| 1. |
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| 2. |
- Alavi, Y., et al.
(författare)
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The dynamics of interactions between Plasmodium and the mosquito : a study of the infectivity of Plasmodium berghei and Plasmodium gallinaceum, and their transmission by Anopheles stephensi, Anopheles gambiae and Aedes aegypti
- 2003
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Ingår i: International Journal of Parasitology. - : Elsevier. - 0020-7519 .- 1879-0135. ; 33:9, s. 933-943
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge of parasite–mosquito interactions is essential to develop strategies that will reduce malaria transmission through the mosquito vector. In this study we investigated the development of two model malaria parasites, Plasmodium berghei and Plasmodium gallinaceum, in three mosquito species Anopheles stephensi, Anopheles gambiae and Aedes aegypti. New methods to study gamete production in vivo in combination with GFP-expressing ookinetes were employed to measure the large losses incurred by the parasites during infection of mosquitoes. All three mosquito species transmitted P. gallinaceum; P. berghei was only transmitted by Anopheles spp. Plasmodium gallinaceum initiates gamete production with high efficiency equally in the three mosquito species. By contrast P. berghei is less efficiently activated to produce gametes, and in Ae. aegypti microgamete formation is almost totally suppressed. In all parasite/vector combinations ookinete development is inefficient, 500–100,000-fold losses were encountered. Losses during ookinete-to-oocyst transformation range from fivefold in compatible vector parasite combinations (P. berghei/An. stephensi), through >100-fold in poor vector/parasite combinations (P. gallinaceum/An. stephensi), to complete blockade (>1,500 fold) in others (P. berghei/Ae. aegypti). Plasmodium berghei ookinetes survive poorly in the bloodmeal of Ae. aegypti and are unable to invade the midgut epithelium. Cultured mature ookinetes of P. berghei injected directly into the mosquito haemocoele produced salivary gland sporozoites in An. stephensi, but not in Ae. aegypti, suggesting that further species-specific incompatibilities occur downstream of the midgut epithelium in Ae. aegypti. These results show that in these parasite–mosquito combinations the susceptibility to malarial infection is regulated at multiple steps during the development of the parasites. Understanding these at the molecular level may contribute to the development of rational strategies to reduce the vector competence of malarial vectors.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Abate, E., et al.
(författare)
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Effects of albendazole on the clinical outcome and immunological responses in helminth co-infected tuberculosis patients: a double blind randomised clinical trial
- 2015
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Ingår i: International Journal of Parasitology. - : Elsevier. - 0020-7519 .- 1879-0135. ; 45:2-3, s. 133-140
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Tidskriftsartikel (refereegranskat)abstract
- Despite several review papers and experimental studies concerning the impact of chronic helminth infection on tuberculosis in recent years, there is a scarcity of data from clinical field studies in highly endemic areas for these diseases. We believe this is the first randomised clinical trial investigating the impact of albendazole treatment on the clinical and immunological outcomes of helminth co-infected tuberculosis patients. A randomised, double-blind, placebo-controlled trial of albendazole (400 mg per day for 3 days) in helminth-positive tuberculosis patients was conducted in Gondar, Ethiopia. The primary outcome was clinical improvement (Delta TB score) after 2 months. Among secondary outcomes were changes in the levels of eosinophils, CD4+ T cells, regulatory T cells, IFN-gamma, IL-5 and IL-10 after 3 months. A total of 140 helminth co-infected tuberculosis patients were included with an HIV co-infection rate of 22.8%. There was no significant effect on the primary outcome (Delta TB score: 5.6 +/- 2.9 for albendazole versus 5.9 +/- 2.5 for placebo, P = 0.59). The albendazole-treated group showed a decline in eosinophil cells (P = 0.001) and IL-10 (P = 0.017) after 3 months. In an exploratory analysis after 12 weeks, the albendazole treated group showed a trend towards weight gain compared with the placebo group (11.2 +/- 8.5 kg versus 8.2 +/- 8.7 kg, P = 0.08)). The reductions in eosinophil counts and IL-10 show that asymptomatic helminth infection significantly affects host immunity during tuberculosis and can be effectively reversed by albendazole treatment. The clinical effects of helminth infection on chronic infectious diseases such as tuberculosis merit further characterisation. (C) 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
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| 7. |
- Balan, Balu, et al.
(författare)
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Multimodal regulation of encystation in Giardia duodenalis revealed by deep proteomics
- 2021
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Ingår i: International Journal of Parasitology. - : Elsevier. - 0020-7519 .- 1879-0135. ; 51:10, s. 809-824
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Tidskriftsartikel (refereegranskat)abstract
- Cyst formation in the parasitic protist Giardia duodenalis is critical to its transmission. Existing proteomic data quantifies only 17% of coding genes transcribed during encystation and does not cover the complete process from trophozoite to mature cyst. Using high-resolution mass spectrometry, we have quantified proteomic changes across encystation and compared this with published transcriptomic data. We reproducibly identified 3863 (64.5% of Giardia proteins) and quantified 3382 proteins (56.5% of Giardia proteins) over standard trophozoite growth (TY), during low-bile encystation priming (LB), 16 h into encystation (EC), and at cyst maturation (C). This work provides the first known expanded observation of encystation at the proteomic level and triples the coverage of previous encystation proteomes. Onethird (1169 proteins) of the quantified proteome is differentially expressed in the mature cyst relative to the trophozoite, including proteasomal machinery, metabolic pathways, and secretory proteins. Changes in lipid metabolism indicated a shift in lipid species dependency during encystation. Consistent with this, we identified the first, putative lipid transporters in this species, representing the steroidogenic acute regulatory protein-related lipid transfer (StARkin), oxysterol binding protein related protein (ORP/Osh) and glycosphingolipid transfer protein (GLTP) families, and follow their differential expression over cyst formation. Lastly, we undertook correlation analyses of the transcriptome and proteome of trophozoites and cysts, and found evidence of post-transcriptional regulation of key protein classes (RNA binding proteins) and stage-specific genes (encystation markers) implicating translationrepression in encystation. We provide the most extensive proteomic analysis of encystation in Giardia to date and the first known exploration across its complete duration. This work identifies encystation as highly coordinated, involving major changes in proteostasis, metabolism and membrane dynamics, and indicates a potential role for post-transcriptional regulation, mediated through RNA-binding proteins. Together our work provides a valuable resource for Giardia research and the development of transmission-blocking anti-giardials. (c) 2021 The Author(s). Published by Elsevier Ltd on behalf of Australian Society for Parasitology.
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| 8. |
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| 9. |
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| 10. |
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| 11. |
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| 12. |
- Ellis, Vincenzo A., et al.
(författare)
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Host specificity of avian haemosporidian parasites is unrelated among sister lineages but shows phylogenetic signal across larger clades
- 2018
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Ingår i: International Journal for Parasitology. - : Elsevier BV. - 0020-7519. ; 48:12, s. 897-902
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Tidskriftsartikel (refereegranskat)abstract
- Parasites can vary in the number of host species they infect, a trait known as “host specificity”. Here we quantify phylogenetic signal—the tendency for closely related species to resemble each other more than distantly related species—in host specificity of avian haemosporidian parasites (genera Plasmodium, Haemoproteus and Leucocytozoon) using data from MalAvi, the global avian haemosporidian database. We used the genetic data (479 base pairs of cytochrome b) that define parasite lineages to produce genus level phylogenies. Combining host specificity data with those phylogenies revealed significant levels of phylogenetic signal while controlling for sampling effects; phylogenetic signal was higher when the phylogenetic diversity of hosts was taken into account. We then tested for correlations in the host specificity of pairs of sister lineages. Correlations were generally close to zero for all three parasite genera. These results suggest that while the host specificity of parasite sister lineages differ, larger clades may be relatively specialised or generalised.
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| 13. |
- Elshafie, Amir I., et al.
(författare)
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Activity and turnover of eosinophil and neutrophil granulocytes are altered in visceral leishmaniasis
- 2011
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Ingår i: International Journal of Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 41:3-4, s. 463-469
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Tidskriftsartikel (refereegranskat)abstract
- Visceral leishmaniasis (VL) is a health issue in Sudan. Our aim was to investigate the involvement of eosinophils and neutrophils in VL by serum and plasma measurements of eosinophil cationic protein (ECP) and myeloperoxidase (MPO) and some key cytokines and chemokines. Blood was collected from 125 VL patients and 181 healthy Sudanese controls from the same rural area. Results showed reduced eosinophil and neutrophil counts in the VL group (P = 0.0001 and P = 0.002, respectively). Serum-ECP levels were higher in the controls (P < 0.0001), while plasma MPO levels were higher in the VL group (P < 0.0001). Levels of IL-5, granulocyte macrophage-colony stimulating factor (GM-CSF) and IL-17 were increased among the VL group (P < 0.0001, P = 0.017 and P = 0.03, respectively), whereas eotaxin and IL-8 levels were reduced (P < 0.0001 and P = 0.002, respectively). Positive correlations were found between IL-8 and ECP/MPO (P < 0.0001). We conclude that eosinophil and neutrophil turnover and activity are increased in subjects in rural areas of Sudan. In VL the turnover was further increased, but the relatively low secretory activity of eosinophils and neutrophils in VL may relate to the reduced production and availability of the chemokines eotaxin and IL-8. The combined assay of ECP and MPO in serum and plasma provides further insight into the mechanisms of eosinophil and neutrophil involvement in disease and constitutes a novel approach to the study of disease processes.
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| 14. |
- Emery-Corbin, Samantha J., et al.
(författare)
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Eukaryote-conserved histone post-translational modification landscape in Giardia duodenalis revealed by mass spectrometry
- 2021
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Ingår i: International Journal of Parasitology. - : Elsevier. - 0020-7519 .- 1879-0135. ; 51:4, s. 225-239
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Tidskriftsartikel (refereegranskat)abstract
- Diarrheal disease caused by Giardia duodenalis is highly prevalent, causing over 200 million cases globally each year. The processes that drive parasite virulence, host immune evasion and transmission involve coordinated gene expression and have been linked to epigenetic regulation. Epigenetic regulatory systems are eukaryote-conserved, including in deep branching excavates such as Giardia, with several studies already implicating histone post-translational modifications in regulation of its pathogenesis and life cycle. However, further insights into Giardia chromatin dynamics have been hindered by a lack of site-specific knowledge of histone modifications. Using mass spectrometry, we have provided the first known molecular map of histone methylation, acetylation and phosphorylation modifications in Giardia core histones. We have identified over 50 previously unreported histone modifications including sites with established roles in epigenetic regulation, and co-occurring modifications indicative of post-translational modification crosstalk. These demonstrate conserved histone modifications in Giardia which are equivalent to many other eukaryotes, and suggest that similar epigenetic mechanisms are in place in this parasite. Further, we used sequence, domain and structural homology to annotate putative histone enzyme networks in Giardia, highlighting representative chromatin modifiers which appear sufficient for identified sites, particularly those from H3 and H4 variants. This study is to our knowledge the first and most comprehensive, complete and accurate view of Giardia histone post-translational modifications to date, and a substantial step towards understanding their associations in parasite development and virulence.
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| 15. |
- Emery-Corbin, Samantha J., et al.
(författare)
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Proteomic diversity in a prevalent human-infective Giardia duodenalis sub-species
- 2018
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Ingår i: International Journal of Parasitology. - : ELSEVIER SCI LTD. - 0020-7519 .- 1879-0135. ; 48:11, s. 817-823
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Tidskriftsartikel (refereegranskat)abstract
- Giardia duodenalis a species complex of gastrointestinal protists, with assemblages A and B infective to humans. To date, post-genomic proteomics are largely derived from Assemblage A, biasing understanding of parasite biology. To address this gap, we quantitatively analysed the proteomes of trophozoites from the genome reference and two clinical Assemblage B isolates, revealing lower spectrum-to-peptide matches in non-reference isolates, resulting in significant losses in peptide and protein identifications, and indicating significant intra-assemblage variation. We also explored differential protein expression between in vitro cultured subpopulations putatively enriched for dividing and feeding cells, respectively. This data is an important proteomic baseline for Assemblage B, highlighting proteomic differences between physiological states, and unique differences relative to Assemblage A.
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| 16. |
- Eriksson, Jenny, et al.
(författare)
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The 434(G>C) polymorphism within the coding sequence of Eosinophil Cationic Protein (ECP) correlates with the natural course of Schistosoma mansoni infection
- 2007
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Ingår i: International Journal of Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 37:12, s. 1359-1366
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Tidskriftsartikel (refereegranskat)abstract
- Schistosomiasis is a chronic parasitic infection with over 200 million people infected worldwide. In Schistosoma mansoni infections, parasite-derived eggs get trapped in the liver, causing the formation of granulomas, which may develop into periportal fibrosis and portal hypertension, and thus severe morbidity. Eosinophil cationic protein (ECP) is a secretory protein of eosinophil granulocytes that efficiently kills the larval stage of S. mansoni, but also affects fibroblast functions. We have investigated the prevalence of the ECP gene polymorphism 434(G>C) in two African populations, from an S. mansoni endemic area in Uganda (n = 297) and from a non-endemic area in Sudan (n - 78), and also compared these with a Swedish population (n = 209). The genotype frequencies in the Ugandan population differed significantly from both the Sudanese and Swedish populations (P < 0.001). In the Ugandan population there was a significant association between genotype and prevalence of infection (P = 0.03), with lower prevalence in subjects with the GG genotype compared with GC (P = 0.02) and CC (P = 0.03). There was also a trend towards an association with periportal fibrosis (P = 0.08) in the Ugandan population. This suggested association was confirmed when the predominant tribe (n = 212) was analysed separately (P = 0.004). Our results suggest that ECP may be an important protein, both in the immune response against S. mansoni and in the development of periportal fibrosis. The results also suggest genetic selection towards the ECP 434CC genotype in populations living in S. mansoni endemic areas.
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| 17. |
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| 18. |
- Gustafsson, Daniel, 1981, et al.
(författare)
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Flyway homogenisation or differentiation? Insights from the phylogeny of the sandpiper (Charadriiformes: Scolopacidae: Calidrinae) wing louse genus Lunaceps (Phthiraptera: Ischnocera).
- 2012
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Ingår i: International Journal of Parasitology. - : Elsevier BV. - 0020-7519. ; 42:1, s. 93-102
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Tidskriftsartikel (refereegranskat)abstract
- The wing louse genus Lunaceps, is the most speciose chewing louse (Phthiraptera) genus inhabiting sandpipers (Charadriiformes: Calidrinae) and is known from almost all sandpiper species. The hosts follow specific flyways from the Arctic breeding grounds to wintering locations in the southern hemisphere, and often form large mixed-species flocks during migration and wintering. We estimated a phylogeny of Lunaceps based on three mitochondrial loci, supporting monophyly of the genus but revealing extensive paraphyly at the species level. We also evaluated the relative importance of flyway differentiation (same host species having different lice along different flyways) and flyway homogenisation (different host species having the same lice along the same flyway). We found that while the lice of smaller sandpipers and stints show some evidence of flyway homogenisation, those of larger sandpipers do not. No investigated host species migrating along more than one flyway showed any evidence of flyway differentiation. The host–parasite associations within Lunaceps are in no case monophyletic, rejecting strict cospeciation.
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| 19. |
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| 20. |
- Hu, Rui-Si, et al.
(författare)
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Differential expression of microRNAs and tRNA fragments mediate the adaptation of the liver fluke Fasciola gigantica to its intermediate snail and definitive mammalian hosts
- 2021
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Ingår i: International Journal of Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 51:5, s. 405-414
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Tidskriftsartikel (refereegranskat)abstract
- The tropical liver fluke Fasciola gigantica affects livestock and humans in many Asian countries, large parts of Africa, and parts of Europe. Despite the public health and economic impacts of F. gigantica, understanding of F. gigantica biology and how the complex lifecycle of this liver fluke is transcriptionally regulated remain unknown. Here, we tested the hypothesis that the regulatory small non-coding RNAs (sncRNAs), microRNAs (miRNAs) and tRNA-derived fragments (tRFs) play roles in the adaptation of F. gigantica to its intermediate and definitive hosts. We sequenced sncRNAs of eight lifecycle stages of F. gigantica. In total, 56 miRNAs from 33 conserved families and four Fasciola-specific miRNAs were identified. Expression analysis of miRNAs suggested clear stage-related patterns. By leveraging the existing transcriptomic data, we predicted a miRNA-based regulation of metabolism, transport, growth and developmental processes. Also, by comparing miRNA complement of F. gigantica with that of Fasciola hepatica, we detected a high level of conservation and identified differences in some miRNAs, which can be used to distinguish the two species. Moreover, we found that tRFs at each lifecycle stage were predominantly derived by tRNA-Lys and tRNA-Gly at 50 half sites, but relatively high expression was related to the buffalo-infecting stages. Taken together, we provided a comprehensive overview of the dynamic transcriptional changes of small RNAs that occur during the developmental stages of F. gigantica. This global analysis of F. gigantica lifecycle stages revealed new roles of miRNAs and tRFs in parasite development and will facilitate future research into understanding of fasciolosis pathobiology.
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| 21. |
- Huang, Xi, et al.
(författare)
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Persistence of avian haemosporidians in the wild : a case study to illustrate seasonal infection patterns in relation to host life stages
- 2020
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Ingår i: International Journal for Parasitology. - : Elsevier BV. - 0020-7519. ; 50:8, s. 611-619
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Tidskriftsartikel (refereegranskat)abstract
- Infection patterns of avian haemosporidians result from the evolution of their associations with hosts, and can be shaped by multiple biotic factors. However, at the level of parasite species, few studies have investigated the details of the temporal dynamics of infection patterns in wild bird communities. We hereby studied a wild bird community in southern Sweden to investigate two generalist parasites (cyt b lineages PARUS1 and WW2) of the morphological species Haemoproteus majoris in their main host species (tits and warblers, respectively) to look for seasonal (spring to autumn) and age class related variation in infection patterns. For both lineages, we detected a similar temporal pattern in prevalence and infection intensity, with peak levels during the main nesting season in adults and a few weeks later in juveniles. Infections in juveniles were detected as soon as they started to be caught by mist nets, implying that they became infected when still in the nest or during the first weeks post-fledging. The initially high intensities in juveniles were followed by a significant decrease during the hatching year, emphasising the importance of studying haemosporidian infections in nestlings and fledglings. Both prevalence and infection intensity in adults increased from spring to early summer, either due to spring relapses or new infections. Both prevalence and infection intensity declined in adults at the time when independent juveniles of the respective species started to appear, suggesting that the rate of parasite withdrawal from blood exceeded the rates of new infections gained and relapses of previous infections. Prevalence in both juveniles and adults approached zero towards the end of the summer.
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| 22. |
- Huang, Xi, et al.
(författare)
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The success of sequence capture in relation to phylogenetic distance from a reference genome : a case study of avian haemosporidian parasites
- 2018
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Ingår i: International Journal for Parasitology. - : Elsevier BV. - 0020-7519. ; 48:12, s. 947-954
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Tidskriftsartikel (refereegranskat)abstract
- Genomic sequencing of avian haemosporidian parasites (Haemosporida) has been challenging due to excessive contamination from host DNA. In this study, we developed a cost-effective protocol to obtain parasite sequences from naturally infected birds, based on targeted sequence capture and next generation sequencing. With the genomic data of Haemoproteus tartakovskyi as a reference, we successfully sequenced up to 1000 genes from each of the 15 selected samples belonging to nine different cytochrome b lineages, eight of which belong to Haemoproteus and one to Plasmodium. The targeted sequences were enriched to ∼104-fold, and mixed infections were identified as well as the proportions of each mixed lineage. We found that the total number of reads and the proportions of exons sequenced decreased when the parasite lineage became more divergent from the reference genome. For each of the samples, the recovery of sequences from different exons varied with the function and GC content of the exon. From the obtained sequences, we detected within-lineage variation in both mitochondrial and nuclear genes, which may be a result of local adaptation to different host species and environmental conditions. This targeted sequence capture protocol can be applied to a broader range of species and will open a new door for further studies on disease diagnostics and comparative analysis of haemosporidians evolution.
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| 23. |
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| 24. |
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| 25. |
- Locke Grandér, Barbara
(författare)
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Honey bee survival mechanisms against the parasite Varroa destructor: a systematic review of phenotypic and genomic research efforts
- 2020
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Ingår i: International Journal for Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 50, s. 433-447
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Forskningsöversikt (refereegranskat)abstract
- The ectoparasitic mite Varroa destructor is the most significant pathological threat to the western honey bee, Apis mellifera, leading to the death of most colonies if left untreated. An alternative approach to chemical treatments is to selectively enhance heritable honey bee traits of resistance or tolerance to the mite through breeding programs, or select for naturally surviving untreated colonies. We conducted a literature review of all studies documenting traits of A. mellifera populations either selectively bred or naturally selected for resistance and tolerance to mite parasitism. This allowed us to conduct an analysis of the diversity, distribution and importance of the traits in different honey bee populations that can survive V. destructor globally. In a second analysis, we investigated the genetic bases of these different phenotypes by comparing 'omics studies (genomics, transcriptomics, and proteomics) of A. mellifera resistance and tolerance to the parasite. Altogether, this review provides a detailed overview of the current state of the research projects and breeding efforts against the most devastating parasite of A. mellifera. By highlighting the most promising traits of Varroa-surviving bees and our current knowledge on their genetic bases, this work will help direct future research efforts and selection programs to control this pest. Additionally, by comparing the diverse populations of honey bees that exhibit those traits, this review highlights the consequences of anthropogenic and natural selection in the interactions between hosts and parasites. (C) 2020 The Authors. Published by Elsevier Ltd on behalf of Australian Society for Parasitology.
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| 26. |
- Ma'ayeh, Showgy Y., et al.
(författare)
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Transcriptional profiling of Giardia intestinalis in response to oxidative stress
- 2015
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Ingår i: International Journal of Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 45:14, s. 925-938
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Tidskriftsartikel (refereegranskat)abstract
- Giardia intestinalis is a microaerophilic parasite that infects the human upper small intestine, an environment that is fairly aerobic with reactive oxygen species being produced to fight off the parasite. It is quite perplexing how Giardia, lacking conventional eukaryotic antioxidant machinery (e.g. catalase, superoxide dismutase and glutathione peroxidase), can cope with the oxidative stress in this environment. We used transcriptomics (RNA sequencing and quantitative PCR) to study giardial gene expression changes in response to oxygen (O-2; 1 h) and hydrogen peroxide (H2O2; 150 mu M, 500 mu M and 1 mM for 1 h). The results showed phenotypic and transcriptional differences between Giardia isolates of different genotypes (WB, assemblage A and GS, assemblage B), with GS being more tolerant to H2O2 and exhibiting higher basic transcript levels of antioxidant genes (e.g. NADH oxidase lateral transfer candidate, peroxiredoxin 1 (Prxl) and thioredoxin (Trx)-like proteins). Cysteine is a major antioxidant in Giardia and its role in oxidative defense could be highlighted here by the up-regulation of gene transcripts encoding the cysteine-rich variable surface proteins (VSPs) and high cysteine membrane proteins (HCMPs). Genes in the thioredoxin system (Prxl, Trx and Trx reductase) occupied a central role in the gene expression response to oxidative stress, together with genes encoding metabolic (NADPH-producing enzymes, glutathione and glycerol biosynthetic enzymes) and O-2-consuming nitric oxide detoxification enzymes (e.g. nitroreductase, flavohemoprotein and a flavodiiron protein). This study reveals the intricate network of genes associated with the oxidative stress response in Giardia, and provides a stepping-stone towards future studies at the protein level.
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| 27. |
- Maciejowski, William J., et al.
(författare)
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Ancient and pervasive expansion of adaptin-related vesicle coat machinery across Parabasalia
- 2023
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Ingår i: International Journal of Parasitology. - : Elsevier. - 0020-7519 .- 1879-0135. ; 53:4, s. 233-245
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Tidskriftsartikel (refereegranskat)abstract
- The eukaryotic phylum Parabasalia is composed primarily of anaerobic, endobiotic organisms such as the veterinary parasite Tritrichomonas foetus and the human parasite Trichomonas vaginalis, the latter causing the most prevalent, non-viral, sexually transmitted disease world-wide. Although a parasitic lifestyle is generally associated with a reduction in cell biology, T. vaginalis provides a striking counter-example. The 2007 T. vaginalis genome paper reported a massive and selective expansion of encoded proteins involved in vesicle trafficking, particularly those implicated in the late secretory and endocytic systems. Chief amongst these were the hetero-tetrameric adaptor proteins or 'adaptins', with T. vaginalis encoding -3.5 times more such proteins than do humans. The provenance of such a complement, and how it relates to the transition from a free-living or endobiotic state to parasitism, remains unclear. In this study, we performed a comprehensive bioinformatic and molecular evolutionary investigation of the heterotetrameric cargo adaptor-derived coats, comparing the molecular complement and evolution of these proteins between T. vaginalis, T. foetus and the available diversity of endobiotic parabasalids. Notably, with the recent discovery of Anaeramoeba spp. as the free-living sister lineage to all parabasalids, we were able to delve back to time points earlier in the lineage's history than ever before. We found that, although T. vaginalis still encodes the most HTAC subunits amongst parabasalids, the duplications giving rise to the complement took place more deeply and at various stages across the lineage. While some duplications appear to have convergently shaped the parasitic lineages, the largest jump is in the transition from free-living to endobiotic lifestyle with both gains and losses shaping the encoded complement. This work details the evolution of a cellular system across an important lineage of parasites and provides insight into the evolutionary dynamics of an example of expansion of protein machinery, counter to the more common trends observed in many parasitic systems.
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| 28. |
- Miller, Andrea, et al.
(författare)
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First identification of Echinococcus multilocularis in rodent intermediate hosts in Sweden
- 2016
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Ingår i: International Journal for Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 5, s. 56-63
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Tidskriftsartikel (refereegranskat)abstract
- Echinococcus multilocularis is a zoonotic tapeworm with a sylvatic lifecycle and an expanding range in Europe. Monitoring efforts following its first identification in 2011 in Sweden have focused on the parasite's definitive host, the red fox (Vulpes vulpes). However, identifying rodent intermediate hosts is important to recognize opportunities for parasite transmission. During 2013-2015, livers from a total of 1566 rodents from four regions in Sweden were examined for E.multilocularis metacestode lesions. Species identity of suspect parasite lesions was confirmed by PCR and sequencing. E.multilocularis positive lesions >6mm in diameter were also examined histologically. One Microtus agrestis out of 187 (0.5%, 95%CI: 0-2.9%), 8/439 (1.8%, 95%CI: 0.8-3.6%) Arvicola amphibius, 0/655 (0%, 95%CI: 0-0.6%) Myodes glareolus, and 0/285 (0%, 95%CI: 0-1.3%) Apodemus spp. contained E.multilocularis metacestode lesions. Presence of protoscoleces was confirmed in the infected M.agrestis and in three of eight infected A.amphibius. Six of the nine positive rodents were captured from the same field. This is the first report of E.multilocularis in intermediate hosts in Sweden. The cluster of positive rodents in one field shows that local parasite prevalence can be high in Sweden despite overall low national prevalence in foxes (<0.1%). The presence of protoscoleces in infected M.agrestis and A.amphibius indicate these species can serve as competent intermediate hosts in Sweden. However, their relative importance for E.multilocularis transmission in the Swedish environment is not yet possible to assess. In contrast, the negative findings in all M.glareolus and Apodemus spp. suggest that these species are of no importance.
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| 29. |
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| 30. |
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| 31. |
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| 32. |
- Neto, Júlio Manuel, et al.
(författare)
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Seasonal dynamics of haemosporidian (Apicomplexa, Haemosporida) parasites in house sparrows Passer domesticus at four European sites : comparison between lineages and the importance of screening methods
- 2020
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Ingår i: International Journal for Parasitology. - : Elsevier BV. - 0020-7519. ; 50:6-7, s. 523-532
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Tidskriftsartikel (refereegranskat)abstract
- Infectious diseases often vary seasonally in a predictable manner, and seasonality may be responsible for geographical differences in prevalence. In temperate regions, vector-borne parasites such as malaria are expected to evolve lower virulence and a time-varying strategy to invest more in transmission when vectors are available. A previous model of seasonal variation of avian malaria described a double peak in prevalence of Plasmodium parasites in multiple hosts resulting from spring relapses and transmission to susceptible individuals in summer. However, this model was rejected by a study describing different patterns of seasonal variation of two Plasmodium spp. at the same site, with the double peak only apparent when these species were combined. Here, we assessed the seasonal variation in prevalence of haemosporidian parasites (Plasmodium, Haemoproteus and Leucocytozoon) in house sparrows (Passer domesticus) sampled across 1 year at four temperate European sites spanning a latitudinal range of 17°. We showed that parasite prevalence and diversity decreased with increasing latitude, but the parasite communities differed between sites, with only one Plasmodium lineage (P_SGS1) occurring at all sites. Moreover, the nested PCR method commonly used to detect and identify haemosporidian parasites strongly underestimated co-infections of Haemoproteus and Plasmodium, significantly biasing the pattern of seasonal variation, so additional molecular methods were used. Finally, we showed that: (i) seasonal variation in prevalence of haemosporidian parasites varied between study sites and parasite lineages/species/genera, describing further cases where the double peak model is not met; (ii) the seasonal dynamics of single lineages (P_SGS1) varied between sites; and (iii) unexpectedly, seasonality was greatest at the southernmost site, a pattern that was mostly driven by lineage H_PADOM05. Limitations of the genotyping methods and consequences of pooling (parasite lineages, sites and years) in studies of haemosporidian parasites are discussed and recommendations proposed, since these actions may obscure the patterns of prevalence and limit ecological inferences.
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| 33. |
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| 34. |
- Nwakanma, Davis, et al.
(författare)
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High gametocyte complexity and mosquito infectivity of Plasmodium falciparum in The Gambia
- 2008
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Ingår i: International journal for parasitology. - 0020-7519. ; 38:2, s. 219-227
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this work was to determine the infectivity to mosquitoes of genetically diverse Plasmodium falciparum clones seen in natural infections in the Gambia. Two principal questions were addressed: (i) how infectious are gametocytes of sub-patent infections, particularly at the end of the dry season; and (ii) are all clones in multiclonal infections equally capable of infecting mosquitoes? The work was carried out with two cohorts of infected individuals. Firstly, a group of 31 P. falciparum-infected people were recruited in the middle of the dry season (May, 2003), then examined for P. falciparum at the beginning (August 2003) and middle (October, 2003) of the transmission season. On each occasion, we examined the genotypes of asexual forms and gametocytes by PCR and RT-PCR, as well as their infectivity to Anopheles gambiae using membrane feeds. One individual gave rise to infected mosquitoes in May, and two in August. Different gametocyte genotypes co-existed in the same infection and fluctuated over time. The mean multiplicity of infection was 1.4, 1.7 and 1.5 clones in May, August and October, respectively. Second, a group of patients undergoing drug-treatment during August 2003 was tested for asexual and gametocyte genotypes and their infectivity to mosquitoes. Forty-three out of 100 feeds produced infections. The genetic complexity of the parasites in mosquitoes was sometimes greater than that detectable in the blood on which the mosquitoes had fed. This suggested that gametocytes of clones existing in the blood below PCR detection limits at the time of the feed were at least as infectious to the mosquitoes as the more abundant clones. These findings emphasise the crucial role of gametocyte complexity and infectivity in generating the remarkable diversity of P. falciparum genotypes seen in infected people, even in an area of seasonal transmission.
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| 35. |
- Olsson, Gert
(författare)
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Reappraisal of Hydatigera taeniaeformis (Batsch, 1786) (Cestoda: Taeniidae) sensu lato with description of Hydatigera kamiyai n. sp.
- 2016
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Ingår i: International Journal for Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 46, s. 361-374
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Tidskriftsartikel (refereegranskat)abstract
- The common cat tapeworm Hydatigera taeniaeformis is a complex of three morphologically cryptic entities, which can be differentiated genetically. To clarify the biogeography and the host spectrum of the cryptic lineages, 150 specimens of H. taeniaeformis in various definitive and intermediate hosts from Eurasia, Africa and Australia were identified with DNA barcoding using partial mitochondrial cytochrome c oxidase subunit 1 gene sequences and compared with previously published data. Additional phylogenetic analyses of selected isolates were performed using nuclear DNA and mitochondrial genome sequences. Based on molecular data and morphological analysis, Hydatigera kamiyai n. sp. Iwaki is proposed for a cryptic lineage, which is predominantly northern Eurasian and uses mainly arvicoline rodents (voles) and mice of the genus Apodemus as intermediate hosts. Hydatigera taeniaeformis sensu stricto (s.s.) is restricted to murine rodents (rats and mice) as intermediate hosts. It probably originates from Asia but has spread worldwide. Despite remarkable genetic divergence between H. taeniaeformis s.s. and H. kamiyai, interspecific morphological differences are evident only in dimensions of rostellar hooks. The third cryptic lineage is closely related to H. kamiyai, but its taxonomic status remains unresolved due to limited morphological, molecular, biogeographical and ecological data. This Hydatigera sp. is confined to the Mediterranean and its intermediate hosts are unknown. Further studies are needed to classify Hydatigera sp. either as a distinct species or a variant of H. kamiyai. According to previously published limited data, all three entities occur in the Americas, probably due to human-mediated introductions. (C) 2016 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
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| 36. |
- Ozerov, Mikhail, et al.
(författare)
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DNA metabarcoding reveals spatial and temporal variation of fish eye fluke communities in lake ecosystems
- 2024
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Ingår i: International Journal for Parasitology. - 0020-7519 .- 1879-0135. ; 54, s. 33-46
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Tidskriftsartikel (refereegranskat)abstract
- Eye flukes (Diplostomidae) are diverse and abundant trematode parasites that form multi-species communities in fish with negative effects on host fitness and survival. However, the environmental factors and host-related characteristics that determine species diversity, composition, and coexistence in such communities remain poorly understood. Here, we developed a cost-effective cox1 region-specific DNA metabarcoding approach to characterize parasitic diplostomid communities in two common fish species (Eurasian perch and common roach) collected from seven temperate lakes in Estonia. We found considerable inter- and intra-lake, as well as inter-host species, variation in diplostomid communities. Sympatric host species characterization revealed that parasite communities were typically more diverse in roach than perch. Additionally, we detected five positive and two negative diplostomid species associations in roach, whereas only a single negative association was observed in perch. These results indicate that diplostomid communities in temperate lakes are complex and dynamic systems exhibiting both spatial and temporal heterogeneity. They are influenced by various environmental factors and by hostparasite and inter-parasite interactions. We expect that the described methodology facilitates ecological and biodiversity research of diplostomid parasites. It is also adaptable to other parasite groups where it could serve to improve current understanding of diversity, distribution, and interspecies interactions of other understudied taxa.
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| 37. |
- Perez-Rodriguez, Anton, et al.
(författare)
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Evolution of seasonal transmission patterns in avian blood-borne parasites
- 2015
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Ingår i: International Journal for Parasitology. - : Elsevier BV. - 0020-7519. ; 45:9-10, s. 605-611
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Tidskriftsartikel (refereegranskat)abstract
- In temperate regions, many vector-borne parasites maximise their transmission prospects by adjusting reproduction to seasonal cycles of host susceptibility and vector availability. Nevertheless, in these regions there are areas where environmental conditions are favourable throughout the year, so that parasites could benefit from a year-round transmission strategy. We analysed how different transmission strategies (strict summer transmission, extended summer transmission - including spring and autumn, and year round transmission) have evolved among the different genetic lineages of Haemoproteus parabelopolskyi, an avian blood-borne parasite shared by three sibling species of passerine hosts. Our results indicate that the ancestral state of this clade of parasites had a strict summer transmission with the blackcap (Sylvia atricapilla) as the host. Other transmission strategies and switches to the other host species (Sylvia abyssinica and Sylvia born) evolved recently, several times, independently. This suggests that, although year-round transmission is ecologically successful at present, seasonal transmission may have become more stable over evolutionary time. Switches from strict summer to an extended or year-round transmission strategy could have ecological consequences, if they promote the spread of parasites into more distant regions, transported by the migrating bird hosts. Therefore, a deeper knowledge of how different parasite transmission strategies are structured among birds in temperate areas is essential for understanding how disease emergence risks may develop in the future. (C) 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
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| 38. |
- Reiner, David S., et al.
(författare)
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Synchronisation of Giardia lamblia : identification of cell cycle stage-specific genes and a differentiation restriction point
- 2008
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Ingår i: International Journal of Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 38:8-9, s. 935-944
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Tidskriftsartikel (refereegranskat)abstract
- The intestinal parasite Giardia lamblia undergoes cell differentiations that entail entry into and departure from the replicative cell cycle. The pathophysiology of giardiasis depends directly upon the ability of the trophozoite form to replicate in the host upper small intestine. Thus, cell proliferation is tightly linked to disease. However, studies of cell cycle regulation in Giardia have been hampered by the inability to synchronise cultures. Here we report that Giardia isolates of the major human genotypes A and B can be synchronised using aphidicolin, a mycotoxin that reversibly inhibits replicative DNA polymerases in eukaryotic cells. Aphidicolin arrests Giardia trophozoites in the early DNA synthesis (S) phase of the cell cycle. We identified a set of cell cycle orthologues in the Giardia genome using bioinformatic analyses and showed that synchronised parasites express these genes in a cell cycle stage-specific manner. The synchronisation method also showed that during encystation, exit from the ordinary cell cycle occurs preferentially in GZ and defines a restriction point for differentiation. Synchronisation opens up possibilities for further molecular and cell biological studies of chromosome replication, mitosis and segregation of the complex cytoskeleton in Giardia.
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| 39. |
- Resende, Mafalda, et al.
(författare)
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Chondroitin sulphate A (CSA)-binding of single recombinant Duffy-binding-like domains is not restricted to Plasmodium falciparum Erythrocyte Membrane Protein 1 expressed by CSA-binding parasites
- 2009
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Ingår i: International Journal of Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 39:11, s. 1195-1204
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Tidskriftsartikel (refereegranskat)abstract
- Individuals living in areas with high Plasmodium falciparum transmission acquire immunity to malaria over time and adults have a markedly reduced risk of contracting severe disease. However, pregnant women constitute an important exception. Pregnancy-associated malaria is a major cause of mother and offspring morbidity, such as severe maternal anaemia and low birth-weight, and is characterised by selective accumulation of parasite-infected erythrocytes (IE) in the placenta. A P. falciparum protein named VAR2CSA, which belongs to the large P. falciparum Erythrocyte Membrane Protein 1 (PfEMP1) family, enables the IE to bind chondroitin sulphate A (CSA) in the placenta. Knock-out studies have demonstrated the exclusive capacity of VAR2CSA to mediate IE binding to CSA, and it has been shown that four of the six Duffy-binding-like (DBL) domains of VAR2CSA have the ability to bind CSA in vitro. In this study, we confirm the CSA-binding of these DBL domains, however, the analysis of a number of DBL domains of a non-VAR2CSA origin shows that CSA-binding is not exclusively restricted to VAR2CSA DBL domains. Furthermore, we show that the VAR2CSA DBL domains as well as other DBL domains also bind heparan sulphate. These data explain a number of publications describing CSA-binding domains derived from PfEMP1 antigens not involved in placental adhesion. The data suggest that the ability of single domains to bind CSA does not predict the functional capacity of the whole PfEMP1 and raises doubt whether the CSA-binding domains of native VAR2CSA have been correctly identified. (C) 2009 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
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| 40. |
- Ringqvist, Emma, 1979-, et al.
(författare)
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Transcriptional changes in Giardia during host-parasite interactions
- 2011
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Ingår i: International Journal for Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 41:3-4, s. 277-285
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Tidskriftsartikel (refereegranskat)abstract
- Giardia intestinalis is one of the major causes of parasite-induced diarrhea. The disease, giardiasis, is caused by trophozoites attaching to the intestinal epithelium, resulting in apoptosis of intestinal epithelial cells, disrupted epithelial barrier function and malabsorption. Microarray studies have detected gene expression changes in intestinal epithelial cells (IECs), during interaction with Giardia trophozoites in vitro. In the present study we examined this host-parasite interaction further by transcriptional profiling of interacting trophozoites using Giardia oligo microarrays. A total of 325 Giardia transcripts were significantly changed during the interaction, lasting 1.5 to 18 hrs in complete DMEM medium. Quantitative real-time reverse transcriptase PCR confirmed these changes in all 12 genes tested using mRNA isolated in a separate experiment. Genes involved in cell division and attachment were down-regulated in the late time-points of interaction. Proteins earlier suggested to be important during host parasite interactions like arginine deiminase and cysteine proteinases changed their expression. Oxygen defense proteins and several members of the high cysteine-rich membrane protein (HCMp) family were up-regulated during the interaction with IECs. Thus, there are extensive gene-expression changes in Giardia trophozoites and IECs during host-parasite interactions and this can be important for establishment of infection and in the induction of giardiasis.
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| 41. |
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| 42. |
- Scaramella, Nicholas, et al.
(författare)
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Host brood traits, independent of adult behaviours, reduce Varroa destructor mite reproduction in resistant honeybee populations
- 2023
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Ingår i: International Journal for Parasitology. - 0020-7519 .- 1879-0135. ; 53, s. 565-571
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Tidskriftsartikel (refereegranskat)abstract
- The ectoparasitic mite Varroa destructor is an invasive species of Western honey bees (Apis mellifera) and the largest pathogenic threat to their health world-wide. Its successful invasion and expansion is related to its ability to exploit the worker brood for reproduction, which results in an exponential population growth rate in the new host. With invasion of the mite, wild honeybee populations have been nearly eradicated from Europe and North America, and the survival of managed honeybee populations relies on mite population control treatments. However, there are a few documented honeybee populations surviving extended periods without control treatments due to adapted host traits that directly impact Varroa mite fitness. The aim of this study was to investigate if Varroa mite reproductive success was affected by traits of adult bee behaviours or by traits of the worker brood, in three mite-resistant honey bee populations from Sweden, France and Norway. The mite's reproductive success was measured and compared in broods that were either exposed to, or excluded from, adult bee access. Mite-resistant bee populations were also compared with a local mite-susceptible population, as a control group. Our results show that mite reproductive success rates and mite fecundity in the three mite-resistant populations were significantly different from the control population, with the French and Swedish populations having significantly lower reproductive rates than the Norwegian population. When comparing mite reproduction in exposed or excluded brood treatments, no differences were observed, regardless of population. This result clearly demonstrates that Varroa mite reproductive success can be suppressed by traits of the brood, independent of adult worker bees.& COPY; 2023 The Author(s). Published by Elsevier Ltd on behalf of Australian Society for Parasitology. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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| 43. |
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| 44. |
- Silverlås, Charlotte, et al.
(författare)
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Is there a need for improved Cryptosporidium diagnostics in Swedish calves?
- 2013
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Ingår i: International Journal for Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 43, s. 155-161
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Tidskriftsartikel (refereegranskat)abstract
- Cryptosporidium parvum is a common pathogen in preweaned calves but in Sweden Cryptosporidium bovis, which is considered apathogenic, is the most common species in this age group and it has been identified in diarrhoeal samples, indicating that it could be a cause of diarrhoea. In routine diagnostic procedures, infection is determined by microscopy, which is not sufficient to differentiate these species. We investigated whether routine Cryptosporidium diagnostic procedures need improvement to include species determination. The relation of Cryptosporidium spp. and subtype with the clinical picture and other pathogens was also investigated. A total of 782 diarrhoeal calf samples were analysed and Cryptosporidium infection was diagnosed in 198 samples. Cryptosporidium parvum was identified in 178, C bovis in six and mixed C bovis/C. parvum in seven samples. Twenty-seven C. parvum subtypes were identified, of which 16 were newly described. Except for three herds, only one subtype per herd was identified. Cryptosporidium parvum-positive calves were younger than C. bovis-positive calves and most C parvum infections were seen at 1-3 weeks of age. Oocyst counts were higher in C parvum samples. Yellow faecal colour was associated with C. parvum infection. Watery faeces had no greater association with C parvum infection. but C parvum subtype family IIa was more common than subtype family IId in watery faecal samples. No other pathogens were detected in the six C. bovis-infected calves, indicating a pathogenic potential. Our results show that species determination does not need to be included in routine Cryptosporidium diagnostic procedures in order to estimate the clinical relevance of infection in diarrhoeal calves. The maximum age when analysis for clinical cryptosporidiosis is performed can be lowered to 6 weeks of age. However, the indicated pathogenic potential of C. bovis warrants further attention. (C) 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
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| 45. |
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| 46. |
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| 47. |
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| 48. |
- Weidner, Jessica M., et al.
(författare)
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Tightly regulated migratory subversion of immune cells promotes the dissemination of Toxoplasma gondii
- 2014
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Ingår i: International Journal of Parasitology. - : Elsevier BV. - 0020-7519 .- 1879-0135. ; 44:2, s. 85-90
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Forskningsöversikt (refereegranskat)abstract
- While the spread of Toxoplasma gondii within the infected human or animal host is associated with pathology, the pathways of dissemination have remained enigmatic. From the time point of entry into the gut, to the quiescent chronic infection in the central nervous system, Toxoplasma is detected and surveyed by immune cells that populate the tissues, for example dendritic cells. Paradoxically, this protective migratory function of leukocytes appears to be targeted by Toxoplasma to mediate its dissemination in the organism. Recent findings show that tightly regulated events take place shortly after host cell invasion that promote the migratory activation of infected dendritic cells. Here, we review the emerging knowledge on how this obligate intracellular protozoan orchestrates the subversion of leukocytes to achieve systemic dissemination and reach peripheral organs where pathology manifests.
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| 49. |
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