scholarly journals Genomic Analysis of the First European Bacteriophages with Depolymerase Activity and Biocontrol Efficacy Against the Phytopathogen Ralstonia solanacearum

2021 ◽  
Author(s):  
Elena G. Biosca ◽  
José F. Català-Senent ◽  
Àngela Figàs-Segura ◽  
Edson Bertolini ◽  
María M. López ◽  
...  
Keyword(s):  
Biological Control ◽  
Ralstonia Solanacearum ◽  
Control Strategies ◽  
Phylogenetic Analyses ◽  
Genomic Analysis ◽  
Bioinformatic Analysis ◽  
Environmental Water ◽  
Plant Diseases ◽  
Host Cells ◽  
Genomic Characterization

Ralstonia solanacearum is the causative agent of bacterial wilt, one of the most destructive plant diseases. While chemical control has an environmental impact, biological control strategies can allow sustainable agrosystems. Three lytic bacteriophages (phages) of R. solanacearum with biocontrol capacity in environmental water and plant were isolated from river water in Europe but not fully characterized, their genomic characterization being fundamental to understand their biology. In this work, the phage genomes were sequenced and subjected to bioinformatic analysis. The morphology was also observed by electron microscopy. Phylogenetic analyses were performed with a selection of phages able to infect R. solanacearum and the closely related phytopathogenic species R. pseudosolanacearum. The results indicated that the genomes of vRsoP-WF2, vRsoP-WM2 and vRsoP-WR2 range from 40,688 to 41,158 bp with almost 59% GC-contents, 52 ORFs in vRsoP-WF2 and vRsoP-WM2, and 53 in vRsoP-WR2 but, with only 22 or 23 predicted proteins with functional homologs in databases. Among them, two lysins and one exopolysaccharide (EPS) depolymerase, this type of depolymerase being identified in R. solanacearum phages for the first time. These three European phages belong to the same novel species within the Gyeongsanvirus, Autographiviridae family (formerly Podoviridae). These genomic data will contribute to a better understanding of the abilities of these phages to damage host cells and, consequently, to an improvement in the biological control of R. solanacearum.

scholarly journals Genomic Analysis of the First European Bacteriophages with Depolymerase Activity and Biocontrol Efficacy against the Phytopathogen Ralstonia solanacearum

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2539
Author(s):  
Elena G. Biosca ◽  
José Francisco Català-Senent ◽  
Àngela Figàs-Segura ◽  
Edson Bertolini ◽  
María M. López ◽  
...  
Keyword(s):  
Biological Control ◽  
Ralstonia Solanacearum ◽  
Control Strategies ◽  
Phylogenetic Analyses ◽  
Genomic Analysis ◽  
Bioinformatic Analysis ◽  
Environmental Water ◽  
Plant Diseases ◽  
Host Cells ◽  
Genomic Characterization

Ralstonia solanacearum is the causative agent of bacterial wilt, one of the most destructive plant diseases. While chemical control has an environmental impact, biological control strategies can allow sustainable agrosystems. Three lytic bacteriophages (phages) of R. solanacearum with biocontrol capacity in environmental water and plants were isolated from river water in Europe but not fully analysed, their genomic characterization being fundamental to understand their biology. In this work, the phage genomes were sequenced and subjected to bioinformatic analysis. The morphology was also observed by electron microscopy. Phylogenetic analyses were performed with a selection of phages able to infect R. solanacearum and the closely related phytopathogenic species R. pseudosolanacearum. The results indicated that the genomes of vRsoP-WF2, vRsoP-WM2 and vRsoP-WR2 range from 40,688 to 41,158 bp with almost 59% GC-contents, 52 ORFs in vRsoP-WF2 and vRsoP-WM2, and 53 in vRsoP-WR2 but, with only 22 or 23 predicted proteins with functional homologs in databases. Among them, two lysins and one exopolysaccharide (EPS) depolymerase, this type of depolymerase being identified in R. solanacearum phages for the first time. These three European phages belong to the same novel species within the Gyeongsanvirus, Autographiviridae family (formerly Podoviridae). These genomic data will contribute to a better understanding of the abilities of these phages to damage host cells and, consequently, to an improvement in the biological control of R. solanacearum.

scholarly journals Identification of a Hypervariable Region Containing New Legionella pneumophila Icm/Dot Translocated Substrates by Using the Conserved icmQ Regulatory Signature

2008 ◽  
Vol 76 (10) ◽  
pp. 4581-4591 ◽  
Author(s):  
Tal Zusman ◽  
Elena Degtyar ◽  
Gil Segal
Keyword(s):  
Legionella Pneumophila ◽  
Regulatory Element ◽  
Hypervariable Region ◽  
Genomic Analysis ◽  
Bioinformatic Analysis ◽  
Genomic Region ◽  
Host Cells ◽  
Regulatory Sequence ◽  
Dependent Manner ◽  
Genomic Regions

ABSTRACT Legionella pneumophila is an intracellular pathogen that has been shown to utilize the Icm/Dot type IV secretion system for pathogenesis. This system was shown to be composed of Icm/Dot complex components, accessory proteins, and a large number of translocated substrates. In this study, comparison of the icmQ regulatory regions from many Legionella species revealed a conserved regulatory sequence that includes the icmQ −10 promoter element. Mutagenesis of this conserved regulatory element indicated that each of the nucleotides in it affects the level of expression of the icmQ gene but not in a uniform fashion. A genomic analysis discovered that four additional genes in L. pneumophila contain this conserved regulatory sequence, which was found to function similarly in these genes as well. Examination of these four genes indicated that they are dispensable for intracellular growth, but two of them were found to encode new Icm/Dot translocated substrates (IDTS). Comparison of the genomic regions encoding these two IDTS among the four available L. pneumophila genomic sequences indicated that one of these genes is located in a hypervariable genomic region, which was shown before to contain an IDTS-encoding gene. Translocation analysis that was performed for nine proteins encoded from this hypervariable genomic region indicated that six of them are new IDTS which are translocated into host cells in an Icm/Dot-dependent manner. Furthermore, a bioinformatic analysis indicated that additional L. pneumophila genomic regions that contain several neighboring IDTS-encoding genes are hypervariable in gene content.

Ecological succession and biological control in the phyllosphere

1995 ◽  
Vol 73 (S1) ◽  
pp. 76-82 ◽  
Author(s):  
J. J. Marois ◽  
P. M. Coleman
Keyword(s):  
Biological Control ◽  
Island Biogeography ◽  
Control Strategies ◽  
Nutrient Utilization ◽  
Ecological Succession ◽  
Plant Diseases ◽  
Plant Debris ◽  
Carbohydrate Utilization ◽  
Plant Parts ◽  
Environmental Requirements

Understanding biological control of plant diseases is dependent on an understanding of succession in microbial communities. The colonization of aboveground plant parts by saprophytic microbes is not well understood, but it appears to follow the same model as that in soil communities. When a nutrient source is added, such as plant debris, there is a succession of organisms organized along a spectrum of complexity of carbohydrate utilization. A similar phenomenon may occur during the colonization of plant parts newly exposed by natural development or by wounds, upon which many pathogens depend to serve as sites of infection. These nutrient utilization strategies have been interpreted as indicative of r (rapidly utilizing simple sugars) and K (slowly utilizing lignin) life strategies. If the concepts of r and K species are applicable to microbes, it could indicate what type of interaction would be most likely to be successful for biological control. For example, pathogens that are r species may be better controlled by competition, and K pathogenic species better controlled by parasitism. However, for any interaction to take place, the control agent's environmental requirements, both biotic and abiotic, must overlap with that of the pathogen. The concepts of ecological succession and r and K species, if appropriate for microorganisms, may prove very valuable when developing biological control strategies. Key words: antibioses, competition, island biogeography, parasitism.

scholarly journals The Abilities of Endophytic and Biofertilizing Bacteria and Their Combinations to Suppress Bacterial Wilt Disease (Ralstonia solanacearum) of Chili

2017 ◽  
Vol 2 (6) ◽  
pp. 296 ◽  
Author(s):  
Noor Istifadaha ◽  
Dewi Nurma Yanti Ningtyasb ◽  
Pujawati Suryatmana ◽  
Betty Natalie Fitriatin
Keyword(s):  
Biological Control ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Endophytic Bacteria ◽  
Disease Incidence ◽  
Wilt Disease ◽  
Plant Diseases ◽  
Disease Suppression ◽  
Bacterial Wilt Disease ◽  
Environmentally Friendly Method

Bacterial wilt disease (Ralstonia solanacearum) is one of the most important diseases in Solanaceae, including chili. Biological control is one of environmentally-friendly method for controlling plant diseases. Microbes that are potential as biological control agents include bacterial endophytes and bacteria that are usually used as biofertilizer. This paper discusses the result of the study that examined the abilities of endophytic and biofertilizing bacteria solely or in combination to suppress bacterial wilt disease (R. solanacearum). The endophytic bacteria isolates tested were Lysinibacillus sp. and Bacillus subtilis, while biofertilizing bacteria used were N-fixing bacteria (Azotobacter chrococcum) and P-solubilizing bacteria (Pseudomonas cepacea). The results showed that the endophytic bacteria, biofertilizing bacteria and their combination inhibited wilt disease incidence in chili by 46.7-80 %. The highest disease suppression (80 %) showed by the endophytic bacteria, B. subtilis. This endophyte was also able to promote a significant chili growth. Keywords: Ralstonia solanacearum, Endophytic bacteria, Biofertilizer, Biological control, Chili.

scholarly journals Genomic Analysis of Carbapenem-Resistant Pseudomonas aeruginosa Isolated From Urban Rivers Confirms Spread of Clone Sequence Type 277 Carrying Broad Resistome and Virulome Beyond the Hospital

2021 ◽  
Vol 12 ◽  
Author(s):  
Fernanda Esposito ◽  
Brenda Cardoso ◽  
Herrison Fontana ◽  
Bruna Fuga ◽  
Adriana Cardenas-Arias ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Galleria Mellonella ◽  
Genomic Analysis ◽  
Bioinformatic Analysis ◽  
Environmental Water ◽  
Multidrug Resistant ◽  
Sequence Type ◽  
Infection Model ◽  
Urban Rivers ◽  
Secretion Systems

The dissemination of antibiotic-resistant priority pathogens beyond hospital settings is both a public health and an environmental problem. In this regard, high-risk clones exhibiting a multidrug-resistant (MDR) or extensively drug-resistant (XDR) phenotype have shown rapid adaptation at the human-animal-environment interface. In this study, we report genomic data and the virulence potential of the carbapenemase, São Paulo metallo-β-lactamase (SPM-1)-producing Pseudomonas aeruginosa strains (Pa19 and Pa151) isolated from polluted urban rivers, in Brazil. Bioinformatic analysis revealed a wide resistome to clinically relevant antibiotics (carbapenems, aminoglycosides, fosfomycin, sulfonamides, phenicols, and fluoroquinolones), biocides (quaternary ammonium compounds) and heavy metals (copper), whereas the presence of exotoxin A, alginate, quorum sensing, types II, III, and IV secretion systems, colicin, and pyocin encoding virulence genes was associated with a highly virulent behavior in the Galleria mellonella infection model. These results confirm the spread of healthcare-associated critical-priority P. aeruginosa belonging to the MDR sequence type 277 (ST277) clone beyond the hospital, highlighting that the presence of these pathogens in environmental water samples can have clinical implications for humans and other animals.

scholarly journals Biological Control of Plant Diseases: An Evolutionary and Eco-Economic Consideration

Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1311
Author(s):  
Dun-Chun He ◽  
Meng-Han He ◽  
Divina M. Amalin ◽  
Wei Liu ◽  
Dionisio G. Alvindia ◽  
...  
Keyword(s):  
Biological Control ◽  
Disease Control ◽  
Comprehensive Evaluation ◽  
Control Strategies ◽  
Crop Productivity ◽  
Ecological Function ◽  
Plant Diseases ◽  
Promising Alternative ◽  
The Sustainable Development ◽  
Positive Externality

Biological control is considered as a promising alternative to pesticide and plant resistance to manage plant diseases, but a better understanding of the interaction of its natural and societal functions is necessary for its endorsement. The introduction of biological control agents (BCAs) alters the interaction among plants, pathogens, and environments, leading to biological and physical cascades that influence pathogen fitness, plant health, and ecological function. These interrelationships generate a landscape of tradeoffs among natural and social functions of biological control, and a comprehensive evaluation of its benefits and costs across social and farmer perspectives is required to ensure the sustainable development and deployment of the approach. Consequently, there should be a shift of disease control philosophy from a single concept that only concerns crop productivity to a multifaceted concept concerning crop productivity, ecological function, social acceptability, and economical accessibility. To achieve these goals, attempts should make to develop “green” BCAs used dynamically and synthetically with other disease control approaches in an integrated disease management scheme, and evolutionary biologists should play an increasing role in formulating the strategies. Governments and the public should also play a role in the development and implementation of biological control strategies supporting positive externality.

scholarly journals IDENTIFICATION OF THE ENTOMOPATHOGENIC FUNGI SAMPLE DL0069 BY COMBINATION OF MORPHOLOGICAL AND MOLECULAR PHYLOGENETIC ANALYSES

2018 ◽  
Vol 55 (1A) ◽  
pp. 117 ◽  
Author(s):  
Vu Tien Luyen
Keyword(s):  
Biological Control ◽  
Entomopathogenic Fungi ◽  
Phylogenetic Analyses ◽  
Plant Diseases ◽  
Morphological Data ◽  
Biological Control Agents ◽  
High Potency ◽  
Mountainous Regions ◽  
Molecular Phylogenetic ◽  
Anamorphic Genus

Species of Simplicillium are biological control agents against certain plant diseases caused by insects and nematodes due to their ability to parasite and kill the host. Recently, this anamorphic genus is classified under Cordycipitaceae as a monophyletic group apart from the type genus Cordyceps. In this current research, we reported the combination of morphological data and molecular phylogenies to identify an entomopathogenic fungal sample (DL0069) found in the mountainous regions of Langbian mountain, Lam Dong Province, Vietnam. Through formation of phialides and conidial chains, DL0069 was most likely a member of Simplicillium genus. From molecular phylogenetic analyses of a portion of the nuclear large ribosomal unit (nrLSU), it was confirmed that DL0069 was most closely related with Simplicillium chinense, a recently found Simplicillium species with a high potency as a biocontrol of nematodes parasiting plants.

Reduce Disease Burden of Human Schistosomiasis in Asia Through Biological Control

2020 ◽  
Vol 20 (12) ◽  
pp. 1118-1132
Author(s):  
Sidra Saleem ◽  
Haroon Ahmed ◽  
Tooba Siddiqui ◽  
Seyma Gunyakti Kilinc ◽  
Aisha Khan ◽  
...  
Keyword(s):  
Biological Control ◽  
Geographical Distribution ◽  
Disease Burden ◽  
Management Practices ◽  
Control Strategies ◽  
Parasitic Disease ◽  
Asian Countries ◽  
Neglected Disease ◽  
Current Review ◽  
Near Future

Schistosomiasis is a chronic parasitic disease caused by a trematode blood fluke of the genus Schistosoma that belongs to the Schistosomatidae family. It is a neglected disease in different regions of Asia. In this review, 218 articles (between 2000 and 2017) related to the topic were collected from PubMed and Google scholar and reviewed. After thoroughly reading collected articles, due to irrelevant topic requirements, 94 articles were excluded. Articles that have data associated with Asian regions are considered. In Asia, the disease is prevalent in China, Philippines, Indonesia, Yemen, Nepal and Laos, etc. While in Pakistan, India and Bangladesh, the disease is not endemic and very few cases were reported. The disease was eliminated from Japan and Iran. The current review highlights the geographical distribution among Asian countries, transmission patterns, diagnosis, control strategies based on the use of anthelmintic plants and management practices implemented in Asia for the control of schistosomiasis. However, new implementations to treat schistosomiasis in humans should be proved to eliminate the disease finally in the future. This review emphasizes the biological control of schistosomiasis for the eradication of the disease from Asia in the near future.

scholarly journals Microbial antagonists against plant pathogens in Iran: A review

2020 ◽  
Vol 5 (1) ◽  
pp. 404-440 ◽  
Author(s):  
Mehrdad Alizadeh ◽  
Yalda Vasebi ◽  
Naser Safaie
Keyword(s):  
Biological Control ◽  
Chemical Control ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Agricultural Products ◽  
Control Measures ◽  
Wide Range ◽  
Plant Disease Management ◽  
Published Research

AbstractThe purpose of this article was to give a comprehensive review of the published research works on biological control of different fungal, bacterial, and nematode plant diseases in Iran from 1992 to 2018. Plant pathogens cause economical loss in many agricultural products in Iran. In an attempt to prevent these serious losses, chemical control measures have usually been applied to reduce diseases in farms, gardens, and greenhouses. In recent decades, using the biological control against plant diseases has been considered as a beneficial and alternative method to chemical control due to its potential in integrated plant disease management as well as the increasing yield in an eco-friendly manner. Based on the reported studies, various species of Trichoderma, Pseudomonas, and Bacillus were the most common biocontrol agents with the ability to control the wide range of plant pathogens in Iran from lab to the greenhouse and field conditions.

scholarly journals Lower Recovery of Nontuberculous Mycobacteria from Outdoor Hawai’i Environmental Water Biofilms Compared to Indoor Samples

2021 ◽  
Vol 9 (2) ◽  
pp. 224
Author(s):  
Ravleen Virdi ◽  
Melissa E. Lowe ◽  
Grant J. Norton ◽  
Stephanie N. Dawrs ◽  
Nabeeh A. Hasan ◽  
...  
Keyword(s):  
Pulmonary Disease ◽  
Environmental Samples ◽  
Nontuberculous Mycobacteria ◽  
Phylogenetic Analyses ◽  
Environmental Water ◽  
Rpob Gene ◽  
The United States ◽  
Indoor Environments ◽  
Respiratory Specimens ◽  
Rpob Sequence

Nontuberculous mycobacteria (NTM) are environmental organisms that can cause opportunistic pulmonary disease with species diversity showing significant regional variation. In the United States, Hawai’i shows the highest rate of NTM pulmonary disease. The need for improved understanding of NTM reservoirs led us to identify NTM from patient respiratory specimens and compare NTM diversity between outdoor and indoor locations in Hawai’i. A total of 545 water biofilm samples were collected from 357 unique locations across Kaua’i (n = 51), O’ahu (n = 202), Maui (n = 159), and Hawai’i Island (n = 133) and divided into outdoor (n = 179) or indoor (n = 366) categories. rpoB sequence analysis was used to determine NTM species and predictive modeling applied to develop NTM risk maps based on geographic characteristics between environments. M. chimaera was frequently identified from respiratory and environmental samples followed by M. chelonae and M. abscessus; yet significantly less NTM were consistently recovered from outdoor compared to indoor biofilms, as exemplified by showerhead biofilm samples. While the frequency of M. chimaera recovery was comparable between outdoor and indoor showerhead biofilms, phylogenetic analyses demonstrate similar rpoB gene sequences between all showerhead and respiratory M. chimaera isolates, supporting outdoor and indoor environments as possible sources for pulmonary M. chimaera infections.

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