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Beckmann JF, Van Vaerenberghe K, Akwa DE, Cooper BS. A single mutation weakens symbiont-induced reproductive manipulation through reductions in deubiquitylation efficiency. Proc Natl Acad Sci U S A 2021; 118:e2113271118. [PMID: 34548405 PMCID: PMC8488622 DOI: 10.1073/pnas.2113271118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 11/18/2022] Open
Abstract
Animals interact with microbes that affect their performance and fitness, including endosymbionts that reside inside their cells. Maternally transmitted Wolbachia bacteria are the most common known endosymbionts, in large part because of their manipulation of host reproduction. For example, many Wolbachia cause cytoplasmic incompatibility (CI) that reduces host embryonic viability when Wolbachia-modified sperm fertilize uninfected eggs. Operons termed cifs control CI, and a single factor (cifA) rescues it, providing Wolbachia-infected females a fitness advantage. Despite CI's prevalence in nature, theory indicates that natural selection does not act to maintain CI, which varies widely in strength. Here, we investigate the genetic and functional basis of CI-strength variation observed among sister Wolbachia that infect Drosophila melanogaster subgroup hosts. We cloned, Sanger sequenced, and expressed cif repertoires from weak CI-causing wYak in Drosophila yakuba, revealing mutations suspected to weaken CI relative to model wMel in D. melanogaster A single valine-to-leucine mutation within the deubiquitylating (DUB) domain of the wYak cifB homolog (cidB) ablates a CI-like phenotype in yeast. The same mutation reduces both DUB efficiency in vitro and transgenic CI strength in the fly, each by about twofold. Our results map hypomorphic transgenic CI to reduced DUB activity and indicate that deubiquitylation is central to CI induction in cid systems. We also characterize effects of other genetic variation distinguishing wMel-like cifs Importantly, CI strength determines Wolbachia prevalence in natural systems and directly influences the efficacy of Wolbachia biocontrol strategies in transinfected mosquito systems. These approaches rely on strong CI to reduce human disease.
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Affiliation(s)
- John F Beckmann
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849;
| | | | - Daniel E Akwa
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849
| | - Brandon S Cooper
- Division of Biological Sciences, University of Montana, Missoula, MT 59801
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2
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Yang S, Ren CL, Ma TY, Zou WQ, Dai L, Tian XY, Liu XH, Tan CX. 1,2,4-Oxadiazole-Based Bio-Isosteres of Benzamides: Synthesis, Biological Activity and Toxicity to Zebrafish Embryo. Int J Mol Sci 2021; 22:ijms22052367. [PMID: 33673430 PMCID: PMC7956408 DOI: 10.3390/ijms22052367] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 02/17/2021] [Accepted: 02/24/2021] [Indexed: 02/07/2023] Open
Abstract
To discover new compounds with broad spectrum and high activity, we designed a series of novel benzamides containing 1,2,4-oxadiazole moiety by bioisosterism, and 28 benzamides derivatives with antifungal activity were synthesized. These compounds were evaluated against four fungi: Botrytis cinereal, FusaHum graminearum, Marssonina mali, and Thanatephorus cucumeris. The results indicated that most of the compounds displayed good fungicidal activities, especially against Botrytis cinereal. For example, 10a (84.4%), 10d (83.6%), 10e (83.3%), 10f (83.1%), 10i (83.3%), and 10l (83.6%) were better than pyraclostrobin (81.4%) at 100 mg/L. In addition, the acute toxicity of 10f to zebrafish embryo was 20.58 mg/L, which was classified as a low-toxicity compound.
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Affiliation(s)
| | | | | | | | | | | | | | - Cheng-Xia Tan
- Correspondence: ; Tel.: +86-571-8832-0238; Fax: +86-571-8832-0238
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3
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Wang X, Ren Y, Li J, Ji Z, Chen F, Wang X. Identification of the 14-3-3 β/α-A protein as a novel maternal peptidoglycan-binding protein that protects embryos of zebrafish against bacterial infections. Dev Comp Immunol 2021; 114:103867. [PMID: 32931839 DOI: 10.1016/j.dci.2020.103867] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/02/2020] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
14-3-3 proteins are widespread in animals, but their functions and mechanisms remain poorly defined. Here we clearly demonstrate that 14-3-3 β/α-A is a newly identified PGN-binding protein present abundantly in the eggs/embryos of zebrafish. We also show that recombinant 14-3-3 β/α-A acts as a pattern recognition receptor capable of identifying the bacterial signature molecule PGN, binding the bacteria, and functions as an antibacterial effector molecule directly killing the bacteria. Importantly, microinjection of r14-3-3 β/α-A into early embryos significantly enhanced the resistance of the embryos against pathogenic A. hydrophila challenge, and this enhanced bacterial resistance was markedly reduced by co-injection of anti-14-3-3 β/α-A antibody. Collectively, these results indicate that 14-3-3 β/α-A is a maternal PGN-binding protein that can protect the early embryos of zebrafish against pathogenic attacks, a novel role assigned to 14-3-3 β/α-A proteins. This work also provides new insights into 14-3-3 proteins that are widely distributed in various animals.
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Affiliation(s)
- Xia Wang
- Shandong Provincial Key Laboratory of Biochemical Engineering, College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
| | - Yiqing Ren
- Shandong Provincial Key Laboratory of Biochemical Engineering, College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China
| | - Jing Li
- Shandong Provincial Key Laboratory of Biochemical Engineering, College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China; East China University of Science and Technology, School of Biotechnology, Shanghai, 200237, China
| | - Zhe Ji
- Shandong Provincial Key Laboratory of Biochemical Engineering, College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China
| | - Fushan Chen
- Shandong Provincial Key Laboratory of Biochemical Engineering, College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China
| | - Xiudan Wang
- Shandong Provincial Key Laboratory of Biochemical Engineering, College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
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4
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Abstract
The development of powerful model systems has been a critical strategy for understanding the mechanisms underlying the progression of an animal through its ontogeny. Here we provide two examples that allow deep and mechanistic insight into the development of specific animal systems. Species of the cnidarian genus Hydra have provided excellent models for studying host-microbe interactions and how metaorganisms function in vivo. Studies of the Hawaiian bobtail squid Euprymna scolopes and its luminous bacterial partner Vibrio fischeri have been used for over 30 years to understand the impact of a broad array of levels, from ecology to genomics, on the development and persistence of symbiosis. These examples provide an integrated perspective of how developmental processes work and evolve within the context of a microbial world, a new view that opens vast horizons for developmental biology research. The Hydra and the squid systems also lend an example of how profound insights can be discovered by taking advantage of the "experiments" that evolution had done in shaping conserved developmental processes.
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Affiliation(s)
- Margaret McFall-Ngai
- Pacific Biosciences Research Center, Kewalo Marine Laboratory, University of Hawai'i at Mānoa, Honolulu, HI, United States.
| | - Thomas C G Bosch
- Zoological Institute, Christian-Albrechts-University Kiel, Kiel, Germany
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5
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Nguyen SV, Muthappa DM, Eshwar AK, Buckley JF, Murphy BP, Stephan R, Lehner A, Fanning S. Comparative genomic insights into Yersinia hibernica - a commonly misidentified Yersinia enterocolitica-like organism. Microb Genom 2020; 6:mgen000411. [PMID: 32701425 PMCID: PMC7643974 DOI: 10.1099/mgen.0.000411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 07/07/2020] [Indexed: 11/18/2022] Open
Abstract
Food-associated outbreaks linked to enteropathogenic Yersinia enterocolitica are of concern to public health. Pigs and their meat are recognized risk factors for transmission of Y. enterocolitica. This study aimed to describe the comparative genomics of Y. enterocolitica along with a number of misclassified Yersinia isolates, now constituting the recently described Yersinia hibernica. The latter was originally cultured from an environmental sample taken at a pig slaughterhouse. Unique features were identified in the genome of Y. hibernica, including a novel integrative conjugative element (ICE), denoted as ICEYh-1 contained within a 255 kbp region of plasticity. In addition, a zebrafish embryo infection model was adapted and applied to assess the virulence potential among Yersinia isolates including Y. hibernica.
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Affiliation(s)
- Scott Van Nguyen
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, Belfield, Dublin D04 N2E5, Ireland
| | - Dechamma Mundanda Muthappa
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, Belfield, Dublin D04 N2E5, Ireland
| | - Athmanya K. Eshwar
- Institute for Food Safety and Hygiene, University of Zurich, Zurich, Switzerland
| | - James F. Buckley
- Veterinary Food Safety Laboratory, Cork County Council, Inniscarra, Co. Cork and Department of Microbiology, National University of Ireland, Cork, College Road, Cork, Ireland
| | - Brenda P. Murphy
- Veterinary Food Safety Laboratory, Cork County Council, Inniscarra, Co. Cork and Department of Microbiology, National University of Ireland, Cork, College Road, Cork, Ireland
| | - Roger Stephan
- Institute for Food Safety and Hygiene, University of Zurich, Zurich, Switzerland
| | - Angelika Lehner
- Institute for Food Safety and Hygiene, University of Zurich, Zurich, Switzerland
| | - Séamus Fanning
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Sports Science, University College Dublin, Belfield, Dublin D04 N2E5, Ireland
- Institute for Global Food Security, Queen’s University Belfast, 19 Chlorine Gardens, Belfast BT9 5AG, UK
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Damjanovic K, Menéndez P, Blackall LL, van Oppen MJH. Early Life Stages of a Common Broadcast Spawning Coral Associate with Specific Bacterial Communities Despite Lack of Internalized Bacteria. Microb Ecol 2020; 79:706-719. [PMID: 31435691 DOI: 10.1007/s00248-019-01428-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 08/13/2019] [Indexed: 06/10/2023]
Abstract
Coral-associated bacteria are critical for the well-being of their host and may play essential roles during ontogeny, as suggested by the vertical transmission of some bacteria in brooding corals. Bacterial acquisition patterns in broadcast spawners remain uncertain, as 16S rRNA gene metabarcoding of coral early life stages suggests the presence of bacterial communities, which have not been detected by microscopic examinations. Here, we combined 16S rRNA gene metabarcoding with fluorescence in situ hybridization (FISH) microscopy to analyze bacterial assemblages in Acropora tenuis egg-sperm bundles, embryos, and larvae following a spawning event. Metabarcoding results indicated that A. tenuis offspring ≤ 4-day-old were associated with diverse and dynamic bacterial microbiomes, dominated by Rhodobacteraceae, Alteromonadaceae, and Oceanospirillaceae. While FISH analyses confirmed the lack of internalized bacteria in A. tenuis offspring, metabarcoding showed that even the earliest life stages examined (egg-sperm bundles and two-cell stages) were associated with a diverse bacterial community, suggesting the bacteria were confined to the mucus layer. These results can be explained by vertical transmission of certain taxa (mainly Endozoicomonas) in the mucus surrounding the gametes within bundles, or by horizontal bacterial transmission through the release of bacteria by spawning adults into the water column.
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Affiliation(s)
- Katarina Damjanovic
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
- Australian Institute of Marine Science, PMB No 3, Townsville MC, QLD, 4810, Australia.
| | - Patricia Menéndez
- Australian Institute of Marine Science, PMB No 3, Townsville MC, QLD, 4810, Australia
- Department of Econometrics and Business Statistics, Monash University, Clayton, VIC, 3800, Australia
| | - Linda L Blackall
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Madeleine J H van Oppen
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia
- Australian Institute of Marine Science, PMB No 3, Townsville MC, QLD, 4810, Australia
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7
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Bing XL, Lu YJ, Xia CB, Xia X, Hong XY. Transcriptome of Tetranychus urticae embryos reveals insights into Wolbachia-induced cytoplasmic incompatibility. Insect Mol Biol 2020; 29:193-204. [PMID: 31596027 DOI: 10.1111/imb.12620] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 09/24/2019] [Accepted: 10/02/2019] [Indexed: 06/10/2023]
Abstract
The endosymbiont Wolbachia is known for manipulating host reproduction in selfish ways. However, the molecular mechanisms have not yet been investigated in embryos. Here, we found that Wolbachia had no effect on the number of deposited eggs in Tetranychus urticae Koch (Acari: Tetranychidae) but caused two types of reproductive manipulation: killing uninfected female embryos via cytoplasmic incompatibility (CI) and increasing the hatching ratio of infected female embryos. RNA sequencing analyses showed that 145 genes were differentially expressed between Wolbachia-infected (WI) and Wolbachia-uninfected (WU) embryos. Wolbachia infection down-regulated messenger RNA (mRNA) expression of glutathione S-transferase that could buffer oxidative stress. In addition, 1613 and 294 genes were identified as CI-specific up-/down-regulated genes. Compared to WU and WI embryos, embryos of CI cross strongly expressed genes involved in transcription, translation, tissue morphogenesis, DNA damage and mRNA surveillance. In contrast, most of the genes associated with energy production and metabolism were down-regulated in the CI embryos compared to the WU and WI embryos, which provides some clues as to the cause of death of CI embryos. These results identify several genes that could be candidates for explaining Wolbachia-induced CI. Our data form a basis to help elucidate the molecular consequences of CI in embryos.
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Affiliation(s)
- X-L Bing
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Y-J Lu
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - C-B Xia
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - X Xia
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - X-Y Hong
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
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8
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Zupo V, Mutalipassi M, Ruocco N, Glaviano F, Pollio A, Langellotti AL, Romano G, Costantini M. Distribution of Toxigenic Halomicronema spp. in Adjacent Environments on the Island of Ischia: Comparison of Strains from Thermal Waters and Free Living in Posidonia Oceanica Meadows. Toxins (Basel) 2019; 11:toxins11020099. [PMID: 30747108 PMCID: PMC6409854 DOI: 10.3390/toxins11020099] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 02/01/2019] [Indexed: 11/30/2022] Open
Abstract
Organisms adaptable to extreme conditions share the ability to establish protective biofilms or secrete defence toxins. The extracellular substances that are secreted may contain monosaccharides and other toxic compounds, but environmental conditions influence biofilm characteristics. Microorganisms that are present in the same environment achieve similar compositions, regardless of their phylogenetic relationships. Alternatively, cyanobacteria phylogenetically related may live in different environments, but we ignore if their physiological answers may be similar. To test this hypothesis, two strains of cyanobacteria that were both ascribed to the genus Halomicronema were isolated. H. metazoicum was isolated in marine waters off the island of Ischia (Bay of Naples, Italy), free living on leaves of Posidonia oceanica. Halomicronema sp. was isolated in adjacent thermal waters. Thus, two congeneric species adapted to different environments but diffused in the same area were polyphasically characterized by microscopy, molecular, and toxicity analyses. A variable pattern of toxicity was exhibited, in accordance with the constraints imposed by the host environments. Cyanobacteria adapted to extreme environments of thermal waters face a few competitors and exhibit a low toxicity; in contrast, congeneric strains that have adapted to stable and complex environments as seagrass meadows compete with several organisms for space and resources, and they produce toxic compounds that are constitutively secreted in the surrounding waters.
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Affiliation(s)
- Valerio Zupo
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy.
| | - Mirko Mutalipassi
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy.
| | - Nadia Ruocco
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy.
| | - Francesca Glaviano
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy.
| | - Antonino Pollio
- Department of Biology, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cinthia, 80126 Naples, Italy.
| | - Antonio Luca Langellotti
- CAISIAL, Aquaculture division, University of Naples Federico II. Via Università, 80055 Portici (NA), Italy.
| | - Giovanna Romano
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy.
| | - Maria Costantini
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy.
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Cafora M, Deflorian G, Forti F, Ferrari L, Binelli G, Briani F, Ghisotti D, Pistocchi A. Phage therapy against Pseudomonas aeruginosa infections in a cystic fibrosis zebrafish model. Sci Rep 2019; 9:1527. [PMID: 30728389 PMCID: PMC6365511 DOI: 10.1038/s41598-018-37636-x] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 12/11/2018] [Indexed: 12/21/2022] Open
Abstract
Cystic fibrosis (CF) is a hereditary disease due to mutations in the CFTR gene and causes mortality in humans mainly due to respiratory infections caused by Pseudomonas aeruginosa. In a previous work we used phage therapy, which is a treatment with a mix of phages, to actively counteract acute P. aeruginosa infections in mice and Galleria mellonella larvae. In this work we apply phage therapy to the treatment of P. aeruginosa PAO1 infections in a CF zebrafish model. The structure of the CFTR channel is evolutionary conserved between fish and mammals and cftr-loss-of-function zebrafish embryos show a phenotype that recapitulates the human disease, in particular with destruction of the pancreas. We show that phage therapy is able to decrease lethality, bacterial burden, and the pro-inflammatory response caused by PAO1 infection. In addition, phage administration relieves the constitutive inflammatory state of CF embryos. To our knowledge, this is the first time that phage therapy is used to cure P. aeruginosa infections in a CF animal model. We also find that the curative effect against PAO1 infections is improved by combining phages and antibiotic treatments, opening a useful therapeutic approach that could reduce antibiotic doses and time of administration.
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Affiliation(s)
- Marco Cafora
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano - LITA, via Fratelli Cervi 93, 20090, Segrate, MI, Italy
| | - Gianluca Deflorian
- Istituto FIRC di Oncologia Molecolare - IFOM, Via Adamello 16, 20139, Milano, Italy
| | - Francesca Forti
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Laura Ferrari
- Istituto FIRC di Oncologia Molecolare - IFOM, Via Adamello 16, 20139, Milano, Italy
| | - Giorgio Binelli
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, Via J.H. Dunant 3, Varese, Italy
| | - Federica Briani
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Daniela Ghisotti
- Dipartimento di Bioscienze, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Anna Pistocchi
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano - LITA, via Fratelli Cervi 93, 20090, Segrate, MI, Italy.
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10
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Babczyńska A, Sułowicz S, Talik E, Hermyt M, Bednarek A, Sawadro M, Molenda A. Sterile Capsule-Egg Cocoon Covering Constitutes an Antibacterial Barrier for Spider Parasteatoda tepidariorum Embryos. Physiol Biochem Zool 2019; 92:115-124. [PMID: 30601104 DOI: 10.1086/701390] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Coexistence of organisms and pathogens has resulted in the evolution of efficient antimicrobial defense, especially at the embryonic stage. This investigation aimed to substantiate the hypothesis that the layers of silk in a spider cocoon play a role in the immunity of the embryos against microorganisms present in the external environment. A two-step interdisciplinary attempt has been made. First, the eggs and empty cocoons of the spider Parasteatoda tepidariorum were incubated on lysogeny broth agar media for 3 d. In the samples of eggs, no growth of bacteria was detected. This indicated that the eggs inside cocoons were sterile. Therefore, in the second step, the cocoons and egg surface were analyzed using SEM, TEM, and LM. The obtained images demonstrated that both inner and outer layers of the silk are built of threads of the same diameter, set in an irregular manner, and randomly clustered into groups. The threads in the outer layer were packed more densely than in the inner one. TEM analysis revealed threads of two types of fibrils and their arrangement. The resultant thread tangle of the cocoon, possibly correlated with the ultrastructure of the fibers, seems to be an example of a structure-function relationship playing a crucial ecoimmunological role in spider embryonic development.
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11
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Ote M, Yamamoto D. The Wolbachia protein TomO interacts with a host RNA to induce polarization defects in Drosophila oocytes. Arch Insect Biochem Physiol 2018; 99:e21475. [PMID: 29851149 DOI: 10.1002/arch.21475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Wolbachia is an endosymbiont prevalent in arthropods. To maximize its transmission thorough the female germline, Wolbachia induces in infected hosts male-to-female transformation, male killing, parthenogenesis, and cytoplasmic incompatibility, depending on the host species and Wolbachia strain involved. However, the molecular mechanisms underlying these host manipulations by Wolbachia remain largely unknown. The Wolbachia strain wMel, an inhabitant of Drosophila melanogaster, impairs host oogenesis only when transplanted into a heterologous host, for example, Drosophila simulans. We found that egg polarity defects induced by wMel infection in D. simulans can be recapitulated in the natural host D. melanogaster by transgenic overexpression of a variant of the Wolbachia protein Toxic manipulator of oogenesis (TomO), TomOwMel∆HS , in the female germline. RNA immunoprecipitation assays demonstrated that TomO physically associates with orb mRNA, which, as a result, fails to interact with the translation repressor Cup. This leads to precocious translation of Orb, a posterior determinant, and thereby to the misspecification of oocytes and accompanying polarity defects. We propose that the ability of TomO to bind to orb mRNA might provide a means for Wolbachia to enter the oocyte located at the posterior end of the egg chamber, thereby accomplishing secure maternal transmission thorough the female germline.
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Affiliation(s)
- Manabu Ote
- Division of Neurogenetics, Tohoku University, Sendai, Miyagi, Japan
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12
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Seemann F, Peterson DR, Chiang MWL, Au DWT. The development of cellular immune defence in marine medaka Oryzias melastigma. Comp Biochem Physiol C Toxicol Pharmacol 2017; 199:81-89. [PMID: 28347744 DOI: 10.1016/j.cbpc.2017.03.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 03/14/2017] [Accepted: 03/19/2017] [Indexed: 12/12/2022]
Abstract
Environmentally induced alterations of the immune system during sensitive developmental stages may manifest as abnormalities in immune organ configuration and/or immune cell differentiation. These not only render the early life stages more vulnerable to pathogens, but may also affect the adult immune competence. Knowledge of these sensitive periods in fish would provide an important prognostic/diagnostic tool for aquatic risk assessment of immunotoxicants. The marine medaka Oryzias melastigma is an emerging seawater fish model for immunotoxicology. Here, the presence and onset of four potentially sensitive periods during the development of innate and adaptive cellular immune defence were revealed in O. melastigma: 1.) initiation of phagocyte differentiation, 2.) migration and expansion of lymphoid progenitor cells, 3.) colonization of immune organs through lymphocyte progenitors and 4.) establishment of immune competence in the thymus. By using an established bacterial resistance assay for O. melastigma, larval immune competence (from newly hatched 1dph to 14dph) was found concomitantly increased with advanced thymus development and the presence of mature T-lymphocytes. A comparison between the marine O. melastigma and the freshwater counterpart Oryzias latipes disclosed a disparity in the T-lymphocyte maturation pattern, resulting in differences in the length of T-lymphocyte maturation. The results shed light on a potential difference between seawater and freshwater medaka in their sensitivity to environmental immunotoxicants. Further, medaka immune system development was compared and contrasted to economically important fish. The present study has provided a strong scientific basis for advanced investigation of critical windows for immune system development in fish.
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Affiliation(s)
- Frauke Seemann
- State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong Special Administrative Region
| | - Drew Ryan Peterson
- State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong Special Administrative Region
| | - Michael Wai Lun Chiang
- State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong Special Administrative Region
| | - Doris Wai Ting Au
- State Key Laboratory in Marine Pollution, Department of Biology and Chemistry, City University of Hong Kong, Hong Kong Special Administrative Region.
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13
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Crim MJ, Lawrence C, Livingston RS, Rakitin A, Hurley SJ, Riley LK. Comparison of Antemortem and Environmental Samples for Zebrafish Health Monitoring and Quarantine. J Am Assoc Lab Anim Sci 2017; 56:412-424. [PMID: 28724491 PMCID: PMC5517331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/14/2016] [Accepted: 01/12/2017] [Indexed: 06/07/2023]
Abstract
Molecular diagnostic assays offer both exquisite sensitivity and the ability to test a wide variety of sample types. Various types of environmental sample, such as detritus and concentrated water, might provide a useful adjunct to sentinels in routine zebrafish health monitoring. Similarly, antemortem sampling would be advantageous for expediting zebrafish quarantine, without euthanasia of valuable fish. We evaluated the detection of Mycobacterium chelonae, M. fortuitum, M. peregrinum, Pseudocapillaria tomentosa, and Pseudoloma neurophilia in zebrafish, detritus, pooled feces, and filter membranes after filtration of 1000-, 500-, and 150-mL water samples by real-time PCR analysis. Sensitivity varied according to sample type and pathogen, and environmental sampling was significantly more sensitive than zebrafish sampling for detecting Mycobacterium spp. but not for Pseudocapillaria neurophilia or Pseudoloma tomentosa. The results of these experiments provide strong evidence of the utility of multiple sample types for detecting pathogens according to each pathogen's life cycle and ecological niche within zebrafish systems. In a separate experiment, zebrafish subclinically infected with M. chelonae, M. marinum, Pleistophora hyphessobryconis, Pseudocapillaria tomentosa, or Pseudoloma neurophilia were pair-spawned and individually tested with subsets of embryos from each clutch that received no rinse, a fluidizing rinse, or were surface-disinfected with sodium hypochlorite. Frequently, one or both parents were subclinically infected with pathogen(s) that were not detected in any embryo subset. Therefore, negative results from embryo samples may not reflect the health status of the parent zebrafish.
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Affiliation(s)
- Marcus J Crim
- IDEXX BioResearch, Columbia, Missouri, Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri;,
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Wambaugh MA, Shakya VPS, Lewis AJ, Mulvey MA, Brown JCS. High-throughput identification and rational design of synergistic small-molecule pairs for combating and bypassing antibiotic resistance. PLoS Biol 2017. [PMID: 28632788 PMCID: PMC5478098 DOI: 10.1371/journal.pbio.2001644] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Antibiotic-resistant infections kill approximately 23,000 people and cost $20,000,000,000 each year in the United States alone despite the widespread use of small-molecule antimicrobial combination therapy. Antibiotic combinations typically have an additive effect: the efficacy of the combination matches the sum of the efficacies of each antibiotic when used alone. Small molecules can also act synergistically when the efficacy of the combination is greater than the additive efficacy. However, synergistic combinations are rare and have been historically difficult to identify. High-throughput identification of synergistic pairs is limited by the scale of potential combinations: a modest collection of 1,000 small molecules involves 1 million pairwise combinations. Here, we describe a high-throughput method for rapid identification of synergistic small-molecule pairs, the overlap2 method (O2M). O2M extracts patterns from chemical-genetic datasets, which are created when a collection of mutants is grown in the presence of hundreds of different small molecules, producing a precise set of phenotypes induced by each small molecule across the mutant set. The identification of mutants that show the same phenotype when treated with known synergistic molecules allows us to pinpoint additional molecule combinations that also act synergistically. As a proof of concept, we focus on combinations with the antibiotics trimethoprim and sulfamethizole, which had been standard treatment against urinary tract infections until widespread resistance decreased efficacy. Using O2M, we screened a library of 2,000 small molecules and identified several that synergize with the antibiotic trimethoprim and/or sulfamethizole. The most potent of these synergistic interactions is with the antiviral drug azidothymidine (AZT). We then demonstrate that understanding the molecular mechanism underlying small-molecule synergistic interactions allows the rational design of additional combinations that bypass drug resistance. Trimethoprim and sulfamethizole are both folate biosynthesis inhibitors. We find that this activity disrupts nucleotide homeostasis, which blocks DNA replication in the presence of AZT. Building on these data, we show that other small molecules that disrupt nucleotide homeostasis through other mechanisms (hydroxyurea and floxuridine) also act synergistically with AZT. These novel combinations inhibit the growth and virulence of trimethoprim-resistant clinical Escherichia coli and Klebsiella pneumoniae isolates, suggesting that they may be able to be rapidly advanced into clinical use. In sum, we present a generalizable method to screen for novel synergistic combinations, to identify particular mechanisms resulting in synergy, and to use the mechanistic knowledge to rationally design new combinations that bypass drug resistance. Antibiotic resistance is a growing problem that threatens our ability to treat systemic bacterial infections. One strategy to combat antibiotic resistance is the use of synergistic antibiotic pairs that, when combined, have activity that is considerably greater than the sum of each individual drug’s activity on its own. Synergistic combinations can even inhibit the growth of bacteria that are resistant to the individual treatment drugs. However, synergistic pairs are rare and difficult to identify. High-throughput identification of synergistic pairs is challenging due to scale: 1 million different pairs are possible for a relatively small collection of 1,000 small molecules. Here, we describe a high-throughput method for rapid identification of synergistic small-molecule pairs, termed the overlap2 method (O2M), that dramatically speeds up the screening process. First, we identify mutants that show the same phenotype when treated with each individual molecule in a synergistic pair, then use this information to guide screens for additional synergistic pairs. As a proof of concept, we studied the synergistic antibiotic pair trimethoprim and sulfamethizole, and we identified several additional synergistic molecules. Among these is the antiviral drug azidothymidine (AZT), which blocks bacterial DNA replication. Trimethoprim and sulfamethizole both inhibit folate biosynthesis, which is necessary for the proper synthesis of nucleotides for DNA replication and repair. We found that reduced nucleotide levels sensitize E. coli cells to AZT. When we substitute trimethoprim with other small molecules that also reduce nucleotide levels, we find that these small molecules also act synergistically with AZT. Indeed, AZT in combination with trimethoprim substitutes inhibits the growth of trimethoprim-resistant clinical isolates more potently than trimethoprim and AZT or trimethoprim and sulfamethizole. This work demonstrates that when we resolve the pathways that underlie synergistic interactions, we can then identify additional small molecules that act by similar mechanisms, providing a means to bypass antibiotic resistance.
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MESH Headings
- Animals
- Anti-Bacterial Agents/chemistry
- Anti-Bacterial Agents/pharmacology
- Anti-Bacterial Agents/therapeutic use
- Anti-Infective Agents, Urinary/chemistry
- Anti-Infective Agents, Urinary/pharmacology
- Anti-Infective Agents, Urinary/therapeutic use
- Bacterial Proteins/antagonists & inhibitors
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- Biological Assay
- Computational Biology
- Drug Design
- Drug Resistance, Multiple, Bacterial
- Drug Synergism
- Drug Therapy, Combination
- Embryo, Nonmammalian/drug effects
- Embryo, Nonmammalian/metabolism
- Embryo, Nonmammalian/microbiology
- Escherichia coli/drug effects
- Escherichia coli/growth & development
- Escherichia coli/metabolism
- Escherichia coli Infections/drug therapy
- Escherichia coli Infections/metabolism
- Escherichia coli Infections/microbiology
- Folic Acid Antagonists/chemistry
- Folic Acid Antagonists/pharmacology
- Folic Acid Antagonists/therapeutic use
- High-Throughput Screening Assays
- Klebsiella Infections/drug therapy
- Klebsiella Infections/metabolism
- Klebsiella Infections/microbiology
- Klebsiella pneumoniae/drug effects
- Klebsiella pneumoniae/growth & development
- Klebsiella pneumoniae/metabolism
- Microbial Sensitivity Tests
- Mutation
- Mutation Rate
- Pattern Recognition, Automated
- Reverse Transcriptase Inhibitors/chemistry
- Reverse Transcriptase Inhibitors/pharmacology
- Reverse Transcriptase Inhibitors/therapeutic use
- Small Molecule Libraries
- Sulfamethizole/agonists
- Sulfamethizole/chemistry
- Sulfamethizole/pharmacology
- Sulfamethizole/therapeutic use
- Trimethoprim/agonists
- Trimethoprim/chemistry
- Trimethoprim/pharmacology
- Trimethoprim/therapeutic use
- Zebrafish/embryology
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Affiliation(s)
- Morgan A. Wambaugh
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Viplendra P. S. Shakya
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Adam J. Lewis
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Matthew A. Mulvey
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Jessica C. S. Brown
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- * E-mail:
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Oliveira JMM, Galhano V, Henriques I, Soares AMVM, Loureiro S. Basagran ® induces developmental malformations and changes the bacterial community of zebrafish embryos. Environ Pollut 2017; 221:52-63. [PMID: 27913070 DOI: 10.1016/j.envpol.2016.10.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 10/07/2016] [Accepted: 10/08/2016] [Indexed: 06/06/2023]
Abstract
This study aimed to assess the effects of Basagran® on zebrafish (Danio rerio) embryos. The embryos were exposed to Basagran® at concentrations ranging from 120.0 to 480.6 mg/L, and the effects on embryo development (up to 96 h) and bacterial communities of 96 h-larvae were assessed. The embryo development response was time-dependent and concentration-dependent (106.35 < EC50 < 421.58 mg/L). The sensitivity of embryo-related endpoints decreased as follows: blood clotting in the head and/or around the yolk sac > delay or anomaly in yolk sac absorption > change in swimming equilibrium > development of pericardial and/or yolk sac oedema > scoliosis. A PCR-DGGE analysis was used to evaluate changes in the structure, richness, evenness and diversity of bacterial communities after herbicide exposure. A herbicide-induced structural adjustment of bacterial community was observed. In this study, it was successfully demonstrated that Basagran® affected zebrafish embryos and associated bacterial communities, showing time-dependent and concentration-dependent embryos' developmental response and structural changes in bacterial community. Thus, this work provides for the first time a complementary approach, which is useful to derive robust toxicity thresholds considering the embryo-microbiota system as a whole. The aquatic hazard assessment will be strengthened by combining current ecotoxicological tests with molecular microbiology tools.
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Affiliation(s)
- Jacinta M M Oliveira
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
| | - Victor Galhano
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
| | - Isabel Henriques
- Department of Biology, CESAM & iBiMED, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
| | - Amadeu M V M Soares
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
| | - Susana Loureiro
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
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16
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De Rijcke M, Van Acker E, Nevejan N, De Schamphelaere KAC, Janssen CR. Toxic dinoflagellates and Vibrio spp. act independently in bivalve larvae. Fish Shellfish Immunol 2016; 57:236-242. [PMID: 27554394 DOI: 10.1016/j.fsi.2016.08.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 08/09/2016] [Accepted: 08/13/2016] [Indexed: 06/06/2023]
Abstract
Harmful algal blooms (HABs) and marine pathogens - like Vibrio spp. - are increasingly common due to climate change. These stressors affect the growth, viability and development of bivalve larvae. Little is known, however, about the potential for interactions between these two concurrent stressors. While some mixed exposures have been performed with adult bivalves, no such work has been done with larvae which are generally more sensitive. This study examines whether dinoflagellates and bacteria may interactively affect the viability and immunological resilience of blue mussel Mytilus edulis larvae. Embryos were exposed to environmentally relevant concentrations (100, 500, 2500 & 12,500 cells ml(-1)) of a dinoflagellate (Alexandrium minutum, Alexandrium ostenfeldii, Karenia mikimotoi, Protoceratium reticulatum, Prorocentrum cordatum, P. lima or P. micans), a known pathogen (Vibrio coralliilyticus/neptunius-like isolate or Vibrio splendidus; 10(5) CFU ml(-1)), or both. After five days of exposure, significant (p < 0.05) adverse effects on larval viability and larval development were found for all dinoflagellates (except P. cordatum) and V. splendidus. Yet, despite the individual effect of each stressor, no significant interactions were found between the pathogens and harmful algae. The larval viability and the phenoloxidase innate immune system responded independently to each stressor. This independence may be related to a differential timing of the effects of HABs and pathogens.
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Affiliation(s)
- M De Rijcke
- Ghent University (UGent), Faculty of Bioscience Engineering, Department of Applied Ecology and Environmental Biology, Laboratory of Environmental Toxicology and Aquatic Ecology, 9000 Ghent, Belgium.
| | - E Van Acker
- Ghent University (UGent), Faculty of Bioscience Engineering, Department of Applied Ecology and Environmental Biology, Laboratory of Environmental Toxicology and Aquatic Ecology, 9000 Ghent, Belgium
| | - N Nevejan
- Ghent University (UGent), Faculty of Bioscience Engineering, Department of Animal Production, Laboratory of Aquaculture and ARC, 9000 Ghent, Belgium
| | - K A C De Schamphelaere
- Ghent University (UGent), Faculty of Bioscience Engineering, Department of Applied Ecology and Environmental Biology, Laboratory of Environmental Toxicology and Aquatic Ecology, 9000 Ghent, Belgium
| | - C R Janssen
- Ghent University (UGent), Faculty of Bioscience Engineering, Department of Applied Ecology and Environmental Biology, Laboratory of Environmental Toxicology and Aquatic Ecology, 9000 Ghent, Belgium
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17
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Jim KK, Engelen-Lee J, van der Sar AM, Bitter W, Brouwer MC, van der Ende A, Veening JW, van de Beek D, Vandenbroucke-Grauls CMJE. Infection of zebrafish embryos with live fluorescent Streptococcus pneumoniae as a real-time pneumococcal meningitis model. J Neuroinflammation 2016; 13:188. [PMID: 27542968 PMCID: PMC4992281 DOI: 10.1186/s12974-016-0655-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/08/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Streptococcus pneumoniae is one of the most important causes of bacterial meningitis, an infection where unfavourable outcome is driven by bacterial and host-derived toxins. In this study, we developed and characterized a pneumococcal meningitis model in zebrafish embryos that allows for real-time investigation of early host-microbe interaction. METHODS Zebrafish embryos were infected in the caudal vein or hindbrain ventricle with green fluorescent wild-type S. pneumoniae D39 or a pneumolysin-deficient mutant. The kdrl:mCherry transgenic zebrafish line was used to visualize the blood vessels, whereas phagocytic cells were visualized by staining with far red anti-L-plastin or in mpx:GFP/mpeg1:mCherry zebrafish, that have green fluorescent neutrophils and red fluorescent macrophages. Imaging was performed by fluorescence confocal and time-lapse microscopy. RESULTS After infection by caudal vein, we saw focal clogging of the pneumococci in the blood vessels and migration of bacteria through the blood-brain barrier into the subarachnoid space and brain tissue. Infection with pneumolysin-deficient S. pneumoniae in the hindbrain ventricle showed attenuated growth and migration through the brain as compared to the wild-type strain. Time-lapse and confocal imaging revealed that the initial innate immune response to S. pneumoniae in the subarachnoid space mainly consisted of neutrophils and that pneumolysin-mediated cytolytic activity caused a marked reduction of phagocytes. CONCLUSIONS This new meningitis model permits detailed analysis and visualization of host-microbe interaction in pneumococcal meningitis in real time and is a very promising tool to further our insights in the pathogenesis of pneumococcal meningitis.
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Affiliation(s)
- Kin Ki Jim
- Department of Medical Microbiology and Infection Control, VU University Medical Center, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
- Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - JooYeon Engelen-Lee
- Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Astrid M van der Sar
- Department of Medical Microbiology and Infection Control, VU University Medical Center, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
| | - Wilbert Bitter
- Department of Medical Microbiology and Infection Control, VU University Medical Center, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands
| | - Matthijs C Brouwer
- Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Arie van der Ende
- Department of Medical Microbiology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
- The Netherlands Reference Laboratory for Bacterial Meningitis, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Jan-Willem Veening
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Synthetic Biology, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands
| | - Diederik van de Beek
- Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Christina M J E Vandenbroucke-Grauls
- Department of Medical Microbiology and Infection Control, VU University Medical Center, De Boelelaan 1108, 1081 HZ, Amsterdam, The Netherlands.
- Department of Medical Microbiology and Infection Control, VU University Medical Center, P.O. Box 7057, 1007 MB, Amsterdam, The Netherlands.
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18
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Sun Y, Zhang L, Zhang M, Li R, Li Y, Hu X, Wang S, Bao Z. Characterization of three mitogen-activated protein kinases (MAPK) genes reveals involvement of ERK and JNK, not p38 in defense against bacterial infection in Yesso scallop Patinopecten yessoensis. Fish Shellfish Immunol 2016; 54:507-515. [PMID: 27155450 DOI: 10.1016/j.fsi.2016.04.139] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 04/28/2016] [Accepted: 04/30/2016] [Indexed: 06/05/2023]
Abstract
Mitogen-activated protein kinases (MAPKs) are protein Ser/Thr kinases that play a vital role in innate immune responses by converting extracellular stimuli into a wide range of cellular responses. Although MAPKs have been extensively studied in various vertebrates and invertebrates, our current understanding of MAPK signaling cascade in scallop is in its infancy. In this study, three MAPK genes (PyERK, PyJNK, and Pyp38) were identified from Yesso scallop Patinopecten yessoensis. The open reading frame of PyERK, PyJNK, and Pyp38 was 1104, 1227, and 1104 bp, encoding 367, 408, and 367 amino acids, respectively. Conservation in some splicing sites was revealed across the three PyMAPKs, suggesting the common descent of MAPKs genes. The expression profiles of PyMAPKs over the course of ten different developmental stages showed that they had different expression patterns. In adult scallops, PyMAPKs were primarily expressed in muscles, hemocytes, gill, and mantle. To gain insights into their role in innate immunity, we investigated their expression profiles after infection with Gram-positive bacteria (Micrococcus luteus) and Gram-negative bacteria (Vibrio anguillarum). Significant difference in gene expression was only found in PyERK and PyJNK, but not Pyp38, suggesting Pyp38 may not participate in immune response to bacterial infection. Besides, PyERK and PyJNK exhibited more drastic change against the invasion of V. anguillarum than M. luteus, suggesting they could be more sensitive to Gram-negative bacteria than Gram-positive bacteria. This study provides valuable resource for elucidating the role of MAPK signal pathway in bivalve innate immune response.
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Affiliation(s)
- Yan Sun
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Lingling Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
| | - Meiwei Zhang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Ruojiao Li
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yangping Li
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Xiaoli Hu
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Shi Wang
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Zhenmin Bao
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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Oliveira JMM, Almeida AR, Pimentel T, Andrade TS, Henriques JF, Soares AMVM, Loureiro S, Gomes NCM, Domingues I. Effect of chemical stress and ultraviolet radiation in the bacterial communities of zebrafish embryos. Environ Pollut 2016; 208:626-636. [PMID: 26552525 DOI: 10.1016/j.envpol.2015.10.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 10/20/2015] [Accepted: 10/22/2015] [Indexed: 06/05/2023]
Abstract
This study aimed to assess the effect of ultraviolet radiation (UVR) and chemical stress (triclosan-TCS; potassium dichromate-PD; prochloraz-PCZ) on bacterial communities of zebrafish (Danio rerio) embryos (ZEBC). Embryos were exposed to two UVR intensities and two chemical concentrations not causing mortality or any developmental effect (equivalent to the No-Observed-Effect Concentration-NOEC; NOEC diluted by 10-NOEC/10). Effects on ZEBC were evaluated using denaturing gradient gel electrophoresis (DGGE) and interpreted considering structure, richness and diversity. ZEBC were affected by both stressors even at concentrations/doses not affecting the host-organism (survival/development). Yet, some stress-tolerant bacterial groups were revealed. The structure of the ZEBC was always affected, mainly due to xenobiotic presence. Richness and diversity decreased after exposure to NOEC of PD. Interactive effects occurred for TCS and UVR. Aquatic microbiota imbalance might have repercussions for the host/aquatic system, particularly in a realistic scenario/climate change perspective therefore, future ecotoxicological models should consider xenobiotics interactions with UVR.
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Affiliation(s)
- Jacinta M M Oliveira
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
| | - Ana Rita Almeida
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
| | - Tânia Pimentel
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
| | - Thayres S Andrade
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
| | - Jorge F Henriques
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
| | - Amadeu M V M Soares
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
| | - Susana Loureiro
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
| | - Newton C M Gomes
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
| | - Inês Domingues
- Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
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Chen YZ, Yang YL, Chu WL, You MS, Lo HJ. Zebrafish Egg Infection Model for Studying Candida albicans Adhesion Factors. PLoS One 2015; 10:e0143048. [PMID: 26569623 PMCID: PMC4646526 DOI: 10.1371/journal.pone.0143048] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 10/30/2015] [Indexed: 12/15/2022] Open
Abstract
Disseminated candidiasis is associated with 30-40% mortality in severely immunocompromised patients. Among the causal agents, Candida albicans is the dominant one. Various animal models have been developed for investigating gene functions in C. albicans. Zebrafish injection models have increasingly been applied in elucidating C. albicans pathogenesis because of the conserved immunity, prolific fecundity of the zebrafish and the low costs of care systems. In this study, we established a simple, noninvasive zebrafish egg bath infection model, defined its optimal conditions, and evaluated the model with various C. albicans mutant strains. The deletion of SAP6 did not have significant effect on the virulence. By contrast, the deletion of BCR1, CPH1, EFG1, or TEC1 significantly reduced the virulence under current conditions. Furthermore, all embryos survived when co-incubated with bcr1/bcr1, cph1/cph1 efg1/efg1, efg1/efg1, or tec1/tec1 mutant cells. The results indicated that our novel zebrafish model is time-saving and cost effective.
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Affiliation(s)
- Yin-Zhi Chen
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Yun-Liang Yang
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu, Taiwan
| | - Wen-Li Chu
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - May-Su You
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Hsiu-Jung Lo
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
- School of Dentistry, China Medical University, Taichung, Taiwan
- * E-mail:
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21
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Belon C, Gannoun-Zaki L, Lutfalla G, Kremer L, Blanc-Potard AB. Mycobacterium marinum MgtC plays a role in phagocytosis but is dispensable for intracellular multiplication. PLoS One 2014; 9:e116052. [PMID: 25545682 PMCID: PMC4278808 DOI: 10.1371/journal.pone.0116052] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 12/04/2014] [Indexed: 01/04/2023] Open
Abstract
MgtC is a virulence factor involved in intramacrophage growth that has been reported in several intracellular pathogens, including Mycobacterium tuberculosis and Salmonella enterica serovar Typhimurium. MgtC participates also in adaptation to Mg2+ deprivation. Herein, we have constructed a mgtC mutant in Mycobacterium marinum to further investigate the role of MgtC in mycobacteria. We show that the M. marinum mgtC gene (Mma mgtC) is strongly induced upon Mg2+ deprivation and is required for optimal growth in Mg2+-deprived medium. The behaviour of the Mma mgtC mutant has been investigated in the Danio rerio infection model using a transgenic reporter zebrafish line that specifically labels neutrophils. Although the mgtC mutant is not attenuated in the zebrafish embryo model based on survival curves, our results indicate that phagocytosis by neutrophils is enhanced with the mgtC mutant compared to the wild-type strain following subcutaneous injection. Increased phagocytosis of the mutant strain is also observed ex vivo with the murine J774 macrophage cell line. On the other hand, no difference was found between the mgtC mutant and the wild-type strain in bacterial adhesion to macrophages and in the internalization into epithelial cells. Unlike the role reported for MgtC in other intracellular pathogens, Mma MgtC does not contribute significantly to intramacrophage replication. Taken together, these results indicate an unanticipated function of Mma MgtC at early step of infection within phagocytic cells. Hence, our results indicate that although the MgtC function is conserved among pathogens regarding adaptation to Mg2+ deprivation, its role towards phagocytic cells can differ, possibly in relation with the specific pathogen's lifestyles.
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Affiliation(s)
- Claudine Belon
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités Montpellier 2 et 1, Place Eugène Bataillon, 34095, Montpellier, Cedex 05, France
- Centre National de la Recherche Scientifique, UMR5235, Montpellier, France
| | - Laïla Gannoun-Zaki
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités Montpellier 2 et 1, Place Eugène Bataillon, 34095, Montpellier, Cedex 05, France
- Centre National de la Recherche Scientifique, UMR5235, Montpellier, France
| | - Georges Lutfalla
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités Montpellier 2 et 1, Place Eugène Bataillon, 34095, Montpellier, Cedex 05, France
- Centre National de la Recherche Scientifique, UMR5235, Montpellier, France
| | - Laurent Kremer
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités Montpellier 2 et 1, Place Eugène Bataillon, 34095, Montpellier, Cedex 05, France
- Centre National de la Recherche Scientifique, UMR5235, Montpellier, France
- Institut national de la santé et de la recherche médicale, Montpellier, France
| | - Anne-Béatrice Blanc-Potard
- Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Universités Montpellier 2 et 1, Place Eugène Bataillon, 34095, Montpellier, Cedex 05, France
- Centre National de la Recherche Scientifique, UMR5235, Montpellier, France
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Teng Z, Sun C, Liu S, Wang H, Zhang S. Functional characterization of chitinase-3 reveals involvement of chitinases in early embryo immunity in zebrafish. Dev Comp Immunol 2014; 46:489-498. [PMID: 24968080 DOI: 10.1016/j.dci.2014.06.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/14/2014] [Accepted: 06/16/2014] [Indexed: 06/03/2023]
Abstract
The function and mechanism of chitinases in early embryonic development remain largely unknown. We show here that recombinant chitinase-3 (rChi3) is able to hydrolyze the artificial chitin substrate, 4-methylumbelliferyl-β-D-N,N',N″-triacetylchitotrioside, and to bind to and inhibit the growth of the fungus Candida albicans, implicating that Chi3 plays a dual function in innate immunity and chitin-bearing food digestion in zebrafish. This is further corroborated by the expression profile of Chi3 in the liver and gut, which are both immune- and digestion-relevant organs. Compared with rChi3, rChi3-CD lacking CBD still retains partial capacity to bind to C. albicans, but its enzymatic and antifungal activities are significantly reduced. By contrast, rChi3-E140N with the putative catalytic residue E140 mutated shows little affinity to chitin, and its enzymatic and antifungal activities are nearly completely lost. These suggest that both enzymatic and antifungal activities of Chi3 are dependent on the presence of CBD and E140. We also clearly demonstrate that in zebrafish, both the embryo extract and the developing embryo display antifungal activity against C. albicans, and all the findings point to chitinase-3 (Chi3) being a newly-identified factor involved in the antifungal activity. Taken together, a dual function in both innate immunity and food digestion in embryo is proposed for zebrafish Chi3. It also provides a new angle to understand the immune role of chitinases in early embryonic development of animals.
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Affiliation(s)
- Zinan Teng
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Chen Sun
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Shousheng Liu
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Hongmiao Wang
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Department of Marine Biology, Ocean University of China, Qingdao 266003, China
| | - Shicui Zhang
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity, Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
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Yang L, Bu L, Sun W, Hu L, Zhang S. Functional characterization of mannose-binding lectin in zebrafish: implication for a lectin-dependent complement system in early embryos. Dev Comp Immunol 2014; 46:314-322. [PMID: 24858663 DOI: 10.1016/j.dci.2014.05.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 05/09/2014] [Accepted: 05/10/2014] [Indexed: 06/03/2023]
Abstract
The lectin pathway involves recognition of pathogen-associated molecular patterns by mannose-binding lectin (MBL), and the subsequent activation of associated enzymes, termed MBL-associated serine proteases (MASPs). In this study, we demonstrate that the transcript of MBL gene is present in the early embryo of zebrafish, and MBL protein is also present in the embryo. In addition, we show that recombinant zebrafish MBL was able to bind the Gram-negative bacterium Escherichia coli and the Gram-positive bacterium Staphylococcus aureus, and rMBL was able to promote the phagocytosis of E. coli and S. aureus by macrophages, indicating that like mammalian MBL, zebrafish MBL performs a dual function in both pattern recognition and opsonization. Importantly, we show that microinjection of anti-MBL antibody into the early developing embryos resulted in a significantly increased mortality in the embryos challenged with Aeromonas hydrophila (pathogenic to zebrafish); and injection of rMBL into the embryos (resulting in increase in MBL in the embryo) markedly promoted their resistance to A. hydrophila; and this promoted bacterial resistance was significantly reduced by the co-injection of anti-MBL antibody with rMBL but not by the injection of anti-actin antibody with rMBL. These suggest that the lectin pathway may be already functional in the early embryos in zebrafish before their immune system is fully matured, protecting the developing embryos from microbial infection. This work provides a new angle to understand the immune role of the lectin pathway in early development of animals.
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Affiliation(s)
- Lili Yang
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, China
| | - Lingzhen Bu
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, China
| | - Weiwei Sun
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, China
| | - Lili Hu
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, China
| | - Shicui Zhang
- Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, China.
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24
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Fenaroli F, Westmoreland D, Benjaminsen J, Kolstad T, Skjeldal FM, Meijer AH, van der Vaart M, Ulanova L, Roos N, Nyström B, Hildahl J, Griffiths G. Nanoparticles as drug delivery system against tuberculosis in zebrafish embryos: direct visualization and treatment. ACS Nano 2014; 8:7014-7026. [PMID: 24945994 DOI: 10.1021/nn5019126] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Nanoparticles (NPs) enclosing antibiotics have provided promising therapy against Mycobacterium tuberculosis (Mtb) in different mammalian models. However, the NPs were not visualized in any of these animal studies. Here, we introduce the transparent zebrafish embryo as a system for noninvasive, simultaneous imaging of fluorescent NPs and the fish tuberculosis (TB) agent Mycobacterium marinum (Mm). The study was facilitated by the use of transgenic lines of macrophages, neutrophils, and endothelial cells expressing fluorescent markers readily visible in the live vertebrate. Intravenous injection of Mm led to phagocytosis by blood macrophages. These remained within the vasculature until 3 days postinfection where they started to extravasate and form aggregates of infected cells. Correlative light/electron microscopy revealed that these granuloma-like structures had significant access to the vasculature. Injection of NPs induced rapid uptake by both infected and uninfected macrophages, the latter being actively recruited to the site of infection, thereby providing an efficient targeting into granulomas. Rifampicin-loaded NPs significantly improved embryo survival and lowered bacterial load, as shown by quantitative fluorescence analysis. Our results argue that zebrafish embryos offer a powerful system for monitoring NPs in vivo and rationalize why NP therapy was so effective against Mtb in earlier studies; bacteria and NPs share the same cellular niche.
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Affiliation(s)
- Federico Fenaroli
- Department of Biosciences, University of Oslo , Blindernveien 31, 0371 Oslo, Norway
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25
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Fenaroli F, Westmoreland D, Benjaminsen J, Kolstad T, Skjeldal FM, Meijer AH, van der Vaart M, Ulanova L, Roos N, Nyström B, Hildahl J, Griffiths G. Nanoparticles as drug delivery system against tuberculosis in zebrafish embryos: direct visualization and treatment. ACS Nano 2014; 8:7014-7026. [PMID: 24945994 DOI: 10.1021/nn5019126/suppl_file/nn5019126_si_014.pdf] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Nanoparticles (NPs) enclosing antibiotics have provided promising therapy against Mycobacterium tuberculosis (Mtb) in different mammalian models. However, the NPs were not visualized in any of these animal studies. Here, we introduce the transparent zebrafish embryo as a system for noninvasive, simultaneous imaging of fluorescent NPs and the fish tuberculosis (TB) agent Mycobacterium marinum (Mm). The study was facilitated by the use of transgenic lines of macrophages, neutrophils, and endothelial cells expressing fluorescent markers readily visible in the live vertebrate. Intravenous injection of Mm led to phagocytosis by blood macrophages. These remained within the vasculature until 3 days postinfection where they started to extravasate and form aggregates of infected cells. Correlative light/electron microscopy revealed that these granuloma-like structures had significant access to the vasculature. Injection of NPs induced rapid uptake by both infected and uninfected macrophages, the latter being actively recruited to the site of infection, thereby providing an efficient targeting into granulomas. Rifampicin-loaded NPs significantly improved embryo survival and lowered bacterial load, as shown by quantitative fluorescence analysis. Our results argue that zebrafish embryos offer a powerful system for monitoring NPs in vivo and rationalize why NP therapy was so effective against Mtb in earlier studies; bacteria and NPs share the same cellular niche.
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Affiliation(s)
- Federico Fenaroli
- Department of Biosciences, University of Oslo , Blindernveien 31, 0371 Oslo, Norway
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26
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Sarmiento-Ramírez JM, Abella-Pérez E, Phillott AD, Sim J, van West P, Martín MP, Marco A, Diéguez-Uribeondo J. Global distribution of two fungal pathogens threatening endangered sea turtles. PLoS One 2014; 9:e85853. [PMID: 24465748 PMCID: PMC3897526 DOI: 10.1371/journal.pone.0085853] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 12/03/2013] [Indexed: 11/18/2022] Open
Abstract
Nascent fungal infections are currently considered as one of the main threats for biodiversity and ecosystem health, and have driven several animal species into critical risk of extinction. Sea turtles are one of the most endangered groups of animals and only seven species have survived to date. Here, we described two pathogenic species, i.e., Fusarium falciforme and Fusarium keratoplasticum, that are globally distributed in major turtle nesting areas for six sea turtle species and that are implicated in low hatch success. These two fungi possess key biological features that are similar to emerging pathogens leading to host extinction, e.g., high virulence, and a broad host range style of life. Their optimal growth temperature overlap with the optimal incubation temperature for eggs, and they are able to kill up to 90% of the embryos. Environmental forcing, e.g., tidal inundation and clay/silt content of nests, were correlated to disease development. Thus, these Fusarium species constitute a major threat to sea turtle nests, especially to those experiencing environmental stressors. These findings have serious implications for the survival of endangered sea turtle populations and the success of conservation programs worldwide.
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Affiliation(s)
| | - Elena Abella-Pérez
- Departamento de Biología de la Conservación, Estación Biológica de Doñana-CSIC, Sevilla, Spain
| | - Andrea D. Phillott
- Faculty of Science, Asian University for Women, Chittagong, Bangladesh
- One Health Research Group, School of Public Health, Tropical Medicine and Rehabilitation Sciences, James Cook University, Townsville, Queensland, Australia
| | - Jolene Sim
- Conservation Office, Ascension Island Government, George Town, Ascension Island
| | - Pieter van West
- Aberdeen Oomycete Laboratory, College of Life Sciences and Medicine, University of Aberdeen, Scotland, United Kingdom
| | - María P. Martín
- Departamento de Micología, Real Jardín Botánico-CSIC, Madrid, Spain
| | - Adolfo Marco
- Departamento de Biología de la Conservación, Estación Biológica de Doñana-CSIC, Sevilla, Spain
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27
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Abstract
In recent years the zebrafish has gained enormous attention in infection biology, and many protocols have been developed to study interaction of both human and fish pathogens, including viruses, fungi, and bacteria, with the host. Especially the extraordinary possibilities for live imaging of disease processes in the transparent embryos using fluorescent bacteria and cell-specific reporter fish combined with gene knockdown, transcriptome, and genetic studies have dramatically advanced our understanding of disease mechanisms. The zebrafish embryo is amenable to study virulence of both extracellular and facultative intracellular pathogens introduced through the technique of microinjection. Several protocols have been published that address the different sites of injection, antisense strategies, imaging, and production of transgenic fish in detail. Here we describe a protocol to study the virulence profiles, ranging from acute fatal to persistent, of bacteria belonging to the Burkholderia cepacia complex. This standard operating protocol combines simple survival assays, analysis of bacterial kinetics, analysis of the early innate immune response with qRT-PCR, and the use of transgenic reporter fish to study interactions with host phagocytes, and is also applicable to other pathogens.
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28
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Kriesner P, Hoffmann AA, Lee SF, Turelli M, Weeks AR. Rapid sequential spread of two Wolbachia variants in Drosophila simulans. PLoS Pathog 2013; 9:e1003607. [PMID: 24068927 PMCID: PMC3771877 DOI: 10.1371/journal.ppat.1003607] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 07/24/2013] [Indexed: 11/19/2022] Open
Abstract
The maternally inherited intracellular bacteria Wolbachia can manipulate host reproduction in various ways that foster frequency increases within and among host populations. Manipulations involving cytoplasmic incompatibility (CI), where matings between infected males and uninfected females produce non-viable embryos, are common in arthropods and produce a reproductive advantage for infected females. CI was associated with the spread of Wolbachia variant wRi in Californian populations of Drosophila simulans, which was interpreted as a bistable wave, in which local infection frequencies tend to increase only once the infection becomes sufficiently common to offset imperfect maternal transmission and infection costs. However, maternally inherited Wolbachia are expected to evolve towards mutualism, and they are known to increase host fitness by protecting against infectious microbes or increasing fecundity. We describe the sequential spread over approximately 20 years in natural populations of D. simulans on the east coast of Australia of two Wolbachia variants (wAu and wRi), only one of which causes significant CI, with wRi displacing wAu since 2004. Wolbachia and mtDNA frequency data and analyses suggest that these dynamics, as well as the earlier spread in California, are best understood as Fisherian waves of favourable variants, in which local spread tends to occur from arbitrarily low frequencies. We discuss implications for Wolbachia-host dynamics and coevolution and for applications of Wolbachia to disease control. Wolbachia are bacteria that live within the cells of arthropod hosts and are widespread in many groups of insects. These bacteria can rapidly spread through a population through a process of cytoplasmic incompatibility whereby females uninfected by Wolbachia show embryo death when they mate with males carrying the bacteria. Because the infected females pass on Wolbachia to their offspring, this places them at a reproductive advantage, ensuring that the infection spreads through insect populations once it reaches a high enough frequency to overcome any negative fitness effects on its host. Yet while such a rapid spread has been predicted, it has rarely been observed in nature. Here we show that a Wolbachia infection of Drosophila simulans flies has spread very rapidly in eastern Australia, replacing another Wolbachia infection that has also spread in recent years. These invasions appear to have taken place from a very low frequency, implying that both infections are likely to have had a benefit to their hosts rather than a cost. These results have implications for the spread of Wolbachia infections currently being introduced into populations of mosquitoes and other insects for disease suppression.
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Affiliation(s)
- Peter Kriesner
- Department of Genetics, University of Melbourne, Parkville, Victoria, Australia
| | - Ary A. Hoffmann
- Department of Genetics, University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
| | - Siu F. Lee
- Department of Genetics, University of Melbourne, Parkville, Victoria, Australia
| | - Michael Turelli
- Department of Evolution and Ecology and Center for Population Biology, University of California, Davis, Davis, California, United States of America
| | - Andrew R. Weeks
- Department of Genetics, University of Melbourne, Parkville, Victoria, Australia
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Wiles TJ, Norton JP, Smith SN, Lewis AJ, Mobley HLT, Casjens SR, Mulvey MA. A phyletically rare gene promotes the niche-specific fitness of an E. coli pathogen during bacteremia. PLoS Pathog 2013; 9:e1003175. [PMID: 23459509 PMCID: PMC3573123 DOI: 10.1371/journal.ppat.1003175] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 12/19/2012] [Indexed: 12/17/2022] Open
Abstract
In bacteria, laterally acquired genes are often concentrated within chromosomal regions known as genomic islands. Using a recently developed zebrafish infection model, we set out to identify unique factors encoded within genomic islands that contribute to the fitness and virulence of a reference urosepsis isolate—extraintestinal pathogenic Escherichia coli strain CFT073. By screening a series of deletion mutants, we discovered a previously uncharacterized gene, neaT, that is conditionally required by the pathogen during systemic infections. In vitro assays indicate that neaT can limit bacterial interactions with host phagocytes and alter the aggregative properties of CFT073. The neaT gene is localized within an integrated P2-like bacteriophage in CFT073, but was rarely found within other proteobacterial genomes. Sequence-based analyses revealed that neaT homologues are present, but discordantly conserved, within a phyletically diverse set of bacterial species. In CFT073, neaT appears to be unameliorated, having an exceptionally A+T-rich composition along with a notably altered codon bias. These data suggest that neaT was recently brought into the proteobacterial pan-genome from an extra-phyletic source. Interestingly, even in G+C-poor genomes, as found within the Firmicutes lineage, neaT-like genes are often unameliorated. Sequence-level features of neaT homologues challenge the common supposition that the A+T-rich nature of many recently acquired genes reflects the nucleotide composition of their genomes of origin. In total, these findings highlight the complexity of the evolutionary forces that can affect the acquisition, utilization, and assimilation of rare genes that promote the niche-dependent fitness and virulence of a bacterial pathogen. Bacterial pathogens, even those belonging to the same species, can be incredibly diverse with regard to the genes they carry. However, the design of vaccines and antibiotics typically relies upon identification of general molecular features shared by the targeted organisms. Thus, we have traditionally focused on broadly conserved characteristics of pathogenic bacteria, often ignoring the genes that account for their individuality. In this article we report the discovery of a unique gene, neaT, that promotes the fitness of a pathogenic Escherichia coli isolate in zebrafish and mouse models of systemic blood infections. Surprisingly, neaT is rarely found in other related strains of E. coli and appears to have been recently acquired from distant lineages of bacteria via a process known as ‘lateral gene transfer’ that is used by microbes to swap genetic material. Expression of the neaT gene appears to help pathogens avoid interactions with host immune cells, possibly by altering bacterial surface structures. This work provides an interesting example of how the lateral acquisition of a rare gene can impact the niche-specific virulence properties of a pathogen, shedding light on the mechanisms that drive pathogen evolution and diversity.
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Affiliation(s)
- Travis J. Wiles
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - J. Paul Norton
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Sara N. Smith
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Adam J. Lewis
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Harry L. T. Mobley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Sherwood R. Casjens
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Matthew A. Mulvey
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
- * E-mail:
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30
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Anand P, Cermelli S, Li Z, Kassan A, Bosch M, Sigua R, Huang L, Ouellette AJ, Pol A, Welte MA, Gross SP. A novel role for lipid droplets in the organismal antibacterial response. eLife 2012; 1:e00003. [PMID: 23150794 PMCID: PMC3491588 DOI: 10.7554/elife.00003] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 09/05/2012] [Indexed: 01/19/2023] Open
Abstract
We previously discovered histones bound to cytosolic lipid droplets (LDs); here we show that this forms a cellular antibacterial defense system. Sequestered on droplets under normal conditions, in the presence of bacterial lipopolysaccharide (LPS) or lipoteichoic acid (LTA), histones are released from the droplets and kill bacteria efficiently in vitro. Droplet-bound histones also function in vivo: when injected into Drosophila embryos lacking droplet-bound histones, bacteria grow rapidly. In contrast, bacteria injected into embryos with droplet-bound histones die. Embryos with droplet-bound histones displayed more than a fourfold survival advantage when challenged with four different bacterial species. Our data suggests that this intracellular antibacterial defense system may function in adult flies, and also potentially in mice.DOI:http://dx.doi.org/10.7554/eLife.00003.001.
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Affiliation(s)
- Preetha Anand
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, United States
| | - Silvia Cermelli
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, United States
| | - Zhihuan Li
- Department of Biology, University of Rochester, Rochester, United States
| | - Adam Kassan
- Equip de Proliferació i Senyalització Cel.lular, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Marta Bosch
- Equip de Proliferació i Senyalització Cel.lular, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Robilyn Sigua
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, United States
| | - Lan Huang
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, United States
- Department of Physiology and Biophysics, University of California Irvine, Irvine, United States
| | - Andre J Ouellette
- Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California, Los Angeles, United States
| | - Albert Pol
- Equip de Proliferació i Senyalització Cel.lular, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
| | - Michael A Welte
- Department of Biology, University of Rochester, Rochester, United States
| | - Steven P Gross
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, United States
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31
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Costechareyre D, Balmand S, Condemine G, Rahbé Y. Dickeya dadantii, a plant pathogenic bacterium producing Cyt-like entomotoxins, causes septicemia in the pea aphid Acyrthosiphon pisum. PLoS One 2012; 7:e30702. [PMID: 22292023 PMCID: PMC3265518 DOI: 10.1371/journal.pone.0030702] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Accepted: 12/28/2011] [Indexed: 01/27/2023] Open
Abstract
Dickeya dadantii (syn. Erwinia chrysanthemi) is a plant pathogenic bacteria that harbours a cluster of four horizontally-transferred, insect-specific toxin genes. It was recently shown to be capable of causing an acute infection in the pea aphid Acyrthosiphon pisum (Insecta: Hemiptera). The infection route of the pathogen, and the role and in vivo expression pattern of these toxins, remain unknown. Using bacterial numeration and immunolocalization, we investigated the kinetics and the pattern of infection of this phytopathogenic bacterium within its insect host. We compared infection by the wild-type strain and by the Cyt toxin-deficient mutant. D. dadantii was found to form dense clusters in many luminal parts of the aphid intestinal tract, including the stomach, from which it invaded internal tissues as early as day 1 post-infection. Septicemia occurred soon after, with the fat body being the main infected tissue, together with numerous early infections of the embryonic chains showing embryonic gut and fat body as the target organs. Generalized septicemia led to insect death when the bacterial load reached about 10(8) cfu. Some individual aphids regularly escaped infection, indicating an effective partial immune response to this bacteria. Cyt-defective mutants killed insects more slowly but were capable of localisation in any type of tissue. Cyt toxin expression appeared to be restricted to the digestive tract where it probably assisted in crossing over the first cell barrier and, thus, accelerating bacterial diffusion into the aphid haemocel. Finally, the presence of bacteria on the surface of leaves hosting infected aphids indicated that the insects could be vectors of the bacteria.
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Affiliation(s)
- Denis Costechareyre
- INRA, UMR203 BF2I, Biologie Fonctionnelle Insecte et Interactions, INSA-Lyon, Villeurbanne, France
- Université de Lyon, Lyon, France
- Université Claude Bernard Lyon 1, UCBL Dept Biologie, Villeurbanne, France
- INSA-Lyon, Biosciences, Villeurbanne, France
- CNRS, UMR5240 MAP, Microbiologie Adaptation et Pathogénie, Villeurbanne, France
| | - Séverine Balmand
- INRA, UMR203 BF2I, Biologie Fonctionnelle Insecte et Interactions, INSA-Lyon, Villeurbanne, France
- Université de Lyon, Lyon, France
- INSA-Lyon, Biosciences, Villeurbanne, France
| | - Guy Condemine
- Université de Lyon, Lyon, France
- Université Claude Bernard Lyon 1, UCBL Dept Biologie, Villeurbanne, France
- INSA-Lyon, Biosciences, Villeurbanne, France
- CNRS, UMR5240 MAP, Microbiologie Adaptation et Pathogénie, Villeurbanne, France
| | - Yvan Rahbé
- INRA, UMR203 BF2I, Biologie Fonctionnelle Insecte et Interactions, INSA-Lyon, Villeurbanne, France
- Université de Lyon, Lyon, France
- INSA-Lyon, Biosciences, Villeurbanne, France
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32
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Cho KO, Kim GW, Lee OK. Wolbachia bacteria reside in host Golgi-related vesicles whose position is regulated by polarity proteins. PLoS One 2011; 6:e22703. [PMID: 21829485 PMCID: PMC3145749 DOI: 10.1371/journal.pone.0022703] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 07/05/2011] [Indexed: 02/07/2023] Open
Abstract
Wolbachia pipientis are intracellular symbiotic bacteria extremely common in various organisms including Drosophila melanogaster, and are known for their ability to induce changes in host reproduction. These bacteria are present in astral microtubule-associated vesicular structures in host cytoplasm, but little is known about the identity of these vesicles. We report here that Wolbachia are restricted only to a group of Golgi-related vesicles concentrated near the site of membrane biogenesis and minus-ends of microtubules. The Wolbachia vesicles were significantly mislocalized in mutant embryos defective in cell/planar polarity genes suggesting that cell/tissue polarity genes are required for apical localization of these Golgi-related vesicles. Furthermore, two of the polarity proteins, Van Gogh/Strabismus and Scribble, appeared to be present in these Golgi-related vesicles. Thus, establishment of polarity may be closely linked to the precise insertion of Golgi vesicles into the new membrane addition site.
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Affiliation(s)
- Kyung-Ok Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon, Korea.
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Li T, Xiao JH, Xu ZH, Murphy RW, Huang DW. Cellular tropism, population dynamics, host range and taxonomic status of an aphid secondary symbiont, SMLS (Sitobion miscanthi L type symbiont). PLoS One 2011; 6:e21944. [PMID: 21789197 PMCID: PMC3137594 DOI: 10.1371/journal.pone.0021944] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Accepted: 06/13/2011] [Indexed: 11/18/2022] Open
Abstract
SMLS (Sitobion miscanthi L type symbiont) is a newly reported aphid secondary symbiont. Phylogenetic evidence from molecular markers indicates that SMLS belongs to the Rickettsiaceae and has a sibling relationship with Orientia tsutsugamushi. A comparative analysis of coxA nucleotide sequences further supports recognition of SMLS as a new genus in the Rickettsiaceae. In situ hybridization reveals that SMLS is housed in both sheath cells and secondary bacteriocytes and it is also detected in aphid hemolymph. The population dynamics of SMLS differ from those of Buchnera aphidicola and titer levels of SMLS increase in older aphids. A survey of 13 other aphids reveals that SMLS only occurs in wheat-associated species.
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Affiliation(s)
- Tong Li
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Graduate School of the Chinese Academy of Sciences, Beijing, China
| | - Jin-Hua Xiao
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Zhao-Huan Xu
- College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong, China
| | - Robert W. Murphy
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada
| | - Da-Wei Huang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, Hebei University, Baoding, Hebei, China
- * E-mail:
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34
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Abstract
Mycoplasma lipofaciens strain ML64, isolated from an egg of a northern goshawk (Accipiter gentilis), has been found to be pathogenic for chicken embryos causing mortality during the first 2 weeks of incubation. The same strain was inoculated in turkey embryos to evaluate its pathogenicity and its ability to be transmitted laterally in the hatchery. The strain was found to be pathogenic for turkey embryos, causing a high mortality (88.9%) during late incubation as well as haemorrhages of the legs, dwarfing, curled toes and a severe, multifocal, purulent to necrotizing bronchopneumonia. In addition, lateral transmission between turkey poults hatched from infected eggs and poults from non-infected controls was observed in the incubator.
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Affiliation(s)
- M Lierz
- Institute for Poultry Diseases, Freie Universitaet Berlin, Berlin, Germany.
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Volkman HE, Pozos TC, Zheng J, Davis JM, Rawls JF, Ramakrishnan L. Tuberculous granuloma induction via interaction of a bacterial secreted protein with host epithelium. Science 2010; 327:466-9. [PMID: 20007864 PMCID: PMC3125975 DOI: 10.1126/science.1179663] [Citation(s) in RCA: 331] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Granulomas, organized aggregates of immune cells, are a hallmark of tuberculosis and have traditionally been thought to restrict mycobacterial growth. However, analysis of Mycobacterium marinum in zebrafish has shown that the early granuloma facilitates mycobacterial growth; uninfected macrophages are recruited to the granuloma where they are productively infected by M. marinum. Here, we identified the molecular mechanism by which mycobacteria induce granulomas: The bacterial secreted protein 6-kD early secreted antigenic target (ESAT-6), which has long been implicated in virulence, induced matrix metalloproteinase-9 (MMP9) in epithelial cells neighboring infected macrophages. MMP9 enhanced recruitment of macrophages, which contributed to nascent granuloma maturation and bacterial growth. Disruption of MMP9 function attenuated granuloma formation and bacterial growth. Thus, interception of epithelial MMP9 production could hold promise as a host-targeting tuberculosis therapy.
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Affiliation(s)
- Hannah E. Volkman
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA, USA
| | - Tamara C. Pozos
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - John Zheng
- Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - J. Muse Davis
- Immunology and Molecular Pathogenesis Graduate Program, Emory University, Atlanta, GA, USA
| | - John F. Rawls
- Department of Cell and Molecular Physiology, University of North Carolina, Chapel Hill, NC, USA
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC, USA
| | - Lalita Ramakrishnan
- Department of Microbiology, University of Washington, Seattle, WA, USA
- Department of Medicine, University of Washington, Seattle, WA, USA
- Department of Immunology, University of Washington, Seattle, WA, USA
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36
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Vlisidou I, Dowling AJ, Evans IR, Waterfield N, ffrench-Constant RH, Wood W. Drosophila embryos as model systems for monitoring bacterial infection in real time. PLoS Pathog 2009; 5:e1000518. [PMID: 19609447 PMCID: PMC2707623 DOI: 10.1371/journal.ppat.1000518] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 06/19/2009] [Indexed: 01/06/2023] Open
Abstract
Drosophila embryos are well studied developmental microcosms that have been used extensively as models for early development and more recently wound repair. Here we extend this work by looking at embryos as model systems for following bacterial infection in real time. We examine the behaviour of injected pathogenic (Photorhabdus asymbiotica) and non-pathogenic (Escherichia coli) bacteria and their interaction with embryonic hemocytes using time-lapse confocal microscopy. We find that embryonic hemocytes both recognise and phagocytose injected wild type, non-pathogenic E. coli in a Dscam independent manner, proving that embryonic hemocytes are phagocytically competent. In contrast, injection of bacterial cells of the insect pathogen Photorhabdus leads to a rapid 'freezing' phenotype of the hemocytes associated with significant rearrangement of the actin cytoskeleton. This freezing phenotype can be phenocopied by either injection of the purified insecticidal toxin Makes Caterpillars Floppy 1 (Mcf1) or by recombinant E. coli expressing the mcf1 gene. Mcf1 mediated hemocyte freezing is shibire dependent, suggesting that endocytosis is required for Mcf1 toxicity and can be modulated by dominant negative or constitutively active Rac expression, suggesting early and unexpected effects of Mcf1 on the actin cytoskeleton. Together these data show how Drosophila embryos can be used to track bacterial infection in real time and how mutant analysis can be used to genetically dissect the effects of specific bacterial virulence factors.
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Affiliation(s)
- Isabella Vlisidou
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Andrea J. Dowling
- School of Biological Sciences, University of Exeter in Cornwall, Penryn, United Kingdom
| | - Iwan R. Evans
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Nicholas Waterfield
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | | | - Will Wood
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
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von Siebenthal BA, Jacob A, Wedekind C. Tolerance of whitefish embryos to Pseudomonas fluorescens linked to genetic and maternal effects, and reduced by previous exposure. Fish Shellfish Immunol 2009; 26:531-535. [PMID: 19232394 DOI: 10.1016/j.fsi.2009.02.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 12/31/2008] [Accepted: 02/05/2009] [Indexed: 05/27/2023]
Abstract
Juvenile or adult fish can alter their behaviour and rely on an innate and adaptive immune system to avoid/counteract pathogens, while fish embryos have to depend on egg characteristics and may be partly protected by their developing immune system that is building up from a certain age on. We developed an infection protocol that allows testing the reaction of individual whitefish embryos (Coregonus palaea) to repeated exposures to Pseudomonas fluorescens, an opportunistic bacterial fish pathogen. We used a full-factorial in vitro breeding design to separately test the effects of paternal and maternal contributions to the embryos' susceptibility to different kinds of pathogen exposure. We found that a first non-lethal exposure had immunosuppressive effects: pre-exposed embryos were more susceptible to future challenges with the same pathogen. At intermediate and high levels of pathogen intensity, maternal effects turned out to be crucial for the embryos' tolerance to infection. Paternal (i.e. genetic) effects played a significant role at the strongest level of infection, i.e. the embryos' own genetics already explained some of the variation in embryo susceptibility. Our findings suggest that whitefish embryos are largely protected by maternally transmitted substances, but build up some own innate immunocompetence several days before hatching.
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Affiliation(s)
- Beat A von Siebenthal
- Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland.
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38
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Voronin DA, Bochernikov AM, Baricheva EM, Zakharov IK, Kiseleva EV. [Influence of Drosophila melanogaster genotype on biological effects of endocymbiont Wolbachia (stamm wMelPop)]. Tsitologiia 2009; 51:335-345. [PMID: 19505052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Comparative analyses of symbiotic bacteria Wolbachia (stamm wMelPop reducing lifespan of flies) morphology in normal and mutant strains of Drosophila melanogaster as well as the influence of Wolbachia on the host cell ultrastructure have been done. Wolbachia infected D. melanogaster mutation strains Trithorax-like -- Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+ have been received by special flies crossing. Uninfected strain D. melanogaster white-1118 (w1118) have been obtained by antibiotic treatment of initially infected strain D. melanogaster [w]w1118. Complex of different methods and approaches let to investigate for the first time the morphology of cell structure before and after bacterial infection of insects and to value the bacterial presence effect on flies viability and reproduction of normal and mutant flies. Morphology af cytoplasmic compartments in early embryos and eggs layed by infected and uninfecyed females Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+ have been analyzed. Electron microscopy has shown that D. melanogaster embryos contain typical Wolbachia contacting with different host organelles that verify preservation of their functional activity. Atificial mitochondria and Wolbachia (wMelPop) of unusual morphology with defective bacterial membranes have been visualised in D. melanogaster [w]Trl362/TM3, Sb1 Ser y+. Wolbachia presence in ovarium cells from strains [w]Trl362/TM3, Sb1 Ser y+ and [w]Trlen82/TM3, Sb1 Ser y+ did not influence on eggs quantity layed by females. We have demonstrated for the first time that lifespan of infected and uninfected strains: D. melanogaster Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+ were similar. However the lifespan of imago from strain [w]w1118 was lower in comparison to those from strains Trl362/TM3, Sb1 Ser y+ and Trlen82/TM3, Sb1 Ser y+. It suggests that either chromosomal balancer TM3 or Trl mutation play an importance role in host-symbiotic relationship. Next experiments have revealed that lifespan of homozygotic flies decreased essentially and was close to lifespan of strain [w]w1118. Data obtained confirm that chromosomal balancer TM3 can affect on symbiont-host relationship.
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39
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Karraker NE, Ruthig GR. Effect of road deicing salt on the susceptibility of amphibian embryos to infection by water molds. Environ Res 2009; 109:40-45. [PMID: 18976747 DOI: 10.1016/j.envres.2008.09.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2008] [Revised: 09/01/2008] [Accepted: 09/04/2008] [Indexed: 05/27/2023]
Abstract
Some causative agents of amphibian declines act synergistically to impact individual amphibians and their populations. In particular, pathogenic water molds (aquatic oomycetes) interact with environmental stressors and increase mortality in amphibian embryos. We documented colonization of eggs of three amphibian species, the wood frog (Rana sylvatica), the green frog (Rana clamitans), and the spotted salamander (Ambystoma maculatum), by water molds in the field and examined the interactive effects of road deicing salt and water molds, two known sources of mortality for amphibian embryos, on two species, R. clamitans and A. maculatum in the laboratory. We found that exposure to water molds did not affect embryonic survivorship in either A. maculatum or R. clamitans, regardless of the concentration of road salt to which their eggs were exposed. Road salt decreased survivorship of A. maculatum, but not R. clamitans, and frequency of malformations increased significantly in both species at the highest salinity concentration. The lack of an effect of water molds on survival of embryos and no interaction between road salt and water molds indicates that observations of colonization of these eggs by water molds in the field probably represent a secondary invasion of unfertilized eggs or of embryos that had died of other causes. Given increasing salinization of freshwater habitats on several continents and the global distribution of water molds, our results suggest that some amphibian species may not be susceptible to the combined effects of these factors, permitting amphibian decline researchers to devote their attention to other potential causes.
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Affiliation(s)
- Nancy E Karraker
- Department of Environmental and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA.
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40
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Abstract
Several lineages of maternally inherited symbionts have evolved the ability to kill infected females' sons, a phenomenon known as male-killing. Male-killing varies in its timing, from early (death during embryogenesis) to late (mortality of late larval instars). Following the observation that treatment of male-killer infected adult females Hypolimnas bolina with tetracycline, a bacteriostatic antibiotic, produces a delay in the timing of male death, we hypothesized that early male-killers possess the ability to kill males through bacterial activity outside of embryogenesis. We verified this hypothesis by showing that treatment of surviving larvae with the bacteriocidal antibiotic rifampicin rescues males. This discounted the hypothesis that delayed death occurred due to postponed effects of toxins produced at earlier stages, and thus supported the importance of bacterial activity in the larval phase in delayed male-killing. These results argue against the view that early male-killing is achieved by specifically targeting an early developmental process within the sex determination pathway.
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Affiliation(s)
- Sylvain Charlat
- Department of Biology, University College London, 4 Stephenson Way, London NW1 2HE, UK.
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41
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Zabalou S, Apostolaki A, Pattas S, Veneti Z, Paraskevopoulos C, Livadaras I, Markakis G, Brissac T, Merçot H, Bourtzis K. Multiple rescue factors within a Wolbachia strain. Genetics 2008; 178:2145-60. [PMID: 18430940 PMCID: PMC2323804 DOI: 10.1534/genetics.107.086488] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2007] [Accepted: 02/06/2008] [Indexed: 11/18/2022] Open
Abstract
Wolbachia-induced cytoplasmic incompatibility (CI) is expressed when infected males are crossed with either uninfected females or females infected with Wolbachia of different CI specificity. In diploid insects, CI results in embryonic mortality, apparently due to the the loss of the paternal set of chromosomes, usually during the first mitotic division. The molecular basis of CI has not been determined yet; however, several lines of evidence suggest that Wolbachia exhibits two distinct sex-dependent functions: in males, Wolbachia somehow "imprints" the paternal chromosomes during spermatogenesis (mod function), whereas in females, the presence of the same Wolbachia strain(s) is able to restore embryonic viability (resc function). On the basis of the ability of Wolbachia to induce the modification and/or rescue functions in a given host, each bacterial strain can be classified as belonging in one of the four following categories: mod(+) resc(+), mod(-) resc(+), mod(-) resc(-), and mod(+) resc(-). A so-called "suicide" mod(+) resc(-) strain has not been found in nature yet. Here, a combination of embryonic cytoplasmic injections and introgression experiments was used to transfer nine evolutionary, distantly related Wolbachia strains (wYak, wTei, wSan, wRi, wMel, wHa, wAu, wNo, and wMa) into the same host background, that of Drosophila simulans (STCP strain), a highly permissive host for CI expression. We initially characterized the modification and rescue properties of the Wolbachia strains wYak, wTei, and wSan, naturally present in the yakuba complex, upon their transfer into D. simulans. Confocal microscopy and multilocus sequencing typing (MLST) analysis were also employed for the evaluation of the CI properties. We also tested the compatibility relationships of wYak, wTei, and wSan with all other Wolbachia infections. So far, the cytoplasmic incompatibility properties of different Wolbachia variants are explained assuming a single pair of modification and rescue factors specific to each variant. This study shows that a given Wolbachia variant can possess multiple rescue determinants corresponding to different CI systems. In addition, our results: (a) suggest that wTei appears to behave in D. simulans as a suicide mod(+) resc(-) strain, (b) unravel unique CI properties, and (c) provide a framework to understand the diversity and the evolution of new CI-compatibility types.
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Affiliation(s)
- Sofia Zabalou
- Institute of Molecular Biology and Biotechnology, FORTH, Vassilika Vouton, Heraklion 71110, Crete, Greece
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42
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Abstract
Among vertebrate model species, the zebrafish embryo combines at an unprecedented level optical accessibility with easy genetic manipulation. As such, it is gaining recognition as a powerful model to study innate immunity. In this chapter, we provide a protocol for the generation of zebrafish embryos deficient in a protein of interest for innate immune signaling using antisense morpholino oligonucleotides, the systemic or local infection of these embryos with bacteria, and the assessment of various aspects of the following immune response with emphasis on microscopic observation. This example can be easily adapted to study the role of other genes, either knocked down or overexpressed, and in response to any other challenge, from purified microbial compounds to pathogenic viruses. This protocol is aimed at people not necessarily familiar with zebrafish biology and handling.
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Affiliation(s)
- Jean-Pierre Levraud
- Unité Macrophages et Développement del'Immunité, Institut Pasteur, Paris, France
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43
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Zhukova MV, Voronin DA, Kiseleva EV. [High temperature initiates changes of Wolbachia ultrastructure in the ovaries and early embryos of Drosophila melanogaster]. Tsitologiia 2008; 50:1050-1060. [PMID: 19198544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Electron microscopic analysis of Drosophila melanogaster (w1118) ovarian cells has demonstrated that stressful heat treatment of flies results in the appearance of electron dense granules and large lysosomes in the cytoplasm of ovarian cells, which is not related with the presence of Wolbachia, as these changes are observed in both the infected and uninfected flies. High temperature initiates essential envelope defects and other structural changes of symbiotic bacteria in the cytoplasm of ovarian cells. Some embryos developing from eggs of heat shocked flies die, however, bacteria in the survival embryos retain their typical morphology. Endosymbionts do not change their localization and their contacts with the mitochondria and endoplasmic reticulum in the ovarian cells and early embryos after heat shock treatment of the flies. The results obtained show that high temperature influences on both the host and the endosymbiont, but does not change their structural mutual interactions.
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Choi CH, Hyun SH, Lee JY, Lee JS, Lee YS, Kim SA, Chae JP, Yoo SM, Lee JC. Acinetobacter baumannii outer membrane protein A targets the nucleus and induces cytotoxicity. Cell Microbiol 2007; 10:309-19. [PMID: 17760880 DOI: 10.1111/j.1462-5822.2007.01041.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Acinetobacter baumannii is an emerging opportunistic pathogen responsible for healthcare-associated infections. The outer membrane protein A of A. baumannii (AbOmpA) is the most abundant surface protein that has been associated with the apoptosis of epithelial cells through mitochondrial targeting. The nuclear translocation of AbOmpA and the subsequent pathology on host cells were further investigated. AbOmpA directly binds to eukaryotic cells. AbOmpA translocates to the nucleus by a novel monopartite nuclear localization signal (NLS). The introduction of rAbOmpA into the cells or a transient expression of AbOmpA-EGFP causes the nuclear localization of these proteins, while the fusion proteins of AbOmpADeltaNLS-EGFP and AbOmpA with substitutions in residues lysine to alanine in the NLS sequences represent an exclusively cytoplasmic distribution. The nuclear translocation of AbOmpA induces cell death in vitro. Furthermore, the microinjection of rAbOmpA into the nucleus of Xenopus laevis embryos fails to develop normal embryogenesis, thus leading to embryonic death. We propose a novel pathogenic mechanism of A. baumannii regarding the nuclear targeting of the bacterial structural protein AbOmpA.
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Affiliation(s)
- Chul Hee Choi
- Department of Microbiology, Kyungpook National University School of Medicine, Daegu, Korea
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45
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Abstract
Wolbachia is a genus of obligate intracellular Alpha-Proteobacteria represented by the type species Wolbachia pipientis (Dumler et al., 2001). Wolbachia commonly reside within cytoplasmic vacuoles of arthropods and helminths (Werren and Windsor, 2000; Casiraghi et al., 2004); vertebrate infections have not been identified. Wolbachia are maternally transmitted from mothers to offspring though the embryonic cytoplasm. Wolbachia are able to induce a diverse range of phenotypes in their invertebrate hosts, ranging from classical mutualism to reproductive parasitism. Examples of the latter include male killing, host feminization, parthenogenesis, and cytoplasmic incompatibility (reviewed in Dobson, 2003a). Current Wolbachia research foci include examining the impacts of Wolbachia infection on host evolution, characterizing the mechanisms by which Wolbachia manipulate invertebrate hosts, and developing applied strategies that employ Wolbachia for pest and disease control. Wolbachia transfection has proven a useful technique for addressing questions within each of these research foci. This unit describes a method for Wolbachia transfection via embryonic microinjection.
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46
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McGraw EA, O'Neill SL. Wolbachia: invasion biology in South pacific butterflies. Curr Biol 2007; 17:R220-1. [PMID: 17371764 DOI: 10.1016/j.cub.2007.01.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Wolbachia ensdosymbionts are well known for their ability to manipulate the population biology and development of their hosts. One of the less studied outcomes of Wolbachia infection with this symbiont is the selective killing of male embryos. Recent work on butterflies living on different South Pacific islands is beginning to help us understand the complexity of the co-evolutionary interactions between these partners.
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Affiliation(s)
- Elizabeth A McGraw
- School of Integrative Biology, The University of Queensland, Brisbane 4072, Australia
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47
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Abstract
Water molds attack aquatic eggs worldwide and have been associated with major mortality events in some cases, but typically only in association with additional stressors. We combined field observations and laboratory experiments to study egg stage defenses against pathogenic water mold in three temperate amphibians. Spotted salamanders (Ambystoma maculatum) wrap their eggs in a protective jelly layer that prevents mold from reaching the embryos. Wood frog (Rana sylvatica) egg masses have less jelly but are laid while ponds are still cold and mold growth is slow. American toad (Bufo americanus) eggs experience the highest infection levels. They are surrounded by thin jelly and are laid when ponds have warmed and mold grows rapidly. Eggs of all three species hatched early when infected, yielding smaller and less developed hatchlings. This response was strongest in B. americanus. Precocious hatching increased vulnerability of wood frog hatchlings to invertebrate predators. Finally, despite being potential toad hatchling predators, R. sylvatica tadpoles can have a positive effect on B. americanus eggs. They eat water mold off infected toad clutches, increasing their hatching success.
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Affiliation(s)
- Ivan Gomez-Mestre
- Department of Biology, Boston University, 5 Cummington Street, Boston, Massachusetts 02215, USA.
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48
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Burýsková B, Hilscherová K, Babica P, Vrsková D, Marsálek B, Bláha L. Toxicity of complex cyanobacterial samples and their fractions in Xenopus laevis embryos and the role of microcystins. Aquat Toxicol 2006; 80:346-54. [PMID: 17092578 DOI: 10.1016/j.aquatox.2006.10.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2006] [Revised: 10/03/2006] [Accepted: 10/03/2006] [Indexed: 05/12/2023]
Abstract
This work evaluated the effects of various cyanobacterial fractions in Frog Embryo Teratogenesis Assay Xenopus (FETAX) with African clawed frog embryos. Fractions were prepared from five biomasses with different dominant genera (Microcystis, Aphanizomenon, Anabaena, Planktothrix) and different microcystin content. Effects of following fractions were investigated: (I) homogenate of complex cyanobacterial biomass, (II) cell debris (pellet) after centrifugation of complex biomass, (III) supernatant after centrifugation of complex biomass (= crude aqueous extract), (IV) permeate after passing of crude extract through C-18 column (fraction devoid of microcystins), and (V) eluate from C-18 column (containing microcystins, if present). Besides classical parameters evaluated in 96 h FETAX (mortality, growth inhibition, malformations), we have also assessed the effects on biochemical markers of oxidative stress and detoxification (glutathione pool, GSH; activity of glutathione peroxidase, GPx; glutathione reductase, GR; activity of glutathione-S-transferase, GST). Complex biomass (I) and aqueous extract (III) were generally the most toxic fractions in terms of mortality and growth inhibition, whereas eluates containing microcystins (V) were generally less toxic. On the other hand, the same fraction (eluates) induced significant malformations in low concentrations but the effects were not related to the content of microcystins. Biomarkers were affected in variable manner but no significant effect or clear relation to microcystin content was observed. Our data support the hypothesis that microcystins are not the only or major toxic compounds in the complex cyanobacterial samples (at least for some species) and that more attention should be paid to other components of complex cyanobacterial biomass including non-specific parameters such as oxygen content or toxic ammonia released during bacterial decay of organic material.
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Affiliation(s)
- Blanka Burýsková
- Centre for Cyanobacteria and their Toxins, Institute of Botany, Czech Academy of Science and RECETOX, Masaryk University, Kamenice 3, CZ62500 Brno, Czech Republic
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Abstract
Sponges are host to extremely diverse bacterial communities, some of which appear to be spatiotemporally stable, though how these consistent associations are assembled and maintained from one sponge generation to the next is not well understood. Here we report that a diverse group of microbes, including both bacteria and archaea, is consistently present in aggregates within embryos of the tropical sponge Corticium sp. The major taxonomic groups represented in bacterial 16S rRNA sequences amplified from the embryos are similar to those previously described in a variety of marine sponges. Three selected bacterial taxa, representing proteobacteria, actinobacteria, and a clade including recently described sponge-associated bacteria, were tested and found to be present in all adult samples tested over a 3-year period and in the embryos throughout development. Specific probes were used in fluorescence in situ hybridization to localize cells of the three types in the embryos and mesohyl. This study confirms the vertical transmission of multiple, phylogenetically diverse microorganisms in a marine sponge, and our findings lay the foundation for future work on exploring vertical transmission of specific, yet diverse, microbial assemblages in marine sponges.
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Affiliation(s)
- Koty H Sharp
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, USA
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