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Claes JM, Haddock SHD, Coubris C, Mallefet J. Systematic Distribution of Bioluminescence in Marine Animals: A Species-Level Inventory. Life (Basel) 2024; 14:432. [PMID: 38672704 PMCID: PMC11051050 DOI: 10.3390/life14040432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/20/2024] [Accepted: 03/22/2024] [Indexed: 04/28/2024] Open
Abstract
Bioluminescence is the production of visible light by an organism. This phenomenon is particularly widespread in marine animals, especially in the deep sea. While the luminescent status of numerous marine animals has been recently clarified thanks to advancements in deep-sea exploration technologies and phylogenetics, that of others has become more obscure due to dramatic changes in systematics (themselves triggered by molecular phylogenies). Here, we combined a comprehensive literature review with unpublished data to establish a catalogue of marine luminescent animals. Inventoried animals were identified to species level in over 97% of the cases and were associated with a score reflecting the robustness of their luminescence record. While luminescence capability has been established in 695 genera of marine animals, luminescence reports from 99 additional genera need further confirmation. Altogether, these luminescent and potentially luminescent genera encompass 9405 species, of which 2781 are luminescent, 136 are potentially luminescent (e.g., suggested luminescence in those species needs further confirmation), 99 are non-luminescent, and 6389 have an unknown luminescent status. Comparative analyses reveal new insights into the occurrence of luminescence among marine animal groups and highlight promising research areas. This work will provide a solid foundation for future studies related to the field of marine bioluminescence.
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Affiliation(s)
- Julien M. Claes
- Marine Biology Laboratory, Earth and Life Institute, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; (C.C.); (J.M.)
| | - Steven H. D. Haddock
- Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039, USA
| | - Constance Coubris
- Marine Biology Laboratory, Earth and Life Institute, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; (C.C.); (J.M.)
| | - Jérôme Mallefet
- Marine Biology Laboratory, Earth and Life Institute, Université catholique de Louvain, 1348 Louvain-la-Neuve, Belgium; (C.C.); (J.M.)
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Ogaya C, Huong N, Touceda-González M, Barg M, Dörfler V, Ehlers RU, Molina C. Monitoring the Photorhabdus spp. bacterial load in Heterorhabditis bacteriophora dauer juveniles over different storage times and temperatures: A molecular approach. J Invertebr Pathol 2024; 203:108048. [PMID: 38159796 DOI: 10.1016/j.jip.2023.108048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/03/2024]
Abstract
Biological control products based on the entomopathogenic nematode Heterorhabditis bacteriophora can vary in virulence (quality). The influence of their symbiotic bacteria Photorhabdus spp. inside the infective dauer juvenile (DJ) on DJ quality has not received much attention in the past. The presence of the bacteria in the DJ is crucial for its biocontrol potential. This investigation provides a method to quantify the bacterial load inside the DJ based on a qPCR technique. Information from the genome of Photorhabdus laumondii strain DE2 was used to identify single copy genes with no homology to any other bacterial accessions. One gene (hereby named CG2) was selected for primers design and for further qPCR experiments. Cross-amplification tests with P. thracensis and P. kayaii, also symbionts of H. bacteriophora, were positive, whereas no amplicons were produced for P. temperata or Xenorhabdus nematophila. We tested our qPCR system in DJ populations carrying defined proportions of bacteria-free (axenic) vs bacteria-carrying nematodes. With an increasing proportion of axenic DJ in a population, virulence declined, and the virulence was proportional to the amount of bacterial DNA detected in the population by qPCR. Along liquid storage over long time, virulence also decreased, and this factor correlated with the reduction of bacterial DNA on the respective DJ population. We observed that stored DJ kept virulent up to 90 days and thereafter the virulence as well as the amount of bacterial DNA drastically decreased. Storage temperature also influenced the bacterial survival. Inside formulated DJ, the loss of bacterial DNA on the DJ population was accelerated under storage temperatures below 7.5 °C, suggesting that reproduction of the bacterial cells takes place when growth temperature is favorable. The role of bacterial survival inside stored DJ can now be adequately addressed using this molecular quality-control technique.
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Affiliation(s)
- Christopher Ogaya
- Faculty of Agricultural and Nutritional Sciences, Christian-Albrechts-University Kiel, Hermann-Rodewald-Str. 4, 24118 Kiel, Germany; e-nema GmbH, Klausdorfer Str. 28-36, 24223 Schwentinental, Germany
| | - Nontarak Huong
- Department of Biology, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium
| | | | - Mike Barg
- e-nema GmbH, Klausdorfer Str. 28-36, 24223 Schwentinental, Germany
| | - Verena Dörfler
- e-nema GmbH, Klausdorfer Str. 28-36, 24223 Schwentinental, Germany
| | - Ralf-Udo Ehlers
- Faculty of Agricultural and Nutritional Sciences, Christian-Albrechts-University Kiel, Hermann-Rodewald-Str. 4, 24118 Kiel, Germany; Department of Biology, Ghent University, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium
| | - Carlos Molina
- e-nema GmbH, Klausdorfer Str. 28-36, 24223 Schwentinental, Germany.
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Wang Z, Ogaya C, Dörfler V, Barg M, Ehlers RU, Molina C. Pheno- and genotyping in vitro dauer juvenile recovery in the nematode Heterorhabditis bacteriophora. Appl Microbiol Biotechnol 2023; 107:7181-7196. [PMID: 37733051 DOI: 10.1007/s00253-023-12775-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/25/2023] [Accepted: 09/03/2023] [Indexed: 09/22/2023]
Abstract
The entomopathogenic nematode (EPN) Heterorhabditis bacteriophora is an effective biological-control agent of insect pests. The dauer juveniles (DJs) seek for, infect insects, and release cells of the carried symbiotic bacterium of the genus Photorhabdus. Inside the host, the DJs perceive signals from the insect's haemolymph that trigger the exit from the arrested stage and the further development to mature adults. This developmental step is called DJ recovery. In commercial production, a high and synchronous DJ recovery determines the success of liquid-culture mass production. To enhance the understanding about genetic components regulating DJ recovery, more than 160 mutant- and 25 wild type inbred lines (WT ILs) were characterized for DJ recovery induced by cell-free bacterial supernatant. The mutant lines exhibited a broader DJ recovery range than WT ILs (4.6-67.2% vs 1.6-35.7%). A subset of mutant lines presented high variability of virulence against mealworm (Tenebrio molitor) (from 22 to 78% mortality) and mean time survival under oxidative stress (70 mM H2O2; from 10 to 151 h). Genotyping by sequencing of 96 mutant lines resulted in more than 150 single nucleotide polymorphisms (SNPs), of which four results are strongly associated with the DJ recovery trait. The present results are the basis for future approaches in improving DJ recovery by breeding under in vitro liquid-culture mass production in H. bacteriophora. This generated platform of EMS-mutants is as well a versatile tool for the investigation of many further traits of interest in EPNs. KEYPOINTS: • Exposure to bacterial supernatants of Photorhabdus laumondii induces the recovery of Heterorhabditis bacteriophora dauer juveniles (DJs). Both, the bacteria and the nematode partner, influence this response. However, the complete identity of its regulators is not known. • We dissected the genetic component of DJ recovery regulation in H. bacteriophora nematodes by generating a large array of EMS mutant lines and characterizing their recovery pheno- and genotypes. • We determined sets of mutants with contrasting DJ recovery and genotyped a subset of the EMS-mutant lines via genotyping by sequencing (GBS) and identified SNPs with significant correlation to the recovery trait.
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Affiliation(s)
- Zhen Wang
- , e-nema GmbH, Klausdorfer Str. 28-36, 24223, Schwentinental, Germany
- Faculty of Agricultural and Nutritional Sciences, Christian-Albrechts-University Kiel, Hermann-Rodewald-Str. 4, 24118, Kiel, Germany
| | - Christopher Ogaya
- , e-nema GmbH, Klausdorfer Str. 28-36, 24223, Schwentinental, Germany
- Faculty of Agricultural and Nutritional Sciences, Christian-Albrechts-University Kiel, Hermann-Rodewald-Str. 4, 24118, Kiel, Germany
| | - Verena Dörfler
- , e-nema GmbH, Klausdorfer Str. 28-36, 24223, Schwentinental, Germany
| | - Mike Barg
- , e-nema GmbH, Klausdorfer Str. 28-36, 24223, Schwentinental, Germany
| | - Ralf-Udo Ehlers
- , e-nema GmbH, Klausdorfer Str. 28-36, 24223, Schwentinental, Germany
- Faculty of Agricultural and Nutritional Sciences, Christian-Albrechts-University Kiel, Hermann-Rodewald-Str. 4, 24118, Kiel, Germany
- Department of Biology, Ghent University-Campus Ledeganck, Karel Lodewijk Ledeganckstraat 35, 9000, Ghent, Belgium
| | - Carlos Molina
- , e-nema GmbH, Klausdorfer Str. 28-36, 24223, Schwentinental, Germany.
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Wang Z, Dhakal M, Vandenbossche B, Dörfler V, Barg M, Strauch O, Ehlers RU, Molina C. Enhancing mass production of Heterorhabditis bacteriophora: influence of different bacterial symbionts (Photorhabdus spp.) and inoculum age on dauer juvenile recovery. World J Microbiol Biotechnol 2023; 40:13. [PMID: 37953398 DOI: 10.1007/s11274-023-03803-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 10/11/2023] [Indexed: 11/14/2023]
Abstract
The entomopathogenic nematode Heterorhabditis bacteriophora (Nematoda: Rhabditidae) is used in biological insect control. Their dauer juveniles (DJs) are free-living and developmentally arrested, invading host insects. They carry cells of their bacterial symbiont Photorhabdus spp. in the intestine. Once inside the insect´s hemolymph the DJs perceive a food signal, triggering them to exit the DJ stage and regurgitate the Photorhabdus cells into the insect's haemocoel, which kill the host and later provide essential nutrients for nematode reproduction. The exit from the DJ stage is called "recovery". For commercial pest control, nematodes are industrially produced in monoxenic liquid cultures. Artificial media are incubated with Photorhabdus before DJs are added. In absence of the insect's food signal, DJs depend on unknown bacterial food signals to trigger exit of the DJ stage. A synchronized and high DJ recovery determines the success of the industrial in vitro production and can significantly vary between nematode strains, inbred lines and mutants. In this study, fourteen bacterial strains from H. bacteriophora were isolated and identified as P. laumondii, P. kayaii and P. thracensis. Although the influence of bacterial supernatants on the DJ recovery of three inbred lines and two mutants differed significantly, the bacterial impact on recovery has a subordinate role whereas nematode factors have a superior influence. Recovery of inbred lines decreased with age of the DJs. One mutant (M31) had very high recovery in bacterial supernatant and spontaneous recovery in Ringer solution. Another mutant (M88) was recovery defective.
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Affiliation(s)
- Zhen Wang
- Faculty of Agricultural and Nutritional Sciences, Christian-Albrechts-University Kiel, Hermann- Rodewald-Str. 4, 24118, Kiel, Germany
- e-nema GmbH, Klausdorfer Str. 28-36, 24223, Schwentinental, Germany
| | - Manoj Dhakal
- Department of Biology, Ghent University, K.L. Ledeganckstraat 35, B-9000, Ghent, Belgium
- Prime Minister Agriculture Modernization Project (PMAMP), Vegetable Superzone, Kaski, Nepal
| | | | - Verena Dörfler
- e-nema GmbH, Klausdorfer Str. 28-36, 24223, Schwentinental, Germany
| | - Mike Barg
- e-nema GmbH, Klausdorfer Str. 28-36, 24223, Schwentinental, Germany
| | - Olaf Strauch
- e-nema GmbH, Klausdorfer Str. 28-36, 24223, Schwentinental, Germany
| | - Ralf-Udo Ehlers
- Faculty of Agricultural and Nutritional Sciences, Christian-Albrechts-University Kiel, Hermann- Rodewald-Str. 4, 24118, Kiel, Germany
- Department of Biology, Ghent University, K.L. Ledeganckstraat 35, B-9000, Ghent, Belgium
| | - Carlos Molina
- e-nema GmbH, Klausdorfer Str. 28-36, 24223, Schwentinental, Germany.
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Machado RAR, Bhat AH, Castaneda-Alvarez C, Askary TH, Půža V, Pagès S, Abolafia J. Xenorhabdus aichiensis sp. nov., Xenorhabdus anantnagensis sp. nov., and Xenorhabdus yunnanensis sp. nov., Isolated from Steinernema Entomopathogenic Nematodes. Curr Microbiol 2023; 80:300. [PMID: 37493817 PMCID: PMC10371910 DOI: 10.1007/s00284-023-03373-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 06/12/2023] [Indexed: 07/27/2023]
Abstract
Three bacterial strains, XENO-2T, XENO-7T, and XENO-10T, isolated from Steinernema entomopathogenic nematodes, were found to represent novel Xenorhabdus species. In this study, we describe these new species by whole-genome and whole-proteome phylogenomic reconstructions, by calculating sequence identity scores using core genome sequences, and by phenotypic characterization. Phylogenomic reconstructions using ribosomal and house-keeping genes, and whole-genome and whole-proteome sequences show that XENO-2T and XENO-10T are closely related to Xenorhabdus japonica DSM 16522T and that XENO-7T is closely related to Xenorhabdus bovienii subsp. africana XENO-1T and to X. bovienii subsp. bovienii T228T. The dDDH values between XENO-2T and XENO-10T and between XENO-2T and X. japonica DSM 16522T are 56.4 and 51.8%, respectively. The dDDH value between XENO-10T and X. japonica DSM 16522T is 53.4%. The dDDH values between XENO-7T and X. bovienii subsp. africana XENO-1T and between XENO-7T and X. bovienii subsp. bovienii T228T are 63.6 and 69.4%, respectively. These dDDH values are below the 70% divergence threshold for prokaryotic species delineation. The newly described species are highly pathogenic to G. mellonella larvae, grow at pH between 5 and 9 (optimum 5-7), at salt concentrations of 1-3% (optimum 1-2%), and temperatures between 20 and 37 °C (optimum 28-30 °C). Biochemical tests such as lysine decarboxylase, ornithine decarboxylase, urease, gelatinase, citrate utilization, indole and acetoin production, and cytochrome oxidase tests allow to differentiate the novel species from their more closely related species. Considering these genetic and phenotypic divergencies, we propose the following new species: Xenorhabdus aichiensis sp. nov. with XENO-7T (= CCM 9233T = CCOS 2024T) as the type strain, Xenorhabdus anantnagensis sp. nov., with XENO-2T (= CCM 9237T = CCOS 2023T) as the type strain, and Xenorhabdus yunnanensis sp. nov., with XENO-10T (= CCM 9322T = CCOS 2071T) as the type strain. Our study contributes to a better understanding of the biodiversity and phylogenetic relationships of entomopathogenic bacteria associated with insect parasitic nematodes.
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Affiliation(s)
- Ricardo A R Machado
- Experimental Biology Research Group, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland.
| | - Aashaq Hussain Bhat
- Experimental Biology Research Group, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland
- Department of Biosciences, University Center for Research and Development, Chandigarh University, Mohali, Punjab, India
| | - Carlos Castaneda-Alvarez
- Experimental Biology Research Group, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas, Universidad de Chile, Santiago, Chile
| | - Tarique Hassan Askary
- Division of Entomology, Faculty of Agriculture, Sher-e-Kashmir University of Agricultural Sciences and Technology, Wadura Campus, Jammu, Jammu and Kashmir, India
| | - Vladimir Půža
- Biology Centre CAS, Institute of Entomology, České Budějovice, Czech Republic
| | - Sylvie Pagès
- INRAe, Université de Montpellier, Montpellier, France
| | - Joaquín Abolafia
- Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Campus 'Las Lagunillas', Jaén, Spain
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Maushe D, Ogi V, Divakaran K, Verdecia Mogena AM, Himmighofen PA, Machado RAR, Towbin BD, Ehlers RU, Molina C, Parisod C, Maud Robert CA. Stress tolerance in entomopathogenic nematodes: Engineering superior nematodes for precision agriculture. J Invertebr Pathol 2023:107953. [PMID: 37336478 DOI: 10.1016/j.jip.2023.107953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 06/13/2023] [Accepted: 06/16/2023] [Indexed: 06/21/2023]
Abstract
Entomopathogenic nematodes (EPNs) are soil-dwelling parasitic roundworms commonly used as biocontrol agents of insect pests in agriculture. EPN dauer juveniles locate and infect a host in which they will grow and multiply until resource depletion. During their free-living stage, EPNs face a series of internal and environmental stresses. Their ability to overcome these challenges is crucial to determine their infection success and survival. In this review, we provide a comprehensive overview of EPN response to stresses associated with starvation, low/elevated temperatures, desiccation, osmotic stress, hypoxia, and ultra-violet light. We further report EPN defense strategies to cope with biotic stressors such as viruses, bacteria, fungi, and predatory insects. By comparing the genetic and biochemical basis of these strategies to the nematode model Caenorhabditis elegans, we provide new avenues and targets to select and engineer precision nematodes adapted to specific field conditions.
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Affiliation(s)
- Dorothy Maushe
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | - Vera Ogi
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | - Keerthi Divakaran
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | | | - Paul Anton Himmighofen
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | - Ricardo A R Machado
- Institute of Biology, University of Neuchâtel, Rue Emile Argand 11, CH-2000 Neuchâtel, Switzerland
| | - Benjamin Daniel Towbin
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, CH-3012 Bern, Switzerland
| | - Ralf-Udo Ehlers
- e- nema GmbH, Klausdorfer Str. 28-36, DE-24223 Schwentinental, Germany
| | - Carlos Molina
- e- nema GmbH, Klausdorfer Str. 28-36, DE-24223 Schwentinental, Germany
| | - Christian Parisod
- Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Christelle Aurélie Maud Robert
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Hochschulstrasse 4, CH-3012 Bern, Switzerland.
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Machado RAR, Bhat AH, Castaneda-Alvarez C, Půža V, San-Blas E. Photorhabdus aballayi sp. nov. and Photorhabdus luminescens subsp. venezuelensis subsp. nov., isolated from Heterorhabditis amazonensis entomopathogenic nematodes. Int J Syst Evol Microbiol 2023; 73. [PMID: 37171451 DOI: 10.1099/ijsem.0.005872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
Abstract
Six Gram-negative, rod-shaped bacterial strains isolated from Heterorhabditis amazonensis entomopathogenic nematodes were characterized to determine their taxonomic position. 16S rRNA and gyrB gene sequences indicate that they belong to the class Gammaproteobacteria, family Morganellaceae and genus Photorhabdus, and that some of them are conspecifics. Two of them, APURET and JART, were selected for further molecular characterization using whole genome- and whole-proteome-based phylogenetic reconstructions and sequence comparisons. Phylogenetic reconstructions using whole genome and whole proteome sequences show that strains APURET and JART are closely related to Photorhabdus luminescens subsp. luminescens ATCC 29999T and to P. luminescens subsp. mexicana MEX47-22T. Moreover, digital DNA-DNA hybridization (dDDH) values between APURET and P. luminescens subsp. luminescens ATCC 29999T, APURET and P. luminescens subsp. mexicana MEX47-22T, and APURET and JART are 61.6, 61.2 and 64.1 %, respectively. These values are below the 70 % divergence threshold that delimits prokaryotic species. dDDH scores between JART and P. luminescens subsp. luminescens ATCC 29999T and between JART and P. luminescens subsp. mexicana MEX47-22T are 71.9 and 74.8 %, respectively. These values are within the 70 and 79 % divergence thresholds that delimit prokaryotic subspecies. Based on these genomic divergence values, APURET and JART represent two different taxa, for which we propose the names: Photorhabdus aballayi sp. nov. with APURET (=CCM 9236T =CCOS 2019T) as type strain and Photorhabdus luminescens subsp. venezuelensis subsp. nov. with JART (=CCM 9235T =CCOS 2021T) as type strain. Our study contributes to a better understanding of the biodiversity of an important bacterial group with enormous biotechnological and agricultural potential.
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Affiliation(s)
- Ricardo A R Machado
- Experimental Biology Research Group, Institute of Biology. University of Neuchâtel, Neuchâtel, Switzerland
| | - Aashaq Hussain Bhat
- Experimental Biology Research Group, Institute of Biology. University of Neuchâtel, Neuchâtel, Switzerland
- Department of Biosciences, University Center for Research and Development, Chandigarh University, Gharuan, Mohali, 140413, Punjab, India
| | - Carlos Castaneda-Alvarez
- Experimental Biology Research Group, Institute of Biology. University of Neuchâtel, Neuchâtel, Switzerland
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas. Universidad de Chile, Santiago, Chile
| | - Vladimir Půža
- Biology Centre CAS, Institute of Entomology, Branišovská 1160/31, 370 05 České Budějovice, Czech Republic
| | - Ernesto San-Blas
- Instituto de Ciencias Agroalimentarias, Animales y Ambientales (ICA3), Universidad de O'Higgins, San Fernando, Chile
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Dominelli N, Regaiolo A, Willy L, Heermann R. Interkingdom Signaling of the Insect Pathogen Photorhabdus luminescens with Plants Via the LuxR solo SdiA. Microorganisms 2023; 11:microorganisms11040890. [PMID: 37110313 PMCID: PMC10143992 DOI: 10.3390/microorganisms11040890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023] Open
Abstract
In bacteria, group-coordinated behavior such as biofilm formation or virulence are often mediated via cell–cell communication, a process referred to as quorum sensing (QS). The canonical QS system of Gram-negative bacteria uses N-acyl homoserine lactones (AHLs) as communication molecules, which are produced by LuxI-type synthases and sensed by cognate LuxR-type receptors. These receptors act as transcriptional regulators controlling the expression of specific genes. Some bacteria harbor LuxR-type receptors lacking a cognate LuxI-type synthases, designated as LuxR solos. Among many other LuxR solos, the entomopathogenic enteric bacterium Photorhabdus luminescens harbors a SdiA-like LuxR solo containing an AHL signal-binding domain, for which a respective signal molecule and target genes have not been identified yet. Here we performed SPR analysis to demonstrate that SdiA acts as a bidirectional regulator of transcription, tightly controlling its own expression and the adjacent PluDJC_01670 (aidA) gene in P. luminescens, a gene supposed to be involved in the colonization of eukaryotes. Via qPCR we could further determine that in sdiA deletion mutant strains, aidA is upregulated, indicating that SdiA negatively affects expression of aidA. Furthermore, the ΔsdiA deletion mutant exhibited differences in biofilm formation and motility compared with the wild-type. Finally, using nanoDSF analysis we could identify putative binding ability of SdiA towards diverse AHLs, but also to plant-derived signals, modulating the DNA-binding capacity of SdiA, suggesting that this LuxR solo acts as an important player in interkingdom signaling between P. luminescens and plants.
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Ogier JC, Akhurst R, Boemare N, Gaudriault S. The endosymbiont and the second bacterial circle of entomopathogenic nematodes. Trends Microbiol 2023; 31:629-643. [PMID: 36801155 DOI: 10.1016/j.tim.2023.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 01/11/2023] [Accepted: 01/13/2023] [Indexed: 02/19/2023]
Abstract
Single host-symbiont interactions should be reconsidered from the perspective of the pathobiome. We revisit here the interactions between entomopathogenic nematodes (EPNs) and their microbiota. We first describe the discovery of these EPNs and their bacterial endosymbionts. We also consider EPN-like nematodes and their putative symbionts. Recent high-throughput sequencing studies have shown that EPNs and EPN-like nematodes are also associated with other bacterial communities, referred to here as the second bacterial circle of EPNs. Current findings suggest that some members of this second bacterial circle contribute to the pathogenic success of nematodes. We suggest that the endosymbiont and the second bacterial circle delimit an EPN pathobiome.
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Affiliation(s)
| | | | - Noël Boemare
- DGIMI, Univ Montpellier, INRAE, Montpellier, France
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10
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Bhat AH, Machado RAR, Abolafia J, Askary TH, Půža V, Ruiz-Cuenca AN, Rana A, Sayed S, Al-Shuraym LA. Multigene Sequence-Based and Phenotypic Characterization Reveals the Occurrence of a Novel Entomopathogenic Nematode Species, Steinernema anantnagense n. sp. J Nematol 2023; 55:20230029. [PMID: 37455851 PMCID: PMC10341053 DOI: 10.2478/jofnem-2023-0029] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Indexed: 07/18/2023] Open
Abstract
Three entomopathogenic nematode populations were isolated from agricultural fields in the Anantnag district of Jammu and Kashmir (India). Sequences of multiple gene regions and phenotypic features show that they are conspecific and represent a novel species. Molecular and morphological features provided evidence for placing the new species into the "Kushidai" clade. Within this clade, analysis of sequence data of the internal transcribed spacer (ITS) gene, the D2D3 region of the 28S rRNA gene, the mitochondrial cytochrome oxidase I (mtCOI) gene, and the mitochondrial 12S (mt12S) gene depicted the novel species as a distinctive entity closely related to Steinernema akhursti, S. kushidai, and S. populi. Phylogenetic analyses also show that the new species is a sister species to S. akhursti, and these two species are closely related to S. kushidai and S. populi. Additionally, the new species does not mate or produce fertile progeny with any of the closely related species, reinforcing its uniqueness from a biological species concept standpoint. The new species is further characterized by the third-stage infective juveniles with almost straight bodies (0.7-0.8 mm length), poorly developed stoma and pharynx, and conoid-elongate tail (49-66 µm) with hyaline posterior part. Adult females are characterized by short and conoid tails bearing a short mucron in the first generation and long conoid tails with thin mucron in the second generation. Adult males have ventrally curved spicules in both generations. Moreover, the first-generation male has rounded manubrium, fusiform gubernaculum, conoid and slightly ventrally curved tails with minute mucron, and the second generation has rhomboid manubrium anteriorly ventrad bent, and tails with long and robust mucron. The morphological, morphometrical, molecular, and phylogenetic analyses support the new species status of this nematode, which is hereby described as Steinernema anantnagense n. sp. The bacterial symbiont associated with S. anantnagense n. sp. represents a novel species, closely related to Xenorhabdus japonica. These findings shed light on the diversity of entomopathogenic nematodes and their symbiotic bacteria, providing valuable information for future studies in this field.
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Affiliation(s)
- Aashaq Hussain Bhat
- Department of Biosciences and University Center for Research and Development, Chandigarh University, Gharuan, Mohali, Punjab, 140413, India
- Experimental Biology Research Group, Institute of Biology, Faculty of Sciences, University of Neuchâtel, Neuchâtel, Switzerland
| | - Ricardo A. R. Machado
- Experimental Biology Research Group, Institute of Biology, Faculty of Sciences, University of Neuchâtel, Neuchâtel, Switzerland
| | - Joaquín Abolafia
- Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Campus “Las Lagunillas”, Jaén, Spain
| | - Tarique Hassan Askary
- Division of Entomology, Faculty of Agriculture, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Wadura Campus, Jammu and Kashmir, India
| | - Vladimír Půža
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 37005České Budějovice, Czech Republic
| | - Alba Nazaret Ruiz-Cuenca
- Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Campus “Las Lagunillas”, Jaén, Spain
| | - Aasha Rana
- Department of Zoology, Faculty of Basic and Applied Sciences, Madhav University, Pindwara (Sirohi), Rajasthan, 307026, India
| | - Samy Sayed
- Department of Economic Entomology and Pesticides, Faculty of Agriculture, Cairo University, 12613, Giza, Egypt
| | - Laila A. Al-Shuraym
- Department of Biology, College of Science, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh11671, Saudi Arabia
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11
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Steinernema africanum n. sp. (Rhabditida, Steinernematidae), a New Entomopathogenic Nematode Species Isolated in the Republic of Rwanda. J Nematol 2022; 54:20220049. [DOI: 10.2478/jofnem-2022-0049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Indexed: 11/06/2022] Open
Abstract
Abstract
Alternatives to hazardous insecticides are urgently needed for an environmentally friendly and effective management of insect pests. One such option is the use of entomopathogenic nematodes (EPN). To increase the availability of EPN with potential for biocontrol, we surveyed agricultural soils in the Republic of Rwanda and collected two Steinernema isolates. Initial molecular characterization showed that they represent a new species, for which we propose the name S. africanum n. sp. To describe this new species, we reconstructed phylogenetic relationships, calculated sequence similarity scores, characterized the nematodes at the morphological level, conducted crossing experiments, and isolated and characterized their symbiotic bacteria. At the molecular level, S. africanum n. sp. is closely related to S. litorale and S. weiseri. At the morphological level, S. africanum n. sp. differs from closely related species by the position of the nerve ring and also because the stoma and pharynx region is longer. The first-generation males have ventrally curved spicules with lanceolate manubrium and fusiform gubernaculum and the second-generation males have rounded manubrium and anteriorly hook-like gubernaculum. Steinernema africanum n. sp. does not mate or produce fertile progeny with any of the closely related species.
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12
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Castaneda-Alvarez C, Machado RAR, Morales-Montero P, Boss A, Muller A, Prodan S, Zamorano A, San-Blas E, Půža V, Aballay E. Photorhabdus antumapuensis sp. nov., a novel symbiotic bacterial species associated with Heterorhabditis atacamensis entomopathogenic nematodes. Int J Syst Evol Microbiol 2022; 72. [DOI: 10.1099/ijsem.0.005525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
One motile, Gram-negative, non-spore-forming and rod-shaped symbiotic bacterium, strain UCH-936T, was isolated from Heterorhabditis atacamensis nematodes. Results of biochemical, physiological, molecular and genomic analyses suggest that it represents a new species, which we propose to name Photorhabdus antumapuensis sp. nov. Digital DNA–DNA hybridization shows that strain UCH-936T is more closely related to
Photorhabdus kleinii
DSM 23513T, but shares solely 50.5 % similarity, which is below the 70% cut-off value that delimits species boundaries in bacteria. Phylogenetic reconstructions using whole-genome sequences show that strain UCH-936T forms a unique clade, suggesting its novel and distinct taxonomic status again. Similarly, comparative genomic analyses shows that the virulence factor flagella-related gene fleR, the type IV pili-related gene pilL and the vibriobactin-related gene vibE are present in the genome of strain UCH-936T but absent in the genomes of its closest relatives. Biochemically and physiologically, UCH-936T differs also from all closely related
Photorhabdus
species. Therefore, Photorhabdus antumapuensis sp. nov. is proposed as a new species with the type strain UCH-936T (CCCT 21.06T=CCM 9188T=CCOS 1991T).
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Affiliation(s)
- Carlos Castaneda-Alvarez
- Programa de Doctorado en Ciencias Silvoagropecuarias y Veterinarias, Campus Sur Universidad de Chile, Santa Rosa 11315, La Pintana, Santiago, CP 8820808, Chile
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas, Universidad de Chile, P.O. Box 1004, Santiago, Chile
| | - Ricardo A. R. Machado
- Experimental Biology Research Group, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Patricia Morales-Montero
- Departamento de Ciencias Vegetales, Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Macul, Santiago, Chile
- Experimental Biology Research Group, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Anja Boss
- Experimental Biology Research Group, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Arthur Muller
- Experimental Biology Research Group, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Simona Prodan
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas, Universidad de Chile, P.O. Box 1004, Santiago, Chile
| | - Alan Zamorano
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas, Universidad de Chile, P.O. Box 1004, Santiago, Chile
| | - Ernesto San-Blas
- Instituto de Ciencias Agroalimentarias, Animales y Ambientales (ICA3), Universidad de O'Higgins, San Pedro, San José Province, Chile
| | - Vladimír Půža
- Laboratory of Entomopathogenic Nematodes, Institute of Entomology, Biology Centre CAS, Branišovská 31, České Budějovice, 370 05, Czechia
| | - Erwin Aballay
- Departamento de Sanidad Vegetal, Facultad de Ciencias Agronómicas, Universidad de Chile, P.O. Box 1004, Santiago, Chile
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13
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Muangpat P, Meesil W, Ngoenkam J, Teethaisong Y, Thummeepak R, Sitthisak S, Tandhavanant S, Chantratita N, Bode HB, Vitta A, Thanwisai A. Genome analysis of secondary metabolite‑biosynthetic gene clusters of Photorhabdus akhurstii subsp. akhurstii and its antibacterial activity against antibiotic-resistant bacteria. PLoS One 2022; 17:e0274956. [PMID: 36129957 PMCID: PMC9491552 DOI: 10.1371/journal.pone.0274956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/08/2022] [Indexed: 11/27/2022] Open
Abstract
Xenorhabdus and Photorhabdus can produce a variety of secondary metabolites with broad spectrum bioactivity against microorganisms. We investigated the antibacterial activity of Xenorhabdus and Photorhabdus against 15 antibiotic-resistant bacteria strains. Photorhabdus extracts had strong inhibitory the growth of Methicillin-resistant Staphylococcus aureus (MRSA) by disk diffusion. The P. akhurstii s subsp. akhurstii (bNN168.5_TH) extract showed lower minimum inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC). The interaction between either P. akhurstii subsp. akhurstii (bNN141.3_TH) or P. akhurstii subsp. akhurstii (bNN168.5_TH) or P. hainanensis (bNN163.3_TH) extract in combination with oxacillin determined by checkerboard assay exhibited partially synergistic interaction with fractional inhibitory concentration index (FICI) of 0.53. Time-killing assay for P. akhurstii subsp. akhurstii (bNN168.5_TH) extract against S. aureus strain PB36 significantly decreased cell viability from 105 CFU/ml to 103 CFU/ml within 30 min (P < 0.001, t-test). Transmission electron microscopic investigation elucidated that the bNN168.5_TH extract caused treated S. aureus strain PB36 (MRSA) cell membrane damage. The biosynthetic gene clusters of the bNN168.5_TH contained non-ribosomal peptide synthetase cluster (NRPS), hybrid NRPS-type l polyketide synthase (PKS) and siderophore, which identified potentially interesting bioactive products: xenematide, luminmide, xenortide A-D, luminmycin A, putrebactin/avaroferrin and rhizomide A-C. This study demonstrates that bNN168.5_TH showed antibacterial activity by disrupting bacterial cytoplasmic membrane and the draft genome provided insights into the classes of bioactive products. This also provides a potential approach in developing a novel antibacterial agent.
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Affiliation(s)
- Paramaporn Muangpat
- Faculty of Medical Science, Department of Microbiology and Parasitology, Naresuan University, Phitsanulok, Thailand
| | - Wipanee Meesil
- Faculty of Medical Science, Department of Microbiology and Parasitology, Naresuan University, Phitsanulok, Thailand
| | - Jatuporn Ngoenkam
- Faculty of Medical Science, Department of Microbiology and Parasitology, Naresuan University, Phitsanulok, Thailand
| | - Yothin Teethaisong
- Faculty of Allied Health Sciences, Department of Biomedical Sciences, Burapha University, Chonburi, Thailand
- Research Unit for Sensor Inovation (RUSI), Burapha University, Chon Buri, Thailand
| | - Rapee Thummeepak
- Faculty of Medical Science, Department of Microbiology and Parasitology, Naresuan University, Phitsanulok, Thailand
| | - Sutthirat Sitthisak
- Faculty of Medical Science, Department of Microbiology and Parasitology, Naresuan University, Phitsanulok, Thailand
| | - Sarunporn Tandhavanant
- Faculty of Tropical Medicine, Department of Microbiology and Immunology, Mahidol University, Bangkok, Thailand
| | - Narisara Chantratita
- Faculty of Tropical Medicine, Department of Microbiology and Immunology, Mahidol University, Bangkok, Thailand
| | - Helge B. Bode
- Molekulare Biotechnologie, Goethe Universität Frankfurt, Frankfurt am Main, Germany
- Department of Natural Products in Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Apichat Vitta
- Faculty of Medical Science, Department of Microbiology and Parasitology, Naresuan University, Phitsanulok, Thailand
- Faculty of Sciences, Center of Excellence for Biodiversity, Naresuan University, Phitsanulok, Thailand
- Faculty of Medical Science, Centre of Excellence in Medical Biotechnology (CEMB), Naresuan University, Phitsanulok, Thailand
| | - Aunchalee Thanwisai
- Faculty of Medical Science, Department of Microbiology and Parasitology, Naresuan University, Phitsanulok, Thailand
- Faculty of Sciences, Center of Excellence for Biodiversity, Naresuan University, Phitsanulok, Thailand
- Faculty of Medical Science, Centre of Excellence in Medical Biotechnology (CEMB), Naresuan University, Phitsanulok, Thailand
- * E-mail:
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14
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Awori RM. Nematophilic bacteria associated with entomopathogenic nematodes and drug development of their biomolecules. Front Microbiol 2022; 13:993688. [PMID: 36187939 PMCID: PMC9520725 DOI: 10.3389/fmicb.2022.993688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 08/24/2022] [Indexed: 11/30/2022] Open
Abstract
The importance of Xenorhabdus and Photorhabdus symbionts to their respective Steinernema and Heterorhabditis nematode hosts is that they not only contribute to their entomopathogenicity but also to their fecundity through the production of small molecules. Thus, this mini-review gives a brief introductory overview of these nematophilic bacteria. Specifically, their type species, nematode hosts, and geographic region of isolations are tabulated. The use of nucleotide sequence-based techniques for their species delineation and how pangenomes can improve this are highlighted. Using the Steinernema–Xenorhabdus association as an example, the bacterium-nematode lifecycle is visualized with an emphasis on the role of bacterial biomolecules. Those currently in drug development are discussed, and two potential antimalarial lead compounds are highlighted. Thus, this mini-review tabulates forty-eight significant nematophilic bacteria and visualizes the ecological importance of their biomolecules. It further discusses three of these biomolecules that are currently in drug development. Through it, one is introduced to Xenorhabdus and Photorhabdus bacteria, their natural production of biomolecules in the nematode-bacterium lifecycle, and how these molecules are useful in developing novel therapies.
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Affiliation(s)
- Ryan Musumba Awori
- Department of Biology, University of Nairobi, Nairobi, Kenya
- Elakistos Biosciences, Nairobi, Kenya
- *Correspondence: Ryan Musumba Awori,
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15
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Gulsen SH, Tileklioglu E, Bode E, Cimen H, Ertabaklar H, Ulug D, Ertug S, Wenski SL, Touray M, Hazir C, Bilecenoglu DK, Yildiz I, Bode HB, Hazir S. Antiprotozoal activity of different Xenorhabdus and Photorhabdus bacterial secondary metabolites and identification of bioactive compounds using the easyPACId approach. Sci Rep 2022; 12:10779. [PMID: 35750682 PMCID: PMC9232601 DOI: 10.1038/s41598-022-13722-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 05/26/2022] [Indexed: 12/20/2022] Open
Abstract
Natural products have been proven to be important starting points for the development of new drugs. Bacteria in the genera Photorhabdus and Xenorhabdus produce antimicrobial compounds as secondary metabolites to compete with other organisms. Our study is the first comprehensive study screening the anti-protozoal activity of supernatants containing secondary metabolites produced by 5 Photorhabdus and 22 Xenorhabdus species against human parasitic protozoa, Acanthamoeba castellanii, Entamoeba histolytica, Trichomonas vaginalis, Leishmania tropica and Trypanosoma cruzi, and the identification of novel bioactive antiprotozoal compounds using the easyPACId approach (easy Promoter Activated Compound Identification) method. Though not in all species, both bacterial genera produce antiprotozoal compounds effective on human pathogenic protozoa. The promoter exchange mutants revealed that antiprotozoal bioactive compounds produced by Xenorhabdus bacteria were fabclavines, xenocoumacins, xenorhabdins and PAX peptides. Among the bacteria assessed, only P. namnaoensis appears to have acquired amoebicidal property which is effective on E. histolytica trophozoites. These discovered antiprotozoal compounds might serve as starting points for the development of alternative and novel pharmaceutical agents against human parasitic protozoa in the future.
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Affiliation(s)
- Sebnem Hazal Gulsen
- Department of Biology, Faculty of Arts and Science, Aydin Adnan Menderes University, Aydin, Türkiye
| | - Evren Tileklioglu
- Department of Parasitology, Faculty of Medicine, Aydin Adnan Menderes University, Aydin, Türkiye
| | - Edna Bode
- Max-Planck-Institute for Terrestrial Microbiology Department, Natural Products in Organismic Interactions, Karl-von-Frisch-Str. 10, 35043, Marburg, Germany
| | - Harun Cimen
- Department of Biology, Faculty of Arts and Science, Aydin Adnan Menderes University, Aydin, Türkiye
| | - Hatice Ertabaklar
- Department of Parasitology, Faculty of Medicine, Aydin Adnan Menderes University, Aydin, Türkiye
| | - Derya Ulug
- Department of Biology, Faculty of Arts and Science, Aydin Adnan Menderes University, Aydin, Türkiye
| | - Sema Ertug
- Department of Parasitology, Faculty of Medicine, Aydin Adnan Menderes University, Aydin, Türkiye
| | - Sebastian L Wenski
- Max-Planck-Institute for Terrestrial Microbiology Department, Natural Products in Organismic Interactions, Karl-von-Frisch-Str. 10, 35043, Marburg, Germany
| | - Mustapha Touray
- Department of Biology, Faculty of Arts and Science, Aydin Adnan Menderes University, Aydin, Türkiye
| | - Canan Hazir
- Aydin Health Services Vocational School, Aydin Adnan Menderes University, 09100, Aydin, Türkiye
| | | | - Ibrahim Yildiz
- Department of Parasitology, Faculty of Medicine, Aydin Adnan Menderes University, Aydin, Türkiye
| | - Helge B Bode
- Max-Planck-Institute for Terrestrial Microbiology Department, Natural Products in Organismic Interactions, Karl-von-Frisch-Str. 10, 35043, Marburg, Germany. .,Molekulare Biotechnologie, Fachbereich Biowissenschaften, Goethe Universität Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany. .,Senckenberg Gesellschaft für Naturforschung, 60325, Frankfurt, Germany.
| | - Selcuk Hazir
- Department of Biology, Faculty of Arts and Science, Aydin Adnan Menderes University, Aydin, Türkiye.
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16
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Dominelli N, Jäger HY, Langer A, Brachmann A, Heermann R. High-throughput sequencing analysis reveals genomic similarity in phenotypic heterogeneous Photorhabdus luminescens cell populations. ANN MICROBIOL 2022. [DOI: 10.1186/s13213-022-01677-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Purpose
Phenotypic heterogeneity occurs in many bacterial populations: single cells of the same species display different phenotypes, despite being genetically identical. The Gram-negative entomopathogenic bacterium Photorhabdus luminescens is an excellent example to investigate bacterial phenotypic heterogeneity. Its dualistic life cycle includes a symbiotic stage interacting with entomopathogenic nematodes (EPNs) and a pathogenic stage killing insect larvae. P. luminescens appears in two phenotypically different cell forms: the primary (1°) and the secondary (2°) cell variants. While 1° cells are bioluminescent, pigmented, and produce a huge set of secondary metabolites, 2° cells lack all these phenotypes. The main difference between both phenotypic variants is that only 1° cells can undergo symbiosis with EPNs, a phenotype that is absent from 2° cells. Recent comparative transcriptome analysis revealed that genes mediating 1° cell-specific traits are modulated differently in 2° cells. Although it was previously suggested that heterogeneity in P. luminescens cells cultures is not genetically mediated by, e.g., larger rearrangements in the genome, the genetic similarity of both cell variants has not clearly been demonstrated yet.
Methods
Here, we analyzed the genomes of both 1° and 2° cells by genome sequencing of each six single 1° and 2° clones that emerged from a single 1° clone after prolonged growth. Using different bioinformatics tools, the sequence data were analyzed for clustered point mutations or genetic rearrangements with respect to the respective phenotypic variant.
Result
We demonstrate that isolated clones of 2° cells that switched from the 1° cell state do not display any noticeable mutation and do not genetically differ from 1° cells.
Conclusion
In summary, we show that the phenotypic differences in P. luminescens cell cultures are obviously not caused by mutations or genetic rearrangements in the genome but truly emerge from phenotypic heterogeneity.
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17
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Parihar RD, Dhiman U, Bhushan A, Gupta PK, Gupta P. Heterorhabditis and Photorhabdus Symbiosis: A Natural Mine of Bioactive Compounds. Front Microbiol 2022; 13:790339. [PMID: 35422783 PMCID: PMC9002308 DOI: 10.3389/fmicb.2022.790339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 02/02/2022] [Indexed: 12/12/2022] Open
Abstract
Phylum Nematoda is of great economic importance. It has been a focused area for various research activities in distinct domains across the globe. Among nematodes, there is a group called entomopathogenic nematodes, which has two families that live in symbiotic association with bacteria of genus Xenorhabdus and Photorhabdus, respectively. With the passing years, researchers have isolated a wide array of bioactive compounds from these symbiotically associated nematodes. In this article, we are encapsulating bioactive compounds isolated from members of the family Heterorhabditidae inhabiting Photorhabdus in its gut. Isolated bioactive compounds have shown a wide range of biological activity against deadly pathogens to both plants as well as animals. Some compounds exhibit lethal effects against fungi, bacteria, protozoan, insects, cancerous cell lines, neuroinflammation, etc., with great potency. The main aim of this article is to collect and analyze the importance of nematode and its associated bacteria, isolated secondary metabolites, and their biomedical potential, which can serve as potential leads for further drug discovery.
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Affiliation(s)
| | | | - Anil Bhushan
- Natural Products and Medicinal Chemistry Division, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Integrative Medicine, Jammu, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Prashant Kumar Gupta
- Department of Horticulture, Rajmata Vijayaraje Scindia Krishi Vishwa Vidyalaya, Gwalior, India
| | - Prasoon Gupta
- Natural Products and Medicinal Chemistry Division, Council of Scientific and Industrial Research (CSIR)-Indian Institute of Integrative Medicine, Jammu, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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18
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Evaluation of the Antifungal Activities of Photorhabdus akhurstii and Its Secondary Metabolites against Phytopathogenic Colletotrichum gloeosporioides. J Fungi (Basel) 2022; 8:jof8040403. [PMID: 35448634 PMCID: PMC9027565 DOI: 10.3390/jof8040403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/12/2022] [Accepted: 04/12/2022] [Indexed: 12/16/2022] Open
Abstract
Colletotrichum gloeosporioides is a phytopathogenic fungus that causes devastating losses in strawberries without effective countermeasures. Members of the genus Photorhabdus exhibit antimicrobial capability and have been found to have the potential for use as biocontrol agents against C. gloeosporioides. Photorhabdus species exhibit two phase variations with a differentiated composition of secondary metabolites designated to each phase. In this study, Photorhabdus akhurstii sp. nov. 0813-124 exhibited phase I (PL1) and phase II (PL2); however, only PL1 displayed distinct inhibition of C. gloeosporioides in the confrontation assay. We identified the bioactive ingredients of P. akhurstii sp. nov. 0813-124 to be glidobactin A and cepafungin I, with MIC values lower than 1.5 and 2.0 µg/mL, respectively. Furthermore, we revealed the biosynthetic gene cluster (BGC) of corresponding bioactive molecules through genomics analysis and determined its expression level in PL1 and PL2. The expression of glidobactin BGC in PL1 increased rapidly within 24 h, while PL2 was eventually stimulated after 60 h. In summary, we demonstrated that P. akhurstii sp. nov. 0813-124 could potentially be used as a biocontrol agent or part of a natural product repertoire for combating C. gloeosporioides.
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19
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Fodor A, Gualtieri M, Zeller M, Tarasco E, Klein MG, Fodor AM, Haynes L, Lengyel K, Forst SA, Furgani GM, Karaffa L, Vellai T. Type Strains of Entomopathogenic Nematode-Symbiotic Bacterium Species, Xenorhabdus szentirmaii (EMC) and X. budapestensis (EMA), Are Exceptional Sources of Non-Ribosomal Templated, Large-Target-Spectral, Thermotolerant-Antimicrobial Peptides (by Both), and Iodinin (by EMC). Pathogens 2022; 11:pathogens11030342. [PMID: 35335666 PMCID: PMC8950435 DOI: 10.3390/pathogens11030342] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/18/2022] [Accepted: 02/23/2022] [Indexed: 01/26/2023] Open
Abstract
Antimicrobial multidrug resistance (MDR) is a global challenge, not only for public health, but also for sustainable agriculture. Antibiotics used in humans should be ruled out for use in veterinary or agricultural settings. Applying antimicrobial peptide (AMP) molecules, produced by soil-born organisms for protecting (soil-born) plants, seems a preferable alternative. The natural role of peptide-antimicrobials, produced by the prokaryotic partner of entomopathogenic-nematode/bacterium (EPN/EPB) symbiotic associations, is to sustain monoxenic conditions for the EPB in the gut of the semi-anabiotic infective dauer juvenile (IJ) EPN. They keep pathobiome conditions balanced for the EPN/EPB complex in polyxenic (soil, vanquished insect cadaver) niches. Xenorhabdus szentirmaii DSM16338(T) (EMC), and X. budapestensis DSM16342(T) (EMA), are the respective natural symbionts of EPN species Steinernema rarum and S. bicornutum. We identified and characterized both of these 15 years ago. The functional annotation of the draft genome of EMC revealed 71 genes encoding non-ribosomal peptide synthases, and polyketide synthases. The large spatial Xenorhabdus AMP (fabclavine), was discovered in EMA, and its biosynthetic pathway in EMC. The AMPs produced by EMA and EMC are promising candidates for controlling MDR prokaryotic and eukaryotic pathogens (bacteria, oomycetes, fungi, protozoa). EMC releases large quantity of iodinin (1,6-dihydroxyphenazine 5,10-dioxide) in a water-soluble form into the media, where it condenses to form spectacular water-insoluble, macroscopic crystals. This review evaluates the scientific impact of international research on EMA and EMC.
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Affiliation(s)
- András Fodor
- Department of Genetics, Eötvös University, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary; (A.M.F.); (K.L.); or (G.M.F.); or (T.V.)
- Department of Genetics, University of Szeged, Középfasor 52, H-6726 Szeged, Hungary
- Correspondence: ; Tel.: +36-(30)-490-9294
| | - Maxime Gualtieri
- Nosopharm, 110 Allée Charles Babbage, Espace Innovation 2, 30000 Nîmes, France;
| | - Matthias Zeller
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47906, USA;
| | - Eustachio Tarasco
- Department of Soil, Plant and Food Sciences, University of Bari “Aldo Moro”, Via Amendola 165/A, 70126 Bari, Italy;
- Institute for Sustainable Plant Protection of CNR, Via Amendola 122/D, 70126 Bari, Italy
| | - Michael G. Klein
- USDA-ARS & Department of Entomology, The Ohio State University, 13416 Claremont Ave, Cleveland, OH 44130, USA;
| | - Andrea M. Fodor
- Department of Genetics, Eötvös University, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary; (A.M.F.); (K.L.); or (G.M.F.); or (T.V.)
| | - Leroy Haynes
- Department of Chemistry, The College of Wooster, Wooster, OH 44691, USA;
| | - Katalin Lengyel
- Department of Genetics, Eötvös University, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary; (A.M.F.); (K.L.); or (G.M.F.); or (T.V.)
- National Institute of Pharmacy and Nutrition (NIPN), Zrinyi utca 3, H-1051 Budapest, Hungary
| | - Steven A. Forst
- Department of Biological Sciences, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, WI 53201, USA;
| | - Ghazala M. Furgani
- Department of Genetics, Eötvös University, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary; (A.M.F.); (K.L.); or (G.M.F.); or (T.V.)
- Department of Plant Protection, Faculty of Agriculture, University of Tripoli, Tripoli P.O. Box 13793, Libya
| | - Levente Karaffa
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem Tér 1, H-4032 Debrecen, Hungary;
- Institute of Metagenomics, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary
| | - Tibor Vellai
- Department of Genetics, Eötvös University, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary; (A.M.F.); (K.L.); or (G.M.F.); or (T.V.)
- MTA-ELTE Genetics Research Group, Pázmány Péter Sétány 1/C, H-1117 Budapest, Hungary
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The Odilorhabdin Antibiotic Biosynthetic Cluster and Acetyltransferase Self-Resistance Locus Are Niche and Species Specific. mBio 2022; 13:e0282621. [PMID: 35012352 PMCID: PMC8749412 DOI: 10.1128/mbio.02826-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Antibiotic resistance is an increasing threat to human health. A direct link has been established between antimicrobial self-resistance determinants of antibiotic producers, environmental bacteria, and clinical pathogens. Natural odilorhabdins (ODLs) constitute a new family of 10-mer linear cationic peptide antibiotics inhibiting bacterial translation by binding to the 30S subunit of the ribosome. These bioactive secondary metabolites are produced by entomopathogenic bacterial symbiont Xenorhabdus (Morganellaceae), vectored by the soil-dwelling nematodes. ODL-producing Xenorhabdus nematophila symbionts have mechanisms of self-protection. In this study, we cloned the 44.5-kb odl biosynthetic gene cluster (odl-BGC) of the symbiont by recombineering and showed that the N-acetyltransferase-encoding gene, oatA, is responsible for ODL resistance. In vitro acetylation and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses showed that OatA targeted the side chain amino group of ODL rare amino acids, leading to a loss of translation inhibition and antibacterial properties. Functional, genomic, and phylogenetic analyses of oatA revealed an exclusive cis-link to the odilorhabdin BGC, found only in X. nematophila and a specific phylogenetic clade of Photorhabdus. This work highlights the coevolution of antibiotic production and self-resistance as ancient features of this unique tripartite complex of host-vector-symbiont interactions without odl-BGC dissemination by lateral gene transfer. IMPORTANCE Odilorhabdins (ODLs) constitute a novel antibiotic family with promising properties for treating problematic multidrug-resistant Gram-negative bacterial infections. ODLs are 10-mer linear cationic peptides inhibiting bacterial translation by binding to the small subunit of the ribosome. These natural peptides are produced by Xenorhabdus nematophila, a bacterial symbiont of entomopathogenic nematodes well known to produce large amounts of specialized secondary metabolites. Like other antimicrobial producers, ODL-producing Xenorhabdus nematophila has mechanisms of self-protection. In this study, we cloned the ODL-biosynthetic gene cluster of the symbiont by recombineering and showed that the N-acetyltransferase-encoding gene, oatA, is responsible for ODL resistance. In vitro acetylation and LC-MS/MS analyses showed that OatA targeted the side chain amino group of ODL rare amino acids, leading to a loss of translation inhibition and antibacterial properties. Functional, genomic, and phylogenetic analyses of oatA revealed the coevolution of antibiotic production and self-resistance as ancient feature of this particular niche in soil invertebrates without resistance dissemination.
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21
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Booysen E, Malan AP, Dicks LM. Colour of Heterorhabditis zealandica-infected-Galleria mellonella dependent on the Photorhabdus symbiont, with two new nematode-symbiotic associations reported. J Invertebr Pathol 2022; 189:107729. [DOI: 10.1016/j.jip.2022.107729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 01/24/2022] [Accepted: 01/31/2022] [Indexed: 10/19/2022]
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22
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Machado RA, Bhat AH, Abolafia J, Muller A, Bruno P, Fallet P, Arce CC, Turlings TC, Bernal JS, Kajuga J, Waweru B, Toepfer S. Multi-locus phylogenetic analyses uncover species boundaries and reveal the occurrence of two new entomopathogenic nematode species, Heterorhabditis ruandica n. sp. and Heterorhabditis zacatecana n. sp. J Nematol 2021; 53:e2021-89. [PMID: 34790901 PMCID: PMC8588743 DOI: 10.21307/jofnem-2021-089] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Indexed: 11/17/2022] Open
Abstract
Species of the nematode genus Heterorhabditis are important biological control agents against agricultural pests. The taxonomy of this group is still unclear as it currently relies on phylogenetic reconstructions based on a few genetic markers with little resolutive power, specially of closely related species. To fill this knowledge gap, we sequenced several phylogenetically relevant genetic loci and used them to reconstruct phylogenetic trees, to calculate sequence similarity scores, and to determine signatures of species- and population-specific genetic polymorphism. In addition, we revisited the current literature related to the description, synonymisation, and declaration as species inquirendae of Heterorhabditis species to compile taxonomically relevant morphological and morphometric characters, characterized new nematode isolates at the morphological and morphometrical level, and conducted self-crossing and cross-hybridization experiments. The results of this study show that the sequences of the mitochondrial cytochrome C oxidase subunit I (COI) gene provide better phylogenetic resolutive power than the sequences of nuclear rRNA genes and that this gene marker can phylogenetically resolve closely related species and even populations of the same species with high precision. Using this gene marker, we found two new species, Heterorhabditis ruandica n. sp. and Heterorhabditis zacatecana n. sp. A detailed characterization of these species at the morphological and morphometric levels and nematode reproduction assays revealed that the threshold for species delimitation in this genus, using COI sequences, is 97% to 98%. Our study illustrates the importance of rigorous morphological and morphometric characterization and multi-locus sequencing for the description of new species within the genus Heterorhabditis, serves to clarify the phylogenetic relationships of this important group of biological control agents, and can inform future species descriptions to advance our efforts towards developing more tools for sustainable and environmentally friendly agriculture.
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Affiliation(s)
- Ricardo A.R. Machado
- Experimental Biology Research Group. Institute of Biology. Faculty of Sciences. University of Neuchâtel. Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Aashaq Hussain Bhat
- Department of Zoology, Government Degree College. Billawar-184204, Kathua, Jammu, Jammu and Kashmir, India
| | - Joaquín Abolafia
- Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Campus ‘Las Lagunillas’ s/n, Edificio B3, 23071 Jaén, Spain
| | - Arthur Muller
- Experimental Biology Research Group. Institute of Biology. Faculty of Sciences. University of Neuchâtel. Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Pamela Bruno
- Laboratory of Fundamental and Applied Research in Chemical Ecology, Institute of Biology. Faculty of Sciences, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Patrick Fallet
- Laboratory of Fundamental and Applied Research in Chemical Ecology, Institute of Biology. Faculty of Sciences, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Carla C.M. Arce
- Laboratory of Fundamental and Applied Research in Chemical Ecology, Institute of Biology. Faculty of Sciences, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Ted C.J. Turlings
- Laboratory of Fundamental and Applied Research in Chemical Ecology, Institute of Biology. Faculty of Sciences, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Julio S. Bernal
- Department of Entomology, Texas A&M University, College Station, TX
| | - Joelle Kajuga
- Department of Crop Innovations & Technology Transfer. Rwanda Agriculture and Animal Resources Development Board, 5016 Kigali-Rwanda
| | - Bancy Waweru
- Department of Crop Innovations & Technology Transfer. Rwanda Agriculture and Animal Resources Development Board, 5016 Kigali-Rwanda
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Hadchity L, Lanois A, Kiwan P, Nassar F, Givaudan A, Khattar ZA. AcrAB, the major RND-type efflux pump of Photorhabdus laumondii, confers intrinsic multidrug-resistance and contributes to virulence in insects. ENVIRONMENTAL MICROBIOLOGY REPORTS 2021; 13:637-648. [PMID: 34002534 DOI: 10.1111/1758-2229.12974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
The resistance-nodulation-division (RND)-type efflux pumps AcrAB and MdtABC contribute to multidrug-resistance (MDR) in Gram-negative bacteria. Photorhabdus is a symbiotic bacterium of soil nematodes that also produces virulence factors killing insects by septicaemia. We previously showed that mdtA deletion in Photorhabdus laumondii TT01 resulted in no detrimental phenotypes. Here, we investigated the roles of the last two putative RND transporters in TT01 genome, AcrAB and AcrAB-like (Plu0759-Plu0758). Only ΔacrA and ΔmdtAΔacrA mutants were multidrug sensitive, even to triphenyltetrazolium chloride and bromothymol blue used for Photorhabdus isolation from nematodes on the nutrient bromothymol blue-triphenyltetrazolium chloride agar (NBTA) medium. Both mutants also displayed slightly attenuated virulence after injection into Spodoptera littoralis. Transcriptional analysis revealed intermediate levels of acrAB expression in vitro, in vivo and post-mortem, whereas its putative transcriptional repressor acrR was weakly expressed. Yet, plasmid-mediated acrR overexpression did not decrease acrAB transcript levels neither MDR in TT01 WT. While no pertinent mutations were detected in acrR of the same P. laumondii strain grown either on NBTA or nutrient agar, we suggest that AcrR-mediated repression of acrAB is not physiologically required under conditions tested. Finally, we propose that AcrAB is the primary RND-efflux pump, which is essential for MDR in Photorhabdus and may confer adaptive advantages during insect infection.
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Affiliation(s)
- Linda Hadchity
- Laboratory of Georesources, Geosciences and Environment (L2GE), Microbiology/Tox-Ecotoxicology team, Faculty of Sciences 2, Lebanese University, Fanar, Lebanon
- DGIMI, Université Montpellier, INRAE, Montpellier, France
| | - Anne Lanois
- DGIMI, Université Montpellier, INRAE, Montpellier, France
| | - Paloma Kiwan
- Laboratory of Georesources, Geosciences and Environment (L2GE), Microbiology/Tox-Ecotoxicology team, Faculty of Sciences 2, Lebanese University, Fanar, Lebanon
| | - Fida Nassar
- Laboratory of Georesources, Geosciences and Environment (L2GE), Microbiology/Tox-Ecotoxicology team, Faculty of Sciences 2, Lebanese University, Fanar, Lebanon
| | - Alain Givaudan
- DGIMI, Université Montpellier, INRAE, Montpellier, France
| | - Ziad Abi Khattar
- Laboratory of Georesources, Geosciences and Environment (L2GE), Microbiology/Tox-Ecotoxicology team, Faculty of Sciences 2, Lebanese University, Fanar, Lebanon
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24
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Machado RAR, Somvanshi VS, Muller A, Kushwah J, Bhat CG. Photorhabdus hindustanensis sp. nov., Photorhabdus akhurstii subsp. akhurstii subsp. nov. , and Photorhabdus akhurstii subsp. bharatensis subsp. nov. , isolated from Heterorhabditis entomopathogenic nematodes. Int J Syst Evol Microbiol 2021; 71. [PMID: 34524954 DOI: 10.1099/ijsem.0.004998] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Two Gram-negative, rod-shaped bacteria, H1T and H3T, isolated from the digestive tract of Heterorhabditis entomopathogenic nematodes were biochemically and molecularly characterized to determine their taxonomic positions. The 16S rRNA gene sequences of these strains indicate that they belong to the Gammaproteobacteria, to the family Morganellaceae, and to the Photorhabdus genus. Deeper analyses using whole genome-based phylogenetic reconstructions show that strains H1T and H3T are closely related to P. akhurstii DSM 15138T, to P. hainanensis DSM 22397T, and to P. namnaonensis PB45.5T. In silico genomic comparisons confirm these observations and show that strain H1T shares 70.6, 66.8, and 63.5 % digital DNA-DNA hybridization (dDDH) with P. akhurstii DSM 15138T, P. hainanensis DSM 22397T, and P. namnaonensis PB45.5T, respectively, and that strain H3T shares 76.6, 69.4, and 59.2 % dDDH with P. akhurstii DSM 15138T, P. hainanensis DSM 22397T, and P. namnaonensis PB45.5T, respectively. Physiological and biochemical characterization reveals that these two strains differ from most of the validly described Photorhabdus species and from their more closely related taxa. Given the clear phylogenetic separations, that the threshold to discriminate species and subspecies is 70 and 79% dDDH, respectively, and that strains H1T and H3T differ physiologically and biochemically from their more closely related taxa, we propose to classify H1T and H3T into new taxa as follows: H3T as a new subspecies within the species P. akhurstii, and H1T as a new species within the Photorhabdus genus, in spite that H1T shares 70.6 % dDDH with P. akhurstii DSM 15138T, score that is slightly higher than the 70 % threshold that delimits species boundaries. The reason for this is that H1T and P. akhurstii DSM 15138T cluster apart in the phylogenetic trees and that dDDH scores between strain H1T and other P. akhurstii strains are lower than 70 %. Hence, the following names are proposed: Photorhabdus hindustanensis sp. nov. with the type strain H1T (=IARI-SGMG3T,=KCTC 82683T=CCM 9150T=CCOS 1975T) and P. akhurstii subsp. bharatensis subsp. nov. with the type strain H3T (=IARI-SGHR2T=KCTC 82684T=CCM 9149T=CCOS 1976T). These propositions automatically create P. akhurstii subsp. akhurstii subsp. nov. with DSM 15138T as the type strain (currently classified as P. akhurstii).
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Affiliation(s)
- Ricardo A R Machado
- Experimental Biology Research Group, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Vishal S Somvanshi
- Division of Nematology, Indian Council of Agricultural Research, Indian Agricultural Research Institute (ICAR-IARI), New Delhi, India
| | - Arthur Muller
- Experimental Biology Research Group, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Jyoti Kushwah
- Division of Nematology, Indian Council of Agricultural Research, Indian Agricultural Research Institute (ICAR-IARI), New Delhi, India
| | - Chaitra G Bhat
- Division of Nematology, Indian Council of Agricultural Research, Indian Agricultural Research Institute (ICAR-IARI), New Delhi, India
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25
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Photorhabdus spp.: An Overview of the Beneficial Aspects of Mutualistic Bacteria of Insecticidal Nematodes. PLANTS 2021; 10:plants10081660. [PMID: 34451705 PMCID: PMC8401807 DOI: 10.3390/plants10081660] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 07/29/2021] [Accepted: 08/03/2021] [Indexed: 11/17/2022]
Abstract
The current approaches to sustainable agricultural development aspire to use safer means to control pests and pathogens. Photorhabdus bacteria that are insecticidal symbionts of entomopathogenic nematodes in the genus Heterorhabditis can provide such a service with a treasure trove of insecticidal compounds and an ability to cope with the insect immune system. This review highlights the need of Photorhabdus-derived insecticidal, fungicidal, pharmaceutical, parasiticidal, antimicrobial, and toxic materials to fit into current, or emerging, holistic strategies, mainly for managing plant pests and pathogens. The widespread use of these bacteria, however, has been slow, due to cost, natural presence within the uneven distribution of their nematode partners, and problems with trait stability during in vitro culture. Yet, progress has been made, showing an ability to overcome these obstacles via offering affordable mass production and mastered genome sequencing, while detecting more of their beneficial bacterial species/strains. Their high pathogenicity to a wide range of arthropods, efficiency against diseases, and versatility, suggest future promising industrial products. The many useful properties of these bacteria can facilitate their integration with other pest/disease management tactics for crop protection.
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26
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Jurėnas D, Payelleville A, Roghanian M, Turnbull KJ, Givaudan A, Brillard J, Hauryliuk V, Cascales E. Photorhabdus antibacterial Rhs polymorphic toxin inhibits translation through ADP-ribosylation of 23S ribosomal RNA. Nucleic Acids Res 2021; 49:8384-8395. [PMID: 34255843 PMCID: PMC8661411 DOI: 10.1093/nar/gkab608] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/10/2021] [Accepted: 07/01/2021] [Indexed: 11/18/2022] Open
Abstract
Bacteria have evolved sophisticated mechanisms to deliver potent toxins into bacterial competitors or into eukaryotic cells in order to destroy rivals and gain access to a specific niche or to hijack essential metabolic or signaling pathways in the host. Delivered effectors carry various activities such as nucleases, phospholipases, peptidoglycan hydrolases, enzymes that deplete the pools of NADH or ATP, compromise the cell division machinery, or the host cell cytoskeleton. Effectors categorized in the family of polymorphic toxins have a modular structure, in which the toxin domain is fused to additional elements acting as cargo to adapt the effector to a specific secretion machinery. Here we show that Photorhabdus laumondii, an entomopathogen species, delivers a polymorphic antibacterial toxin via a type VI secretion system. This toxin inhibits protein synthesis in a NAD+-dependent manner. Using a biotinylated derivative of NAD, we demonstrate that translation is inhibited through ADP-ribosylation of the ribosomal 23S RNA. Mapping of the modification further showed that the adduct locates on helix 44 of the thiostrepton loop located in the GTPase-associated center and decreases the GTPase activity of the EF-G elongation factor.
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Affiliation(s)
- Dukas Jurėnas
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies et Biotechnologie (IM2B), Aix-Marseille Université - CNRS, UMR 7255, Marseille, France
| | - Amaury Payelleville
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies et Biotechnologie (IM2B), Aix-Marseille Université - CNRS, UMR 7255, Marseille, France.,DGIMI, Univ Montpellier, INRAE, Montpellier, France
| | - Mohammad Roghanian
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden, Umeå University, 901 87 Umeå, Sweden
| | | | | | | | - Vasili Hauryliuk
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden.,Laboratory for Molecular Infection Medicine Sweden, Umeå University, 901 87 Umeå, Sweden.,Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden.,University of Tartu, Institute of Technology, 50411 Tartu, Estonia
| | - Eric Cascales
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie, Bioénergies et Biotechnologie (IM2B), Aix-Marseille Université - CNRS, UMR 7255, Marseille, France
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27
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Hill V, Kuhnert P, Erb M, Machado RAR. Identification of Photorhabdus symbionts by MALDI-TOF MS. MICROBIOLOGY-SGM 2021; 166:522-530. [PMID: 32301690 DOI: 10.1099/mic.0.000905] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Species of the bacterial genus Photorhabus live in a symbiotic relationship with Heterorhabditis entomopathogenic nematodes. Besides their use as biological control agents against agricultural pests, some Photorhabdus species are also a source of natural products and are of medical interest due to their ability to cause tissue infections and subcutaneous lesions in humans. Given the diversity of Photorhabdus species, rapid and reliable methods to resolve this genus to the species level are needed. In this study, we evaluated the potential of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the identification of Photorhabdus species. To this end, we established a collection of 54 isolates consisting of type strains and multiple field strains that belong to each of the validly described species and subspecies of this genus. Reference spectra for the strains were generated and used to complement a currently available database. The extended reference database was then used for identification based on the direct transfer sample preparation method and the protein fingerprint of single colonies. High-level discrimination of distantly related species was observed. However, lower discrimination was observed with some of the most closely related species and subspecies. Our results therefore suggest that MALDI-TOF MS can be used to correctly identify Photorhabdus strains at the genus and species level, but has limited resolution power for closely related species and subspecies. Our study demonstrates the suitability and limitations of MALDI-TOF-based identification methods for assessment of the taxonomic position and identification of Photorhabdus isolates.
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Affiliation(s)
- Virginia Hill
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Switzerland.,Institute of Plant Sciences, University of Bern, Switzerland
| | - Peter Kuhnert
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Switzerland
| | - Matthias Erb
- Institute of Plant Sciences, University of Bern, Switzerland
| | - Ricardo A R Machado
- Experimental Biology Research Group, University of Neuchatel, Switzerland.,Institute of Plant Sciences, University of Bern, Switzerland
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28
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Hummadi EH, Dearden A, Generalovic T, Clunie B, Harrott A, Cetin Y, Demirbek M, Khoja S, Eastwood D, Dudley E, Hazir S, Touray M, Ulug D, Hazal Gulsen S, Cimen H, Butt T. Volatile organic compounds of Metarhizium brunneum influence the efficacy of entomopathogenic nematodes in insect control. BIOLOGICAL CONTROL : THEORY AND APPLICATIONS IN PEST MANAGEMENT 2021; 155:104527. [PMID: 33814871 PMCID: PMC7923176 DOI: 10.1016/j.biocontrol.2020.104527] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 12/03/2020] [Accepted: 12/25/2020] [Indexed: 06/12/2023]
Abstract
The entomopathogenic fungus (EPF) Metarhizium brunneum occupies the same ecological niche as entomopathogenic nematodes (EPN), with both competing for insects as a food source in the rhizosphere. Interactions between these biocontrol agents can be antagonistic or synergistic. To better understand these interactions, this study focussed on investigating the effect of M. brunneum volatile organic compounds (VOCs), 1-octen-3-ol and 3-octanone, on EPN survival and behaviour. These VOCs proved to be highly toxic to the infective juveniles (IJs) of the EPN Steinernema carpocapsae, Steinernema feltiae and Heterorhabditis bacteriophora with mortality being dose dependent. Chemotaxis studies of H. bacteriophora IJs in Pluronic F127 gel revealed significant preference for the VOCs compared with controls for all tested concentrations. The VOCs also impacted on the test insects in a dose-dependent manner with 3-octanone being more toxic to Galleria mellonella, Cydia splendana and Curculio elephas larvae than 1-octen-3-ol. Mortality of C. splendana and G. mellonella larvae was significantly higher when exposed to relatively high doses (>25%) of 3-octanone. Lower doses of 3-octanone and 1-octen-3-ol immobilised test insects, which recovered after exposure to fresh air for 2 hrs. In depth studies on H. bacteriophora showed that exposure of IJs to > 10% concentration of 3-octanone or 1-octen-3-ol negatively affected infectivity whereas exposure to lower doses (0.1%, 0.01%) had no effect. The VOCs affected IJs, reducing penetration efficacy and the number of generations inside G. mellonella but they failed to inhibit the bacterial symbiont, Photorhabdus kayaii. The ecological significance of VOCs and how they could influence EPF-EPN insect interactions is discussed.
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Affiliation(s)
- Esam H. Hummadi
- Department of Biotechnology, College of Science, University of Diyala, Diyala, Iraq
- Department of Biosciences, College of Science, Swansea University, SA2 8PP, UK
| | - Alexander Dearden
- Department of Biosciences, College of Science, Swansea University, SA2 8PP, UK
| | - Tomas Generalovic
- Department of Biosciences, College of Science, Swansea University, SA2 8PP, UK
| | - Benjamin Clunie
- Department of Biosciences, College of Science, Swansea University, SA2 8PP, UK
| | - Alexandria Harrott
- Department of Biosciences, College of Science, Swansea University, SA2 8PP, UK
| | - Yarkin Cetin
- Department of Biosciences, College of Science, Swansea University, SA2 8PP, UK
| | - Merve Demirbek
- Department of Biosciences, College of Science, Swansea University, SA2 8PP, UK
| | - Salim Khoja
- Department of Biosciences, College of Science, Swansea University, SA2 8PP, UK
| | - Dan Eastwood
- Department of Biosciences, College of Science, Swansea University, SA2 8PP, UK
| | - Ed Dudley
- School of Medicine, Swansea University, Singleton Park, SA2 8PP, UK
| | - Selcuk Hazir
- Department of Biology, Faculty of Arts and Sciences, Aydin Adnan Menderes University, Aydin, Turkey
| | - Mustapha Touray
- Department of Biology, Faculty of Arts and Sciences, Aydin Adnan Menderes University, Aydin, Turkey
| | - Derya Ulug
- Department of Biology, Faculty of Arts and Sciences, Aydin Adnan Menderes University, Aydin, Turkey
| | - Sebnem Hazal Gulsen
- Department of Biology, Faculty of Arts and Sciences, Aydin Adnan Menderes University, Aydin, Turkey
| | - Harun Cimen
- Department of Biology, Faculty of Arts and Sciences, Aydin Adnan Menderes University, Aydin, Turkey
| | - Tariq Butt
- Department of Biosciences, College of Science, Swansea University, SA2 8PP, UK
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Gajdos L, Blakeley MP, Kumar A, Wimmerová M, Haertlein M, Forsyth VT, Imberty A, Devos JM. Visualization of hydrogen atoms in a perdeuterated lectin-fucose complex reveals key details of protein-carbohydrate interactions. Structure 2021; 29:1003-1013.e4. [PMID: 33765407 DOI: 10.1016/j.str.2021.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/01/2021] [Accepted: 03/03/2021] [Indexed: 11/30/2022]
Abstract
Carbohydrate-binding proteins from pathogenic bacteria and fungi have been shown to be implicated in various pathological processes, where they interact with glycans present on the surface of the host cells. These interactions are part of the initial processes of infection of the host and are very important to study at the atomic level. Here, we report the room temperature neutron structures of PLL lectin from Photorhabdus laumondii in its apo form and in complex with deuterated L-fucose, which is, to our knowledge, the first neutron structure of a carbohydrate-binding protein in complex with a fully deuterated carbohydrate ligand. A detailed structural analysis of the lectin-carbohydrate interactions provides information on the hydrogen bond network, the role of water molecules, and the extent of the CH-π stacking interactions between fucose and the aromatic amino acids in the binding site.
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Affiliation(s)
- Lukas Gajdos
- Life Sciences Group, Institut Laue-Langevin, 38000 Grenoble, France; Partnership for Structural Biology (PSB), 38000 Grenoble, France; Université Grenoble Alpes, CNRS, CERMAV, 38000 Grenoble, France
| | - Matthew P Blakeley
- Large Scale Structures Group, Institut Laue-Langevin, 38000 Grenoble, France
| | - Atul Kumar
- CEITEC, Masaryk University, 625 00 Brno, Czech Republic; NCBR, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic; Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Michaela Wimmerová
- CEITEC, Masaryk University, 625 00 Brno, Czech Republic; NCBR, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
| | - Michael Haertlein
- Life Sciences Group, Institut Laue-Langevin, 38000 Grenoble, France; Partnership for Structural Biology (PSB), 38000 Grenoble, France
| | - V Trevor Forsyth
- Life Sciences Group, Institut Laue-Langevin, 38000 Grenoble, France; Partnership for Structural Biology (PSB), 38000 Grenoble, France; Faculty of Natural Sciences, Keele University, ST5 5BG Staffordshire, UK
| | - Anne Imberty
- Université Grenoble Alpes, CNRS, CERMAV, 38000 Grenoble, France.
| | - Juliette M Devos
- Life Sciences Group, Institut Laue-Langevin, 38000 Grenoble, France; Partnership for Structural Biology (PSB), 38000 Grenoble, France.
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Bhat AH, Chaubey AK, Shokoohi E, Machado RAR. Molecular and Phenotypic Characterization of Heterorhabditis indica (Nematoda: Rhabditida) Nematodes Isolated During a Survey of Agricultural Soils in Western Uttar Pradesh, India. Acta Parasitol 2021; 66:236-252. [PMID: 32970280 DOI: 10.1007/s11686-020-00279-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 08/31/2020] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Entomopathogenic nematodes (EPNs) are important biocontrol agents of insect pests. To increase the availability of locally adapted entomopathogenic nematode isolates for biocontrol programs, a survey of several agricultural soils in Western Uttar Pradesh, India was conducted. MATERIALS AND METHODS Eight hundred and sixty soil samples from the districts Meerut, Bulandshahr, Baghpat, and Bijnor were collected and examined for the presence of entomopathogenic nematodos using the "Galleria baiting method". Steinernema and Heterorhabditis nematodes were recovered. The isolated Heterorhabditis nematodes were molecularly, and morphologically characterized, and their biocontrol potential was evaluated against Spodoptera litura. Finally, the geographical distribution of entomopathogenic nematodes was studied based on the analysis of ITS GenBank records. RESULTS A small proportion of the collected soil samples were positive for Heterorhabditis and Steinernema nematodes. Twelve soil samples were positive for the presence of Heterorhabditis nematodes, and 29 samples were positive for Steinernema. The Heterorhabditis nematodes were identified as Heterorhabditis indica based on morphological, morphometrical and molecular analyses. No other species of Heterorhabditis were isolated from the soil samples analyzed, suggesting that this species is dominant in the western part of Uttar Pradesh, India. The morphology of the nematode isolates was somewhat similar to the morphology of the H. indica isolate used for the original description of this species, with a notable exception mucrons were present in the hermaphrodite and female specimens we collected, but this structure was not observed in the specimens used for the original description of the species. Principal component analyses (PCA) show small inter- and intraspecific morphological variability between the nematodes species of the "Indica" clade. The insecticide properties of one isolate, CH7, were evaluated against Spodoptera litura, and the results show that this isolate effectively killed this pest under laboratory conditions, demonstrating its potential as a biocontrol agent. CONCLUSION This study sets the basis for establishing new biocontrol agents to be used in future pest management programs in India.
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Affiliation(s)
- Aashaq Hussain Bhat
- Nematology Laboratory, Department of Zoology, Chaudhary Charan Singh University, Meerut, 250004, India.
- Department of Zoology, Government Degree College Billawar-184204, University of Jammu, Billawar, Jammu, Jammu and Kashmir, India.
| | - Ashok Kumar Chaubey
- Nematology Laboratory, Department of Zoology, Chaudhary Charan Singh University, Meerut, 250004, India
| | - Ebrahim Shokoohi
- Green Biotechnologies Research Centre of Excellence, University of Limpopo, Private Bag X1106, Sovenga, 0727, Republic of South Africa
| | - Ricardo A R Machado
- Experimental Biology Research Group, Institute of Biology, University of Neuchatel, 2000, Neuchatel, Switzerland
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31
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Munson E, Carroll KC. Summary of Novel Bacterial Isolates Derived from Human Clinical Specimens and Nomenclature Revisions Published in 2018 and 2019. J Clin Microbiol 2021; 59:e01309-20. [PMID: 32967902 PMCID: PMC8111135 DOI: 10.1128/jcm.01309-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Knowledge of novel prokaryotic taxon discovery and nomenclature revisions is of importance to clinical microbiology laboratory practice, infectious disease epidemiology, and studies of microbial pathogenesis. Relative to bacterial isolates derived from human clinical specimens, we present an in-depth summary of novel taxonomic designations and revisions to prokaryotic taxonomy that were published in 2018 and 2019. Included are several changes pertinent to former designations of or within Propionibacterium spp., Corynebacterium spp., Clostridium spp., Mycoplasma spp., Methylobacterium spp., and Enterobacteriaceae Future efforts to ascertain clinical relevance for many of these changes may be augmented by a document development committee that has been appointed by the Clinical and Laboratory Standards Institute.
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Affiliation(s)
- Erik Munson
- College of Health Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Karen C Carroll
- Division of Medical Microbiology, Department of Pathology, the Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Machado RAR, Muller A, Ghazal SM, Thanwisai A, Pagès S, Bode HB, Hussein MA, Khalil KM, Tisa LS. Photorhabdus heterorhabditis subsp. aluminescens subsp. nov., Photorhabdus heterorhabditis subsp. heterorhabditis subsp. nov., Photorhabdus australis subsp. thailandensis subsp. nov., Photorhabdus australis subsp. australis subsp. nov., and Photorhabdus aegyptia sp. nov. isolated from Heterorhabditis entomopathogenic nematodes. Int J Syst Evol Microbiol 2021; 71. [PMID: 33464198 DOI: 10.1099/ijsem.0.004610] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Three Gram-stain-negative, rod-shaped, non-spore-forming bacteria, BA1T, Q614T and PB68.1T, isolated from the digestive system of Heterorhabditis entomopathogenic nematodes, were biochemically and molecularly characterized to clarify their taxonomic affiliations. The 16S rRNA gene sequences of these strains suggest that they belong to the Gammaproteobacteria, to the family Morganellacea, and to the genus Photorhabdus. Deeper analyses using whole genome-based phylogenetic reconstructions suggest that BA1T is closely related to Photorhabdus akhursti, that Q614T is closely related to Photorhabdus heterorhabditis, and that PB68.1T is closely related to Photorhabdus australis. In silico genomic comparisons confirm these observations: BA1T and P. akhursti 15138T share 68.8 % digital DNA-DNA hybridization (dDDH), Q614T and P. heterorhabditis SF41T share 75.4 % dDDH, and PB68.1T and P. australis DSM 17609T share 76.6 % dDDH. Physiological and biochemical characterizations reveal that these three strains also differ from all validly described Photorhabdus species and from their more closely related taxa, contrary to what was previously suggested. We therefore propose to classify BA1T as a new species within the genus Photorhabdus, Q614T as a new subspecies within P. heterorhabditis, and PB68.1T as a new subspecies within P. australis. Hence, the following names are proposed for these strains: Photorhabdus aegyptia sp. nov. with the type strain BA1T(=DSM 111180T=CCOS 1943T=LMG 31957T), Photorhabdus heterorhabditis subsp. aluminescens subsp. nov. with the type strain Q614T (=DSM 111144T=CCOS 1944T=LMG 31959T) and Photorhabdus australis subsp. thailandensis subsp. nov. with the type strain PB68.1T (=DSM 111145T=CCOS 1942T). These propositions automatically create Photorhabdus heterorhabditis subsp. heterorhabditis subsp. nov. with SF41T as the type strain (currently classified as P. heterorhabditis) and Photorhabdus australis subsp. australis subsp. nov. with DSM17609T as the type strain (currently classified as P. australis).
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Affiliation(s)
- Ricardo A R Machado
- Experimental Biology Research Group, Institute of Biology. University of Neuchâtel, Neuchâtel, Switzerland
| | - Arthur Muller
- Experimental Biology Research Group, Institute of Biology. University of Neuchâtel, Neuchâtel, Switzerland
| | - Shimaa M Ghazal
- Genetics and Cytology Department, Genetic Engineering and Biotechnology Division, National Research Center, Cairo, Egypt.,Department of Biological Sciences, University of New Hampshire, Durham, New Hampshire, USA
| | - Aunchalee Thanwisai
- Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Sylvie Pagès
- INRAe, Université de Montpellier, UMR1333-DGIMI, 34095 Montpellier Cedex 05, France
| | - Helge B Bode
- Molekulare Biotechnologie, Fachbereich Biowissenschaften & Buchmann Institute for Molecular Life Sciences (BMLS), Goethe-Universität Frankfurt am Main & Senckenberg Gesellschaft für Naturforschung, Frankfurt, Germany
| | - Mona A Hussein
- Department of Pests and Plant Protection, Agricultural and Biological Division, National Research Centre, Dokki, Cairo, Egypt
| | - Kamal M Khalil
- Genetics and Cytology Department, Genetic Engineering and Biotechnology Division, National Research Center, Cairo, Egypt
| | - Louis S Tisa
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, USA
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Maher AMD, Asaiyah M, Quinn S, Burke R, Wolff H, Bode HB, Griffin CT. Competition and Co-existence of Two Photorhabdus Symbionts with a Nematode Host. MICROBIAL ECOLOGY 2021; 81:223-239. [PMID: 32827089 DOI: 10.1007/s00248-020-01573-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 08/05/2020] [Indexed: 06/11/2023]
Abstract
Photorhabdus spp. (Enterobacteriales: Morganellaceae) occur exclusively as symbionts of Heterorhabditis nematodes for which they provide numerous services, including killing insects and providing nutrition and defence within the cadavers. Unusually, two species (Photorhabdus cinerea and Photorhabdus temperata) associate with a single population of Heterorhabditis downesi at a dune grassland site. Building on previous work, we investigated competition between these two Photorhabdus species both at the regional (between insects) and local (within insect) level by trait comparison and co-culture experiments. There was no difference between the species with respect to supporting nematode reproduction and protection of cadavers against invertebrate scavengers, but P. cinerea was superior to P. temperata in several traits: faster growth rate, greater antibacterial and antifungal activity and colonisation of a higher proportion of nematodes in co-culture. Moreover, where both bacterial symbionts colonised single nematode infective juveniles, P. cinerea tended to dominate in numbers. Differences between Photorhabdus species were detected in the suite of secondary metabolites produced: P. temperata produced several compounds not produced by P. cinerea including anthraquinone pigments. Bioluminescence emitted by P. temperata also tended to be brighter than that from P. cinerea. Bioluminescence and pigmentation may protect cadavers against scavengers that rely on sight. We conclude that while P. cinerea may show greater local level (within-cadaver) competitive success, co-existence of the two Photorhabdus species in the spatially heterogeneous environment of the dunes is favoured by differing specialisations in defence of the cadaver against differing locally important threats.
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Affiliation(s)
- Abigail M D Maher
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | - Mohamed Asaiyah
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | - Sarajane Quinn
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | - Riona Burke
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland
| | - Hendrik Wolff
- Molecular Biotechnology, Department of Biosciences, Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, and Senckenberg Gesellschaft für Naturforschung, Frankfurt, Germany
| | - Helge B Bode
- Molecular Biotechnology, Department of Biosciences, Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, and Senckenberg Gesellschaft für Naturforschung, Frankfurt, Germany
| | - Christine T Griffin
- Department of Biology, Maynooth University, Maynooth, County Kildare, Ireland.
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A toxin complex protein from Photorhabdus akhurstii conferred oral insecticidal activity against Galleria mellonella by targeting the midgut epithelium. Microbiol Res 2020; 242:126642. [PMID: 33191102 DOI: 10.1016/j.micres.2020.126642] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/16/2020] [Accepted: 10/30/2020] [Indexed: 02/08/2023]
Abstract
The nematode-bacterium pair Heterorhabditis indica-Photorhabdus akhurstii is a malleable model system to investigate mutualistic relations. A number of toxins produced by P. akhurstii allow the bacterium to kill the insect host. However, a few of these heterologously expressed toxins are orally active against different insects which possibly caused neglected attention to Photorhabdus toxins compared to Bt (Bacillus thuringiensis). In the current study, a functional subunit of orally active toxin complex (Tc) protein, TcaB (63 kDa), isolated from two strains of P. akhurstii namely IARI-SGHR2 and IARI-SGMS1, was tested for biological activity against Galleria mellonella. A force feeding-based administration of the toxin translated into LD50 values of 45.63-58.90 ng/g which was even lower compared to injection LD50 values (51.48-64.30 ng/g) at 48 h after inoculation. An oral uptake of 500 ng toxin caused extensive gut damage in G. mellonella during 6-24 h incubation period coupled with a gradual disruption of gut integrity leading to escape of TcaB into the hemocoel. This finding was supported by the cytotoxic and immune-stimulatory effect of TcaB in the insect hemocoel at 6-24 h after force feeding. The circulatory hemocyte numbers and cell viability was markedly reduced to 0.66-0.68 × 106 ml-1 and 49-52 %, respectively, in TcaB force fed insect at 24 h, compared to control (2.55 × 106 ml-1; 100 %). The hemolymph phenoloxidase (PO) activity was elevated by 10.2-fold in force fed larvae than control at 24 h. An in silico docking study revealed that TcaB putatively interacts with a number of G. mellonella receptor proteins in order to become a gut-active toxin. Present research reinforces the potential of gut-active Photorhabdus toxins for their inclusion in sustainable insect management tactics and strengthens the existing Bt-dominated management repository.
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35
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Hapeshi A, Healey JRJ, Mulley G, Waterfield NR. Temperature Restriction in Entomopathogenic Bacteria. Front Microbiol 2020; 11:548800. [PMID: 33101227 PMCID: PMC7554251 DOI: 10.3389/fmicb.2020.548800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 09/08/2020] [Indexed: 11/21/2022] Open
Abstract
Temperature plays an important role in bacteria-host interactions and can be a determining factor for host switching. In this study we sought to investigate the reasons behind growth temperature restriction in the entomopathogenic enterobacterium Photorhabdus. Photorhabdus has a complex dual symbiotic and pathogenic life cycle. The genus consists of 19 species but only one subgroup, previously all classed together as Photorhabdus asymbiotica, have been shown to cause human disease. These clinical isolates necessarily need to be able to grow at 37°C, whilst the remaining species are largely restricted to growth temperatures below 34°C and are therefore unable to infect mammalian hosts. Here, we have isolated spontaneous mutant lines of Photorhabdus laumondii DJC that were able to grow up to 36-37°C. Following whole genome sequencing of 29 of these mutants we identified a single gene, encoding a protein with a RecG-like helicase domain that for the majority of isolates contained single nucleotide polymorphisms. Importantly, provision of the wild-type allele of this gene in trans restored the temperature restriction, confirming the mutations are recessive, and the dominant effect of the protein product of this gene. The gene appears to be part of a short three cistron operon, which we have termed the Temperature Restricting Locus (TRL). Transcription reporter strains revealed that this operon is induced upon the switch from 30 to 36°C, leading to replication arrest of the bacteria. TRL is absent from all of the human pathogenic species so far examined, although its presence is not uniform in different strains of the Photorhabdus luminescens subgroup. In a wider context, the presence of this gene is not limited to Photorhabdus, being found in phylogenetically diverse proteobacteria. We therefore suggest that this system may play a more fundamental role in temperature restriction in diverse species, relating to as yet cryptic aspects of their ecological niches and life cycle requirements.
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Affiliation(s)
- Alexia Hapeshi
- Microbiology and Infection Unit, Warwick Medical School, The University of Warwick, Coventry, United Kingdom
| | - Joseph R. J. Healey
- Microbiology and Infection Unit, Warwick Medical School, The University of Warwick, Coventry, United Kingdom
| | - Geraldine Mulley
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Nicholas R. Waterfield
- Microbiology and Infection Unit, Warwick Medical School, The University of Warwick, Coventry, United Kingdom
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Fujdiarová E, Houser J, Dobeš P, Paulíková G, Kondakov N, Kononov L, Hyršl P, Wimmerová M. Heptabladed β‐propeller lectins PLL2 and PHL from
Photorhabdus
spp. recognize
O
‐methylated sugars and influence the host immune system. FEBS J 2020; 288:1343-1365. [DOI: 10.1111/febs.15457] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 04/19/2020] [Accepted: 06/15/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Eva Fujdiarová
- Central European Institute of Technology (CEITEC) Masaryk University Brno Czech Republic
- National Centre for Biomolecular Research Faculty of Science Masaryk University Brno Czech Republic
| | - Josef Houser
- Central European Institute of Technology (CEITEC) Masaryk University Brno Czech Republic
- National Centre for Biomolecular Research Faculty of Science Masaryk University Brno Czech Republic
| | - Pavel Dobeš
- National Centre for Biomolecular Research Faculty of Science Masaryk University Brno Czech Republic
- Section of Animal Physiology and Immunology Department of Experimental Biology Faculty of Science Masaryk University Brno Czech Republic
| | - Gita Paulíková
- Central European Institute of Technology (CEITEC) Masaryk University Brno Czech Republic
- National Centre for Biomolecular Research Faculty of Science Masaryk University Brno Czech Republic
| | - Nikolay Kondakov
- N.D. Zelinsky Institute of Organic Chemistry Russian Academy of Sciences Moscow Russia
| | - Leonid Kononov
- N.D. Zelinsky Institute of Organic Chemistry Russian Academy of Sciences Moscow Russia
| | - Pavel Hyršl
- Section of Animal Physiology and Immunology Department of Experimental Biology Faculty of Science Masaryk University Brno Czech Republic
| | - Michaela Wimmerová
- Central European Institute of Technology (CEITEC) Masaryk University Brno Czech Republic
- National Centre for Biomolecular Research Faculty of Science Masaryk University Brno Czech Republic
- Department of Biochemistry Faculty of Science Masaryk University Brno Czech Republic
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Dutta TK, Mathur C, Mandal A, Somvanshi VS. The differential strain virulence of the candidate toxins of Photorhabdus akhurstii can be correlated with their inter-strain gene sequence diversity. 3 Biotech 2020; 10:299. [PMID: 32550116 DOI: 10.1007/s13205-020-02288-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 06/01/2020] [Indexed: 02/06/2023] Open
Abstract
Photorhabdus akhurstii is an insect-parasitic bacterium that symbiotically associates with the nematode, Heterorhabditis indica. The bacterium possesses several pathogenicity islands that aids in conferring toxicity to different insects. Herein, we constructed the plasmid clones of coding sequences of four toxin genes (pirA, tcaA, tccA and tccC; each was isolated from four P. akhurstii strains IARI-SGMG3, IARI-SGGJ2, IARI-SGHR2 and IARI-SGMS1) in Escherichia coli and subsequently, their biological activity were investigated against the fourth-instar larvae of the model insect, Galleria mellonella via intra-hemocoel injection. Bioinformatics analyses indicated inter-strain amino acid sequence difference at several positions of the candidate toxins. In corroboration, differential insecticidal activity of the identical toxin protein (PirA, TcaA, TccA and TccC conferred 15-59, 27-100, 25-100 and 33-98% insect mortality, respectively, across the strains) derived from the different bacterial strains was observed, suggesting that the diverse gene pool in Indian strains of P. akhurstii leads to strain-specific virulence in this bacterium. These toxin candidates appear to be an attractive option to deploy them in biopesticide development for managing the insect pests globally.
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Affiliation(s)
- Tushar K Dutta
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | - Chetna Mathur
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | - Abhishek Mandal
- Division of Agricultural Chemicals, ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | - Vishal S Somvanshi
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
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Shankhu PY, Mathur C, Mandal A, Sagar D, Somvanshi VS, Dutta TK. Txp40, a protein from Photorhabdus akhurstii, conferred potent insecticidal activity against the larvae of Helicoverpa armigera, Spodoptera litura and S. exigua. PEST MANAGEMENT SCIENCE 2020; 76:2004-2014. [PMID: 31867818 DOI: 10.1002/ps.5732] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/28/2019] [Accepted: 12/22/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Txp40, a 37 kDa protein, previously characterized from the Gram-negative bacterium Photorhabdus akhurstii (symbiotically associates with insect-parasitic nematode, Heterorhabditis indica), conferred insecticidal activity against Galleria mellonella. Here, the biological activity of Txp40 was evaluated against economically important insects, including Helicoverpa armigera, Spodoptera litura and S. exigua. RESULTS When both intra-hemocoel injected and orally fed to test insects, comparatively greater oral LD50 (187.7-522 ng g-1 ) than injection LD50 (32.33-150.6 ng g-1 ) was obtained with Txp40 derived from P. akhurstii strain IARI-SGMG3. Injection of purified Txp40 caused a dose-dependent reduction in the total circulatory hemocytes and hemocyte viability of fourth-instar larvae of the test insects at 12 h post incubation; unlike healthy cells toxin-treated ones displayed aggregated distribution. Injection of Txp40 significantly elevated the phenoloxidase activity of insect hemolymph, which potentially led to unrestrained melanization reaction and ultimately larval death. Histological analyses showed the primary site of action of Txp40 in the insect midgut. Extensive damage to midgut epithelium 24 h after injection of the Txp40 explains the access of the toxin from hemocoel to midgut via leaky septate junctions. In silico analyses suggested that Txp40 can potentially interact with H. armigera midgut receptor proteins cadherin, ATP-binding cassettes, aminopeptidase N1 and alkaline phosphatase to exert toxicity. CONCLUSION We propose Txp40 as an attractive alternative to Cry toxins of Bacillus thuringiensis, the transgenic expression of which is reported to cause resistance development in insects. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Prakash Y Shankhu
- Division of Nematology, ICAR - Indian Agricultural Research Institute, New Delhi, India
| | - Chetna Mathur
- Division of Nematology, ICAR - Indian Agricultural Research Institute, New Delhi, India
| | - Abhishek Mandal
- Division of Agricultural Chemicals, ICAR - Indian Agricultural Research Institute, New Delhi, India
| | - Doddachowdappa Sagar
- Division of Entomology, ICAR - Indian Agricultural Research Institute, New Delhi, India
| | - Vishal S Somvanshi
- Division of Nematology, ICAR - Indian Agricultural Research Institute, New Delhi, India
| | - Tushar K Dutta
- Division of Nematology, ICAR - Indian Agricultural Research Institute, New Delhi, India
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Bruno P, Machado RAR, Glauser G, Köhler A, Campos-Herrera R, Bernal J, Toepfer S, Erb M, Robert CAM, Arce CCM, Turlings TCJ. Entomopathogenic nematodes from Mexico that can overcome the resistance mechanisms of the western corn rootworm. Sci Rep 2020; 10:8257. [PMID: 32427834 PMCID: PMC7237494 DOI: 10.1038/s41598-020-64945-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 02/28/2020] [Indexed: 12/30/2022] Open
Abstract
Natural enemies of herbivores are expected to adapt to the defence strategies of their preys or hosts. Such adaptations may also include their capacity to cope with plant metabolites that herbivores sequester as a defence. In this study, we evaluated the ability of Mexican entomopathogenic nematodes (EPN) to resist benzoxazinoids that are sequestered from maize roots by the western corn rootworm (WCR, Diabrotica virgifera virgifera; Coleoptera: Chrysomelidae), an important maize pest in America and Europe. From maize fields throughout Mexico, we retrieved 40 EPN isolates belonging to five different species, with a majority identified as Heterorhabditis bacteriophora. In the laboratory, all nematodes readily infected non-sequestering larvae of the banded cucumber beetle (D. balteata), while infectivity varied strongly for WCR larvae. While some H. bacteriophora isolates seemed negatively affected by benzoxazinoids, most showed to be resistant. Thus, EPN from Mexican maize fields can cope with these plant defence metabolites, but the results also indicate that WCR larvae possess other mechanisms that help to resist EPN. This work contributes to a better understanding of the capacity of herbivore natural enemies to resist plant defence metabolites. Furthermore, it identifies several benzoxazinoid-resistant EPN isolates that may be used to control this important maize pest.
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Affiliation(s)
- Pamela Bruno
- Laboratory of Fundamental and Applied Research in Chemical Ecology, University of Neuchâtel, Emile-Argand 11, 2000, Neuchâtel, Switzerland
| | | | - Gaétan Glauser
- Neuchâtel Platform of Analytical Chemistry, University of Neuchâtel, Neuchâtel, Switzerland
| | - Angela Köhler
- Laboratory of Fundamental and Applied Research in Chemical Ecology, University of Neuchâtel, Emile-Argand 11, 2000, Neuchâtel, Switzerland
- Friedrich Schiller University Jena, Jena, Germany
| | - Raquel Campos-Herrera
- Instituto de Ciencias de la Vid y del Vino (Universidad de La Rioja, CSIC, Gobierno de La Rioja), Logroño, La Rioja, Spain
| | - Julio Bernal
- Department of Entomology, Texas A&M University, Texas, USA
| | - Stefan Toepfer
- CABI, c/o Plant Protection and Soil Conservation Directorate, Hódmezővásárhely, Hungary
| | - Matthias Erb
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | | | - Carla C M Arce
- Laboratory of Fundamental and Applied Research in Chemical Ecology, University of Neuchâtel, Emile-Argand 11, 2000, Neuchâtel, Switzerland.
| | - Ted C J Turlings
- Laboratory of Fundamental and Applied Research in Chemical Ecology, University of Neuchâtel, Emile-Argand 11, 2000, Neuchâtel, Switzerland.
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Abstract
Different model systems have, over the years, contributed to our current understanding of the molecular mechanisms underpinning the various types of interaction between bacteria and their animal hosts. The genus
Photorhabdus
comprises Gram-negative insect pathogenic bacteria that are normally found as symbionts that colonize the gut of the infective juvenile stage of soil-dwelling nematodes from the family Heterorhabditis. The nematodes infect susceptible insects and release the bacteria into the insect haemolymph where the bacteria grow, resulting in the death of the insect. At this stage the nematodes feed on the bacterial biomass and, following several rounds of reproduction, the nematodes develop into infective juveniles that leave the insect cadaver in search of new hosts. Therefore
Photorhabdus
has three distinct and obligate roles to play during this life-cycle: (1)
Photorhabdus
must kill the insect host; (2)
Photorhabdus
must be capable of supporting nematode growth and development; and (3)
Photorhabdus
must be able to colonize the gut of the next generation of infective juveniles before they leave the insect cadaver. In this review I will discuss how genetic analysis has identified key genes involved in mediating, and regulating, the interaction between
Photorhabdus
and each of its invertebrate hosts. These studies have resulted in the characterization of several new families of toxins and a novel inter-kingdom signalling molecule and have also uncovered an important role for phase variation in the regulation of these different roles.
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Affiliation(s)
- David J Clarke
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland
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41
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Janda JM. Proposed nomenclature or classification changes for bacteria of medical importance: taxonomic update 5. Diagn Microbiol Infect Dis 2020; 97:115047. [PMID: 32321664 DOI: 10.1016/j.diagmicrobio.2020.115047] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/21/2020] [Accepted: 03/23/2020] [Indexed: 01/23/2023]
Abstract
A key aspect of medical, public health, and diagnostic microbiology laboratories is the accurate identification and rapid reporting and communication to medical staff regarding patients with infectious agents of clinical importance. Microbial taxonomy continues to change at a very rapid rate in the era of molecular diagnostics including whole genome sequencing. This update focuses on taxonomic changes and proposals that may be of medical importance from 2018 to 2020.
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Affiliation(s)
- J Michael Janda
- Public Health Laboratory, Public Health Services Department, Kern County, Bakersfield, CA 93306-3302.
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42
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Engineering bacterial symbionts of nematodes improves their biocontrol potential to counter the western corn rootworm. Nat Biotechnol 2020; 38:600-608. [PMID: 32066956 DOI: 10.1038/s41587-020-0419-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 01/10/2020] [Indexed: 01/18/2023]
Abstract
The western corn rootworm (WCR) decimates maize crops worldwide. One potential way to control this pest is treatment with entomopathogenic nematodes (EPNs) that harbor bacterial symbionts that are pathogenic to insects. However, WCR larvae sequester benzoxazinoid secondary metabolites that are produced by maize and use them to increase their resistance to the nematodes and their symbionts. Here we report that experimental evolution and selection for bacterial symbionts that are resistant to benzoxazinoids improve the ability of a nematode-symbiont pair to kill WCR larvae. We isolated five Photorhabdus symbionts from different nematodes and increased their benzoxazinoid resistance through experimental evolution. Benzoxazinoid resistance evolved through multiple mechanisms, including a mutation in the aquaporin-like channel gene aqpZ. We reintroduced benzoxazinoid-resistant Photorhabdus strains into their original EPN hosts and identified one nematode-symbiont pair that was able to kill benzoxazinoid-sequestering WCR larvae more efficiently. Our results suggest that modification of bacterial symbionts might provide a generalizable strategy to improve biocontrol of agricultural pests.
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43
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Sajnaga E, Kazimierczak W. Evolution and taxonomy of nematode-associated entomopathogenic bacteria of the genera Xenorhabdus and Photorhabdus: an overview. Symbiosis 2020. [DOI: 10.1007/s13199-019-00660-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
AbstractEntomopathogenic bacteria from the genera Photorhabdus and Xenorhabdus are closely related Gram-negative bacilli from the family Enterobacteriaceae (γ-Proteobacteria). They establish obligate mutualistic associations with soil nematodes from the genera Steinernema and Heterorhabditis to facilitate insect pathogenesis. The research of these two bacterial genera is focused mainly on their unique interactions with two different animal hosts, i.e. nematodes and insects. So far, studies of the mutualistic bacteria of nematodes collected from around the world have contributed to an increase in the number of the described Xenorhabdus and Photorhabdus species. Recently, the classification system of entomopatogenic nematode microsymbionts has undergone profound revision and now 26 species of the genus Xenorhabdus and 19 species of the genus Photorhabdus have been identified. Despite their similar life style and close phylogenetic origin, Photorhabdus and Xenorhabdus bacterial species differ significantly in e.g. the nematode host range, symbiotic strategies for parasite success, and arrays of released antibiotics and insecticidal toxins. As the knowledge of the diversity of entomopathogenic nematode microsymbionts helps to enable the use thereof, assessment of the phylogenetic relationships of these astounding bacterial genera is now a major challenge for researchers. The present article summarizes the main information on the taxonomy and evolutionary history of Xenorhabdus and Photorhabdus, entomopathogenic nematode symbionts.
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44
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Eckstein S, Heermann R. Regulation of Phenotypic Switching and Heterogeneity in Photorhabdus luminescens Cell Populations. J Mol Biol 2019; 431:4559-4568. [DOI: 10.1016/j.jmb.2019.04.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/22/2019] [Accepted: 04/12/2019] [Indexed: 11/26/2022]
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Abstract
Certain adapted insect herbivores utilize plant toxins for self-defense against their own enemies. These adaptations structure ecosystems and limit our capacity to use biological control agents to manage specialized agricultural pests. We show that entomopathogenic nematodes that are exposed to the western corn rootworm, an important agricultural pest that sequesters defense metabolites from maize, can evolve resistance to these defenses. Resisting the plant defense metabolites likely allows the nematodes to infect and kill the western corn rootworm more efficiently. These findings illustrate how predators can counter the plant-based resistance strategies of specialized insect herbivores. Breeding or engineering biological control agents that resist plant defense metabolites may improve their capacity to kill important agricultural pests such as the western corn rootworm. Plants defend themselves against herbivores through the production of toxic and deterrent metabolites. Adapted herbivores can tolerate and sometimes sequester these metabolites, allowing them to feed on defended plants and become toxic to their own enemies. Can herbivore natural enemies overcome sequestered plant defense metabolites to prey on adapted herbivores? To address this question, we studied how entomopathogenic nematodes cope with benzoxazinoid defense metabolites that are produced by grasses and sequestered by a specialist maize herbivore, the western corn rootworm. We find that nematodes from US maize fields in regions in which the western corn rootworm was present over the last 50 y are behaviorally and metabolically resistant to sequestered benzoxazinoids and more infective toward the western corn rootworm than nematodes from other parts of the world. Exposure of a benzoxazinoid-susceptible nematode strain to the western corn rootworm for 5 generations results in higher behavioral and metabolic resistance and benzoxazinoid-dependent infectivity toward the western corn rootworm. Thus, herbivores that are exposed to a plant defense sequestering herbivore can evolve both behavioral and metabolic resistance to plant defense metabolites, and these traits are associated with higher infectivity toward a defense sequestering herbivore. We conclude that plant defense metabolites that are transferred through adapted herbivores may result in the evolution of resistance in herbivore natural enemies. Our study also identifies plant defense resistance as a potential target for the improvement of biological control agents.
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46
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Fucosylated inhibitors of recently identified bangle lectin from Photorhabdus asymbiotica. Sci Rep 2019; 9:14904. [PMID: 31624296 PMCID: PMC6797808 DOI: 10.1038/s41598-019-51357-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 09/30/2019] [Indexed: 02/06/2023] Open
Abstract
A recently described bangle lectin (PHL) from the bacterium Photorhabdus asymbiotica was identified as a mainly fucose-binding protein that could play an important role in the host-pathogen interaction and in the modulation of host immune response. Structural studies showed that PHL is a homo-dimer that contains up to seven l-fucose-specific binding sites per monomer. For these reasons, potential ligands of the PHL lectin: α-l-fucopyranosyl-containing mono-, di-, tetra-, hexa- and dodecavalent ligands were tested. Two types of polyvalent structures were investigated – calix[4]arenes and dendrimers. The shared feature of all these structures was a C-glycosidic bond instead of the more common but physiologically unstable O-glycosidic bond. The inhibition potential of the tested structures was assessed using different techniques – hemagglutination, surface plasmon resonance, isothermal titration calorimetry, and cell cross-linking. All the ligands proved to be better than free l-fucose. The most active hexavalent dendrimer exhibited affinity three orders of magnitude higher than that of standard l-fucose. To determine the binding mode of some ligands, crystal complex PHL/fucosides 2 – 4 were prepared and studied using X-ray crystallography. The electron density in complexes proved the presence of the compounds in 6 out of 7 fucose-binding sites.
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47
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Damascena AP, Ferreira JCA, Costa MGS, de Araujo Junior LM, Wilcken SRS. Hatching and Mortality of Meloidogyne enterolobii Under the Interference of Entomopathogenic Nematodes In vitro. J Nematol 2019; 51:e2019-58. [PMID: 34179792 PMCID: PMC6909014 DOI: 10.21307/jofnem-2019-058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Plant parasitic nematodes have become one of the main problems in the tomato cultivation. Among these, Meloidogyne enterolobii presents great challenges to the farmer, since it is a polyphagous species and difficult to control. The entomopathogenic nematodes (EPNs) present as potential for biological control of this pathogen. The objective of the study was to evaluate the interference of EPNs S. brazilense, S. feltiae, S. rarum, H. amazonensis and H. bacteriophora on hatching and mortality of M. enterolobii. 500 eggs of this nematode and 1.000 infective juveniles of each EPN species were placed in a plastic pot totaling 25 mL of suspension and kept in an incubator at 25°C. The number of juveniles hatched in the suspension was counted every 2 days, until 10 days. After 10 days of evaluations, the remaining suspension (15 mL) containing M. enterolobii and EPNs was inoculated into Rutgers tomato seedlings. The suspension contained approximately in 300 eggs of M. enterolobii occasional juveniles and 600 IJ of each nematode species. Sixty days after inoculation were evaluated gall indexes, egg mass indexes, total number of eggs and juveniles of M. enterolobii and reproductive factor was calculated. In the mortality experiment, 500 infective juveniles of M. enterolobii and 1.000 juveniles of each EPN species were placed in a plastic pot totaling 25 mL of suspension. The evaluation of juvenile mortality was performed by counting of the mobile and immotile nematodes, by adding two drops of NaOH to the nematode suspension. It was verified that on the 10th day all ENPs provided reduction in the hatching of M. enterolobii. In the pot experiment it was found thato gall index, egg mass indexm, nematodes total number and reproduction factor were significantly reduced in treatments with all species of EPNs tested. However, in the mortality test, only EPNs S. brazilense and S. rarum provided mortality on the second day and H. bacteriophora affected mortality on the 4th day. In the other evaluations, there was no statistical difference. The results highlight the potential of the use of EPNs in programs of integrated management of M. enterolobii in tomato.
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Affiliation(s)
- Alixelhe Pacheco Damascena
- Universidade Estadual Paulista (UNESP), Faculty of Agronomic Sciences, Department of Plant Protection, 18610-034, Botucatu, São Paulo, Brazil
| | - Júlio César Antunes Ferreira
- Universidade Estadual Paulista (UNESP), Faculty of Agronomic Sciences, Department of Plant Protection, 18610-034, Botucatu, São Paulo, Brazil
| | - Marylia Gabriella Silva Costa
- Universidade Estadual Paulista (UNESP), Faculty of Agronomic Sciences, Department of Plant Protection, 18610-034, Botucatu, São Paulo, Brazil
| | - Luis Moreira de Araujo Junior
- University Federal of Espírito Santo - UFES, Department of Agronomy, Laboratory of Entomology/NUDEMAFI, Alegre, ES, Brazil
| | - Silvia Renata Siciliano Wilcken
- Universidade Estadual Paulista (UNESP), Faculty of Agronomic Sciences, Department of Plant Protection, 18610-034, Botucatu, São Paulo, Brazil
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48
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Vlisidou I, Hapeshi A, Healey JR, Smart K, Yang G, Waterfield NR. The Photorhabdus asymbiotica virulence cassettes deliver protein effectors directly into target eukaryotic cells. eLife 2019; 8:46259. [PMID: 31526474 PMCID: PMC6748792 DOI: 10.7554/elife.46259] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/12/2019] [Indexed: 01/19/2023] Open
Abstract
Photorhabdus is a highly effective insect pathogen and symbiont of insecticidal nematodes. To exert its potent insecticidal effects, it elaborates a myriad of toxins and small molecule effectors. Among these, the Photorhabdus Virulence Cassettes (PVCs) represent an elegant self-contained delivery mechanism for diverse protein toxins. Importantly, these self-contained nanosyringes overcome host cell membrane barriers, and act independently, at a distance from the bacteria itself. In this study, we demonstrate that Pnf, a PVC needle complex associated toxin, is a Rho-GTPase, which acts via deamidation and transglutamination to disrupt the cytoskeleton. TEM and Western blots have shown a physical association between Pnf and its cognate PVC delivery mechanism. We demonstrate that for Pnf to exert its effect, translocation across the cell membrane is absolutely essential.
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Affiliation(s)
- Isabella Vlisidou
- All Wales Genetics Laboratory, Institute of Medical Genetics, University Hospital of Wales, Cardiff, United Kingdom
| | - Alexia Hapeshi
- Warwick Medical School, Warwick University, Coventry, United Kingdom
| | - Joseph Rj Healey
- Warwick Medical School, Warwick University, Coventry, United Kingdom
| | - Katie Smart
- Warwick Medical School, Warwick University, Coventry, United Kingdom
| | - Guowei Yang
- Beijing Friendship Hospital, Capital Medical University, Beijing, China
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Zhang X, Machado RA, Doan CV, Arce CC, Hu L, Robert CA. Entomopathogenic nematodes increase predation success by inducing cadaver volatiles that attract healthy herbivores. eLife 2019; 8:46668. [PMID: 31509107 PMCID: PMC6739876 DOI: 10.7554/elife.46668] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 08/24/2019] [Indexed: 12/28/2022] Open
Abstract
Herbivore natural enemies protect plants by regulating herbivore populations. Whether they can alter the behavior of their prey to increase predation success is unknown. We investigate if and how infection by the entomopathogenic nematode Heterorhabditis bacteriophora changes the behavior of healthy larvae of the western corn rootworm (Diabrotica virgifera), a major pest of maize. We found that nematode-infected rootworm cadavers are attractive to rootworm larvae, and that this behavior increases nematode reproductive success. Nematode-infected rootworms release distinct volatile bouquets, including the unusual volatile butylated hydroxytoluene (BHT). BHT alone attracts rootworms, and increases nematode reproductive success. A screen of different nematode and herbivore species shows that attraction of healthy hosts to nematode-infected cadavers is widespread and likely involves species-specific volatile cues. This study reveals a new facet of the biology of herbivore natural enemies that boosts their predation success by increasing the probability of host encounters.
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Affiliation(s)
- Xi Zhang
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | | | - Cong Van Doan
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Carla Cm Arce
- Institute of Biology, University of Neuchatel, Neuchatel, Switzerland
| | - Lingfei Hu
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
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50
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Mathur C, Phani V, Kushwah J, Somvanshi VS, Dutta TK. TcaB, an insecticidal protein from Photorhabdus akhurstii causes cytotoxicity in the greater wax moth, Galleria mellonella. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2019; 157:219-229. [PMID: 31153472 DOI: 10.1016/j.pestbp.2019.03.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 03/22/2019] [Accepted: 03/31/2019] [Indexed: 06/09/2023]
Abstract
Photorhabdus akhurstii can produce a variety of proteins that aid this bacterium and its mutualistic nematode vector, Heterorhabditis indica to kill the insect host. Herein, we characterized (by heterologously expressing in E. coli) an open reading frame (1713 bp) of the toxin complex protein, TcaB from P. akhurstii strains IARI-SGHR2 and IARI-SGMS1 and assessed its toxic effect on G. mellonella larvae. The intra-hemocoel injection of purified TcaB (molecular weight-63 kDa) caused fourth instar larval bodies to blacken and die with LD50 values of 67.25 (IARI-SGHR2) and 52.08 (IARI-SGMS1) ng per larva at 12 h. Additionally, oral administration of the toxin caused larval mortality with LD50 values of 709.55 (IARI-SGHR2) and 598.44 (IARI-SGMS1) ng per g diet per larva at 7 days post feeding. Injection of purified TcaB caused loss of viability of fourth instar G. mellonella hemocytes at 6 h post incubation; cells displayed morphological changes typical of apoptosis, including cell shrinkage, membrane blebbing, nuclear condensation and disintegration. Injection of TcaB also elevated the phenoloxidase activity in insect hemolymph which triggers an extensive immune response that potentially leads to larval death. Similar to other bacterial toxins TcaB possesses potent biological activity which may enable it to be used as an efficient agent for pest management.
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Affiliation(s)
- Chetna Mathur
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Victor Phani
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Jyoti Kushwah
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Vishal S Somvanshi
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Tushar K Dutta
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
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