Nejvíce citovaný článek - PubMed ID 25233121
Hemolivia and hepatozoon: haemogregarines with tangled evolutionary relationships
The Australian skink Egernia stokesii had been recognised as a host of two species of Plasmodium, Plasmodium mackerrasae and P. circularis; nevertheless, molecular data are available for only a single haemosporidian species of this host. Its sequences are labelled as "Plasmodium sp." or "Plasmodium mackerrasae", but morphological characteristics of this isolate are unavailable. Phylogenetic analyses of these sequences placed them into the clade of the genus Haemocystidium. In this study, blood samples of six E. stokesii were analysed by both, molecular and microscopic methods to clarify the haemosporidia of this lizard. Application of these approaches offered discordant results. Whereas sequence analysis clustered our isolates with lizard species of Haemocystidium, morphology of blood stages is more akin to Plasmodium than Haemocystidium. However, limited sampling, indistinguishable nuclei/merozoites and risk of possible hidden presence of mixed infection prevent reliable species identification of detected parasites or their description as new species of Haemocystidium.
- Klíčová slova
- Egernia stokesii, Haemocystidium, Plasmodium mackerrasae, Australia, Haemosporidia, Lizard,
- MeSH
- fylogeneze * MeSH
- Haemosporida * genetika klasifikace izolace a purifikace MeSH
- ještěři * parazitologie MeSH
- krev parazitologie MeSH
- mikroskopie MeSH
- molekulární sekvence - údaje MeSH
- protozoální DNA genetika MeSH
- protozoální infekce zvířat parazitologie MeSH
- ribozomální DNA genetika MeSH
- RNA ribozomální 18S genetika MeSH
- sekvenční analýza DNA MeSH
- shluková analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Austrálie MeSH
- Názvy látek
- protozoální DNA MeSH
- ribozomální DNA MeSH
- RNA ribozomální 18S MeSH
Blood parasites of the genus Hemolivia Petit, Landau, Baccam and Lainson, 1990 (Adeleorina: Karyolysidae) are hemogregarines of ectothermic vertebrates, such as lizards, chelonians, and toads. Only five species of Hemolivia from vertebrate hosts and one from their tick vector have been described so far. In the present study, Central American wood turtles (Rhinoclemmys pulcherrima manni) originating from Southern Nicaragua were screened for the presence of hemogregarines. Ten out of 30 specimens (33.3%) were positive for Hemolivia using both approaches - microscopy and PCR-based analyses. Phylogenetic analyses based on the 18S rRNA gene revealed the presence of two haplotypes, both placed as sister taxa in the Hemolivia clade. Their phylogenetic position was supported by high bootstrap values and high posterior probabilities, suggesting that there are at least two new distinct haplotypes corresponding to two distinct species. However, the specimens of each haplotype were microscopically indistinguishable from each other based on the gamont morphology, therefore, only a single species could be described and named, as Hemolivia pulcherrima n. sp. We consider that the uniform morphology of the most common blood stages of species of the genus Hemolivia complicates their differential diagnosis. Sequence divergence and different host spectra, therefore, remain the only differentiating tools.
TITLE: Espèces d’Hemolivia infectant les tortues peintes d’Amérique centrale (Rhinoclemmys pulcherrima manni) et problèmes de diagnostic différentiel au sein du genre Hemolivia. ABSTRACT: Les parasites sanguins du genre Hemolivia Petit, Landau, Baccam et Lainson, 1990 (Adeleorina : Karyolysidae) sont des hémogrégarines de vertébrés ectothermes, tels que les lézards, les tortues et les crapauds. Seules cinq espèces d’Hemolivia provenant d’hôtes vertébrés et une de leur tique vectrice ont été décrites jusqu’à présent. Dans cette étude, des tortues peintes d’Amérique centrale (Rhinoclemmys pulcherrima manni) originaires du sud du Nicaragua ont été examinées pour détecter la présence d’hémogrégarines. Dix tortues sur 30 (33,3 %) étaient positives pour Hemolivia en utilisant les deux approches de microscopie et d’analyse de PCR. Les analyses phylogénétiques basées sur le gène de l’ARNr 18S ont révélé la présence de deux haplotypes, tous deux placés comme taxons frères dans le clade Hemolivia. Leur position phylogénétique était étayée par des valeurs de bootstrap et des probabilités postérieures élevées, suggérant qu’il existe au moins deux nouveaux haplotypes distincts correspondant à deux espèces distinctes. Cependant, les spécimens de chaque haplotype étaient impossibles à distinguer les uns des autres au microscope sur la base de la morphologie des gamontes. Par conséquent, une seule espèce a pu être décrite et nommée, comme Hemolivia pulcherrima n. sp. Nous considérons que l’uniformité de la morphologie des stades sanguins les plus courants des espèces du genre Hemolivia complique leur diagnostic différentiel. Les divergences de séquences et les différents spectres d’hôtes restent donc les seuls outils de différenciation.
- Klíčová slova
- Differential diagnosis, Hemogregarine, Hemolivia, Morphology, Nicaragua,
- MeSH
- diferenciální diagnóza MeSH
- fylogeneze MeSH
- ještěři * parazitologie MeSH
- želvy * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Střední Amerika MeSH
BACKGROUND: Babesia spp. are apicomplexan parasites which infect a wide range of mammalian hosts. Historically, most Babesia species were described based on the assumed host specificity and morphological features of the intraerythrocytic stages. New DNA-based approaches challenge the traditional species concept and host specificity in Babesia. Using such tools, the presence of Babesia DNA was reported in non-specific mammalian hosts, including B. canis in feces and tissues of insectivorous bats, opening questions on alternative transmission routes. The aim of the present study was to evaluate if B. canis DNA can be detected in tissues of laboratory rodents following oral inoculation with infected ticks. METHODS: Seventy-five questing adult Dermacentor reticulatus ticks were longitudinally cut in two halves and pooled. Each pool consisted of halves of 5 ticks, resulting in two analogous sets. One pool set (n = 15) served for DNA extraction, while the other set (n = 15) was used for oral inoculation of experimental animals (Mus musculus, line CD-1 and Meriones unguiculatus). Blood was collected three times during the experiment (before the inoculation, at 14 days post-inoculation and at 30 days post-inoculation). All animals were euthanized 30 days post-inoculation. At necropsy, half of the heart, lung, liver, spleen and kidneys were collected from each animal. The presence of Babesia DNA targeting the 18S rRNA gene was evaluated from blood and tissues samples. For histopathology, the other halves of the tissues were used. Stained blood smears were used for the light microscopy detection of Babesia. RESULTS: From the 15 pools of D. reticulatus used for the oral inoculation, six were PCR-positive for B. canis. DNA of B. canis was detected in blood and tissues of 33.3% of the animals (4 out of 12) inoculated with a B. canis-positive pool. No Babesia DNA was detected in the other 18 animals which received B. canis-negative tick pools. No Babesia was detected during the histological examination and all blood smears were microscopically negative. CONCLUSIONS: Our findings demonstrate that B. canis DNA can be detected in tissues of mammalian hosts following ingestion of infected ticks and opens the question of alternative transmission routes for piroplasms.
- Klíčová slova
- Babesia canis, Dermacentor reticulatus, Gerbil, Mouse, Oral inoculation,
- MeSH
- aplikace orální MeSH
- Babesia genetika MeSH
- babezióza krev parazitologie MeSH
- Dermacentor parazitologie MeSH
- Gerbillinae MeSH
- hlodavci parazitologie MeSH
- infestace klíšťaty parazitologie MeSH
- myši MeSH
- protozoální DNA analýza MeSH
- RNA ribozomální 18S genetika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- protozoální DNA MeSH
- RNA ribozomální 18S MeSH
BACKGROUND: Blood parasites of the genus Karyolysus Labbé, 1894 (Apicomplexa: Adeleida: Karyolysidae) represent the protozoan haemogregarines found in various genera of lizards, including Lacerta, Podarcis, Darevskia (Lacertidae) and Mabouia (Scincidae). The vectors of parasites are gamasid mites from the genus Ophionyssus. METHODS: A total of 557 individuals of lacertid lizards were captured in four different localities in Europe (Hungary, Poland, Romania and Slovakia) and blood was collected. Samples were examined using both microscopic and molecular methods, and phylogenetic relationships of all isolates of Karyolysus sp. were assessed for the first time. Karyolysus sp. 18S rRNA isolates were evaluated using Bayesian and Maximum Likelihood analyses. RESULTS: A total of 520 blood smears were examined microscopically and unicellular protozoan parasites were found in 116 samples (22.3% prevalence). The presence of two Karyolysus species, K. latus and K. lacazei was identified. In total, of 210 samples tested by polymerase chain reaction (PCR), the presence of parasites was observed in 64 individuals (prevalence 30.5%). Results of phylogenetic analyses revealed the existence of four haplotypes, all part of the same lineage, with other parasites identified as belonging to the genus Hepatozoon. CONCLUSIONS: Classification of these parasites using current taxonomy is complex - they were identified in both mites and ticks that typically are considered to host Karyolysus and Hepatozoon respectively. Furthermore although distortions to the intermediate host erythrocyte nuclei were observed, the defining characteristic of Karyolysus, the haplotypes were nearly identical to those reported from lizards in the Iberian Peninsula, where such distortions were not reported and which were thus identified as Hepatozoon. Based on the phylogenetic analyses, neither vertebrate host, nor geographical patterns of the studied blood parasites could be established.
- MeSH
- Coccidia cytologie genetika izolace a purifikace MeSH
- DNA helmintů chemie genetika MeSH
- fylogeneze MeSH
- ještěři parazitologie MeSH
- krev parazitologie MeSH
- mikroskopie MeSH
- molekulární sekvence - údaje MeSH
- protozoální DNA chemie genetika MeSH
- ribozomální DNA chemie genetika MeSH
- RNA ribozomální 18S genetika MeSH
- sekvenční analýza DNA MeSH
- shluková analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
- Názvy látek
- DNA helmintů MeSH
- protozoální DNA MeSH
- ribozomální DNA MeSH
- RNA ribozomální 18S MeSH