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FinO/ProQ-family proteins: an evolutionary perspective. Biosci Rep 2023; 43:232566. [PMID: 36787218 PMCID: PMC9977716 DOI: 10.1042/bsr20220313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 02/02/2023] [Accepted: 02/14/2023] [Indexed: 02/15/2023] Open
Abstract
RNA-binding proteins are key actors of post-transcriptional networks. Almost exclusively studied in the light of their interactions with RNA ligands and the associated functional events, they are still poorly understood as evolutionary units. In this review, we discuss the FinO/ProQ family of bacterial RNA chaperones, how they evolve and spread across bacterial populations and what properties and opportunities they provide to their host cells. We reflect on major conserved and divergent themes within the family, trying to understand how the same ancestral RNA-binding fold, augmented with additional structural elements, could yield either highly specialised proteins or, on the contrary, globally acting regulatory hubs with a pervasive impact on gene expression. We also consider dominant convergent evolutionary trends that shaped their RNA chaperone activity and recurrently implicated the FinO/ProQ-like proteins in bacterial DNA metabolism, translation and virulence. Finally, we offer a new perspective in which FinO/ProQ-family regulators emerge as active evolutionary players with both negative and positive roles, significantly impacting the evolutionary modes and trajectories of their bacterial hosts.
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Bhat CG, Budhwar R, Godwin J, Dillman AR, Rao U, Somvanshi VS. RNA-Sequencing of Heterorhabditis nematodes to identify factors involved in symbiosis with Photorhabdus bacteria. BMC Genomics 2022; 23:741. [PMCID: PMC9639317 DOI: 10.1186/s12864-022-08952-4] [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: 08/08/2022] [Accepted: 10/07/2022] [Indexed: 11/09/2022] Open
Abstract
Background Nematodes are a major group of soil inhabiting organisms. Heterorhabditis nematodes are insect-pathogenic nematodes and live in a close symbiotic association with Photorhabdus bacteria. Heterorhabditis-Photorhabdus pair offers a powerful and genetically tractable model to study animal-microbe symbiosis. It is possible to generate symbiont bacteria free (axenic) stages in Heterorhabditis. Here, we compared the transcriptome of symbiotic early-adult stage Heterorhabditis nematodes with axenic early-adult nematodes to determine the nematode genes and pathways involved in symbiosis with Photorhabdus bacteria. Results A de-novo reference transcriptome assembly of 95.7 Mb was created for H. bacteriophora by using all the reads. The assembly contained 46,599 transcripts with N50 value of 2,681 bp and the average transcript length was 2,054 bp. The differentially expressed transcripts were identified by mapping reads from symbiotic and axenic nematodes to the reference assembly. A total of 754 differentially expressed transcripts were identified in symbiotic nematodes as compared to the axenic nematodes. The ribosomal pathway was identified as the most affected among the differentially expressed transcripts. Additionally, 12,151 transcripts were unique to symbiotic nematodes. Endocytosis, cAMP signalling and focal adhesion were the top three enriched pathways in symbiotic nematodes, while a large number of transcripts coding for various responses against bacteria, such as bacterial recognition, canonical immune signalling pathways, and antimicrobial effectors could also be identified. Conclusions The symbiotic Heterorhabditis nematodes respond to the presence of symbiotic bacteria by expressing various transcripts involved in a multi-layered immune response which might represent non-systemic and evolved localized responses to maintain mutualistic bacteria at non-threatening levels. Subject to further functional validation of the identified transcripts, our findings suggest that Heterorhabditis nematode immune system plays a critical role in maintenance of symbiosis with Photorhabdus bacteria. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08952-4.
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Affiliation(s)
- Chaitra G. Bhat
- grid.418196.30000 0001 2172 0814Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, Delhi, 110012 India
| | - Roli Budhwar
- Bionivid Technology Private Limited, 209, 4th Cross Rd., B. Channasandra, Kasturi Nagar, Bengaluru, Karnataka 560043 India
| | - Jeffrey Godwin
- Bionivid Technology Private Limited, 209, 4th Cross Rd., B. Channasandra, Kasturi Nagar, Bengaluru, Karnataka 560043 India
| | - Adler R. Dillman
- grid.266097.c0000 0001 2222 1582Department of Nematology, University of California, Riverside, 92521 USA
| | - Uma Rao
- grid.418196.30000 0001 2172 0814Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, Delhi, 110012 India
| | - Vishal S. Somvanshi
- grid.418196.30000 0001 2172 0814Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, Delhi, 110012 India
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3
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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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4
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Erwinia carotovora Quorum Sensing System Regulates Host-Specific Virulence Factors and Development Delay in Drosophila melanogaster. mBio 2020; 11:mBio.01292-20. [PMID: 32576677 PMCID: PMC7315124 DOI: 10.1128/mbio.01292-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Integration of genetic networks allows bacteria to rapidly adapt to changing environments. This is particularly important in bacteria that interact with multiple hosts. Erwinia carotovora is a plant pathogen that uses Drosophila melanogaster as a vector. To interact with these two hosts, Ecc15 uses different sets of virulence factors: plant cell wall-degrading enzymes to infect plants and the Erwinia virulence factor (evf) to infect Drosophila. Our work shows that, despite the virulence factors being specific for each host, both sets are coactivated by homoserine lactone quorum sensing and by the two-component GacS/A system in infected plants. This regulation is essential for Ecc15 loads in the gut of Drosophila and minimizes the developmental delay caused by the bacteria with respect to the insect vector. Our findings provide evidence that coactivation of the host-specific factors in the plant may function as a predictive mechanism to maximize the probability of transit of the bacteria between hosts. Multihost bacteria have to rapidly adapt to drastic environmental changes, relying on a fine integration of multiple stimuli for an optimal genetic response. Erwinia carotovora spp. are phytopathogens that cause soft-rot disease. Strain Ecc15 in particular is a model for bacterial oral-route infection in Drosophila melanogaster as it harbors a unique gene, evf, that encodes the Erwinia virulence factor (Evf), which is a major determinant for infection of the D. melanogaster gut. However, the factors involved in the regulation of evf expression are poorly understood. We investigated whether evf could be controlled by quorum sensing as, in the Erwinia genus, quorum sensing regulates pectolytic enzymes, the major virulence factors needed to infect plants. Here, we show that transcription of evf is positively regulated by quorum sensing in Ecc15 via acyl-homoserine lactone (AHL) signal synthase ExpI and AHL receptors ExpR1 and ExpR2. We also show that the load of Ecc15 in the gut depends upon the quorum sensing-mediated regulation of evf. Furthermore, we demonstrate that larvae infected with Ecc15 suffer a developmental delay as a direct consequence of the regulation of evf via quorum sensing. Finally, we demonstrate that evf is coexpressed with plant cell wall-degrading enzymes (PCWDE) during plant infection in a quorum sensing-dependent manner. Overall, our results show that Ecc15 relies on quorum sensing to control production of both pectolytic enzymes and Evf. This regulation influences the interaction of Ecc15 with its two known hosts, indicating that quorum sensing signaling may impact bacterial dissemination via insect vectors that feed on rotting plants.
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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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6
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Hapeshi A, Benarroch JM, Clarke DJ, Waterfield NR. Iso-propyl stilbene: a life cycle signal? MICROBIOLOGY-SGM 2019; 165:516-526. [PMID: 30882293 DOI: 10.1099/mic.0.000790] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Members of the Gram-negative bacterial genus Photorhabdus are all highly insect pathogenic and exist in an obligate symbiosis with the entomopathogenic nematode worm Heterorhabditis. All members of the genus produce the small-molecule 3,5-dihydroxy-4-isopropyl-trans-stilbene (IPS) as part of their secondary metabolism. IPS is a multi-potent compound that has antimicrobial, antifungal, immunomodulatory and anti-cancer activities and also plays an important role in symbiosis with the nematode. In this study we have examined the response of Photorhabdus itself to exogenous ectopic addition of IPS at physiologically relevant concentrations. We observed that the bacteria had a measureable phenotypic response, which included a decrease in bioluminescence and pigment production. This was reflected in changes in its transcriptomic response, in which we reveal a reduction in transcript levels of genes relating to many fundamental cellular processes, such as translation and oxidative phosphorylation. Our observations suggest that IPS plays an important role in the biology of Photorhabdus bacteria, fulfilling roles in quorum sensing, antibiotic-competition advantage and maintenance of the symbiotic developmental cycle.
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Affiliation(s)
- Alexia Hapeshi
- Microbiology and Infection Unit, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Jonatan Mimon Benarroch
- Microbiology and Infection Unit, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - David James Clarke
- School of Microbiology and APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Nicholas Robin Waterfield
- Microbiology and Infection Unit, Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
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Olejniczak M, Storz G. ProQ/FinO-domain proteins: another ubiquitous family of RNA matchmakers? Mol Microbiol 2017; 104:905-915. [PMID: 28370625 DOI: 10.1111/mmi.13679] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2017] [Indexed: 02/02/2023]
Abstract
Small RNAs (sRNAs), particularly those that act by limited base pairing with mRNAs, are part of most regulatory networks in bacteria. In many cases, the base-pairing interaction is facilitated by the RNA chaperone Hfq. However, not all bacteria encode Hfq and some base-pairing sRNAs do not require Hfq raising the possibility of other RNA chaperones. Candidates are proteins with homology to FinO, a factor that promotes base pairing between the FinP antisense sRNA and the traJ mRNA to control F plasmid transfer. Recent papers have shown that the Salmonella enterica FinO-domain protein ProQ binds a large suite of sRNAs, including the RaiZ sRNA, which represses translation of the hupA mRNA, and the Legionella pneumophila protein RocC binds the RocR sRNA, which blocks expression of competence genes. Here we discuss what is known about FinO-domain structures, including the recently solved Escherichia coli ProQ structure, as well as the RNA binding properties of this family of proteins and evidence they act as chaperones. We compare these properties with those of Hfq. We further summarize what is known about the physiological roles of FinO-domain proteins and enumerate outstanding questions whose answers will establish whether they constitute a second major class of RNA chaperones.
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Affiliation(s)
- Mikolaj Olejniczak
- Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, Poznan, 61-614, Poland
| | - Gisela Storz
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, Bethesda, MD, 20892-4417, USA
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8
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Valverde C. Who's the boss here? The post‐transcriptional global regulator
H
fq takes over control of secondary metabolite production in the nematode symbiont
P
hotorhabdus luminiscens. Environ Microbiol 2017; 19:21-24. [DOI: 10.1111/1462-2920.13635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Claudio Valverde
- Departamento de Ciencia y Tecnología, LBMIBSUniversidad Nacional de Quilmes – CONICETBernalB1876BXD Argentina
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9
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Kumar R, Kushwah J, Ganguly S, Garg V, Somvanshi VS. Proteomic Investigation of Photorhabdus Bacteria for Nematode-Host Specificity. Indian J Microbiol 2016; 56:361-367. [PMID: 27407301 DOI: 10.1007/s12088-016-0594-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 05/05/2016] [Indexed: 01/17/2023] Open
Abstract
Majority of animals form symbiotic relationships with bacteria. Based on the number of bacterial species associating with an animal, these symbiotic associations can be mono-specific, relatively simple (2-25 bacterial species/animal) or highly complex (>10(2)-10(3) bacterial species/animal). Photorhabdus (family-Enterobacteriaceae) forms a mono-specific symbiotic relationship with the entomopathogenic nematode Heterorhabditis. This system provides a tractable genetic model for animal-microbe symbiosis studies. Here, we investigated the bacterial factors that may be responsible for governing host specificity between nematode and their symbiont bacteria using proteomics approach. Total protein profiles of P. luminescens ssp. laumondii (host nematode- H. bacteriophora) and P. luminescens ssp. akhurstii (host nematode- H. indica) were compared using 2-D gel electrophoresis, followed by identification of differentially expressed proteins by MALDI-TOF MS. Thirty-nine unique protein spots were identified - 24 from P. luminescens ssp. laumondii and 15 from P. luminescens ssp. akhurstii. These included proteins that might be involved in determining host specificity directly (for e.g. pilin FimA, outer membrane protein A), indirectly through effect on bacterial secondary metabolism (for e.g. malate dehydrogenase Mdh, Pyruvate formate-lyase PflA, flavo protein WrbA), or in a yet unknown manner (for e.g. hypothetical proteins, transcription regulators). Further functional validation is needed to establish the role of these bacterial proteins in nematode-host specificity.
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Affiliation(s)
- Ram Kumar
- Division of Nematology, ICAR- Indian Agricultural Research Institute, Pusa Campus, New Delhi, 110012 India.,ICAR-National Research Center on Plant Biotechnology, Pusa Campus, New Delhi, 110012 India
| | - Jyoti Kushwah
- Division of Nematology, ICAR- Indian Agricultural Research Institute, Pusa Campus, New Delhi, 110012 India
| | - Sudershan Ganguly
- Division of Nematology, ICAR- Indian Agricultural Research Institute, Pusa Campus, New Delhi, 110012 India
| | - Veena Garg
- Department of Biotechnology and Biosciences, Banasthali Vidyapeeth, Jaipur, Rajasthan India
| | - Vishal S Somvanshi
- Division of Nematology, ICAR- Indian Agricultural Research Institute, Pusa Campus, New Delhi, 110012 India
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10
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Joyce SA, Lango L, Clarke DJ. The Regulation of Secondary Metabolism and Mutualism in the Insect Pathogenic Bacterium Photorhabdus luminescens. ADVANCES IN APPLIED MICROBIOLOGY 2016; 76:1-25. [PMID: 21924970 DOI: 10.1016/b978-0-12-387048-3.00001-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Photorhabdus is a genus of insect-pathogenic Gram-negative bacteria that also maintain a mutualistic interaction with nematodes from the family Heterorhabditis. This complex life cycle, involving different interactions with different invertebrate hosts, coupled with the amenability of the system to laboratory culture has resulted in the development of Photorhabdus as a model system for studying bacterial-host interactions. Photorhabdus is predicted to have an extensive secondary metabolism with the genetic potential to produce >20 different small secondary metabolites. Therefore, this system also presents us with a unique opportunity to study the contribution of secondary metabolism to the environmental fitness of the producing organism in its natural habitat (i.e., the insect and/or the nematode). In vivo and in vitro studies have revealed that the vast majority of the genetic loci in Photorhabdus predicted to be involved in the production of secondary metabolites appear to be cryptic and, to date, although several have been characterized, only three compounds have been studied in any great detail: 3,5-dihydroxy-4-isopropylstilbene, the β-lactam antibiotic carbapenem, and an anthraquinone pigment. In this chapter, we describe how these compounds are made and the role (if any) that they have during the interactions between Photorhabdus and its invertebrate hosts. We will also outline recent work on the regulation of secondary metabolism in Photorhabdus and comment on how this has led to an increased understanding of mutualism in this bacterium.
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Affiliation(s)
- Susan A Joyce
- Department of Microbiology, University College Cork, Cork, Ireland
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11
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Lacey L, Grzywacz D, Shapiro-Ilan D, Frutos R, Brownbridge M, Goettel M. Insect pathogens as biological control agents: Back to the future. J Invertebr Pathol 2015. [DOI: 10.1016/j.jip.2015.07.009] [Citation(s) in RCA: 545] [Impact Index Per Article: 60.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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12
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Identification of a new Alcaligenes faecalis strain MOR02 and assessment of its toxicity and pathogenicity to insects. BIOMED RESEARCH INTERNATIONAL 2015; 2015:570243. [PMID: 25667924 PMCID: PMC4312618 DOI: 10.1155/2015/570243] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 12/16/2014] [Accepted: 12/17/2014] [Indexed: 01/12/2023]
Abstract
We report the isolation of a bacterium from Galleria mellonella larva and its identification using genome sequencing and phylogenomic analysis. This bacterium was named Alcaligenes faecalis strain MOR02. Microscopic analyses revealed that the bacteria are located in the esophagus and intestine of the nematodes Steinernema feltiae, S. carpocapsae, and H. bacteriophora. Using G. mellonella larvae as a model, when the larvae were injected with 24,000 CFU in their hemocoel, more than 96% mortality was achieved after 24 h. Additionally, toxicity assays determined that 1 μg of supernatant extract from A. faecalis MOR02 killed more than 70% G. mellonella larvae 96 h after injection. A correlation of experimental data with sequence genome analyses was also performed. We discovered genes that encode proteins and enzymes that are related to pathogenicity, toxicity, and host/environment interactions that may be responsible for the observed phenotypic characteristics. Our data demonstrates that the bacteria are able to use different strategies to colonize nematodes and kill insects to their own benefit. However, there remains an extensive group of unidentified microorganisms that could be participating in the infection process. Additionally, a nematode-bacterium association could be established probably as a strategy of dispersion and colonization.
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13
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Sato K, Yoshiga T, Hasegawa K. Activated and inactivated immune responses in Caenorhabditis elegans against Photorhabdus luminescens TT01. SPRINGERPLUS 2014; 3:274. [PMID: 25279274 PMCID: PMC4171960 DOI: 10.1186/2193-1801-3-274] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Accepted: 05/26/2014] [Indexed: 11/13/2022]
Abstract
The Gram-negative bacterium Photorhabdus luminescens which symbiotically associates with the entomopathogenic nematode Heterorhabditis bacteriophora, has a broad insecticidal and nematicidal activity. The virulence of P. luminescens toward the non-mutualistic nematode Caenorhabditis elegans has not been described. We showed that when fed on P. luminescens, the intestinal cells of C. elegans worms become delicate and some crystal-like structure was developed within the intestinal lumen. Next, we examined the requirement of the p38 mitogen-activated protein kinase (MAPK) and insulin/IGF-1 signaling pathway against P. luminescens. Depletion of pmk-1 by RNAi enhances susceptibility to P. luminescens, and numerous downstream targets regulated by the p38 MAPK pathway were induced when fed on P. luminescens. On the other hand, knockdown of daf-16 has no effects on C. elegans lifespan, but knockdown of daf-2 dramatically increased resistance to P. luminescens in a daf-16-dependent manner. We also revealed one of the daf-2 ligands ins-7 was induced and ins-7 deletion mutant survived longer when fed on P. luminescens. These results suggest the p38 MAPK pathway is activated and required for the host defense against P. luminescens. Insulin/IGF-1 signaling pathway is inactivated by P. luminescens through the overexpression of insulin-like gene.
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Affiliation(s)
- Kazuki Sato
- Laboratory of Nematology, Department of Applied Biological Sciences, Saga University, Saga, 840-8502 Japan ; Laboratory of Terrestrial Microbial Ecology, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, 606-8502 Japan ; The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima, 890-8580 Japan
| | - Toyoshi Yoshiga
- Laboratory of Nematology, Department of Applied Biological Sciences, Saga University, Saga, 840-8502 Japan ; Laboratory of Terrestrial Microbial Ecology, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, 606-8502 Japan
| | - Koichi Hasegawa
- Department of Environmental Biology, College of Bioscience & Biotechnology, Chubu University, 1200 Matsumoto, Kasugai, 487-8501 Japan
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14
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The genetic basis of the symbiosis between Photorhabdus and its invertebrate hosts. ADVANCES IN APPLIED MICROBIOLOGY 2014; 88:1-29. [PMID: 24767424 DOI: 10.1016/b978-0-12-800260-5.00001-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Photorhabdus is a pathogen of insects that also maintains a mutualistic association with nematodes from the family Heterorhabditis. Photorhabdus colonizes the gut of the infective juvenile (IJ) stage of the nematode. The IJ infects an insect and regurgitates the bacteria and the bacteria reproduce to kill the insect. The nematodes feed on the resulting bacterial biomass until a new generation of IJs emerges from the insect cadaver. Therefore, during its life cycle, Photorhabdus must (1) kill the insect host, (2) support nematode growth and development, and (3) be able to colonize the new generation of IJs. In this review, functional genomic studies that have been aimed at understanding the molecular mechanisms underpinning each of these roles will be discussed. These studies have begun to reveal that distinct gene sets may be required for each of these interactions, suggesting that there is only a minimal genetic overlap between pathogenicity and mutualism in Photorhabdus.
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15
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Murfin KE, Chaston J, Goodrich-Blair H. Visualizing bacteria in nematodes using fluorescent microscopy. J Vis Exp 2012:4298. [PMID: 23117838 DOI: 10.3791/4298] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Symbioses, the living together of two or more organisms, are widespread throughout all kingdoms of life. As two of the most ubiquitous organisms on earth, nematodes and bacteria form a wide array of symbiotic associations that range from beneficial to pathogenic (1-3). One such association is the mutually beneficial relationship between Xenorhabdus bacteria and Steinernema nematodes, which has emerged as a model system of symbiosis (4). Steinernema nematodes are entomopathogenic, using their bacterial symbiont to kill insects (5). For transmission between insect hosts, the bacteria colonize the intestine of the nematode's infective juvenile stage (6-8). Recently, several other nematode species have been shown to utilize bacteria to kill insects (9-13), and investigations have begun examining the interactions between the nematodes and bacteria in these systems (9). We describe a method for visualization of a bacterial symbiont within or on a nematode host, taking advantage of the optical transparency of nematodes when viewed by microscopy. The bacteria are engineered to express a fluorescent protein, allowing their visualization by fluorescence microscopy. Many plasmids are available that carry genes encoding proteins that fluoresce at different wavelengths (i.e. green or red), and conjugation of plasmids from a donor Escherichia coli strain into a recipient bacterial symbiont is successful for a broad range of bacteria. The methods described were developed to investigate the association between Steinernema carpocapsae and Xenorhabdus nematophila (14). Similar methods have been used to investigate other nematode-bacterium associations (9) (,) (15-18)and the approach therefore is generally applicable. The method allows characterization of bacterial presence and localization within nematodes at different stages of development, providing insights into the nature of the association and the process of colonization (14) (,) (16) (,) (19). Microscopic analysis reveals both colonization frequency within a population and localization of bacteria to host tissues (14) (,) (16) (,) (19-21). This is an advantage over other methods of monitoring bacteria within nematode populations, such as sonication (22)or grinding (23), which can provide average levels of colonization, but may not, for example, discriminate populations with a high frequency of low symbiont loads from populations with a low frequency of high symbiont loads. Discriminating the frequency and load of colonizing bacteria can be especially important when screening or characterizing bacterial mutants for colonization phenotypes (21) (,) (24). Indeed, fluorescence microscopy has been used in high throughput screening of bacterial mutants for defects in colonization (17) (,) (18), and is less laborious than other methods, including sonication (22) (,) (25-27)and individual nematode dissection (28) (,) (29).
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Affiliation(s)
- Kristen E Murfin
- Department of Bacteriology, University of Wisconsin-Madison, USA
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Murfin KE, Dillman AR, Foster JM, Bulgheresi S, Slatko BE, Sternberg PW, Goodrich-Blair H. Nematode-bacterium symbioses--cooperation and conflict revealed in the "omics" age. THE BIOLOGICAL BULLETIN 2012; 223:85-102. [PMID: 22983035 PMCID: PMC3508788 DOI: 10.1086/bblv223n1p85] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Nematodes are ubiquitous organisms that have a significant global impact on ecosystems, economies, agriculture, and human health. The applied importance of nematodes and the experimental tractability of many species have promoted their use as models in various research areas, including developmental biology, evolutionary biology, ecology, and animal-bacterium interactions. Nematodes are particularly well suited for the investigation of host associations with bacteria because all nematodes have interacted with bacteria during their evolutionary history and engage in a variety of association types. Interactions between nematodes and bacteria can be positive (mutualistic) or negative (pathogenic/parasitic) and may be transient or stably maintained (symbiotic). Furthermore, since many mechanistic aspects of nematode-bacterium interactions are conserved, their study can provide broader insights into other types of associations, including those relevant to human diseases. Recently, genome-scale studies have been applied to diverse nematode-bacterial interactions and have helped reveal mechanisms of communication and exchange between the associated partners. In addition to providing specific information about the system under investigation, these studies also have helped inform our understanding of genome evolution, mutualism, and innate immunity. In this review we discuss the importance and diversity of nematodes, "omics"' studies in nematode-bacterial systems, and the wider implications of the findings.
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Affiliation(s)
- Kristen E. Murfin
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706
| | - Adler R. Dillman
- HHMI and Division of Biology, California Institute of Technology, 156-29, Pasadena, CA 91125, USA
| | - Jeremy M. Foster
- Parasitology Division, New England Biolabs, Inc., 240 County Rd, Ipswich, MA 01938, USA
| | - Silvia Bulgheresi
- Department of Genetics in Ecology, University of Vienna, Vienna, Austria
| | - Barton E. Slatko
- Parasitology Division, New England Biolabs, Inc., 240 County Rd, Ipswich, MA 01938, USA
| | - Paul W. Sternberg
- HHMI and Division of Biology, California Institute of Technology, 156-29, Pasadena, CA 91125, USA
| | - Heidi Goodrich-Blair
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706
- Corresponding author Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Dr., Madison, WI 53706, , phone: 608-265-4537, fax: 608-262-9865
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Wijedoru LPM, Kumar V, Chanpheaktra N, Chheng K, Smits HL, Pastoor R, Nga TVT, Baker S, Wuthiekanun V, Peacock SJ, Putchhat H, Parry CM. Typhoid fever among hospitalized febrile children in Siem Reap, Cambodia. J Trop Pediatr 2012; 58:68-70. [PMID: 21508082 PMCID: PMC3739416 DOI: 10.1093/tropej/fmr032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Typhoid fever was confirmed by positive blood culture in 5 (3.7%) of 134 febrile children hospitalized in Cambodia. Typhoid was suspected in an additional 25 (18.7 %) blood culture-negative children based on: a positive immunoglobulin M lateral flow assay (IgMFA) (16); a positive polymerase chain reaction (PCR) for Salmonella typhi (2); or clinical assessment (7). The specificity of the IgMFA and PCR assays requires further study.
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Affiliation(s)
- Lalith P. M. Wijedoru
- Child and Reproductive Health Group, Liverpool School of Tropical Medicine (LSTM), Liverpool, UK
| | - Varun Kumar
- Angkor Hospital for Children (AHC), Siem Reap, Cambodia
| | | | - Kheng Chheng
- Angkor Hospital for Children (AHC), Siem Reap, Cambodia
| | - Henk L. Smits
- KIT Biomedical Research, Royal Tropical Institute (KIT), Amsterdam, The Netherlands
| | - Rob Pastoor
- KIT Biomedical Research, Royal Tropical Institute (KIT), Amsterdam, The Netherlands
| | - Tran Vu Thieu Nga
- Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam
| | - Stephen Baker
- Oxford University Clinical Research Unit (OUCRU), Ho Chi Minh City, Vietnam
| | | | - Sharon J. Peacock
- Mahidol-Oxford Tropical Medicine Unit (MORU), Bangkok, Thailand,Department of Medicine, University of Cambridge, Cambridge, UK
| | - Hor Putchhat
- Angkor Hospital for Children (AHC), Siem Reap, Cambodia
| | - Christopher M. Parry
- Angkor Hospital for Children (AHC), Siem Reap, Cambodia,Mahidol-Oxford Tropical Medicine Unit (MORU), Bangkok, Thailand
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Easom CA, Clarke DJ. HdfR is a regulator in Photorhabdus luminescens that modulates metabolism and symbiosis with the nematode Heterorhabditis. Environ Microbiol 2011; 14:953-66. [DOI: 10.1111/j.1462-2920.2011.02669.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Chaston JM, Suen G, Tucker SL, Andersen AW, Bhasin A, Bode E, Bode HB, Brachmann AO, Cowles CE, Cowles KN, Darby C, de Léon L, Drace K, Du Z, Givaudan A, Herbert Tran EE, Jewell KA, Knack JJ, Krasomil-Osterfeld KC, Kukor R, Lanois A, Latreille P, Leimgruber NK, Lipke CM, Liu R, Lu X, Martens EC, Marri PR, Médigue C, Menard ML, Miller NM, Morales-Soto N, Norton S, Ogier JC, Orchard SS, Park D, Park Y, Qurollo BA, Sugar DR, Richards GR, Rouy Z, Slominski B, Slominski K, Snyder H, Tjaden BC, van der Hoeven R, Welch RD, Wheeler C, Xiang B, Barbazuk B, Gaudriault S, Goodner B, Slater SC, Forst S, Goldman BS, Goodrich-Blair H. The entomopathogenic bacterial endosymbionts Xenorhabdus and Photorhabdus: convergent lifestyles from divergent genomes. PLoS One 2011; 6:e27909. [PMID: 22125637 PMCID: PMC3220699 DOI: 10.1371/journal.pone.0027909] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 10/27/2011] [Indexed: 12/15/2022] Open
Abstract
Members of the genus Xenorhabdus are entomopathogenic bacteria that associate with nematodes. The nematode-bacteria pair infects and kills insects, with both partners contributing to insect pathogenesis and the bacteria providing nutrition to the nematode from available insect-derived nutrients. The nematode provides the bacteria with protection from predators, access to nutrients, and a mechanism of dispersal. Members of the bacterial genus Photorhabdus also associate with nematodes to kill insects, and both genera of bacteria provide similar services to their different nematode hosts through unique physiological and metabolic mechanisms. We posited that these differences would be reflected in their respective genomes. To test this, we sequenced to completion the genomes of Xenorhabdus nematophila ATCC 19061 and Xenorhabdus bovienii SS-2004. As expected, both Xenorhabdus genomes encode many anti-insecticidal compounds, commensurate with their entomopathogenic lifestyle. Despite the similarities in lifestyle between Xenorhabdus and Photorhabdus bacteria, a comparative analysis of the Xenorhabdus, Photorhabdus luminescens, and P. asymbiotica genomes suggests genomic divergence. These findings indicate that evolutionary changes shaped by symbiotic interactions can follow different routes to achieve similar end points.
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Affiliation(s)
- John M. Chaston
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Garret Suen
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Sarah L. Tucker
- Monsanto Company, St. Louis, Missouri, United States of America
| | - Aaron W. Andersen
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Archna Bhasin
- Department of Biology, Valdosta State University, Valdosta, Georgia, United States of America
| | - Edna Bode
- Institut für Molekulare Biowissenschaften, Goethe Universität Frankfurt, Frankfurt am Main, Germany
| | - Helge B. Bode
- Institut für Molekulare Biowissenschaften, Goethe Universität Frankfurt, Frankfurt am Main, Germany
| | - Alexander O. Brachmann
- Institut für Molekulare Biowissenschaften, Goethe Universität Frankfurt, Frankfurt am Main, Germany
| | - Charles E. Cowles
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kimberly N. Cowles
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Creg Darby
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, California, United States of America
| | - Limaris de Léon
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kevin Drace
- Department of Biology, Mercer University, Macon, Georgia, United States of America
| | - Zijin Du
- Monsanto Company, St. Louis, Missouri, United States of America
| | - Alain Givaudan
- Institut National de la Recherche Agronomique-Université de Montpellier II, Montpellier, France
- Université Montpellier, Montpellier, France
| | - Erin E. Herbert Tran
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kelsea A. Jewell
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jennifer J. Knack
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | | | - Ryan Kukor
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Anne Lanois
- Institut National de la Recherche Agronomique-Université de Montpellier II, Montpellier, France
- Université Montpellier, Montpellier, France
| | - Phil Latreille
- Monsanto Company, St. Louis, Missouri, United States of America
| | | | - Carolyn M. Lipke
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Renyi Liu
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, United States of America
| | - Xiaojun Lu
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Eric C. Martens
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Pradeep R. Marri
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, United States of America
| | - Claudine Médigue
- Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de Génomique, Genoscope and CNRS-UMR 8030, Laboratoire d'Analyse Bioinformatique en Génomique et Métabolisme, Evry, France
| | - Megan L. Menard
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Nancy M. Miller
- Monsanto Company, St. Louis, Missouri, United States of America
| | - Nydia Morales-Soto
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Stacie Norton
- Monsanto Company, St. Louis, Missouri, United States of America
| | - Jean-Claude Ogier
- Institut National de la Recherche Agronomique-Université de Montpellier II, Montpellier, France
- Université Montpellier, Montpellier, France
| | - Samantha S. Orchard
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Dongjin Park
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Youngjin Park
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | | | - Darby Renneckar Sugar
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Gregory R. Richards
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Zoé Rouy
- Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de Génomique, Genoscope and CNRS-UMR 8030, Laboratoire d'Analyse Bioinformatique en Génomique et Métabolisme, Evry, France
| | - Brad Slominski
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kathryn Slominski
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Holly Snyder
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Brian C. Tjaden
- Department of Computer Science, Wellesley College, Wellesley, Massachusetts, United States of America
| | - Ransome van der Hoeven
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Roy D. Welch
- Department of Biology, Syracuse University, Syracuse, New York, United States of America
| | - Cathy Wheeler
- Department of Biology, Hiram College, Hiram, Ohio, United States of America
| | - Bosong Xiang
- Monsanto Company, St. Louis, Missouri, United States of America
| | - Brad Barbazuk
- Department of Biology, University of Florida, Gainesville, Florida, United States of America
| | - Sophie Gaudriault
- Institut National de la Recherche Agronomique-Université de Montpellier II, Montpellier, France
- Université Montpellier, Montpellier, France
| | - Brad Goodner
- Department of Biology, Hiram College, Hiram, Ohio, United States of America
| | - Steven C. Slater
- DOE Great Lakes Bioenergy Research Center, Madison, Wisconsin, United States of America
| | - Steven Forst
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Barry S. Goldman
- Monsanto Company, St. Louis, Missouri, United States of America
- * E-mail: (B.Goldman); (HG-B)
| | - Heidi Goodrich-Blair
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail: (B.Goldman); (HG-B)
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Influence of the Photorhabdus luminescens phosphomannose isomerase gene, manA, on mannose utilization, exopolysaccharide structure, and biofilm formation. Appl Environ Microbiol 2010; 77:776-85. [PMID: 21148694 DOI: 10.1128/aem.02326-10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Extracellular polysaccharide (EPS) is produced by diverse bacterial pathogens and fulfills assorted roles, including providing a structural matrix for biofilm formation and more specific functions in virulence, such as protection against immune defenses. We report here the first investigation of some of the genes important for biofilm formation in Photorhabdus luminescens and demonstrate the key role of the phosphomannose isomerase gene, manA, in the structure of functional EPS. Phenotypic analyses of a manA-deficient mutant showed the importance of EPS in motility, insect virulence, and biofilm formation on abiotic surfaces as well as the requirement of this gene for the use of mannose as the sole carbon source. Conversely, this defect had no apparent impact on symbiosis with the heterorhabditid nematode vector. A more detailed analysis of biofilm formation revealed that the manA mutant was able to attach to surfaces with the same efficiency as that of the wild-type strain but could not develop the more extended biofilm matrix structures. A compositional analysis of P. luminescens EPS reveals how the manA mutation has a major effect on the formation of a complete, branched EPS.
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Eleftherianos I, ffrench-Constant RH, Clarke DJ, Dowling AJ, Reynolds SE. Dissecting the immune response to the entomopathogen Photorhabdus. Trends Microbiol 2010; 18:552-60. [PMID: 21035345 DOI: 10.1016/j.tim.2010.09.006] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Revised: 09/20/2010] [Accepted: 09/27/2010] [Indexed: 11/29/2022]
Abstract
Bacterial pathogens either hide from or modulate the host's immune response to ensure their survival. Photorhabdus is a potent insect pathogenic bacterium that uses entomopathogenic nematodes as vectors in a system that represents a useful tool for probing the molecular basis of immunity. During the course of infection, Photorhabdus multiplies rapidly within the insect, producing a range of toxins that inhibit phagocytosis of the invading bacteria and eventually kill the insect host. Photorhabdus bacteria have recently been established as a tool for investigating immune recognition and defense mechanisms in model hosts such as Manduca and Drosophila. Such studies pave the way for investigations of gene interactions between pathogen virulence factors and host immune genes, which ultimately could lead to an understanding of how some Photorhabdus species have made the leap to becoming human pathogens.
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Affiliation(s)
- Ioannis Eleftherianos
- Department of Biological Sciences, The George Washington University, 336 Lisner Hall, 2023 G Street NW, Washington, DC 20052, USA.
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Somvanshi VS, Kaufmann-Daszczuk B, Kim KS, Mallon S, Ciche TA. Photorhabdus phase variants express a novel fimbrial locus, mad, essential for symbiosis. Mol Microbiol 2010; 77:1021-38. [PMID: 20572934 DOI: 10.1111/j.1365-2958.2010.07270.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Fimbriae are adhesive organelles known to enable pathogens to colonize animal tissue, but little is known of their function in mutualistic symbioses. Photorhabdus colonization of Heterorhabditis bacteriophora nematodes is essential for the pair's insect pathogenic lifestyle. Maternal nematodes acquire Photorhabdus symbionts as a persistent intestinal biofilm prior to transmission to infective juvenile (IJ) stage offspring developing inside the maternal body. Screening 8000 Photorhabdus mutants for defects in IJ colonization revealed that a single fimbrial locus, named mad for maternal adhesion defective, is essential. The mad genes encode a novel usher/chaperone assembled fimbria regulated by an ON/OFF invertible promoter switch. Adherent Photorhabdus cells in maternal nematode intestines had the switch ON opposite to the OFF orientation of most other cells. A ΔmadA mutant failed to adhere to maternal intestines and be transmitted to the IJs. Mad fimbriae were detected on TT01 phase ON cells but not on ΔmadA phase ON cells. Also required for transmission is madJ, predicted to encode a transcriptional activator related to GrlA. Expression of madA-K or madIJK restored the ability of madJ mutant to adhere. The Mad fimbriae were not required for insect pathogenesis, indicating the specialized function of Mad fimbriae for symbiosis.
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Affiliation(s)
- Vishal S Somvanshi
- Department of Microbiology and Molecular Genetics and the Center for Microbial Pathogenesis, Michigan State University, East Lansing, MI 48824, USA
| | - Bettina Kaufmann-Daszczuk
- Department of Microbiology and Molecular Genetics and the Center for Microbial Pathogenesis, Michigan State University, East Lansing, MI 48824, USA
| | - Kwi-Suk Kim
- Department of Microbiology and Molecular Genetics and the Center for Microbial Pathogenesis, Michigan State University, East Lansing, MI 48824, USA
| | - Shane Mallon
- Department of Microbiology and Molecular Genetics and the Center for Microbial Pathogenesis, Michigan State University, East Lansing, MI 48824, USA
| | - Todd A Ciche
- Department of Microbiology and Molecular Genetics and the Center for Microbial Pathogenesis, Michigan State University, East Lansing, MI 48824, USA
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