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Anne Geiger - One of the best experts on this subject based on the ideXlab platform.

  • Molecular identification of
    'EDP Sciences', 2019
    Co-Authors: Gustave Simo, Anne Geiger, Oumarou Farikou, Sartrien Tagueu Kanté, Joule Madinga, Ginette Kame, Gillon Ilombe, Pascal Lutumba, Flobert Njiokou
    Abstract:

    During the last 30 years, investigations on the microbiome of different tsetse species have generated substantial data on the bacterial flora of these cyclical vectors of African trypanosomes, with the overarching goal of improving the control of trypanosomiases. It is in this context that the presence of Wolbachia and Sodalis glossinidius was studied in wild populations of Glossina fuscipes quanzensis from the Democratic Republic of Congo. Tsetse flies were captured with pyramidal traps. Of the 700 Glossina f. quanzensis captured, 360 were dissected and their midguts collected and analyzed. Sodalis glossinidius and Wolbachia were identified by PCR. The Wolbachia-positive samples were genetically characterized with five molecular markers. PCR revealed 84.78% and 15.55% midguts infected by Wolbachia and S. glossinidius, respectively. The infection rates varied according to capture sites. Of the five molecular markers used to characterize Wolbachia, only the fructose bis-phosphate aldolase gene was amplified for about 60% of midguts previously found with Wolbachia infections. The sequencing results confirmed the presence of Wolbachia and revealed the presence of S. glossinidius in the midgut of Glossina f. quanzensis. A low level of midguts were naturally co-infected by both bacteria. The data generated in this study open a framework for investigations aimed at understanding the contribution of these symbiotic microorganisms to the vectorial competence of Glossina fuscipes quanzensis

  • Prevalence of symbionts and trypanosome infections in tsetse flies of two villages of the “Faro and Déo” division of the Adamawa region of Cameroon
    BMC Microbiology, 2018
    Co-Authors: Ginette Irma Kame-ngasse, Gustave Simo, Flobert Njiokou, Oumarou Farikou, Tito Trésor Melachio-tanekou, Anne Geiger
    Abstract:

    Background Tsetse flies are vectors of human and animal African trypanosomiasis. In spite of many decades of chemotherapy and vector control, the disease has not been eradicated. Other methods like the transformation of tsetse fly symbionts to render the fly refractory to trypanosome infection are being evaluated. The aim of the present study was to evaluate the association between trypanosome infections and the presence of symbionts in these tsetse species. Tsetse flies were trapped in two villages of the “Faro and Déo” Division of the Adamawa region of Cameroon. In the field, tsetse fly species were identified and their infection by trypanosomes was checked by microscopy. In the laboratory, DNA was extracted from their midguts and the presence of symbionts ( Sodalis glossinidius and Wolbachia sp.) and trypanosomes was checked by PCR. Symbionts/trypanosomes association tests were performed. Results Three tsetse fly species including Glossina tachinoides (90.1%), Glossina morsitans submorsitans (9.4%) and Glossina fuscipes fuscipes (0.5%) were caught. In all the population we obtained an occurrence rate of 37.2% for Sodalis glossinidius and 67.6% for Wolbachia irrespective to tsetse flies species. S. glossinidius and Wolbachia sp. occurrence rates were respectively 37 and 68% for G. tachinoides and 28.6 and 59.5% for G. m. submorsitans . Between Golde Bourle and Mayo Dagoum significant differences were observed in the prevalence of symbionts. Prevalence of trypanosomes were 34.8% for Glossina tachinoides and 40.5% for Glossina morsitans submorsitans. In G. tachinoides, the trypanosome infection rates were 11, 2.6 and 13.7%, respectively, for T. brucei s.l., T. congolense forest type and T. congolense savannah type. In G. m. submorsitans, these infection rates were 16.7, 9.5 and, 2.4% respectively, for T. brucei s.l. , T. congolense forest type and T. congolense savannah type. Conclusions The rate of tsetse fly infection by trypanosomes was low compared to those obtained in HAT foci of south Cameroon, and this rate was not statistically linked to the rate of symbiont occurrence. This study allowed to show for the first time the presence of Wolbachia sp. in the tsetse fly sub-species Glossina morsitans submorsitans and Glossina tachinoides .

  • Comparative Genomics of Glossina palpalis gambiensis and G. morsitans morsitans to Reveal Gene Orthologs Involved in Infection by Trypanosoma brucei gambiense
    Frontiers in Microbiology, 2017
    Co-Authors: Illiassou Hamidou Soumana, Bernadette Tchicaya, Stéphanie Rialle, Hugues Parrinello, Anne Geiger
    Abstract:

    Blood-feeding Glossina palpalis gambiense (Gpg) fly transmits the single-celled eukaryotic parasite Trypanosoma brucei gambiense (Tbg), the second Glossina fly African trypanosome pair being Glossina morsitans/T.brucei rhodesiense. Whatever the T. brucei subspecies, whereas the onset of their developmental program in the zoo-anthropophilic blood feeding flies does unfold in the fly midgut, its completion is taking place in the fly salivary gland where does emerge a low size metacyclic trypomastigote population displaying features that account for its establishment in mammals-human individuals included. Considering that the two Glossina-T. brucei pairs introduced above share similarity with respect to the developmental program of this African parasite, we were curious to map on the Glossina morsitans morsitans (Gmm), the Differentially Expressed Genes (DEGs) we listed in a previous study. Briefly, using the gut samples collected at days 3, 10, and 20 from Gpg that were fed or not at day 0 on Tbg-hosting mice, these DGE lists were obtained from RNA seq-based approaches. Here, post the mapping on the quality controlled DEGs on the Gmm genome, the identified ortholog genes were further annotated, the resulting datasets being compared. Around 50% of the Gpg DEGs were shown to have orthologs in the Gmm genome. Under one of the three Glossina midgut sampling conditions, the number of DEGs was even higher when mapping on the Gmm genome than initially recorded. Many Gmm genes annotated as "Hypothetical" were mapped and annotated on many distinct databases allowing some of them to be properly identified. We identify Glossina fly candidate genes encoding (a) a broad panel of proteases as well as (b) chitin-binding proteins, (c) antimicrobial peptide production-Pro3 protein, transferrin, mucin, atttacin, cecropin, etc-to further select in functional studies, the objectives being to probe and validated fly genome manipulation that prevents the onset of the developmental program of one or the other T. brucei spp. stumpy form sampled by one of the other bloodfeeding Glossina subspecies.

  • tsetse fly blood meal modification and trypanosome identification in two sleeping sickness foci in the forest of southern cameroon
    Acta Tropica, 2010
    Co-Authors: Oumarou Farikou, Gérard Cuny, Gustave Simo, Flobert Njiokou, T. Asonganyi, Anne Geiger
    Abstract:

    The blood meal origins of 222 tsetse flies (213 Glossina palpalis palpalis, 7 Glossina pallicera pallicera, one Glossina nigrofusca and one Glossina caliginea) caught in 2008 in two Human African trypanosomiasis foci (Bipindi and Campo) of south Cameroon were investigated. 88.7% of tsetse flies blood meals were identified using the heteroduplex method and the origin of the remaining blood meals (11.3%) was identified by sequencing the cytochrome B gene. Most of the meals were from humans (45.9%) and pigs (37.4%), 16.7% from wild animals. Interestingly, new tsetse fly hosts including turtle (Trionyx and Kinixys) and snake (Python sebae) were identified. Significant differences were recorded between Bipindi where the blood meals from pigs were predominant (66.7% vs 23.5% from humans) and Campo where blood meals from humans were predominant (62.9% vs 22.7% from pigs). Comparison with the data recorded in 2004 in the same foci (and with the same molecular approach) demonstrated significant modifications of the feeding patterns: increase in blood meals from pigs in Bipindi (66.7% in 2008 vs 44.8% in 2004) and in Campo (20.5% in 2008 vs 6.8% in 2004), decrease in that from human (significant in Bipindi only). 12.6%, 8.1% and 2.7% of the flies were, respectively, Trypanosoma congolense forest type, Trypanosoma congolense savannah type and Trypanosoma brucei gambiense infected. These results demonstrate that tsetse fly feeding patterns can be specific of a given area and can evolve rapidly with time. They show an active circulation of a variety of trypanosomes in sleeping sickness foci of southern Cameroon.

  • Vector Competence of Glossina palpalis gambiensis for Trypanosoma brucei s.l. and Genetic Diversity of the Symbiont Sodalis glossinidius
    Molecular biology and evolution, 2006
    Co-Authors: Anne Geiger, Sophie Ravel, Gérard Cuny, Thierry Mateille, Jérome Janelle, Delphine Patrel, Roger Frutos
    Abstract:

    Tsetse flies transmit African trypanosomes, responsible for sleeping sickness in humans and nagana in animals. This disease affects many people with considerable impact on public health and economy in sub-Saharan Africa, whereas trypanosomes' resistance to drugs is rising. The symbiont Sodalis glossinidius is considered to play a role in the ability of the fly to acquire trypanosomes. Different species of Glossina were shown to harbor genetically distinct populations of S. glossinidius. We therefore investigated whether vector competence for a given trypanosome species could be linked to the presence of specific genotypes of S. glossinidius. Glossina palpalis gambiensis individuals were fed on blood infected either with Trypanosoma brucei gambiense or Trypanosoma brucei brucei. The genetic diversity of S. glossinidius strains isolated from infected and noninfected dissected flies was investigated using amplified fragment length polymorphism markers. Correspondence between occurrence of these markers and parasite establishment was analyzed using multivariate analysis. Sodalis glossinidius strains isolated from T. brucei gambiense-infected flies clustered differently than that isolated from T. brucei brucei-infected individuals. The ability of T. brucei gambiense and T. brucei brucei to establish in G. palpalis gambiensis insect midgut is statistically linked to the presence of specific genotypes of S. glossinidius. This could explain variations in Glossina vector competence in the wild. Then, assessment of the prevalence of specific S. glossinidius genotypes could lead to novel risk management strategies. (Resume d'auteur)

Serap Aksoy - One of the best experts on this subject based on the ideXlab platform.

  • genome wide comparative analysis of chemosensory gene families in five tsetse fly species
    PLOS Neglected Tropical Diseases, 2016
    Co-Authors: Serap Aksoy, Rosaline W. Macharia, Grace Murilla, Paul O. Mireji, Edwin Murungi, Alan Christoffels, Daniel Masiga
    Abstract:

    For decades, odour-baited traps have been used for control of tsetse flies (Diptera; Glossinidae), vectors of African trypanosomes. However, differential responses to known attractants have been reported in different Glossina species, hindering establishment of a universal vector control tool. Availability of full genome sequences of five Glossina species offers an opportunity to compare their chemosensory repertoire and enhance our understanding of their biology in relation to chemosensation. Here, we identified and annotated the major chemosensory gene families in Glossina. We identified a total of 118, 115, 124, and 123 chemosensory genes in Glossina austeni, G. brevipalpis, G. f. fuscipes, G. pallidipes, respectively, relative to 127 reported in G. m. morsitans. Our results show that tsetse fly genomes have fewer chemosensory genes when compared to other dipterans such as Musca domestica (n>393), Drosophila melanogaster (n = 246) and Anopheles gambiae (n>247). We also found that Glossina chemosensory genes are dispersed across distantly located scaffolds in their respective genomes, in contrast to other insects like D. melanogaster whose genes occur in clusters. Further, Glossina appears to be devoid of sugar receptors and to have expanded CO2 associated receptors, potentially reflecting Glossina's obligate hematophagy and the need to detect hosts that may be out of sight. We also identified, in all species, homologs of Ir84a; a Drosophila-specific ionotropic receptor that promotes male courtship suggesting that this is a conserved trait in tsetse flies. Notably, our selection analysis revealed that a total of four gene loci (Gr21a, GluRIIA, Gr28b, and Obp83a) were under positive selection, which confers fitness advantage to species. These findings provide a platform for studies to further define the language of communication of tsetse with their environment, and influence development of novel approaches for control.

  • Phylogeny of gustatory receptors.
    2016
    Co-Authors: Rosaline W. Macharia, Serap Aksoy, Grace Murilla, Paul O. Mireji, Edwin Murungi, Alan Christoffels, Daniel Masiga
    Abstract:

    Gustatory receptors responsible for CO2 detection show expansion in Glossina species and Musca domestica relative to Drosophila. On the contrary, all receptors responsible for sugar detection are found to be absent in Glossina. Different symbols depict GRs from the different species at the terminal nodes: Glossina austeni (red*), Glossina brevipalpis (purple*), Glossina fuscipes fuscipes (pink*), Glossina morsitans morsitans (dark blue*), Glossina pallidipes (light orange*), Drosophila melanogaster (black*), Anopheles gambiae (sky blue*) and Musca domestica (lime green*). The symbol * represents the name of the specific GR. Sequence alignment was performed using MuSCLE v3.8.31 and phylogeny relationship was inferred using RAxML v8 with best fitting Wheelan and Goldman (WAG) model and 1000 bootstrap iterations.

  • Phylogeny of odorant receptors.
    2016
    Co-Authors: Rosaline W. Macharia, Serap Aksoy, Grace Murilla, Paul O. Mireji, Edwin Murungi, Alan Christoffels, Daniel Masiga
    Abstract:

    Expansion of cis-Vaccenyl acetate receptor (Or67d), 4-Methylphenol receptor (Or46a) and aggregation-linked receptor (Or7a) is observed in Glossina species and Musca domestica relative to Drosophila. Sequence alignment was performed using MuSCLE v3.8.31 and phylogeny relationship was inferred using RAxML v8 with best fitting Wheelan and Goldman (WAG) model and 1000 bootstrap iterations. Different symbols and colors were used to depict ORs from the different species at the terminal nodes: Glossina austeni (red*), Glossina brevipalpis (purple*), Glossina fuscipes fuscipes (pink*), Glossina morsitans morsitans (dark blue*), Glossina pallidipes (light orange*), Drosophila melanogaster (black*) and Musca domestica (lime green*). The symbol * represents the name of the specific OR.

  • Phylogeny of ionotropic glutamate receptors and kainate receptors.
    2016
    Co-Authors: Rosaline W. Macharia, Serap Aksoy, Grace Murilla, Paul O. Mireji, Edwin Murungi, Alan Christoffels, Daniel Masiga
    Abstract:

    Sequence alignment was performed using MuSCLE v3.8.31 and phylogeny relationship inferred using RAxML v8 with best fitting Wheelan and Goldman (WAG) model and 1000 bootstrap iterations. Different symbols and colors were used to depict IGluRs from the different species at the terminal nodes: Glossina austeni (red*), Glossina brevipalpis (purple*), Glossina fuscipes fuscipes (pink*), Glossina morsitans morsitans (dark blue*), Glossina pallidipes (light orange*), Drosophila melanogaster (black*), Musca domestica (lime green*) and Anopheles gambiae (sky blue*). The symbol * represents the name of the specific IGluR.

  • Phylogeny of divergent ionotropic receptors.
    2016
    Co-Authors: Rosaline W. Macharia, Serap Aksoy, Grace Murilla, Paul O. Mireji, Edwin Murungi, Alan Christoffels, Daniel Masiga
    Abstract:

    Sequence alignment was performed using MuSCLE v3.8.31 and phylogeny relationship inferred using RAxML v8 with best fitting Wheelan and Goldman (WAG) model and 1000 bootstrap iterations. Different symbols and colors were used to depict IRs from the different species at the terminal nodes: Glossina austeni (red*), Glossina brevipalpis (purple*), Glossina fuscipes fuscipes (pink*), Glossina morsitans morsitans (dark blue*), Glossina pallidipes (light orange*), Drosophila melanogaster (black*), Musca domestica (lime green*) and Anopheles gambiae (sky blue*). The symbol * represents the name of the specific IR.

Adly M M Abd-alla - One of the best experts on this subject based on the ideXlab platform.

  • Comparative genomic analysis of six Glossina genomes, vectors of African trypanosomes
    Genome biology, 2019
    Co-Authors: Geoffrey M Attardo, Kostas Bourtzis, Adly M M Abd-alla, Alvaro Acosta-serrano, James E. Allen, Rosemary Bateta, Jelle Caers, Guy Caljon, Mikkel B. Christensen
    Abstract:

    Tsetse flies (Glossina sp.) are the vectors of human and animal trypanosomiasis throughout sub-Saharan Africa. Tsetse flies are distinguished from other Diptera by unique adaptations, including lactation and the birthing of live young (obligate viviparity), a vertebrate blood-specific diet by both sexes, and obligate bacterial symbiosis. This work describes the comparative analysis of six Glossina genomes representing three sub-genera: Morsitans (G. morsitans morsitans, G. pallidipes, G. austeni), Palpalis (G. palpalis, G. fuscipes), and Fusca (G. brevipalpis) which represent different habitats, host preferences, and vectorial capacity. Genomic analyses validate established evolutionary relationships and sub-genera. Syntenic analysis of Glossina relative to Drosophila melanogaster shows reduced structural conservation across the sex-linked X chromosome. Sex-linked scaffolds show increased rates of female-specific gene expression and lower evolutionary rates relative to autosome associated genes. Tsetse-specific genes are enriched in protease, odorant-binding, and helicase activities. Lactation-associated genes are conserved across all Glossina species while male seminal proteins are rapidly evolving. Olfactory and gustatory genes are reduced across the genus relative to other insects. Vision-associated Rhodopsin genes show conservation of motion detection/tracking functions and variance in the Rhodopsin detecting colors in the blue wavelength ranges. Expanded genomic discoveries reveal the genetics underlying Glossina biology and provide a rich body of knowledge for basic science and disease control. They also provide insight into the evolutionary biology underlying novel adaptations and are relevant to applied aspects of vector control such as trap design and discovery of novel pest and disease control strategies.

  • The Glossina Genome Cluster: Comparative Genomic Analysis of the Vectors of African Trypanosomes
    2019
    Co-Authors: Geoffrey M Attardo, Kostas Bourtzis, Adly M M Abd-alla, Alvaro Acosta-serrano, James E. Allen, Rosemary Bateta, Jelle Caers, Guy Caljon, Mikkel B. Christensen
    Abstract:

    Background: Tsetse flies (Glossina sp.) are the sole vectors of human and animal trypanosomiasis throughout sub-Saharan Africa. Tsetse are distinguished from other Diptera by unique adaptations, including lactation and the birthing of live young (obligate viviparity), a vertebrate blood specific diet by both sexes and obligate bacterial symbiosis. This work describes comparative analysis of six Glossina genomes representing three sub-genera: Morsitans (G. morsitans morsitans (G.m. morsitans), G. pallidipes, G. austeni), Palpalis (G. palpalis, G. fuscipes) and Fusca (G. brevipalpis) which represent different habitats, host preferences and vectorial capacity. Results: Genomic analyses validate established evolutionary relationships and sub-genera. Syntenic analysis of Glossina relative to Drosophila melanogaster shows reduced structural conservation across the sex-linked X chromosome. Sex linked scaffolds show increased rates of female specific gene expression and lower evolutionary rates relative to autosome associated genes. Tsetse specific genes are enriched in protease, odorant binding and helicase activities. Lactation associated genes are conserved across all Glossina species while male seminal proteins are rapidly evolving. Olfactory and gustatory genes are reduced across the genus relative to other characterized insects. Vision associated Rhodopsin genes show conservation of motion detection/tracking functions and significant variance in the Rhodopsin detecting colors in the blue wavelength ranges. Conclusions: Expanded genomic discoveries reveal the genetics underlying Glossina biology and provide a rich body of knowledge for basic science and disease control. They also provide insight into the evolutionary biology underlying novel adaptations and are relevant to applied aspects of vector control such as trap design and discovery of novel pest and disease control strategies.

  • Comparative genomic analysis of six Glossina genomes, vectors of African trypanosomes
    'Springer Science and Business Media LLC', 2019
    Co-Authors: Attardo, Geoffrey M, Adly M M Abd-alla, Acosta-serrano Alvaro, Allen, James E, Bateta Rosemary, Benoit, Joshua B, Bourtzis Kostas, Caers Jelle, Caljon Guy, Christensen, Mikkel B
    Abstract:

    BACKGROUND: Tsetse flies (Glossina sp.) are the vectors of human and animal trypanosomiasis throughout sub-Saharan Africa. Tsetse flies are distinguished from other Diptera by unique adaptations, including lactation and the birthing of live young (obligate viviparity), a vertebrate blood-specific diet by both sexes, and obligate bacterial symbiosis. This work describes the comparative analysis of six Glossina genomes representing three sub-genera: Morsitans (G. morsitans morsitans, G. pallidipes, G. austeni), Palpalis (G. palpalis, G. fuscipes), and Fusca (G. brevipalpis) which represent different habitats, host preferences, and vectorial capacity. RESULTS: Genomic analyses validate established evolutionary relationships and sub-genera. Syntenic analysis of Glossina relative to Drosophila melanogaster shows reduced structural conservation across the sex-linked X chromosome. Sex-linked scaffolds show increased rates of female-specific gene expression and lower evolutionary rates relative to autosome associated genes. Tsetse-specific genes are enriched in protease, odorant-binding, and helicase activities. Lactation-associated genes are conserved across all Glossina species while male seminal proteins are rapidly evolving. Olfactory and gustatory genes are reduced across the genus relative to other insects. Vision-associated Rhodopsin genes show conservation of motion detection/tracking functions and variance in the Rhodopsin detecting colors in the blue wavelength ranges. CONCLUSIONS: Expanded genomic discoveries reveal the genetics underlying Glossina biology and provide a rich body of knowledge for basic science and disease control. They also provide insight into the evolutionary biology underlying novel adaptations and are relevant to applied aspects of vector control such as trap design and discovery of novel pest and disease control strategies.status: publishe

  • Hytrosavirus genetic diversity and eco-regional spread in Glossina species
    BMC Microbiology, 2018
    Co-Authors: Irene K. Meki, Andrew G. Parker, Henry M. Kariithi, Mehrdad Ahmadi, Marc J. B. Vreysen, Just M. Vlak, Monique M. Van Oers, Adly M M Abd-alla
    Abstract:

    Background The management of the tsetse species Glossina pallidipes (Diptera; Glossinidae) in Africa by the sterile insect technique (SIT) has been hindered by infections of G. pallidipes production colonies with Glossina pallidipes salivary gland hypertrophy virus (GpSGHV; Hytrosaviridae family). This virus can significantly decrease productivity of the G. pallidipes colonies. Here, we used three highly diverged genes and two variable number tandem repeat regions (VNTRs) of the GpSGHV genome to identify the viral haplotypes in seven Glossina species obtained from 29 African locations and determine their phylogenetic relatedness. Results GpSGHV was detected in all analysed Glossina species using PCR. The highest GpSGHV prevalence was found in G. pallidipes colonized at FAO/IAEA Insect Pest Control Laboratory (IPCL) that originated from Uganda (100%) and Tanzania (88%), and a lower prevalence in G. morsitans morsitans from Tanzania (58%) and Zimbabwe (20%). Whereas GpSGHV was detected in 25–40% of G. fuscipes fuscipes in eastern Uganda, the virus was not detected in specimens of neighboring western Kenya. Most of the identified 15 haplotypes were restricted to specific Glossina species in distinct locations. Seven haplotypes were found exclusively in G. pallidipes . The reference haplotype H1 (GpSGHV-Uga; Ugandan strain) was the most widely distributed, but was not found in G. swynnertoni GpSGHV. The 15 haplotypes clustered into three distinct phylogenetic clades, the largest contained seven haplotypes, which were detected in six Glossina species. The G. pallidipes -infecting haplotypes H10, H11 and H12 (from Kenya) clustered with H7 (from Ethiopia), which presumably corresponds to the recently sequenced GpSGHV-Eth (Ethiopian) strain. These four haplotypes diverged the most from the reference H1 (GpSGHV-Uga). Haplotypes H1, H5 and H14 formed three main genealogy hubs, potentially representing the ancestors of the 15 haplotypes. Conclusion These data identify G. pallidipes as a significant driver for the generation and diversity of GpSGHV variants. This information may provide control guidance when new tsetse colonies are established and hence, for improved management of the virus in tsetse rearing facilities that maintain multiple Glossina species.

  • Table_2_Expression Profile of Glossina pallidipes MicroRNAs During Symptomatic and Asymptomatic Infection With Glossina pallidipes Salivary Gland Hypertrophy Virus (Hytrosavirus).XLSX
    2018
    Co-Authors: Irene K. Meki, Andrew G. Parker, Henry M. Kariithi, Just M. Vlak, Monique M. Van Oers, Ikbal Agah Ince, Drion G. Boucias, Orhan Ozcan, Adly M M Abd-alla
    Abstract:

    The Glossina pallidipes salivary gland hypertrophy virus (GpSGHV) infects tsetse flies predominantly asymptomatically and occasionally symptomatically. Symptomatic infections are characterized by overt salivary gland hypertrophy (SGH) in mass reared tsetse flies, which causes reproductive dysfunctions and colony collapse, thus hindering tsetse control via sterile insect technique (SIT). Asymptomatic infections have no apparent cost to the fly’s fitness. Here, small RNAs were sequenced and profiles in asymptomatically and symptomatically infected G. pallidipes flies determined. Thirty-eight host-encoded microRNAs (miRNAs) were present in both the asymptomatic and symptomatic fly profiles, while nine host miRNAs were expressed specifically in asymptomatic flies versus 10 in symptomatic flies. Of the shared 38 miRNAs, 15 were differentially expressed when comparing asymptomatic with symptomatic flies. The most up-regulated host miRNAs in symptomatic flies was predicted to target immune-related mRNAs of the host. Six GpSGHV-encoded miRNAs were identified, of which five of them were only in symptomatic flies. These virus-encoded miRNAs may not only target host immune genes but may also participate in viral immune evasion. This evidence of differential host miRNA profile in Glossina in symptomatic flies advances our understanding of the GpSGHV-Glossina interactions and provides potential new avenues, for instance by utilization of particular miRNA inhibitors or mimics to better manage GpSGHV infections in tsetse mass-rearing facilities, a prerequisite for successful SIT implementation.

Andrew G. Parker - One of the best experts on this subject based on the ideXlab platform.

  • Prevalence of trypanosomes, salivary gland hypertrophy virus and Wolbachia in wild populations of tsetse flies from West Africa
    BMC Microbiology, 2018
    Co-Authors: Gisele M. S. Ouedraogo, Andrew G. Parker, Güler Demirbas-uzel, Jean-baptiste Rayaisse, Geoffrey Gimonneau, Astan C. Traore, Antonios Avgoustinos, Issa Sidibe, Anicet G. Ouedraogo, Amadou Traore
    Abstract:

    Background Tsetse flies are vectors of African trypanosomes, protozoan parasites that cause sleeping sickness (or human African trypanosomosis) in humans and nagana (or animal African trypanosomosis) in livestock. In addition to trypanosomes, four symbiotic bacteria Wigglesworthia glossinidia , Sodalis glossinidius, Wolbachia, Spiroplasma and one pathogen, the salivary gland hypertrophy virus (SGHV), have been reported in different tsetse species. We evaluated the prevalence and coinfection dynamics between Wolbachia , trypanosomes, and SGHV in four tsetse species ( Glossina palpalis gambiensis , G. tachinoides, G. morsitans submorsitans , and G. medicorum ) that were collected between 2008 and 2015 from 46 geographical locations in West Africa, i.e. Burkina Faso, Mali, Ghana, Guinea, and Senegal. Results The results indicated an overall low prevalence of SGHV and Wolbachia and a high prevalence of trypanosomes in the sampled wild tsetse populations. The prevalence of all three infections varied among tsetse species and sample origin. The highest trypanosome prevalence was found in Glossina tachinoides (61.1%) from Ghana and in Glossina palpalis gambiensis (43.7%) from Senegal. The trypanosome prevalence in the four species from Burkina Faso was lower, i.e. 39.6% in Glossina medicorum, 18.08%; in Glossina morsitans submorsitans, 16.8%; in Glossina tachinoides and 10.5% in Glossina palpalis gambiensis . The trypanosome prevalence in Glossina palpalis gambiensis was lowest in Mali (6.9%) and Guinea (2.2%). The prevalence of SGHV and Wolbachia was very low irrespective of location or tsetse species with an average of 1.7% for SGHV and 1.0% for Wolbachia . In some cases, mixed infections with different trypanosome species were detected. The highest prevalence of coinfection was Trypanosoma vivax and other Trypanosoma species ( 9.5%) followed by coinfection of T. congolense with other trypanosomes (7.5%). The prevalence of coinfection of T. vivax and T. congolense was (1.0%) and no mixed infection of trypanosomes, SGHV and Wolbachia was detected. Conclusion The results indicated a high rate of trypanosome infection in tsetse wild populations in West African countries but lower infection rate of both Wolbachia and SGHV. Double or triple mixed trypanosome infections were found. In addition, mixed trypanosome and SGHV infections existed however no mixed infections of trypanosome and/or SGHV with Wolbachia were found.

  • Hytrosavirus genetic diversity and eco-regional spread in Glossina species
    BMC Microbiology, 2018
    Co-Authors: Irene K. Meki, Andrew G. Parker, Henry M. Kariithi, Mehrdad Ahmadi, Marc J. B. Vreysen, Just M. Vlak, Monique M. Van Oers, Adly M M Abd-alla
    Abstract:

    Background The management of the tsetse species Glossina pallidipes (Diptera; Glossinidae) in Africa by the sterile insect technique (SIT) has been hindered by infections of G. pallidipes production colonies with Glossina pallidipes salivary gland hypertrophy virus (GpSGHV; Hytrosaviridae family). This virus can significantly decrease productivity of the G. pallidipes colonies. Here, we used three highly diverged genes and two variable number tandem repeat regions (VNTRs) of the GpSGHV genome to identify the viral haplotypes in seven Glossina species obtained from 29 African locations and determine their phylogenetic relatedness. Results GpSGHV was detected in all analysed Glossina species using PCR. The highest GpSGHV prevalence was found in G. pallidipes colonized at FAO/IAEA Insect Pest Control Laboratory (IPCL) that originated from Uganda (100%) and Tanzania (88%), and a lower prevalence in G. morsitans morsitans from Tanzania (58%) and Zimbabwe (20%). Whereas GpSGHV was detected in 25–40% of G. fuscipes fuscipes in eastern Uganda, the virus was not detected in specimens of neighboring western Kenya. Most of the identified 15 haplotypes were restricted to specific Glossina species in distinct locations. Seven haplotypes were found exclusively in G. pallidipes . The reference haplotype H1 (GpSGHV-Uga; Ugandan strain) was the most widely distributed, but was not found in G. swynnertoni GpSGHV. The 15 haplotypes clustered into three distinct phylogenetic clades, the largest contained seven haplotypes, which were detected in six Glossina species. The G. pallidipes -infecting haplotypes H10, H11 and H12 (from Kenya) clustered with H7 (from Ethiopia), which presumably corresponds to the recently sequenced GpSGHV-Eth (Ethiopian) strain. These four haplotypes diverged the most from the reference H1 (GpSGHV-Uga). Haplotypes H1, H5 and H14 formed three main genealogy hubs, potentially representing the ancestors of the 15 haplotypes. Conclusion These data identify G. pallidipes as a significant driver for the generation and diversity of GpSGHV variants. This information may provide control guidance when new tsetse colonies are established and hence, for improved management of the virus in tsetse rearing facilities that maintain multiple Glossina species.

  • Table_2_Expression Profile of Glossina pallidipes MicroRNAs During Symptomatic and Asymptomatic Infection With Glossina pallidipes Salivary Gland Hypertrophy Virus (Hytrosavirus).XLSX
    2018
    Co-Authors: Irene K. Meki, Andrew G. Parker, Henry M. Kariithi, Just M. Vlak, Monique M. Van Oers, Ikbal Agah Ince, Drion G. Boucias, Orhan Ozcan, Adly M M Abd-alla
    Abstract:

    The Glossina pallidipes salivary gland hypertrophy virus (GpSGHV) infects tsetse flies predominantly asymptomatically and occasionally symptomatically. Symptomatic infections are characterized by overt salivary gland hypertrophy (SGH) in mass reared tsetse flies, which causes reproductive dysfunctions and colony collapse, thus hindering tsetse control via sterile insect technique (SIT). Asymptomatic infections have no apparent cost to the fly’s fitness. Here, small RNAs were sequenced and profiles in asymptomatically and symptomatically infected G. pallidipes flies determined. Thirty-eight host-encoded microRNAs (miRNAs) were present in both the asymptomatic and symptomatic fly profiles, while nine host miRNAs were expressed specifically in asymptomatic flies versus 10 in symptomatic flies. Of the shared 38 miRNAs, 15 were differentially expressed when comparing asymptomatic with symptomatic flies. The most up-regulated host miRNAs in symptomatic flies was predicted to target immune-related mRNAs of the host. Six GpSGHV-encoded miRNAs were identified, of which five of them were only in symptomatic flies. These virus-encoded miRNAs may not only target host immune genes but may also participate in viral immune evasion. This evidence of differential host miRNA profile in Glossina in symptomatic flies advances our understanding of the GpSGHV-Glossina interactions and provides potential new avenues, for instance by utilization of particular miRNA inhibitors or mimics to better manage GpSGHV infections in tsetse mass-rearing facilities, a prerequisite for successful SIT implementation.

  • Susceptibility of Tsetse Species to Glossina pallidipes Salivary Gland Hypertrophy Virus (GpSGHV)
    Frontiers Media S.A., 2018
    Co-Authors: Andrew G. Parker, Güler Demirbas-uzel, Henry M. Kariithi, Marc J. B. Vreysen, Robert L. Mach, Adly M M Abd-alla
    Abstract:

    Salivary gland hytrosaviruses (SGHVs, family Hytrosaviridae) are non-occluded dsDNA viruses that are pathogenic to some dipterans. SGHVs primarily replicate in salivary glands (SG), thereby inducing overt salivary gland hypertrophy (SGH) symptoms in their adult hosts. SGHV infection of non-SG tissues results in distinct pathobiologies, including reproductive dysfunctions in tsetse fly, Glossina pallidipes (Diptera: Glossinidae) and house fly. Infection with the G. pallidipes virus (GpSGHV) resulted in the collapse of several laboratory colonies, which hindered the implementation of area wide integrated pest management (AW-IPM) programs that had a sterile insect technique (SIT) component. Although the impact of GpSGHV infection has been studied in some detail in G. pallidipes, the impact of the virus infection on other tsetse species remains largely unknown. In the current study, we assessed the susceptibility of six Glossina species (G. pallidipes, G. brevipalpis, G. m. morsitans, G. m. centralis, G. f. fuscipes, and G. p. gambiensis) to GpSGHV infections, and the impact of the viral infection on the fly pupation rate, adult emergence, and virus replication and transmission from the larval to adult stages. We also evaluated the ability of the virus to infect conspecific Glossina species through serial passages. The results indicate that the susceptibility of Glossina to GpSGHV varied widely amongst the tested species, with G. pallidipes and G. brevipalpis being the most susceptible and most refractory to the virus, respectively. Further, virus injection into the hemocoel of teneral flies led to increased viral copy number over time, while virus injection into the third instar larvae delayed adult eclosion. Except in G. pallidipes, virus injection either into the larvae or teneral adults did not induce any detectable SGH symptoms, although virus infections were PCR-detectable in the fly carcasses. Taken together, our results indicate that although GpSGHV may only cause minor damage in the mass-rearing of tsetse species other than G. pallidipes, preventive control measures are required to avoid viral contamination and transmission in the fly colonies, particularly in the facilities where multiple tsetse species are reared

  • Data_Sheet_1.PDF
    2018
    Co-Authors: Güler Demirbas-uzel, Andrew G. Parker, Henry M. Kariithi, Marc J. B. Vreysen, Robert L. Mach, Adly M M Abd-alla
    Abstract:

    Salivary gland hytrosaviruses (SGHVs, family Hytrosaviridae) are non-occluded dsDNA viruses that are pathogenic to some dipterans. SGHVs primarily replicate in salivary glands (SG), thereby inducing overt salivary gland hypertrophy (SGH) symptoms in their adult hosts. SGHV infection of non-SG tissues results in distinct pathobiologies, including reproductive dysfunctions in tsetse fly, Glossina pallidipes (Diptera: Glossinidae) and house fly. Infection with the G. pallidipes virus (GpSGHV) resulted in the collapse of several laboratory colonies, which hindered the implementation of area wide integrated pest management (AW-IPM) programs that had a sterile insect technique (SIT) component. Although the impact of GpSGHV infection has been studied in some detail in G. pallidipes, the impact of the virus infection on other tsetse species remains largely unknown. In the current study, we assessed the susceptibility of six Glossina species (G. pallidipes, G. brevipalpis, G. m. morsitans, G. m. centralis, G. f. fuscipes, and G. p. gambiensis) to GpSGHV infections, and the impact of the viral infection on the fly pupation rate, adult emergence, and virus replication and transmission from the larval to adult stages. We also evaluated the ability of the virus to infect conspecific Glossina species through serial passages. The results indicate that the susceptibility of Glossina to GpSGHV varied widely amongst the tested species, with G. pallidipes and G. brevipalpis being the most susceptible and most refractory to the virus, respectively. Further, virus injection into the hemocoel of teneral flies led to increased viral copy number over time, while virus injection into the third instar larvae delayed adult eclosion. Except in G. pallidipes, virus injection either into the larvae or teneral adults did not induce any detectable SGH symptoms, although virus infections were PCR-detectable in the fly carcasses. Taken together, our results indicate that although GpSGHV may only cause minor damage in the mass-rearing of tsetse species other than G. pallidipes, preventive control measures are required to avoid viral contamination and transmission in the fly colonies, particularly in the facilities where multiple tsetse species are reared.

Roger Frutos - One of the best experts on this subject based on the ideXlab platform.

  • Vector Competence of Glossina palpalis gambiensis for Trypanosoma brucei s.l. and Genetic Diversity of the Symbiont Sodalis glossinidius
    Molecular biology and evolution, 2006
    Co-Authors: Anne Geiger, Sophie Ravel, Gérard Cuny, Thierry Mateille, Jérome Janelle, Delphine Patrel, Roger Frutos
    Abstract:

    Tsetse flies transmit African trypanosomes, responsible for sleeping sickness in humans and nagana in animals. This disease affects many people with considerable impact on public health and economy in sub-Saharan Africa, whereas trypanosomes' resistance to drugs is rising. The symbiont Sodalis glossinidius is considered to play a role in the ability of the fly to acquire trypanosomes. Different species of Glossina were shown to harbor genetically distinct populations of S. glossinidius. We therefore investigated whether vector competence for a given trypanosome species could be linked to the presence of specific genotypes of S. glossinidius. Glossina palpalis gambiensis individuals were fed on blood infected either with Trypanosoma brucei gambiense or Trypanosoma brucei brucei. The genetic diversity of S. glossinidius strains isolated from infected and noninfected dissected flies was investigated using amplified fragment length polymorphism markers. Correspondence between occurrence of these markers and parasite establishment was analyzed using multivariate analysis. Sodalis glossinidius strains isolated from T. brucei gambiense-infected flies clustered differently than that isolated from T. brucei brucei-infected individuals. The ability of T. brucei gambiense and T. brucei brucei to establish in G. palpalis gambiensis insect midgut is statistically linked to the presence of specific genotypes of S. glossinidius. This could explain variations in Glossina vector competence in the wild. Then, assessment of the prevalence of specific S. glossinidius genotypes could lead to novel risk management strategies. (Resume d'auteur)

  • vector competence of Glossina palpalis gambiensis for trypanosoma brucei s l and genetic diversity of the symbiont sodalis glossinidius
    Molecular Biology and Evolution, 2006
    Co-Authors: Anne Geiger, Sophie Ravel, Gérard Cuny, Thierry Mateille, Jérome Janelle, Delphine Patrel, Roger Frutos
    Abstract:

    Tsetse flies transmit African trypanosomes, responsible for sleeping sickness in humans and nagana in animals. This disease affects many people with considerable impact on public health and economy in sub-Saharan Africa, whereas trypanosomes' resistance to drugs is rising. The symbiont Sodalis glossinidius is considered to play a role in the ability of the fly to acquire trypanosomes. Different species of Glossina were shown to harbor genetically distinct populations of S. glossinidius. We therefore investigated whether vector competence for a given trypanosome species could be linked to the presence of specific genotypes of S. glossinidius. Glossina palpalis gambiensis individuals were fed on blood infected either with Trypanosoma brucei gambiense or Trypanosoma brucei brucei. The genetic diversity of S. glossinidius strains isolated from infected and noninfected dissected flies was investigated using amplified fragment length polymorphism markers. Correspondence between occurrence of these markers and parasite establishment was analyzed using multivariate analysis. Sodalis glossinidius strains isolated from T. brucei gambiense-infected flies clustered differently than that isolated from T. brucei brucei-infected individuals. The ability of T. brucei gambiense and T. brucei brucei to establish in G. palpalis gambiensis insect midgut is statistically linked to the presence of specific genotypes of S. glossinidius. This could explain variations in Glossina vector competence in the wild. Then, assessment of the prevalence of specific S. glossinidius genotypes could lead to novel risk management strategies.

  • Sodalis glossinidius (Enterobacteriaceae) and Vectorial Competence of Glossina palpalis gambiensis and Glossina morsitans morsitans for Trypanosoma congolense Savannah Type
    Current Microbiology, 2005
    Co-Authors: Anne Geiger, Sophie Ravel, Roger Frutos, Gérard Cuny
    Abstract:

    Sodalis glossinidius is an endosymbiont of Glossina palpalis gambiensis and Glossina morsitans morsitans , the vectors of Trypanosoma congolense. The presence of the symbiont was investigated by PCR in Trypanosoma congolense savannah type-infected and noninfected midguts of both fly species, and into the probosces of flies displaying either mature or immature infection, to investigate possible correlation with the vectorial competence of tsetse flies. Sodalis glossinidius was detected in all midguts, infected or not, from both Glossina species. It was also detected in probosces from Glossina palpalis gambiensis flies displaying mature or immature infection, but never in probosces from Glossina morsitans morsitans . These results suggest that, a) there might be no direct correlation between the presence of Sodalis glossinidius and the vectorial competence of Glossina , and b) the symbiont is probably not involved in Trypanosoma congolense savannah type maturation. It could however participate in the establishment process of the parasite.

  • Two Tsetse Fly Species, Glossina palpalis gambiensis and Glossina morsitans morsitans, Carry Genetically Distinct Populations of the Secondary Symbiont Sodalis glossinidius
    Applied and environmental microbiology, 2005
    Co-Authors: Anne Geiger, Gérard Cuny, Roger Frutos
    Abstract:

    Genetic diversity among Sodalis glossinidius populations was investigated using amplified fragment length polymorphism markers. Strains collected from Glossina palpalis gambiensis and Glossina morsitans morsitans flies group into separate clusters, being differentially structured. This differential structuring may reflect different host-related selection pressures and may be related to the different vector competences of Glossina spp.