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Andreas Leclerque - One of the best experts on this subject based on the ideXlab platform.
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Beyond Bt: New Bacterial Resources for Insect Biocontrol
Institution of the Agricultural Research and Higher Education, 2018Co-Authors: Andreas LeclerqueAbstract:The Gram-positive bacterium Bacillus thuringiensis (Bt) is the economically most important entomopathogen for insect biocontrol, and for excellent reason a large part of the effort invested in the development of microbial insecticides has concentrated on Bt strains and their cry genes. Hundreds of cry gene sequences have been determined from nature, and molecular modeling has been used to create artificial recombinant Cry proteins with potentially new properties. However, alternative insect biocontrol agents are increasingly solicited. More recently, research efforts have concentrated upon bacterial insect-pathogens as potential biocontrol resources as, e.g., non-cry toxins of Bt and other bacteria of the family Bacillaceae as well as the bacterium Saccharopolyspora spinosa (Actinobacteria). Moreover, several different γ-proteobacterial entomopathogens belonging to the species Serratia entomophila, Yersinia entomophaga or Pseudomonas entomophila as well as to the genera Providencia or Rickettsiella are currently being evaluated for their biocontrol potential. The present literature review gives a brief update on these entomopathogens and toxins
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A survey of microbial antagonists of Agriotes wireworms from Germany and Italy
Journal of Pest Science, 2013Co-Authors: Regina G Kleespies, Claudia Ritter, Frank Burghause, Simon Feiertag, Gisbert Zimmermann, Andreas LeclerqueAbstract:Wireworms of the genus Agriotes (Coleoptera: Elateridae) are severe and widespread agricultural pests affecting numerous crops throughout the world and causing damage of economic importance. Between 2008 and 2011, a survey of the occurrence of natural microbial antagonists of wireworms was conducted. Altogether, 3,420 wireworms and two dead beetles from agricultural habitats and grassland of various parts of Germany and 700 lab-reared wireworms from Italy were screened for the presence of disease. Of these, 283 selected dead and moribund Agriotes specimens were diagnosed by light and electron microscopy for insect pathogens; 66 wireworms contained unspecified bacterial infections; and 86 specimens displayed fungal growth with 25 infected by the entomopathogenic taxa Beauveria bassiana , Metarhizium anisopliae , Isaria fumosorosea , Isaria spp. and Lecanicillium sp. Nematodes were observed in 29 dead individuals, and 141 individuals showed no distinguishable pathogens. In one dead Agriotes larva, an intracellular bacterium was identified as a new Rickettsiella pathotype named ‘ Rickettsiella agriotidis ’. The survey resulted in a natural infection rate of 0.66 %. The possible use of these pathogens as biocontrol agents is discussed.
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ribosomal rna phylogeny of bacterial and fungal pathogens of agriotes wireworms
Journal of Pest Science, 2013Co-Authors: Andreas Leclerque, Polina V Mitkovets, Anacristina Fatu, Christina Schuster, Regina G KleespiesAbstract:Wireworms, the polyphagous larvae of click beetles belonging to the genus Agriotes (Coleoptera: Elateridae), are severe and widespread agricultural pests affecting numerous crops. Biological control agents and methods for this general pest are highly solicited. In a screening for microbial Agriotes pathogens, an intracellular bacterium and a mitosporic fungus were isolated. Phylogenetic analysis based on ribosomal RNA operon sequences of both micro-organisms corroborated their previous morphology-based taxonomic classification. The bacterial pathogen has been assigned to the taxonomic genus Rickettsiella (Gammaproteobacteria) wherein it represents a new pathotype, ‘Rickettsiella agriotidis’, that appears most closely related to subjective synonyms of the nomenclatural type species, Rickettsiella popillae. The fungal pathogen has been shown to belong to the form-species Beauveria bassiana, i.e., an obligate anamorph related to the genus Cordyceps (Ascomycota: Hypocreales). Furthermore, the B. bassiana strain from Agriotes has been shown to be potentially susceptible to identification by gIi-diagnosis, i.e., a diagnostic method making use of the strain-specific presence of self-splicing group-I introns within the ribosomal RNA operons of certain hyphomycetous fungi.
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Electron microscope and genetic analysis of an intracellular bacterium associated with the common rough woodlouse, Porcellio scaber (Isopoda, Porcellionidae)
2013Co-Authors: Regina G Kleespies, Andreas LeclerqueAbstract:The common rough woodlouse, Porcellio scaber, is a common and widespread isopod species of Western and Northern Europe. A previously unknown intracellular bacterium has been identified in a diseased Porcellio larva. Microscopic studies revealed the subcellular structures characteristic of infection by Rickettsiella-like bacteria. Molecular phylogenetic analysis based on the 16S ribosomal RNA encoding rrs gene demonstrated that the woodlouse pathogen belongs to the taxonomic genus Rickettsiella (Gammaproteobacteria; Legionellales). Moreover, genetic analysis makes it likely that this new pathotype should be considered a member of the “Rickettsiella armadillidii complex”, i.e. a group of Rickettsiella bacteria found mainly in terrestrial isopods. R. armadillidii is currently placed in synonymy with the nomenclatural type species, Rickettsiella popilliae. The present study does not lend support to this synonymization.
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Generation of candidate tree topologies for likelihood-based significance testing based on MLST markers.
2013Co-Authors: Andreas Leclerque, Regina G KleespiesAbstract:15 candidate topologies were generated from a four organism basic tree (A) comprising Coxiella burnetii (acronym “Cbu”) as outgroup together with three Rickettsiella strains in positions a–c. The candidate topologies tested (B) were generated from this basic tree by the following steps: 1. Permutative addition of three Rickettsiella strains representing the species Rickettsiella grylli (“Rgr”) and the pathotypes ‘Rickettsiella melolonthae’ (“Rme”) and ‘Rickettsiella tipulae’ (“Rti”) to positions a–c generates a maximum of six tree topologies that are pair-wise identical, i.e. a total of three different topologies. 2. Subsequent addition of the pathotype ‘Rickettsiella ixodidis’ (“Rix”) to any of the five branches indicated by a black dot in any of the previously generated trees.
Regina G Kleespies - One of the best experts on this subject based on the ideXlab platform.
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A survey of microbial antagonists of Agriotes wireworms from Germany and Italy
Journal of Pest Science, 2013Co-Authors: Regina G Kleespies, Claudia Ritter, Frank Burghause, Simon Feiertag, Gisbert Zimmermann, Andreas LeclerqueAbstract:Wireworms of the genus Agriotes (Coleoptera: Elateridae) are severe and widespread agricultural pests affecting numerous crops throughout the world and causing damage of economic importance. Between 2008 and 2011, a survey of the occurrence of natural microbial antagonists of wireworms was conducted. Altogether, 3,420 wireworms and two dead beetles from agricultural habitats and grassland of various parts of Germany and 700 lab-reared wireworms from Italy were screened for the presence of disease. Of these, 283 selected dead and moribund Agriotes specimens were diagnosed by light and electron microscopy for insect pathogens; 66 wireworms contained unspecified bacterial infections; and 86 specimens displayed fungal growth with 25 infected by the entomopathogenic taxa Beauveria bassiana , Metarhizium anisopliae , Isaria fumosorosea , Isaria spp. and Lecanicillium sp. Nematodes were observed in 29 dead individuals, and 141 individuals showed no distinguishable pathogens. In one dead Agriotes larva, an intracellular bacterium was identified as a new Rickettsiella pathotype named ‘ Rickettsiella agriotidis ’. The survey resulted in a natural infection rate of 0.66 %. The possible use of these pathogens as biocontrol agents is discussed.
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ribosomal rna phylogeny of bacterial and fungal pathogens of agriotes wireworms
Journal of Pest Science, 2013Co-Authors: Andreas Leclerque, Polina V Mitkovets, Anacristina Fatu, Christina Schuster, Regina G KleespiesAbstract:Wireworms, the polyphagous larvae of click beetles belonging to the genus Agriotes (Coleoptera: Elateridae), are severe and widespread agricultural pests affecting numerous crops. Biological control agents and methods for this general pest are highly solicited. In a screening for microbial Agriotes pathogens, an intracellular bacterium and a mitosporic fungus were isolated. Phylogenetic analysis based on ribosomal RNA operon sequences of both micro-organisms corroborated their previous morphology-based taxonomic classification. The bacterial pathogen has been assigned to the taxonomic genus Rickettsiella (Gammaproteobacteria) wherein it represents a new pathotype, ‘Rickettsiella agriotidis’, that appears most closely related to subjective synonyms of the nomenclatural type species, Rickettsiella popillae. The fungal pathogen has been shown to belong to the form-species Beauveria bassiana, i.e., an obligate anamorph related to the genus Cordyceps (Ascomycota: Hypocreales). Furthermore, the B. bassiana strain from Agriotes has been shown to be potentially susceptible to identification by gIi-diagnosis, i.e., a diagnostic method making use of the strain-specific presence of self-splicing group-I introns within the ribosomal RNA operons of certain hyphomycetous fungi.
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Electron microscope and genetic analysis of an intracellular bacterium associated with the common rough woodlouse, Porcellio scaber (Isopoda, Porcellionidae)
2013Co-Authors: Regina G Kleespies, Andreas LeclerqueAbstract:The common rough woodlouse, Porcellio scaber, is a common and widespread isopod species of Western and Northern Europe. A previously unknown intracellular bacterium has been identified in a diseased Porcellio larva. Microscopic studies revealed the subcellular structures characteristic of infection by Rickettsiella-like bacteria. Molecular phylogenetic analysis based on the 16S ribosomal RNA encoding rrs gene demonstrated that the woodlouse pathogen belongs to the taxonomic genus Rickettsiella (Gammaproteobacteria; Legionellales). Moreover, genetic analysis makes it likely that this new pathotype should be considered a member of the “Rickettsiella armadillidii complex”, i.e. a group of Rickettsiella bacteria found mainly in terrestrial isopods. R. armadillidii is currently placed in synonymy with the nomenclatural type species, Rickettsiella popilliae. The present study does not lend support to this synonymization.
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Generation of candidate tree topologies for likelihood-based significance testing based on MLST markers.
2013Co-Authors: Andreas Leclerque, Regina G KleespiesAbstract:15 candidate topologies were generated from a four organism basic tree (A) comprising Coxiella burnetii (acronym “Cbu”) as outgroup together with three Rickettsiella strains in positions a–c. The candidate topologies tested (B) were generated from this basic tree by the following steps: 1. Permutative addition of three Rickettsiella strains representing the species Rickettsiella grylli (“Rgr”) and the pathotypes ‘Rickettsiella melolonthae’ (“Rme”) and ‘Rickettsiella tipulae’ (“Rti”) to positions a–c generates a maximum of six tree topologies that are pair-wise identical, i.e. a total of three different topologies. 2. Subsequent addition of the pathotype ‘Rickettsiella ixodidis’ (“Rix”) to any of the five branches indicated by a black dot in any of the previously generated trees.
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Significance testing results for 16 S rRNA and MLST markers in a five organism model.
2013Co-Authors: Andreas Leclerque, Regina G KleespiesAbstract:1sKH test results across the 15 candidate tree topologies presented in Figure 4B with respect to different marker sequence alignments. For the protein-encoding marker genes gidA and sucB both the hypervariability filtered nucleotide and the deduced amino acid sequence levels were explored. For the 16 S rRNA marker, two data sets comprising sequences from different Rickettsiella grylli strains were analyzed. The p-values attributed to a tree topology by the 1sKH test are interpreted under assumption of an exogenous 5% significance threshold as “B” for a data set specific best tree, “U” for an unrejected second-best tree, and “R” for a rejected tree. Data set specific best trees are indicated in bold type.
Olivier Duron - One of the best experts on this subject based on the ideXlab platform.
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Sex ratios of the tick Ixodes arboricola are strongly female-biased, but there are no indications of sex-distorting bacteria
Ticks and Tick-borne Diseases, 2018Co-Authors: A. Raoul Van Oosten, Olivier Duron, Dieter J.a. HeylenAbstract:Studies on sex ratio are of fundamental importance for understanding the biology of populations and biological control of pests and pathogens. In most Ixodes tick species, only females feed in the adult stage and, hence, contribute to pathogen transmission. The tree-hole tick Ixodes arboricola infests cavity-nesting birds and has limited dispersal possibilities. It plays an important role in the maintenance of zoonotic disease cycles. Here, we quantified the sex ratio of 718 adult I. arboricola ticks obtained from a laboratory stock at nine distinct periods (cohorts) from 2008 to 2015. In addition, we screened 93 specimens, collected from four study sites in 2011 and 2012, for the presence of six maternally inherited bacterial parasites known to manipulate arthropod sex ratios. We found significantly female-biased sex ratios in seven out of nine cohorts. There were no infections with members of the Wolbachia, Arsenophonus or Cardinium bacterial genera, whereas 96.8% of the screened ticks were infected with Rickettsia vini, 22.6% with Rickettsiella sp., and 14.0% with Spiroplasma ixodetis. Male and female I. arboricola were found equally infected. Our results suggest skewed sex ratios in I. arboricola are not caused by these bacterial infections, although there may be other, untested candidates driving sex ratios. Alternatively, female-biased sex ratios may be an adaptation in females to high local densities and low dispersal, where the production of daughters has a selective advantage because a few sons can fertilise all daughters.
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the high diversity and global distribution of the intracellular bacterium Rickettsiella in the polar seabird tick ixodes uriae
Microbial Ecology, 2016Co-Authors: Olivier Duron, Julie Cremaschi, Karen D. MccoyAbstract:Obligate intracellular bacteria of the Rickettsiella genus are emerging as both widespread and biologically diverse in arthropods. Some Rickettsiella strains are highly virulent entomopathogenic agents, whereas others are maternally inherited endosymbionts exerting very subtle manipulations on host phenotype to promote their own spread. Recently, a variety of Rickettsiella strains have been reported from ticks, but their biology is entirely unknown. In the present study, we examined the incidence and diversity of Rickettsiella in 11 geographically distinct populations of the polar seabird tick Ixodes uriae. We found Rickettsiella in most tick populations with a prevalence ranging from 3 to 24 %. 16S ribosomal RNA (rRNA) and GroEL gene sequences revealed an unexpected diversity of Rickettsiella, with 12 genetically distinct Rickettsiella strains present in populations of I. uriae. Phylogenetic investigations further revealed that these Rickettsiella strains do not cluster within a tick-specific clade but rather exhibit distinct evolutionary origins demonstrating frequent horizontal transfers between distantly related arthropod species. Tick rearing further showed that Rickettsiella are present in eggs laid by infected females with no evidence of abortive development. Using this data set, we discuss the potential biological significance of Rickettsiella in seabird ticks. Most notably, we suggest that these organisms may not be pathogenic forms but rather use more subtle adaptive strategies to persist within tick populations.
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the is1111 insertion sequence used for detection of coxiella burnetii is widespread in coxiella like endosymbionts of ticks
Fems Microbiology Letters, 2015Co-Authors: Olivier DuronAbstract:Coxiella is a genus of obligate intracellular bacteria engaged in a variety of interactions with eukaryotes. The type species, Coxiella burnetii , infects several vertebrate species, including humans, and is the causative agent of Q fever. Multiple copies of a specific transposable element, the insertion sequence IS1111, are present in the genome of C. burnetii and are routinely used for confirmation of Q fever cases. Recently, many Coxiella -like bacteria that are closely related but genetically distinct to C. burnetii have been found in ticks. These Coxiella -like bacteria are maternally inherited endosymbionts, present at high prevalence in tick populations and engaged in mutualistic interactions with their arthropod hosts. In this study, the presence of IS1111 was examined in the Coxiella -like endosymbionts and in bacteria of the Coxiella sister-genus, Rickettsiella . This screening reveals that a wide range of IS1111 copies were present in the Coxiella -like endosymbionts of ticks. DNA sequencing further identified genetically divergent IS1111 copies, including degraded copies that constitute an important genomic fossil record of past IS1111 expansions. These results show that IS1111 is not specific to C. burnetii , suggesting that Q fever detection assays based only on this element may lead to misidentification with Coxiella -like endosymbionts.
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Phylogenetic network with concatenated 16S rRNA, 23S rRNA, GroEL, rpoB and dnaK sequences (3009 unambiguously aligned bp), including 71 Coxiella-like strains of ticks, 15 C. burnetii reference strains, and bacterial outgroups.
2015Co-Authors: Olivier Duron, Karen D. Mccoy, Valérie Noël, Matteo Bonazzi, Karim Sidi-boumedine, Olivier Morel, Fabrice Vavre, Lionel Zenner, Elsa Jourdain, Patrick DurandAbstract:The four Coxiella clades are labeled A to D. A zoom on the A clade which contains C. burnetii isolates is shown in Supplementary Fig C in S1 Text. Each number corresponds to one tick species as detailed in Table 1. Blue—Coxiella-like organisms; red—C. burnetii; green—Rickettsiella; black- other bacteria. All multi-locus typing of Coxiella and Rickettsiella of ticks are new sequences from this study. The scale bar is in units of substitution/site.
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List of tick species and populations included in the analysis, with details on their origin, the population sample size, and the prevalence of Coxiella spp. and Rickettsiella spp.
2015Co-Authors: Olivier Duron, Karen D. Mccoy, Valérie Noël, Matteo Bonazzi, Karim Sidi-boumedine, Olivier Morel, Fabrice Vavre, Lionel Zenner, Elsa Jourdain, Patrick DurandAbstract:List of tick species and populations included in the analysis, with details on their origin, the population sample size, and the prevalence of Coxiella spp. and Rickettsiella spp.
Tsutomu Tsuchida - One of the best experts on this subject based on the ideXlab platform.
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Genomic Insight into Symbiosis-Induced Insect Color Change by a Facultative Bacterial Endosymbiont, “Candidatus Rickettsiella viridis”
American Society for Microbiology, 2018Co-Authors: Naruo Nikoh, Ryuichi Koga, Tsutomu Tsuchida, Taro Maeda, Katsushi Yamaguchi, Shuji Shigenobu, Takema FukatsuAbstract:Members of the genus Rickettsiella are bacterial pathogens of insects and other arthropods. Recently, a novel facultative endosymbiont, “Candidatus Rickettsiella viridis,” was described in the pea aphid Acyrthosiphon pisum, whose infection causes a striking host phenotype: red and green genetic color morphs exist in aphid populations, and upon infection with the symbiont, red aphids become green due to increased production of green polycyclic quinone pigments. Here we determined the complete genome sequence of the symbiont. The 1.6-Mb circular genome, harboring some 1,400 protein-coding genes, was similar to the genome of entomopathogenic Rickettsiella grylli (1.6 Mb) but was smaller than the genomes of phylogenetically allied human pathogens Coxiella burnetii (2.0 Mb) and Legionella pneumophila (3.4 Mb). The symbiont’s metabolic pathways exhibited little complementarity to those of the coexisting primary symbiont Buchnera aphidicola, reflecting the facultative nature of the symbiont. The symbiont genome harbored neither polyketide synthase genes nor the evolutionarily allied fatty acid synthase genes that are suspected to catalyze the polycyclic quinone synthesis, indicating that the green pigments are produced not by the symbiont but by the host aphid. The symbiont genome retained many type IV secretion system genes and presumable effector protein genes, whose homologues in L. pneumophila were reported to modulate a variety of the host's cellular processes for facilitating infection and virulence. These results suggest the possibility that the symbiont is involved in the green pigment production by affecting the host’s metabolism using the secretion machineries for delivering the effector molecules into the host cells.Insect body color is relevant to a variety of biological aspects such as species recognition, sexual selection, mimicry, aposematism, and crypsis. Hence, the bacterial endosymbiont “Candidatus Rickettsiella viridis,” which alters aphid body color from red to green, is of ecological interest, given that different predators preferentially exploit either red- or green-colored aphids. Here we determined the complete 1.6-Mb genome of the symbiont and uncovered that, although the red-green color transition was ascribed to upregulated production of green polycyclic quinone pigments, the symbiont genome harbored few genes involved in the polycyclic quinone biosynthesis. Meanwhile, the symbiont genome contained type IV secretion system genes and presumable effector protein genes, whose homologues modulate eukaryotic cellular processes for facilitating infection and virulence in the pathogen Legionella pneumophila. We propose the hypothesis that the symbiont may upregulate the host’s production of polycyclic quinone pigments via cooption of secretion machineries and effector molecules for pathogenicity
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Conditional Reduction of Predation Risk Associated with a Facultative Symbiont in an Insect
PLoS ONE, 2015Co-Authors: Sarah Polin, Tsutomu Tsuchida, Jean-christophe Simon, Jean Francois Le Gallic, Yannick OutremanAbstract:Symbionts are widespread among eukaryotes and their impacts on the ecology and evolution of their hosts are meaningful. Most insects harbour obligate and facultative symbiotic bacteria that can influence their phenotype. In the pea aphid Acyrthosiphon pisum, an astounding symbiotic-mediated phenotype has been recently observed: when infected with the symbiotic bacteria Rickettsiella viridis, young red aphid larvae become greener at adulthood and even darker green when co-infected with Rickettsiella viridis and Hamiltonella defensa. As body colour affects the susceptibility towards natural enemies in aphids, the influence of the colour change due to these facultative symbionts on the host survival in presence of predators was tested. Our results suggested that the Rickettsiella viridis infection may impact positively host survival by reducing predation risk. Due to results from uninfected aphids (i.e., more green ones attacked), the main assumption is that this symbiotic infection would deter the predatory ladybird feeding by reducing the profitability of their hosts rather than decreasing host detection through body colour change. Aphids coinfected with Rickettsiella viridis and Hamiltonella defensa were, however, more exposed to predation suggesting an ecological cost associated with multiple infections. The underlying mechanisms and ecological consequences of these symbiotic effects are discussed.
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The experimental treatments.
2015Co-Authors: Sarah Polin, Tsutomu Tsuchida, Jean-christophe Simon, Jean-françois Le Gallic, Yannick OutremanAbstract:The six experimental treatments combining pairs of aphid types in order to test the effects of colour and symbiotic complement on aphid survival under predation pressure. Aphid type was defined as a combination of aphid colour and symbiotype. The aphid survival rate was tested (A) between red and green aphid types with different symbiotic complement and (B) among green types differing by their symbiotic complements. Letters reported in the aphids stand for the symbiotic complement including the obligate symbiont Buchnera (B) and the two facultative symbionts, Rickettsiella (R) and Hamiltonella (H). The name code of each treatment is indicated on the link between considered aphid types (Capital letter: the aphid colour; Subscript letters: symbiotic complement).
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phenotypic effect of candidatus Rickettsiella viridis a facultative symbiont of the pea aphid acyrthosiphon pisum and its interaction with a coexisting symbiont
Applied and Environmental Microbiology, 2014Co-Authors: Tsutomu Tsuchida, Ryuichi Koga, Akiko Fujiwara, Takema FukatsuAbstract:A gammaproteobacterial facultative symbiont of the genus Rickettsiella was recently identified in the pea aphid, Acyrthosiphon pisum. Infection with this symbiont altered the color of the aphid body from red to green, potentially affecting the host's ecological characteristics, such as attractiveness to different natural enemies. In European populations of A. pisum, the majority of Rickettsiella-infected aphids also harbor another facultative symbiont, of the genus Hamiltonella. We investigated this Rickettsiella symbiont for its interactions with the coinfecting Hamiltonella symbiont, its phenotypic effects on A. pisum with and without Hamiltonella coinfection, and its infection prevalence in A. pisum populations. Histological analyses revealed that coinfecting Rickettsiella and Hamiltonella exhibited overlapping localizations in secondary bacteriocytes, sheath cells, and hemolymph, while Rickettsiella-specific localization was found in oenocytes. Rickettsiella infections consistently altered hosts' body color from red to green, where the greenish hue was affected by both host and symbiont genotypes. Rickettsiella-Hamiltonella coinfections also changed red aphids to green; this greenish hue tended to be enhanced by Hamiltonella coinfection. With different host genotypes, Rickettsiella infection exhibited either weakly beneficial or nearly neutral effects on host fitness, whereas Hamiltonella infection and Rickettsiella-Hamiltonella coinfection had negative effects. Despite considerable frequencies of Rickettsiella infection in European and North American A. pisum populations, no Rickettsiella infection was detected among 1,093 insects collected from 14 sites in Japan. On the basis of these results, we discuss possible mechanisms for the interaction of Rickettsiella with other facultative symbionts, their effects on their hosts' phenotypes, and their persistence in natural host populations. We propose the designation “Candidatus Rickettsiella viridis” for the symbiont.
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Symbiotic bacterium modifies aphid body color
Science, 2010Co-Authors: Tsutomu Tsuchida, Ryuichi Koga, Mitsuyo Horikawa, Tetsuto Tsunoda, Takashi Maoka, Shogo Matsumoto, Jean-christophe SimonAbstract:Color variation within populations of the pea aphid influences relative susceptibility to predators and parasites. We have discovered that infection with a facultative endosymbiont of the genus Rickettsiella changes the insects’ body color from red to green in natural populations. Approximately 8% of pea aphids collected in Western Europe carried the Rickettsiella infection. The infection increased amounts of blue-green polycyclic quinones, whereas it had less of an effect on yellow-red carotenoid pigments. The effect of the endosymbiont on body color is expected to influence prey-predator interactions, as well as interactions with other endosymbionts.
Olivier Sparagano - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Microbiomes between Red Poultry Mite Populations (Dermanyssus gallinae): Predominance of Bartonella-like Bacteria
Microbial Ecology, 2017Co-Authors: Jan Hubert, Tomas Erban, Jan Kopecky, Bruno Sopko, Marta Nesvorna, Martina Lichovnikova, Sabine Schicht, Olivier SparaganoAbstract:Blood feeding red poultry mites (RPM) serve as vectors of pathogenic bacteria and viruses among vertebrate hosts including wild birds, poultry hens, mammals, and humans. The microbiome of RPM has not yet been studied by high-throughput sequencing. RPM eggs, larvae, and engorged adult/nymph samples obtained in four poultry houses in Czechia were used for microbiome analyses by Illumina amplicon sequencing of the 16S ribosomal RNA (rRNA) gene V4 region. A laboratory RPM population was used as positive control for transcriptome analysis by pyrosequencing with identification of sequences originating from bacteria. The samples of engorged adult/nymph stages had 100-fold more copies of 16S rRNA gene copies than the samples of eggs and larvae. The microbiome composition showed differences among the four poultry houses and among observed developmental stadia. In the adults’ microbiome 10 OTUs comprised 90 to 99% of all sequences. Bartonella -like bacteria covered between 30 and 70% of sequences in RPM microbiome and 25% bacterial sequences in transcriptome. The phylogenetic analyses of 16S rRNA gene sequences revealed two distinct groups of Bartonella -like bacteria forming sister groups: (i) symbionts of ants; (ii) Bartonella genus. Cardinium , Wolbachia , and Rickettsiella sp. were found in the microbiomes of all tested stadia, while Spiroplasma eriocheiris and Wolbachia were identified in the laboratory RPM transcriptome. The microbiomes from eggs, larvae, and engorged adults/nymphs differed. Bartonella -like symbionts were found in all stadia and sampling sites. Bartonella- like bacteria was the most diversified group within the RPM microbiome. The presence of identified putative pathogenic bacteria is relevant with respect to human and animal health issues while the identification of symbiontic bacteria can lead to new control methods targeting them to destabilize the arthropod host.
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endosymbiotic bacteria living inside the poultry red mite dermanyssus gallinae
Experimental and Applied Acarology, 2009Co-Authors: Carlos J De Luna, Lionel Zenner, Claire Valiente Moro, J H Guy, Olivier SparaganoAbstract:This study investigated the endosymbiotic bacteria living inside the poultry red mite collected from five samples of one commercial farm from the UK and 16 farms from France using genus-specific PCR, PCR-TTGE and DNA sequencing. Endosymbiotic bacteria are intracellular obligate organisms that can cause several phenotypic and reproductive anomalies to their host and they are found widespread living inside arthropods. The farm sampled from the UK was positive for bacteria of the genera Cardinium sp. and Spiroplasma sp. From France, 7 farms were positive for Cardinium sp., 1 farm was positive for Spiroplasma sp., 1 farm was positive for Rickettsiella sp. and 2 farms were positive for Schineria sp. However, it was not possible to detect the presence of the genus Wolbachia sp. which has been observed in other ectoparasites. This study is the first report of the presence of endosymbionts living inside the poultry red mite. The results obtained suggest that it may be possible that these bacterial endosymbionts cause biological modifications to the poultry red mite.
