

...

Keyword(s):

Cell Adhesion ◽

Quorum Sensing ◽

Biofilm Formation ◽

Spatial Organization ◽

Xylella Fastidiosa ◽

Cell Formation ◽

Formation Mechanisms ◽

Cell Morphogenesis ◽

Cell Clusters ◽

Filamentous Cell

The morphological plasticity of bacteria to form filamentous cells commonly represents an adaptive strategy induced by stresses. In contrast, for diverse pathogens filamentous cells have been observed during biofilm formation, with function yet to be elucidated. To identify prior hypothesized quorum sensing as trigger of such cell morphogenesis, spatially controlled cell adhesion is pivotal. Here, we demonstrate highly-selective cell adhesion of the biofilm-forming phytopathogen Xylella fastidiosa to gold-patterned SiO2 substrates with well-defined geometries and dimensions. The consequent control of both cell density and distances between cell clusters using these patterns provided evidence of quorum sensing governing filamentous cell formation. While cell morphogenesis is induced by cell cluster density, filamentous cell growth is oriented towards neighboring cell clusters and distance-dependent; large interconnected cell clusters create the early biofilm structural framework. Together, our findings and investigative platform could facilitate therapeutic developments targeting biofilm formation mechanisms of X. fastidiosa and other pathogens.

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Adenotonsillar microbiome: an update

Postgraduate Medical Journal ◽

10.1136/postgradmedj-2018-135602 ◽

2018 ◽

Vol 94 (1113) ◽

pp. 398-403 ◽

Cited By ~ 7

Author(s):

James Jordan Johnston ◽

Richard Douglas

Keyword(s):

Pathogenic Bacteria ◽

Current Knowledge ◽

Otitis Media With Effusion ◽

Paediatric Population ◽

Sleep Apnoea ◽

Recurrent Tonsillitis ◽

Surface Culture ◽

Upper Airways ◽

Palatine Tonsils ◽

Obstructive Sleep

Pathogenic bacteria associated with the adenoids and tonsils cause much morbidity in the paediatric population. Hyperplasia of the adenoids is associated with otitis media with effusion and hyperplasia of the palatine tonsils is associated with both recurrent tonsillitis and obstructive sleep apnoea. Most current knowledge of the microbiology of the upper airways has been derived from culture-based studies, which usually reflect only a small fraction of the bacteria present on the mucosal surface. Culture-independent molecular surveys based on 16S ribosomal RNA sequencing are now being employed to determine the microbiota on the surface and within the tissue of adenoids and palatine tonsils. This review describes the new techniques applied in determining the microbiome and summarises the results of studies employing these techniques.

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Increase in ring width, vessel number and δ18O in olive trees infected with Xylella fastidiosa

Tree Physiology ◽

10.1093/treephys/tpaa095 ◽

2020 ◽

Vol 40 (11) ◽

pp. 1583-1594

Author(s):

Erika Sabella ◽

Samuele Moretti ◽

Holger Gärtner ◽

Andrea Luvisi ◽

Luigi De Bellis ◽

...

Keyword(s):

Xylella Fastidiosa ◽

Ring Width ◽

Plant Diseases ◽

Susceptible Cultivar ◽

Water Conductivity ◽

Leaf Transpiration ◽

Leaf Level ◽

Olive Quick Decline Syndrome ◽

Olive Trees ◽

Tree Stem

Abstract Xylella fastidiosa (Xf) Wells, Raju et al., 1986 is a bacterium that causes plant diseases in the Americas. In Europe, it was first detected on the Salento Peninsula (Italy), where it was found to be associated with the olive quick decline syndrome. Here, we present the results of the first tree-ring study of infected and uninfected olive trees (Olea europaea L.) of two different cultivars, one resistant and one susceptible, to establish the effects induced by the spread of the pathogen inside the tree. Changes in wood anatomical characteristics, such as an increase in the number of vessels and in ring width, were observed in the infected plants of both the cultivars Cellina di Nardò (susceptible to Xf infection) and Leccino (resistant to Xf infection). Thus, whether infection affects the mortality of the tree or not, the tree shows a reaction to it. The presence of occlusions was detected in the wood of both 4-year-old branches and the tree stem core. As expected, the percentage of occluded vessels in the Xf-susceptible cultivar Cellina di Nardò was significantly higher than in the Xf-resistant cultivar Leccino. The δ 18O of the 4-year-old branches was significantly higher in infected trees of both cultivars than in noninfected trees, while no variations in δ 13C were observed. This suggests a reduction in leaf transpiration rates during infection and seems to be related to the occlusions observed in rings of the 4-year-old branches. Such occlusions can determine effects at leaf level that could influence stomatal activity. On the other hand, the significant increase in the number of vessels in infected trees could be related to the tree’s attempt to enhance water conductivity in response to the pathogen-induced vessel occlusions.

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Economic aspects of management and planning of waste processing system development

E3S Web of Conferences ◽

10.1051/e3sconf/201911002079 ◽

2019 ◽

Vol 110 ◽

pp. 02079

Author(s):

Edvard Tshovrebov ◽

Evgeniy Velichko ◽

Ural Niyazgulov ◽

Yuliya Sadchikova

Keyword(s):

System Development ◽

Processing System ◽

Cost Effective ◽

Environmental Safety ◽

Economic Incentives ◽

Economic Damage ◽

Environmental Damage ◽

Natural Ecosystems ◽

Technological Infrastructure ◽

Production And Consumption

Annually, increasing volumes of industrial and municipal waste generation and disposal, leading to increasing anthropogenic environmental and sanitary-epidemiological pressure on the environment and, as a consequence, significant environmental damage and associated economic damage to natural ecosystems, represent one of the main threats to environmental safety territories, life and health of the population. At the same time, numerous valuable components extracted from processed production and consumption wastes can be an important source of reserve for the development of industries and sectors of the economy, entrepreneurial activities in the use of secondary resources for production, services, works and energy. This factor dictates the need to search for new sound management, economic, organizational and technical approaches and solutions to lawmaking, planning and forecasting the cost-effective organization of the system of separate collection, processing, disposal, disposal of production and consumption waste, the development of an appropriate industrial, scientific and technological infrastructure, increasing the share of secondary material and energy resources extracted from waste, the development of instruments of state oh support and economic incentives for this activity.

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Eco-Epidemiological Uncertainties of Emerging Plant Diseases: The Challenge of Predicting Xylella fastidiosa Dynamics in Novel Environments

Phytopathology ◽

10.1094/phyto-03-20-0098-rvw ◽

2020 ◽

Vol 110 (11) ◽

pp. 1740-1750

Author(s):

Flavia Occhibove ◽

Daniel S. Chapman ◽

Alexander J. Mastin ◽

Stephen S. R. Parnell ◽

Barbara Agstner ◽

...

Keyword(s):

Environmental Conditions ◽

Disease Risk ◽

Xylella Fastidiosa ◽

Management Strategies ◽

Plant Diseases ◽

Disease Spread ◽

Future Research ◽

Bacterial Strains ◽

Novel Environments ◽

Epidemiological Characteristics

In order to prevent and control the emergence of biosecurity threats such as vector-borne diseases of plants, it is vital to understand drivers of entry, establishment, and spatiotemporal spread, as well as the form, timing, and effectiveness of disease management strategies. An inherent challenge for policy in combatting emerging disease is the uncertainty associated with intervention planning in areas not yet affected, based on models and data from current outbreaks. Following the recent high-profile emergence of the bacterium Xylella fastidiosa in a number of European countries, we review the most pertinent epidemiological uncertainties concerning the dynamics of this bacterium in novel environments. To reduce the considerable ecological and socio-economic impacts of these outbreaks, eco-epidemiological research in a broader range of environmental conditions needs to be conducted and used to inform policy to enhance disease risk assessment, and support successful policy-making decisions. By characterizing infection pathways, we can highlight the uncertainties that surround our knowledge of this disease, drawing attention to how these are amplified when trying to predict and manage outbreaks in currently unaffected locations. To help guide future research and decision-making processes, we invited experts in different fields of plant pathology to identify data to prioritize when developing pest risk assessments. Our analysis revealed that epidemiological uncertainty is mainly driven by the large variety of hosts, vectors, and bacterial strains, leading to a range of different epidemiological characteristics further magnified by novel environmental conditions. These results offer new insights on how eco-epidemiological analyses can enhance understanding of plant disease spread and support management recommendations. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

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