Host–symbiont specificity determined by microbe–microbe competition in an insect gut

Despite the omnipresence of specific host–symbiont associations with acquisition of the microbial symbiont from the environment, little is known about how the specificity of the interaction evolved and is maintained. The bean bug Riptortus pedestris acquires a specific bacterial symbiont of the genus Burkholderia from environmental soil and harbors it in midgut crypts. The genus Burkholderia consists of over 100 species, showing ecologically diverse lifestyles, and including serious human pathogens, plant pathogens, and nodule-forming plant mutualists, as well as insect mutualists. Through infection tests of 34 Burkholderia species and 18 taxonomically diverse bacterial species, we demonstrate here that nonsymbiotic Burkholderia and even its outgroup Pandoraea could stably colonize the gut symbiotic organ and provide beneficial effects to the bean bug when inoculated on aposymbiotic hosts. However, coinoculation revealed that the native symbiont always outcompeted the nonnative bacteria inside the gut symbiotic organ, explaining the predominance of the native Burkholderia symbiont in natural bean bug populations. Hence, the abilities for colonization and cooperation, usually thought of as specific traits of mutualists, are not unique to the native Burkholderia symbiont but, to the contrary, competitiveness inside the gut is a derived trait of the native symbiont lineage only and was thus critical in the evolution of the insect gut symbiont.

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Multidrug Pump Inhibitors Uncover Remarkable Activity of Plant Antimicrobials

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.46.10.3133-3141.2002 ◽

2002 ◽

Vol 46 (10) ◽

pp. 3133-3141 ◽

Cited By ~ 294

Author(s):

George Tegos ◽

Frank R. Stermitz ◽

Olga Lomovskaya ◽

Kim Lewis

Keyword(s):

Broad Spectrum ◽

Plant Pathogens ◽

Bacterial Species ◽

Permeability Barrier ◽

Gram Negative Bacteria ◽

Human Pathogens ◽

Gram Negative ◽

Low Level ◽

Broad Spectrum Antibiotics ◽

Level Of Activity

ABSTRACT Plant antimicrobials are not used as systemic antibiotics at present. The main reason for this is their low level of activity, especially against gram-negative bacteria. The reported MIC is often in the range of 100 to 1,000 μg/ml, orders of magnitude higher than those of common broad-spectrum antibiotics from bacteria or fungi. Major plant pathogens belong to the gram-negative bacteria, which makes the low level of activity of plant antimicrobials against this group of microorganisms puzzling. Gram-negative bacteria have an effective permeability barrier, comprised of the outer membrane, which restricts the penetration of amphipathic compounds, and multidrug resistance pumps (MDRs), which extrude toxins across this barrier. It is possible that the apparent ineffectiveness of plant antimicrobials is largely due to the permeability barrier. We tested this hypothesis in the present study by applying a combination of MDR mutants and MDR inhibitors. A panel of plant antimicrobials was tested by using a set of bacteria representing the main groups of plant pathogens. The human pathogens Pseudomonas aeruginosa, Escherichia coli, and Salmonella enterica serovar Typhimurium were also tested. The results show that the activities of the majority of plant antimicrobials were considerably greater against the gram-positive bacteria Staphylococcus aureus and Bacillus megaterium and that disabling of the MDRs in gram-negative species leads to a striking increase in antimicrobial activity. Thus, the activity of rhein, the principal antimicrobial from rhubarb, was potentiated 100- to 2,000-fold (depending on the bacterial species) by disabling the MDRs. Comparable potentiation of activity was observed with plumbagin, resveratrol, gossypol, coumestrol, and berberine. Direct measurement of the uptake of berberine, a model plant antimicrobial, confirmed that disabling of the MDRs strongly increases the level of penetration of berberine into the cells of gram-negative bacteria. These results suggest that plants might have developed means of delivering their antimicrobials into bacterial cells. These findings also suggest that plant antimicrobials might be developed into effective, broad-spectrum antibiotics in combination with inhibitors of MDRs.

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Potential Human and Plant Pathogenic Species in Airborne PM10 Samples and Relationships with Chemical Components and Meteorological Parameters

Atmosphere ◽

10.3390/atmos12050654 ◽

2021 ◽

Vol 12 (5) ◽

pp. 654

Author(s):

Salvatore Romano ◽

Mattia Fragola ◽

Pietro Alifano ◽

Maria Rita Perrone ◽

Adelfia Talà

Keyword(s):

Plant Pathogens ◽

Meteorological Parameters ◽

Bacterial Species ◽

Correlation Coefficients ◽

Chemical Components ◽

Rrna Gene ◽

Pathogenic Species ◽

Spearman Correlation ◽

Human Pathogens ◽

Central Mediterranean

A preliminary local database of potential (opportunistic) airborne human and plant pathogenic and non-pathogenic species detected in PM10 samples collected in winter and spring is provided, in addition to their seasonal dependence and relationships with meteorological parameters and PM10 chemical species. The PM10 samples, collected at a Central Mediterranean coastal site, were analyzed by the 16S rRNA gene metabarcoding approach, and Spearman correlation coefficients and redundancy discriminant analysis tri-plots were used to investigate the main relationships. The screening of 1187 detected species allowed for the detection of 76 and 27 potential (opportunistic) human and plant pathogens, respectively. The bacterial structure of both pathogenic and non-pathogenic species varied from winter to spring and, consequently, the inter-species relationships among potential human pathogens, plant pathogens, and non-pathogenic species varied from winter to spring. Few non-pathogenic species and even fewer potential human pathogens were significantly correlated with meteorological parameters, according to the Spearman correlation coefficients. Conversely, several potential plant pathogens were strongly and positively correlated with temperature and wind speed and direction both in winter and in spring. The number of strong relationships between presumptive (human and plant) pathogens and non-pathogens, and meteorological parameters slightly increased from winter to spring. The sample chemical composition also varied from winter to spring. Some potential human and plant pathogens were correlated with chemicals mainly associated with marine aerosol and/or with soil dust, likely because terrestrial and aquatic environments were the main habitats of the detected bacterial species. The carrier role on the species seasonal variability was also investigated.

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Defensive Role of Plant-Derived Secondary Metabolites: Indole and Its’ Derivatives

Current Biotechnology ◽

10.2174/2211550109999200728153839 ◽

2020 ◽

Vol 9 (2) ◽

pp. 78-88

Author(s):

Mulugeta Mulat ◽

Raksha Anand ◽

Fazlurrahman Khan

Keyword(s):

Biofilm Formation ◽

Growth And Development ◽

Functional Role ◽

Plant Pathogens ◽

Bacterial Species ◽

Indole Derivatives ◽

Resistance Level ◽

Defensive Role ◽

Insect Attack

The diversity of indole concerning its production and functional role has increased in both prokaryotic and eukaryotic systems. The bacterial species produce indole and use it as a signaling molecule at interspecies, intraspecies, and even at an interkingdom level for controlling the capability of drug resistance, level of virulence, and biofilm formation. Numerous indole derivatives have been found to play an important role in the different systems and are reported to occur in various bacteria, plants, human, and plant pathogens. Indole and its derivatives have been recognized for a defensive role against pests and insects in the plant kingdom. These indole derivatives are produced as a result of the breakdown of glucosinolate products at the time of insect attack or physical damages. Apart from the defensive role of these products, in plants, they also exhibit several other secondary responses that may contribute directly or indirectly to the growth and development. The present review summarized recent signs of progress on the functional properties of indole and its derivatives in different plant systems. The molecular mechanism involved in the defensive role played by indole as well as its’ derivative in the plants has also been explained. Furthermore, the perspectives of indole and its derivatives (natural or synthetic) in understanding the involvement of these compounds in diverse plants have also been discussed.

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The impact of bZIP Atf1ortholog global regulators in fungi

Applied Microbiology and Biotechnology ◽

10.1007/s00253-021-11431-7 ◽

2021 ◽

Author(s):

Éva Leiter ◽

Tamás Emri ◽

Klaudia Pákozdi ◽

László Hornok ◽

István Pócsi

Keyword(s):

Transcription Factors ◽

Stress Response ◽

Secondary Metabolite ◽

Plant Pathogens ◽

Leucine Zipper ◽

Secondary Metabolite Production ◽

Special Focus ◽

Human Pathogens ◽

Metabolite Production ◽

The Impact

Abstract Regulation of signal transduction pathways is crucial for the maintenance of cellular homeostasis and organismal development in fungi. Transcription factors are key elements of this regulatory network. The basic-region leucine zipper (bZIP) domain of the bZIP-type transcription factors is responsible for DNA binding while their leucine zipper structural motifs are suitable for dimerization with each other facilitiating the formation of homodimeric or heterodimeric bZIP proteins. This review highlights recent knowledge on the function of fungal orthologs of the Schizosaccharomyces pombe Atf1, Aspergillus nidulans AtfA, and Fusarium verticillioides FvAtfA, bZIP-type transcription factors with a special focus on pathogenic species. We demonstrate that fungal Atf1-AtfA-FvAtfA orthologs play an important role in vegetative growth, sexual and asexual development, stress response, secondary metabolite production, and virulence both in human pathogens, including Aspergillus fumigatus, Mucor circinelloides, Penicillium marneffei, and Cryptococcus neoformans and plant pathogens, like Fusarium ssp., Magnaporthe oryzae, Claviceps purpurea, Botrytis cinerea, and Verticillium dahliae. Key points • Atf1 orthologs play crucial role in the growth and development of fungi. • Atf1 orthologs orchestrate environmental stress response of fungi. • Secondary metabolite production and virulence are coordinated by Atf1 orthologs.

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An Overview of Metabolic Activity, Beneficial and Pathogenic Aspects of Burkholderia Spp

Metabolites ◽

10.3390/metabo11050321 ◽

2021 ◽

Vol 11 (5) ◽

pp. 321

Author(s):

Hazem S. Elshafie ◽

Ippolito Camele

Keyword(s):

Secondary Metabolites ◽

Plant Growth ◽

Biochemical Characterization ◽

Bacterial Species ◽

Promoting Effect ◽

Important Species ◽

Beneficial Effects ◽

Plant Growth Promoting ◽

Rhizosphere Competence

Burkholderia is an important bacterial species which has different beneficial effects, such as promoting the plant growth, including rhizosphere competence for the secretion of allelochemicals, production of antibiotics, and siderophores. In addition, most of Burkholderia species have demonstrated promising biocontrol action against different phytopathogens for diverse crops. In particular, Burkholderia demonstrates significant biotechnological potential as a source of novel antibiotics and bioactive secondary metabolites. The current review is concerned with Burkholderia spp. covering the following aspects: discovering, classification, distribution, plant growth promoting effect, and antimicrobial activity of different species of Burkholderia, shedding light on the most important secondary metabolites, their pathogenic effects, and biochemical characterization of some important species of Burkholderia, such as B. cepacia, B. andropogonis, B. plantarii, B. rhizoxinica, B. glumae, B. caryophylli and B. gladioli.

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Innate Immune Response as a New Challenge in Periodontal Inflammation

10.5772/intechopen.96801 ◽

2021 ◽

Author(s):

Ana Marina Andrei ◽

Elena Cristina Andrei ◽

Elena Camelia Stănciulescu ◽

Mihaela Cezarina Mehedinți ◽

Mihaela Jana Țuculină ◽

...

Keyword(s):

Immune Response ◽

Innate Immune Response ◽

Periodontal Diseases ◽

Bacterial Species ◽

Innate Immune ◽

Beneficial Effects ◽

Periodontal Tissues ◽

Periodontal Inflammation ◽

Genetic And Environmental Factors ◽

Tlr Signalling

Gingivitis and periodontitis are induced by numerous pathogenic microbiota hosted in the subgingival biofilm that first trigger the innate immune response. Innate immune response is part of a homeostatic system which is the first line defence and defines the host inherited resistance to infection. Both genetic and environmental factors are involved in variable individual susceptibility to inflammation of periodontal tissues. That is why, although more than 600 bacterial species have been detected in the periodontal plaque, the type of bacteria incriminated in the development of the inflammation is still unclear. Moreover, in the last decade gene polymorphisms have been largely recognised as important conditions associated with increased susceptibility to periodontal diseases. Manipulating the immune response by the development of drugs that inhibit adverse host reactions and promote beneficial effects might be of therapeutic or prophylactic importance. This work intends to assess the importance of Toll-like receptors as main effectors of the innate immune response in the triggering, maintenance and progression of periodontal inflammation, as well as of the involvement of synthetic molecules targeting TLR signalling pathways in treating periodontal diseases.

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The Diversity of Bacteria Associated with the Invasive Gall Wasp Dryocosmus kuriphilus, Its Galls and a Specialist Parasitoid on Chestnuts

Insects ◽

10.3390/insects13010086 ◽

2022 ◽

Vol 13 (1) ◽

pp. 86

Author(s):

Xiaohui Yang ◽

Yu Hui ◽

Daohong Zhu ◽

Yang Zeng ◽

Lvquan Zhao ◽

...

Keyword(s):

Pathogenic Bacteria ◽

Plant Pathogens ◽

High Throughput Sequencing ◽

Bacterial Species ◽

Gall Wasp ◽

Potential Vector ◽

Dryocosmus Kuriphilus ◽

Torymus Sinensis ◽

Galling Insects ◽

First Time

Dryocosmus kuriphilus (Hymenoptera: Cynipidae) induces galls on chestnut trees, which results in massive yield losses worldwide. Torymus sinensis (Hymenoptera: Torymidae) is a host-specific parasitoid that phenologically synchronizes with D. kuriphilus. Bacteria play important roles in the life cycle of galling insects. The aim of this research is to investigate the bacterial communities and predominant bacteria of D. kuriphilus, T. sinensis, D. kuriphilus galls and the galled twigs of Castanea mollissima. We sequenced the V5–V7 region of the bacterial 16S ribosomal RNA in D. kuriphilus, T. sinensis, D. kuriphilus galls and galled twigs using high-throughput sequencing for the first time. We provide the first evidence that D. kuriphilus shares most bacterial species with T. sinensis, D. kuriphilus galls and galled twigs. The predominant bacteria of D. kuriphilus are Serratia sp. and Pseudomonas sp. Furthermore, the bacterial community structures of D. kuriphilus and T. sinensis clearly differ from those of the other groups. Many species of the Serratia and Pseudomonas genera are plant pathogenic bacteria, and we suggest that D. kuriphilus may be a potential vector of plant pathogens. Furthermore, a total of 111 bacteria are common to D. kuriphilus adults, T. sinensis, D. kuriphilus galls and galled twigs, and we suggest that the bacteria may transmit horizontally among D. kuriphilus, T. sinensis, D. kuriphilus galls and galled twigs on the basis of their ecological associations.

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THE ANTIBIOTIC ACTIVITY OF SOIL MICROORGANISMS AS RELATED TO BACTERIAL PLANT PATHOGENS

Canadian Journal of Botany ◽

10.1139/b54-064 ◽

1954 ◽

Vol 32 (5) ◽

pp. 705-735 ◽

Cited By ~ 15

Author(s):

Z. A. Patrick

Keyword(s):

Plant Pathogens ◽

Bacterial Species ◽

High Specificity ◽

Soft Rot ◽

Soil Microflora ◽

Antibiotic Activity ◽

Pathogenic Species ◽

Xanthomonas Species ◽

Test Organisms ◽

Antibiotic Reactions

In an attempted evaluation of the importance of soil antagonisms as a possible factor in the different survival capabilities of some bacterial plant pathogens in the soil environment, a comparison was made of the numbers of antagonists detected when different plant pathogenic species were used as test organisms in determining the "antibiotic potential" of nine "virgin" soils. It was found that there are present among the soil flora a great abundance of microorganisms intrinsically capable of antagonizing most of the bacterial pathogens tested and only for a few species are such antagonists relatively rare. There were great differences in the number of isolates antagonistic to the different pathogenic species, even in the same genus, and there seemed to be a correlation between the numbers of antagonists, as found here, and the capability of a species to maintain itself for long periods in the soil. For the most part the Xanthomonas species appeared to be most sensitive to the antagonistic soil microflora while the soft-rot-causing Erwinia species were most resistant.A comparative study of the antibiotic activity of 120 of the most active antagonistic isolates tested against 28 bacterial plant pathogens showed that each antagonist was characterized by a specific antibacterial spectrum and those antagonists having the most intense antibiotic activity usually inhibited the greatest number of bacterial species. Many antagonists were highly specific, affecting only certain groups or even certain species. The high specificity which characterized some of the antibiotic reactions was used to separate sharply, consistently, and with minimum effort such closely related species as E. carotovora and E. atroseptica or X. corylina and X. juglandis.

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The functional ClpXP protease of Chlamydia trachomatis requires distinct clpP genes from separate genetic loci

Scientific Reports ◽

10.1038/s41598-019-50505-5 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 9

Author(s):

Stefan Pan ◽

Imran T. Malik ◽

Dhana Thomy ◽

Beate Henrichfreise ◽

Peter Sass

Keyword(s):

Chlamydia Trachomatis ◽

Bacterial Species ◽

Human Pathogens ◽

Bacterial Physiology ◽

Sexually Transmitted ◽

Clp Proteases ◽

Obligate Intracellular Pathogen ◽

Antibacterial Target ◽

Insight Into

Abstract Clp proteases play a central role in bacterial physiology and, for some bacterial species, are even essential for survival. Also due to their conservation among bacteria including important human pathogens, Clp proteases have recently attracted considerable attention as antibiotic targets. Here, we functionally reconstituted and characterized the ClpXP protease of Chlamydia trachomatis (ctClpXP), an obligate intracellular pathogen and the causative agent of widespread sexually transmitted diseases in humans. Our in vitro data show that ctClpXP is formed by a hetero-tetradecameric proteolytic core, composed of two distinct homologs of ClpP (ctClpP1 and ctClpP2), that associates with the unfoldase ctClpX via ctClpP2 for regulated protein degradation. Antibiotics of the ADEP class interfere with protease functions by both preventing the interaction of ctClpX with ctClpP1P2 and activating the otherwise dormant proteolytic core for unregulated proteolysis. Thus, our results reveal molecular insight into ctClpXP function, validating this protease as an antibacterial target.

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High Resolution Melt Assays to Detect and Identify Vibrio parahaemolyticus, Bacillus cereus, Escherichia coli, and Clostridioides difficile Bacteria

Microorganisms ◽

10.3390/microorganisms8040561 ◽

2020 ◽

Vol 8 (4) ◽

pp. 561

Author(s):

Allison C. Bender ◽

Jessica A. Faulkner ◽

Katherine Tulimieri ◽

Thomas H. Boise ◽

Kelly M. Elkins

Keyword(s):

Escherichia Coli ◽

High Resolution ◽

Bacillus Cereus ◽

Vibrio Parahaemolyticus ◽

Bacterial Species ◽

Human Pathogens ◽

High Resolution Melt ◽

E Coli ◽

Clostridioides Difficile ◽

Sensitivity Specificity

Over one hundred bacterial species have been determined to comprise the human microbiota in a healthy individual. Bacteria including Escherichia coli, Bacillus cereus, Clostridioides difficile, and Vibrio parahaemolyticus are found inside of the human body and B. cereus and E. coli are also found on the skin. These bacteria can act as human pathogens upon ingestion of contaminated food or water, if they enter an open wound, or antibiotics, and environment or stress can alter the microbiome. In this study, we present new polymerase chain reaction (PCR) high-resolution melt (HRM) assays to detect and identify the above microorganisms. Amplified DNA from C. difficile, E. coli, B. cereus, and V. parahaemolyticus melted at 80.37 ± 0.45 °C, 82.15 ± 0.37 °C, 84.43 ± 0.50 °C, and 86.74 ± 0.65 °C, respectively. A triplex PCR assay was developed to simultaneously detect and identify E. coli, B. cereus, and V. parahaemolyticus, and cultured microorganisms were successfully amplified, detected, and identified. The assays demonstrated sensitivity, specificity, reproducibility, and robustness in testing.

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