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Barnes M, Price DC. Endogenous Viral Elements in Ixodid Tick Genomes. Viruses 2023; 15:2201. [PMID: 38005880 PMCID: PMC10675110 DOI: 10.3390/v15112201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/19/2023] [Accepted: 10/23/2023] [Indexed: 11/26/2023] Open
Abstract
The documentation of endogenous viral elements (EVEs; virus-derived genetic material integrated into the genome of a nonviral host) has offered insights into how arthropods respond to viral infection via RNA interference pathways. Small non-coding RNAs derived from EVE loci serve to direct RNAi pathways in limiting replication and infection from cognate viruses, thus benefiting the host's fitness and, potentially, vectorial capacity. Here we use informatic approaches to analyze nine available genome sequences of hard ticks (Acari: Ixodidae; Rhipicephalus sanguineus, R. microplus, R. annulatus, Ixodes ricinus, I. persulcatus, I. scapularis, Hyalomma asiaticum, Haemaphysalis longicornis, and Dermacentor silvarum) to identify endogenous viral elements and to illustrate the shared ancestry of all elements identified. Our results highlight a broad diversity of viral taxa as having given rise to 1234 identified EVEs in ticks, with Mononegavirales (specifically Rhabdoviridae) well-represented in this subset of hard ticks. Further investigation revealed extensive adintovirus integrations in several Ixodes species, the prevalence of Bunyavirales EVEs (notably not observed in mosquitoes), and the presence of several elements similar to known emerging human and veterinary pathogens. These results will inform subsequent work on current and past associations with tick species with regard to the viruses from which their "viral fossils" are derived and may serve as a reference for quality control of various tick-omics data that may suffer from misidentification of EVEs as viral genetic material.
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Affiliation(s)
| | - Dana C. Price
- Center for Vector Biology, Department of Entomology, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA;
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Bondaryuk AN, Belykh OI, Andaev EI, Bukin YS. Inferring Evolutionary Timescale of Omsk Hemorrhagic Fever Virus. Viruses 2023; 15:1576. [PMID: 37515262 PMCID: PMC10385366 DOI: 10.3390/v15071576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/15/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Until 2020, there were only three original complete genome (CG) nucleotide sequences of Omsk hemorrhagic fever virus (OHFV) in GenBank. For this reason, the evolutionary rate and divergence time assessments reported in the literature were based on the E gene sequences, but notably without temporal signal evaluation, such that their reliability is unclear. As of July 2022, 47 OHFV CG sequences have been published, which enables testing of temporal signal in the data and inferring unbiased and reliable substitution rate and divergence time values. Regression analysis in the TempEst software demonstrated a stronger clocklike behavior in OHFV samples for the complete open reading frame (ORF) data set (R2 = 0.42) than for the E gene data set (R2 = 0.11). Bayesian evaluation of temporal signal indicated very strong evidence, with a log Bayes factor of more than 5, in favor of temporal signal in all data sets. Our results based on the complete ORF sequences showed a more precise OHFV substitution rate (95% highest posterior density (HPD) interval, 9.1 × 10-5-1.8 × 10-4 substitutions per site per year) and tree root height (416-896 years ago) compared with previous assessments. The rate obtained is significantly higher than tick-borne encephalitis virus by at least 3.8-fold. The phylogenetic analysis and past population dynamics reconstruction revealed the declining trend of OHFV genetic diversity, but there was phylogenomic evidence that implicit virus subpopulations evolved locally and underwent an exponential growth phase.
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Affiliation(s)
- Artem N Bondaryuk
- Laboratory of Natural Focal Viral Infections, Irkutsk Antiplague Research Institute of Siberia and the Far East, Irkutsk 664047, Russia
- Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk 664033, Russia
| | - Olga I Belykh
- Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk 664033, Russia
| | - Evgeny I Andaev
- Laboratory of Natural Focal Viral Infections, Irkutsk Antiplague Research Institute of Siberia and the Far East, Irkutsk 664047, Russia
| | - Yurij S Bukin
- Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk 664033, Russia
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Mohammed OB, Amor NMS, Omer SA, Alagaili AN. Molecular detection and characterization of Theileria sp. from hedgehogs (Paraechinus aethiopicus) in Saudi Arabia. Lett Appl Microbiol 2020; 72:476-483. [PMID: 33306194 DOI: 10.1111/lam.13438] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/25/2020] [Accepted: 11/30/2020] [Indexed: 12/21/2022]
Abstract
In this study, we conducted molecular detection and characterization of piroplasms that infect the Ethiopian or desert hedgehogs (Paraechinus aethiopicus) in Saudi Arabia. Blood samples from 112 (68 males and 44 females) desert hedgehogs from Unaizah, Central Saudi Arabia were screened for Theileria/Babesia DNA using the polymerase chain reaction (PCR) employing specific primers amplifying the partial 18S small subunit rRNA gene. Theileria DNA was detected in 51 samples (45·5%), giving a prevalence of 45·5%. Theileria DNA was found in 33 (48·5%) males and 18 (40·9%) females, and there was no significant difference (P > 0·05) in the prevalence between males and females. Similarly, there was no significant difference (P > 0·05) in the prevalence between juveniles (40%) and adults (46·7%). There was a significant difference in the prevalence of Theileria in hedgehogs collected from May to September and the period from October to April (P = 0·003). Four haplotypes of Theileria sp. in hedgehogs were detected and designated as H1-H4. H1 was the predominant haplotype and found in 80·8% of the positive individuals. Partial sequences of the 18S rRNA of Theileria sp. from hedgehogs grouped with Theileria spp. that are benign. This study is the first report of the occurrence of Theileria spp. in Saudi Arabian desert hedgehogs.
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Affiliation(s)
- O B Mohammed
- Mammals Research Chair, Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - N M S Amor
- Mammals Research Chair, Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia.,Laboratory of Biodiversity, Parasitology and Ecology of Aquatic Ecosystem, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - S A Omer
- Department of Zoology, College of Science, King Saud University, University Centre for Women Students, Riyadh, Saudi Arabia
| | - A N Alagaili
- Mammals Research Chair, Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia
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Nayyar Ghauri H, Ijaz M, Farooqi SH, Ali A, Ghaffar A, Saleem S, Iqbal MK, Aziz MU, Ghani U, Ullah MR, Ahmad HM. A comprehensive review on past, present and future aspects of canine theileriosis. Microb Pathog 2018; 126:116-122. [PMID: 30385396 DOI: 10.1016/j.micpath.2018.10.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/25/2018] [Accepted: 10/26/2018] [Indexed: 10/28/2022]
Abstract
Canine theileriosis is a notorious tick borne piroplasmid infection of wild and domestic canines. The causative agent has not yet been accurately classified. PCR studies revealed that causative agent resembles to Theileria genus and thus provisionally named as Theileria annae. The other Theileria species reported in canines is Theileria annulata, Theileria equi and unnamed Theileria specie. This emergent canine infection is considered to be endemic in most of the European countries. However in Asia this disease has not been reported till date. The vectors responsible for transmission of this disease have not been determined. It has been suggested that DNA of Theileria annae has been detected in hard tick Ixodes hexagonus in Northwestern Spain and several other tick species. Clinically canine theileriosis is characterized by severe weakness, fever, hemoglobinuria and anemia. Recently atovaquone or buparvaquone plus azithromycin therapy showed better clinical efficacy. This comprehensive review is intended to summarize the current knowledge on prevalence and epidemiology of canine theileriosis in different countries of the world and associated tick vectors.
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Affiliation(s)
- Hammad Nayyar Ghauri
- Department of Clinical Medicine and Surgery, University of Veterinary and Animal Sciences, 54600, Lahore, Pakistan
| | - Muhammad Ijaz
- Department of Clinical Medicine and Surgery, University of Veterinary and Animal Sciences, 54600, Lahore, Pakistan.
| | - Shahid Hussain Farooqi
- Department of Clinical Sciences, KBCMA, College of Veterinary and Animal Sciences, 51600, Narowal, Pakistan
| | - Ahmad Ali
- Department of Clinical Medicine and Surgery, University of Veterinary and Animal Sciences, 54600, Lahore, Pakistan
| | - Awais Ghaffar
- Department of Clinical Medicine and Surgery, University of Veterinary and Animal Sciences, 54600, Lahore, Pakistan
| | - Sehrish Saleem
- Department of Clinical Medicine and Surgery, University of Veterinary and Animal Sciences, 54600, Lahore, Pakistan
| | - Muhammad Kashif Iqbal
- Department of Clinical Medicine and Surgery, University of Veterinary and Animal Sciences, 54600, Lahore, Pakistan
| | - Muhammad Umair Aziz
- Department of Clinical Medicine and Surgery, University of Veterinary and Animal Sciences, 54600, Lahore, Pakistan
| | - Usman Ghani
- Department of Clinical Medicine and Surgery, University of Veterinary and Animal Sciences, 54600, Lahore, Pakistan
| | - Muhammad Rafi Ullah
- Department of Clinical Sciences, KBCMA, College of Veterinary and Animal Sciences, 51600, Narowal, Pakistan
| | - Hafiz Manzoor Ahmad
- Department of Clinical Sciences, KBCMA, College of Veterinary and Animal Sciences, 51600, Narowal, Pakistan
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Hekimoglu O, Ozer AN. Distribution and phylogeny of Hyalomma ticks (Acari: Ixodidae) in Turkey. EXPERIMENTAL & APPLIED ACAROLOGY 2017; 73:501-519. [PMID: 29177952 DOI: 10.1007/s10493-017-0192-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 11/17/2017] [Indexed: 05/10/2023]
Abstract
The genus Hyalomma includes some of the most medically and veterinarily important tick species in the world. To clarify and identify the current distribution of the species of Hyalomma, field studies were conducted in 65 localities in Turkey and five localities in Cyprus. Additionally, using mitochondrial 12S and 16S ribosomal DNA, specimens of Hyalomma from Turkey, H. excavatum from Cyprus, H. marginatum from Spain and Italy were evaluated together with the available sequences obtained from Genbank. Morphological and molecular analyses demonstrated the presence of four species in Turkey: H. marginatum, H. excavatum, H. aegyptium and H. asiaticum. Hyalomma marginatum is the dominant species in the Central and Northern parts of Turkey, whereas H. excavatum distributes mostly in the Southern parts. Hyalomma asiaticum is restricted to the Southeastern Anatolia. However, some sympatric regions were observed for these species. Phylogenetic trees obtained with Maximum Likelihood method demonstrated five clades. Data supported previous conclusions, but placed H. asiaticum, H. scupense, H. dromedarii and H. aegyptium in different clades with high bootstrap values. Specimens of H. anatolicum group and H. marginatum complex are sister groups. Pairwise distance analyses of these groups showed 2.8 and 3% differences for 12S rDNA and 16S rDNA, respectively. Therefore, additional analyses with the samples from different locations using different markers need to evaluate the exact status of the species of these groups.
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Affiliation(s)
- Olcay Hekimoglu
- Division of Ecology, Department of Biology, Faculty of Science, Hacettepe University, Beytepe, 06800, Ankara, Turkey.
| | - Ayşe Nurdan Ozer
- Division of Ecology, Department of Biology, Faculty of Science, Hacettepe University, Beytepe, 06800, Ankara, Turkey
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Antunes S, Rosa C, Couto J, Ferrolho J, Domingos A. Deciphering Babesia-Vector Interactions. Front Cell Infect Microbiol 2017; 7:429. [PMID: 29034218 PMCID: PMC5627281 DOI: 10.3389/fcimb.2017.00429] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 09/19/2017] [Indexed: 12/11/2022] Open
Abstract
Understanding host-pathogen-tick interactions remains a vitally important issue that might be better understood by basic research focused on each of the dyad interplays. Pathogens gain access to either the vector or host during tick feeding when ticks are confronted with strong hemostatic, inflammatory and immune responses. A prominent example of this is the Babesia spp.—tick—vertebrate host relationship. Babesia spp. are intraerythrocytic apicomplexan organisms spread worldwide, with a complex life cycle. The presence of transovarial transmission in almost all the Babesia species is the main difference between their life cycle and that of other piroplasmida. With more than 100 species described so far, Babesia are the second most commonly found blood parasite of mammals after trypanosomes. The prevalence of Babesia spp. infection is increasing worldwide and is currently classified as an emerging zoonosis. Babesia microti and Babesia divergens are the most frequent etiological agents associated with human babesiosis in North America and Europe, respectively. Although the Babesia-tick system has been extensively researched, the currently available prophylactic and control methods are not efficient, and chemotherapeutic treatment is limited. Studying the molecular changes induced by the presence of Babesia in the vector will not only elucidate the strategies used by the protozoa to overcome mechanical and immune barriers, but will also contribute toward the discovery of important tick molecules that have a role in vector capacity. This review provides an overview of the identified molecules involved in Babesia-tick interactions, with an emphasis on the fundamentally important ones for pathogen acquisition and transmission.
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Affiliation(s)
- Sandra Antunes
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Catarina Rosa
- Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Joana Couto
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Joana Ferrolho
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Ana Domingos
- Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
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Hornok S, Wang Y, Otranto D, Keskin A, Lia RP, Kontschán J, Takács N, Farkas R, Sándor AD. Phylogenetic analysis of Haemaphysalis erinacei Pavesi, 1884 (Acari: Ixodidae) from China, Turkey, Italy and Romania. Parasit Vectors 2016; 9:643. [PMID: 27978852 PMCID: PMC5159981 DOI: 10.1186/s13071-016-1927-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 12/02/2016] [Indexed: 01/11/2023] Open
Abstract
Background Haemaphysalis erinacei is one of the few ixodid tick species for which valid names of subspecies exist. Despite their disputed taxonomic status in the literature, these subspecies have not yet been compared with molecular methods. The aim of the present study was to investigate the phylogenetic relationships of H. erinacei subspecies, in the context of the first finding of this tick species in Romania. Results After morphological identification, DNA was extracted from five adults of H. e. taurica (from Romania and Turkey), four adults of H. e. erinacei (from Italy) and 17 adults of H. e. turanica (from China). From these samples fragments of the cytochrome c oxidase subunit 1 (cox1) and 16S rRNA genes were amplified via PCR and sequenced. Results showed that cox1 and 16S rRNA gene sequence divergences between H. e. taurica from Romania and H. e. erinacei from Italy were below 2%. However, the sequence divergences between H. e. taurica from Romania and H. e. turanica from China were high (up to 7.3% difference for the 16S rRNA gene), exceeding the reported level of sequence divergence between closely related tick species. At the same time, two adults of H. e. taurica from Turkey had higher 16S rRNA gene similarity to H. e. turanica from China (up to 97.5%) than to H. e. taurica from Romania (96.3%), but phylogenetically clustered more closely to H. e. taurica than to H. e. turanica. Conclusions This is the first finding of H. erinacei in Romania, and the first (although preliminary) phylogenetic comparison of H. erinacei subspecies. Phylogenetic analyses did not support that the three H. erinacei subspecies evaluated here are of equal taxonomic rank, because the genetic divergence between H. e. turanica from China and H. e. taurica from Romania exceeded the usual level of sequence divergence between closely related tick species, suggesting that they might represent different species. Therefore, the taxonomic status of the subspecies of H. erinacei needs to be revised based on a larger number of specimens collected throughout its geographical range.
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Affiliation(s)
- Sándor Hornok
- Department of Parasitology and Zoology, University of Veterinary Medicine, Budapest, Hungary.
| | - Yuanzhi Wang
- Department of Pathogenic Biology, School of Medicine, Shihezi University, Shihezi, China
| | - Domenico Otranto
- Department of Animal Health and Welfare of the Faculty of Veterinary Medicine, University of Bari, Bari, Italy
| | - Adem Keskin
- Department of Biology, Gaziosmanpasa University, Tasliciftlik-Tokat, Turkey
| | - Riccardo Paolo Lia
- Department of Animal Health and Welfare of the Faculty of Veterinary Medicine, University of Bari, Bari, Italy
| | - Jenő Kontschán
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary
| | - Nóra Takács
- Department of Parasitology and Zoology, University of Veterinary Medicine, Budapest, Hungary
| | - Róbert Farkas
- Department of Parasitology and Zoology, University of Veterinary Medicine, Budapest, Hungary
| | - Attila D Sándor
- Department of Parasitology and Parasitic Diseases, University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Romania
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Dunlop JA, Apanaskevich DA, Lehmann J, Hoffmann R, Fusseis F, Ehlke M, Zachow S, Xiao X. Microtomography of the Baltic amber tick Ixodes succineus reveals affinities with the modern Asian disease vector Ixodes ovatus. BMC Evol Biol 2016; 16:203. [PMID: 27724841 PMCID: PMC5057450 DOI: 10.1186/s12862-016-0777-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 09/29/2016] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Fossil ticks are extremely rare and Ixodes succineus Weidner, 1964 from Eocene (ca. 44-49 Ma) Baltic amber is one of the oldest examples of a living hard tick genus (Ixodida: Ixodidae). Previous work suggested it was most closely related to the modern and widespread European sheep tick Ixodes ricinus (Linneaus, 1758). RESULTS Restudy using phase contrast synchrotron x-ray tomography yielded images of exceptional quality. These confirm the fossil's referral to Ixodes Latreille, 1795, but the characters resolved here suggest instead affinities with the Asian subgenus Partipalpiger Hoogstraal et al., 1973 and its single living (and medically significant) species Ixodes ovatus Neumann, 1899. We redescribe the amber fossil here as Ixodes (Partipalpiger) succineus. CONCLUSIONS Our data suggest that Ixodes ricinus is unlikely to be directly derived from Weidner's amber species, but instead reveals that the Partipalpiger lineage was originally more widely distributed across the northern hemisphere. The closeness of Ixodes (P.) succineus to a living vector of a wide range of pathogens offers the potential to correlate its spatial and temporal position (northern Europe, nearly 50 million years ago) with the estimated origination dates of various tick-borne diseases.
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Affiliation(s)
- Jason A. Dunlop
- Museum für Naturkunde, Leibniz Institute for Research on Evolution and Biodiversity, Invalidenstrasse 43, D-10115 Berlin, Germany
| | - Dmitry A. Apanaskevich
- United States National Tick Collection, The James H. Oliver, Jr. Institute for Coastal Plain Science, Georgia Southern University, Statesboro, GA 30460-8056 USA
| | - Jens Lehmann
- Faculty of Geosciences, University of Bremen, D-28357 Bremen, Germany
| | - René Hoffmann
- Department of Earth Sciences, Ruhr-Universität Bochum, Institute of Geology, Mineralogy, and Geophysics, D-44801 Bochum, Germany
| | - Florian Fusseis
- School of Geosciences, The University of Edinburgh, Grant Institute, King’s Buildings, West Mains Road, Edinburgh, EH9 3JW UK
| | - Moritz Ehlke
- Medical Planning Group, Zuse Institute Berlin, Department Visualization and Data Analysis, D-14195 Berlin, Germany
| | - Stefan Zachow
- Medical Planning Group, Zuse Institute Berlin, Department Visualization and Data Analysis, D-14195 Berlin, Germany
| | - Xianghui Xiao
- Advanced Photon Source, Argonne National Laboratory, 9700 S. Cass Ave, Lemont, IL 60439 USA
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Extensive Shared Chemosensitivity between Malaria and Babesiosis Blood-Stage Parasites. Antimicrob Agents Chemother 2016; 60:5059-63. [PMID: 27246780 DOI: 10.1128/aac.00928-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 05/23/2016] [Indexed: 11/20/2022] Open
Abstract
The apicomplexan parasites that cause malaria and babesiosis invade and proliferate within erythrocytes. To assess the potential for common antiparasitic treatments, we measured the sensitivities of multiple species of Plasmodium and Babesia parasites to the chemically diverse collection of antimalarial compounds in the Malaria Box library. We observed that these parasites share sensitivities to a large fraction of the same inhibitors and we identified compounds with strong babesiacidal activity.
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The PCR detection and phylogenetic characterization of Babesia microti in questing ticks in Mongolia. Parasitol Int 2015. [DOI: 10.1016/j.parint.2015.07.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Paparini A, Macgregor J, Ryan UM, Irwin PJ. First Molecular Characterization of Theileria ornithorhynchi Mackerras, 1959: yet Another Challenge to the Systematics of the Piroplasms. Protist 2015; 166:609-20. [PMID: 26599724 DOI: 10.1016/j.protis.2015.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 07/29/2015] [Accepted: 10/03/2015] [Indexed: 01/10/2023]
Abstract
Piroplasms, tick-transmitted Apicomplexa of the genera Theileria, Babesia and Cytauxzoon, are blood-borne parasites of clinical and veterinary importance. The order Piroplasmida shows a puzzling systematics characterized by multiple clades, soft polytomies and paraphyletic/polyphyletic genera. In the present study, screening of platypuses (Ornithorhynchus anatinus), was performed to infer the parasite molecular phylogeny. DNA was extracted from blood, ectoparasites and tick eggs and the 18S rRNA- hsp70-genes were used for the phylogenetic reconstructions. Microscopic analyses detected pleomorphic intra-erythrocytic organisms and tetrads consistent with previous descriptions of Theileria ornithorhynchi Mackerras, 1959, but observation of possible schizonts could not be confirmed. DNA sequences obtained from blood and ticks allowed resolving the systematics of the first piroplasm infecting a monotreme host. Molecularly, T. ornithorhynchi formed a novel monophyletic group, basal to most known piroplasms' clades. The ancestral position of this clade, isolated from an ancient lineage of mammalian host appears particularly fascinating. The present paper discusses the inadequacies of the current molecular systematics for the Piroplasmida and the consequences of incomplete sampling, morphology-based classification and ambiguous microscopic identifications. Likely when the current sampling bias is rectified and more sequence data is made available, the phylogenetic position of T. ornithorhynchi will be further contextualized without ambiguity.
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Affiliation(s)
- Andrea Paparini
- Vector- and Water-Borne Pathogen Research Group, School of Veterinary & Life Sciences, Molecular and Biomedical Sciences, Murdoch University, Murdoch WA, 6150, Australia.
| | - James Macgregor
- College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia, 6150
| | - Una M Ryan
- Vector- and Water-Borne Pathogen Research Group, School of Veterinary & Life Sciences, Molecular and Biomedical Sciences, Murdoch University, Murdoch WA, 6150, Australia
| | - Peter J Irwin
- Vector- and Water-Borne Pathogen Research Group, School of Veterinary & Life Sciences, Molecular and Biomedical Sciences, Murdoch University, Murdoch WA, 6150, Australia
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A member of the HSP90 family from ovine Babesia in China: molecular characterization, phylogenetic analysis and antigenicity. Parasitology 2015; 142:1387-97. [PMID: 26156495 DOI: 10.1017/s0031182015000797] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Heat shock protein 90 (HSP90) is a key component of the molecular chaperone complex essential for activating many signalling proteins involved in the development and progression of pathogenic cellular transformation. A Hsp90 gene (BQHsp90) was cloned and characterized from Babesia sp. BQ1 (Lintan), an ovine Babesia isolate belonging to Babesia motasi-like group, by screening a cDNA expression library and performing rapid amplification of cDNA ends. The full-length cDNA of BQHsp90 is 2399 bp with an open reading frame of 2154 bp encoding a predicted 83 kDa polypeptide with 717 amino acid residues. It shows significant homology and similar structural characteristics to Hsp90 of other apicomplex organisms. Phylogenetic analysis, based on the HSP90 amino acid sequences, showed that the Babesia genus is clearly separated from other apicomplexa genera. Five Chinese ovine Babesia isolates were divided into 2 phylogenetic clusters, namely Babesia sp. Xinjiang (previously designated a new species) cluster and B. motasi-like cluster which could be further divided into 2 subclusters (Babesia sp. BQ1 (Lintan)/Babesia sp. Tianzhu and Babesia sp. BQ1 (Ningxian)/Babesia sp. Hebei). Finally, the antigenicity of rBQHSP90 protein from prokaryotic expression was also evaluated using western blot and enzyme-linked immunosorbent assay (ELISA).
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Baneth G, Florin-Christensen M, Cardoso L, Schnittger L. Reclassification of Theileria annae as Babesia vulpes sp. nov. Parasit Vectors 2015; 8:207. [PMID: 25890372 PMCID: PMC4393874 DOI: 10.1186/s13071-015-0830-5] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 03/26/2015] [Indexed: 12/04/2022] Open
Abstract
Background Theileria annae is a tick-transmitted small piroplasmid that infects dogs and foxes in North America and Europe. Due to disagreement on its placement in the Theileria or Babesia genera, several synonyms have been used for this parasite, including Babesia Spanish dog isolate, Babesia microti-like, Babesia (Theileria) annae, and Babesia cf. microti. Infections by this parasite cause anemia, thrombocytopenia, and azotemia in dogs but are mostly subclinical in red foxes (Vulpes vulpes). Furthermore, high infection rates have been detected among red fox populations in distant regions strongly suggesting that these canines act as the parasite’s natural host. This study aims to reassess and harmonize the phylogenetic placement and binomen of T. annae within the order Piroplasmida. Methods Four molecular phylogenetic trees were constructed using a maximum likelihood algorithm based on DNA alignments of: (i) near-complete 18S rRNA gene sequences (n = 76 and n = 93), (ii) near-complete and incomplete 18S rRNA gene sequences (n = 92), and (iii) tubulin-beta gene sequences (n = 32) from B. microti and B. microti-related parasites including those detected in dogs and foxes. Results All phylogenetic trees demonstrate that T. annae and its synonyms are not Theileria parasites but are most closely related with B. microti. The phylogenetic tree based on the 18S rRNA gene forms two separate branches with high bootstrap value, of which one branch corresponds to Babesia species infecting rodents, humans, and macaques, while the other corresponds to species exclusively infecting carnivores. Within the carnivore group, T. annae and its synonyms from distant regions segregate into a single clade with a highly significant bootstrap value corroborating their separate species identity. Conclusion Phylogenetic analysis clearly shows that T. annae and its synonyms do not pertain to Theileria and can be clearly defined as a separate species. Based on the facts that T. annae and its synonyms have not been shown to have a leukocyte stage, as expected in Theileria, do not infect humans and rodents as B. microti, and cluster phylogenetically as a separate species, this study proposes to name this parasite Babesia vulpes sp. nov., after its natural host, the red fox V. vulpes. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-0830-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gad Baneth
- Koret School of Veterinary Medicine, Hebrew University, P.O. Box 12, Rehovot, 76100, Israel.
| | - Monica Florin-Christensen
- Institute of Pathobiology, Center of Research in Veterinary and Agronomic Sciences, INTA-Castelar, 1686, Hurlingham, Argentina. .,CONICET, Ciudad Autónoma de Buenos Aires, Argentina.
| | - Luís Cardoso
- Department of Veterinary Sciences, School of Agrarian and Veterinary Sciences, University of Trás-os-Montes e Alto Douro (UTAD), Vila Real, Portugal.
| | - Leonhard Schnittger
- Institute of Pathobiology, Center of Research in Veterinary and Agronomic Sciences, INTA-Castelar, 1686, Hurlingham, Argentina. .,CONICET, Ciudad Autónoma de Buenos Aires, Argentina.
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Mans BJ, Pienaar R, Latif AA. A review of Theileria diagnostics and epidemiology. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2015; 4:104-18. [PMID: 25830110 PMCID: PMC4356873 DOI: 10.1016/j.ijppaw.2014.12.006] [Citation(s) in RCA: 169] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 11/28/2022]
Abstract
Serological and molecular assays exist for most economic important Theileria species. Molecular assays are constantly being improved with regard to sensitivity and specificity. The concept of what constitute a Theileria species impacts on accurate diagnostics. Analytical specificity of molecular assays are >800 000 parasites/L blood. Parasitemia ranges may determine practical limits of detection.
An extensive range of serological and molecular diagnostic assays exist for most of the economically important Theileira species such as T. annulata, T. equi, T. lestoquardi, T. parva, T. uilenbergi and other more benign species. Diagnostics of Theileria is considered with regard to sensitivity and specificity of current molecular and serological assays and their use in epidemiology. In the case of serological assays, cross-reactivity of genetically closely related species reduces the use of the gold standard indirect fluorescent antibody test (IFAT). Development of antigen-specific assays does not necessarily address this problem, since closely related species will potentially have similar antigens. Even so, serological assays remain an important line of enquiry in epidemiological surveys. Molecular based assays have exploded in the last decade with significant improvements in sensitivity and specificity. In this review, the current interpretation of what constitute a species in Theileria and its impact on accurate molecular diagnostics is considered. Most molecular assays based on conventional or real-time PCR technology have proven to be on standard with regard to analytical sensitivity. However, consideration of the limits of detection in regard to total blood volume of an animal indicates that most assays may only detect >400,000 parasites/L blood. Even so, natural parasitaemia distribution in carrier-state animals seems to be above this limit of detection, suggesting that most molecular assays should be able to detect the majority of infected individuals under endemic conditions. The potential for false-negative results can, however, only be assessed within the biological context of the parasite within its vertebrate host, i.e. parasitaemia range in the carrier-state that will support infection of the vector and subsequent transmission.
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Affiliation(s)
- Ben J Mans
- Parasites, Vectors and Vector-Borne Diseases, Agricultural Research Council-Onderstepoort Veterinary Institute, Onderstepoort 0110, South Africa ; The Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa ; Department of Life and Consumer Sciences, University of South Africa, South Africa
| | - Ronel Pienaar
- Parasites, Vectors and Vector-Borne Diseases, Agricultural Research Council-Onderstepoort Veterinary Institute, Onderstepoort 0110, South Africa
| | - Abdalla A Latif
- Parasites, Vectors and Vector-Borne Diseases, Agricultural Research Council-Onderstepoort Veterinary Institute, Onderstepoort 0110, South Africa ; The Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
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15
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Sivakumar T, Hayashida K, Sugimoto C, Yokoyama N. Evolution and genetic diversity of Theileria. INFECTION GENETICS AND EVOLUTION 2014; 27:250-63. [PMID: 25102031 DOI: 10.1016/j.meegid.2014.07.013] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 07/11/2014] [Accepted: 07/15/2014] [Indexed: 11/16/2022]
Abstract
Theileria parasites infect a wide range of domestic and wild ruminants worldwide, causing diseases with varying degrees of severity. A broad classification, based on the parasite's ability to transform the leukocytes of host animals, divides Theileria into two groups, consisting of transforming and non-transforming species. The evolution of transforming Theileria has been accompanied by drastic changes in its genetic makeup, such as acquisition or expansion of gene families, which are thought to play critical roles in the transformation of host cells. Genetic variation among Theileria parasites is sometimes linked with host specificity and virulence in the parasites. Immunity against Theileria parasites primarily involves cell-mediated immune responses in the host. Immunodominance and major histocompatibility complex class I phenotype-specificity result in a host immunity that is tightly focused and strain-specific. Immune escape in Theileria is facilitated by genetic diversity in its antigenic determinants, which potentially results in a loss of T cell receptor recognition in its host. In the recent past, several reviews have focused on genetic diversity in the transforming species, Theileriaparva and Theileriaannulata. In contrast, genetic diversity in Theileriaorientalis, a benign non-transforming parasite, which occasionally causes disease outbreaks in cattle, has not been extensively examined. In this review, therefore, we provide an outline of the evolution of Theileria, which includes T. orientalis, and discuss the possible mechanisms generating genetic diversity among parasite populations. Additionally, we discuss the potential implications of a genetically diverse parasite population in the context of Theileria vaccine development.
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Affiliation(s)
- Thillaiampalam Sivakumar
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan; Veterinary Research Institute, Peradeniya, Sri Lanka
| | - Kyoko Hayashida
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Chihiro Sugimoto
- Division of Collaboration and Education, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Naoaki Yokoyama
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
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