Sarcocystis Attenuati N. Sp. (Apicomplexa: Sarcocystidae) Infecting the Asian Gray Shrew, Crocidura Attenuata (Insectivora: Soricidae), in China

Abstract Background: There are limited data on Sarcocystis in insectivores. The Asian gray shrew, Crocidura attenuata, is one of the most common species of insectivores in the family Soricidae distributed in South Asia and Southeast Asia. To date, Sarcocystis has never been recorded in this host.Methods: Tissues from 42 Asian gray shrews were collected in China in 2017 and 2018. Sarcocysts were observed using light (LM) and transmission electron microscopy (TEM). To complete the parasite life cycle, muscle tissues of the host infected with sarcocysts were force-fed to two beauty rat snakes, Elaphe taeniura. Individual sarcocysts from different Asian gray shrews and oocysts/sporocysts isolated from the small intestines and feces of the experimental snakes were selected for DNA extraction, and seven genetic markers, including two nuclear loci (18S rDNA and ITS1), three mitochondrial genes (cox1, cox3 and cytb), and two apicoplastic genes (rpoB and clpC), were amplified, sequenced and analyzed.Results: Sarcocysts were found in 17 of 42 (40.5%) Asian gray shrews. Under LM, the microscopic sarcocysts were exhibited saw-tooth-like protrusions measuring 3.3–4.5 μm. Ultrastructurally, the sarcocyst wall contained numerous lancet- or leaf-like villous protrusions, similar to type 9h. The experimental beauty rat snakes shed oocysts/sporcysts measuring 11.9–16.7 × 9.2–10.6 μm with a prepatent period of 10 to 11 days. Comparing these sequences with those previously deposited in GenBank revealed that the 18S rDNA sequences and cox1 sequences shared the highest similarity with those of S. scandentiborneensis recorded in tree shrews, Tuaia minor and T. tana (i.e., 97.6–98.3% and 100% identity, respectively). Phylogenetic analysis based on 18S rDNA, ITS1 or cox1 sequences revealed that this parasite formed an independent clade with Sarcocystis spp. that utilize small animals as intermediate hosts and snakes as the known or presumed definitive host. On the basis of morphological and molecular characteristics and host specificity, the parasite was proposed as a new species, named S. attenuati.Conclusions: Sarcocysts were recorded in Asian gray shrews for the first time. The sarcocysts were characterized morphologically and molecularly. The 18S rDNA and cox1 sequences of S. attenuati, named in the present study, shared the highest identities with those of S. scandentiborneensis. However, the sarcocysts of the two species of Sarcocystis were quite different under LM and TEM. Based on experimental infection, beauty rat snakes have been proven to be a definitive host of S. attenuati. As more species of Sarcocystis from insectivores and other small mammals are properly morphologically and molecularly characterized, we may gain a better understanding of the biodiversity, host specificity and evolution of Sarcocystis in the future.

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Infection of the Asian gray shrew Crocidura attenuata (Insectivora: Soricidae) with Sarcocystis attenuati n. sp. (Apicomplexa: Sarcocystidae) in China

Parasites & Vectors ◽

10.1186/s13071-021-05136-z ◽

2022 ◽

Vol 15 (1) ◽

Author(s):

Junjie Hu ◽

Jun Sun ◽

Yanmei Guo ◽

Hongxia Zeng ◽

Yunzhi Zhang ◽

...

Keyword(s):

New Species ◽

18S Rdna ◽

Common Species ◽

Molecular Characteristics ◽

Intermediate Hosts ◽

Parasite Life Cycle ◽

Internal Transcribed Spacer Region ◽

Tree Shrews ◽

Polymerase Beta ◽

A New Species

Abstract Background Data on the genus Sarcocystis in insectivores are limited. The Asian gray shrew Crocidura attenuata is one of the most common species of the insectivore family Soricidae in South Asia and Southeast Asia. To our knowledge, species of Sarcocystis have never been recorded previously in this host. Methods Tissues were obtained from 42 Asian gray shrews caught in 2017 and 2018 in China. Sarcocysts were observed using light microscopy (LM) and transmission electron microscopy (TEM). To describe the parasite life cycle, muscle tissues of the host infected with sarcocysts were force-fed to two beauty rat snakes Elaphe taeniura. Individual sarcocysts from different Asian gray shrews, and oocysts/sporocysts isolated from the small intestines and feces of the experimental snakes, were selected for DNA extraction, and seven genetic markers, namely, two nuclear loci [18S ribosomal DNA (18S rDNA) and internal transcribed spacer region 1 (ITS1)], three mitochondrial genes [cytochrome oxidase subunit 1 (cox1), cox3 and cytochrome b], and two apicoplast genes (RNA polymerase beta subunit and caseinolytic protease C), were amplified, sequenced and analyzed. Results Sarcocysts were found in 17 of the 42 (40.5%) Asian gray shrews. Under LM, the microscopic sarcocysts showed saw- or tooth-like protrusions measuring 3.3–4.5 μm. Ultrastructurally, the sarcocyst wall contained numerous lancet- or leaf-like villous protrusions, similar to those described for type 9h of the common cyst wall classification. The experimental beauty rat snakes shed oocysts/sporocysts measuring 11.9–16.7 × 9.2–10.6 μm with a prepatent period of 10–11 days. Comparison of the newly obtained sequences with those previously deposited in GenBank revealed that those of 18S rDNA and cox1 were most similar to those of Sarcocystis scandentiborneensis recorded in the tree shrews Tupaia minor and Tupaiatana (i.e., 97.6–98.3% and 100% identity, respectively). Phylogenetic analysis based on 18S rDNA or ITS1 sequences placed this parasite close to Sarcocystis spp. that utilize small animals as intermediate hosts and snakes as the known or presumed definitive host. On the basis of morphological and molecular characteristics and host specificity, the parasite was proposed as a new species, named Sarcocystis attenuati. Conclusions Sarcocysts were recorded in Asian gray shrews, to our knowledge for the first time. Based on morphological and molecular characterization, a new species of parasite is proposed: Sarcocystisattenuati. According to the LM and TEM results, S. attenuati sarcocysts are distinct from those of Sarcocystis spp. in other insectivores and those of S. scandentiborneensis in tree shrews. The 18S rDNA or cox1 sequences of Sarcocystis attenuati shared high similarity with those of Sarcocystisscandentiborneensis, Sarcocystis zuoi, Sarcocystis cf. zuoi in the Malayan field rat, and Sarcocystis sp. in the greater white-toothed shrew. Therefore, we suggest that more research on the relationships of these closely related taxa should be undertaken in the future. Graphical abstract

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Haemogregarines from western Palaearctic freshwater turtles (generaEmys, Mauremys) are conspecific withHaemogregarina stepanowiDanilewsky, 1885

Parasitology ◽

10.1017/s0031182013001820 ◽

2013 ◽

Vol 141 (4) ◽

pp. 522-530 ◽

Cited By ~ 20

Author(s):

NELA DVOŘÁKOVÁ ◽

JANA KVIČEROVÁ ◽

IVO PAPOUŠEK ◽

HOSSEIN JAVANBAKHT ◽

GHOULEM TIAR ◽

...

Keyword(s):

Host Specificity ◽

18S Rdna ◽

Phylogenetic Analyses ◽

Wide Distribution ◽

Freshwater Turtles ◽

Turtle Species ◽

Rdna Sequences ◽

Mauremys Leprosa ◽

18S Rdna Sequences ◽

Western Palaearctic

SUMMARYThe majority ofHaemogregarinaspecies have been based on the morphology of their erythrocytic stages and supposed strict host specificity. The quantity of species with a limited number of overlapping diagnostic traits has led to a considerable mess in haemogregarine taxonomy and significant synonymy. We analysed host specificity, intra- and interspecific variability, evolutionary relationships, and the distribution of the type species of the genusHaemogregarina–H. stepanowi.The morphology of blood stages and 18S rDNA sequences of this haemogregarine from four western Palaearctic hard-shelled freshwater turtles (Emys orbicularis, Mauremys caspica, Mauremys leprosaandMauremys rivulata) were compared withHaemogregarina balli. Additional sequences of 18S rDNA ofHaemogregarina-like isolates collected from three species of African hinged terrapins (genusPelusios) were used to enlarge the dataset for phylogenetic analyses. Thirteen sequences (1085 bp) ofHaemogregarinarepresenting all four western Palaearctic turtle species were identical, corresponding toH. stepanowi, which is closely related to the Nearctic speciesH. balli. In our analyses,Haemogregarinaspp. constituted a monophyletic clade sister to the genusHepatozoon. Haemogregarina stepanowipossesses a wide distribution range from the Maghreb, through Europe, Turkey and the Middle East to Iran. We consider that the genusHaemogregarinahas a low host specificity crossing the family level of its vertebrate hosts and that its distribution is likely to be linked to the vector and definitive host – the leech.

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Distribution of the cestode Urocystis prolifer Villot, 1880 (Cyclophyllidea: Hymenolepididae) in the Palaearctic and new data on its postembryonic development

Journal of Helminthology ◽

10.1017/s0022149x21000249 ◽

2021 ◽

Vol 95 ◽

Author(s):

S.A. Kornienko ◽

L.A. Ishigenova

Keyword(s):

Host Specificity ◽

Geographical Distribution ◽

Experimental Infection ◽

Definitive Host ◽

Intestinal Parasite ◽

Geographic Area ◽

Postembryonic Development ◽

Generic Diagnosis ◽

Intermediate Hosts ◽

Very High

Abstract Urocystis prolifer Villot, 1880 is an intestinal parasite of Sorex spp. In the Palaearctic. There are significant differences in the descriptions of both adults and stages of ontogenesis of U. prolifer as described by various authors. The experimental infection of intermediate hosts with cestodes has been conducted. An overview of the geographical distribution, infestation of the definitive hosts and the development of the metacestode stages of U. prolifer are presented. The cestode is characterized by an extensive geographic area in the Palaearctic, wide host specificity and very high rates of infection of its definitive host. Urocystis prolifer has been recorded mostly in the taiga and forest zones of Palaearctic. Fourteen species of Sorex were registered as the definitive host. Redescription of U. prolifer and an amended generic diagnosis are provided. A complete description of the ontogeny from oncosphere to fully developed metacestode is given. Features of development of the metacestode are an asexual larval reproduction, the absence of the anterior and posterior obturator valve in the cyst of the fully developed urocyst, as well as excretory bodies.

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Phylogeny of the Thoracican Barnacles Based on 18S rDNA Sequences

Journal of Crustacean Biology ◽

10.1163/20021975-99990049 ◽

2000 ◽

Vol 20 (2) ◽

pp. 393-398 ◽

Cited By ~ 13

Author(s):

D. James Harris ◽

Laura S. Maxson ◽

Lee F. Braithwaite ◽

Keith A. Crandall

Keyword(s):

18S Rdna ◽

Rdna Sequences ◽

18S Rdna Sequences

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Assessing the Biodiversity of Monoraphidium Using 18S rDNA Sequences

Journal of Phycology ◽

10.1046/j.1529-8817.38.s1.25.x ◽

2002 ◽

Vol 38 (s1) ◽

pp. 9-9

Author(s):

M. W. Fawley ◽

K. P. Fawley ◽

M. L. Dean

Keyword(s):

18S Rdna ◽

Rdna Sequences ◽

18S Rdna Sequences

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Unexplored diversity of microscopic myxomycetes: evidence from environmental DNA

Plant Ecology and Evolution ◽

10.5091/plecevo.2019.1621 ◽

2019 ◽

Vol 152 (3) ◽

pp. 499-506 ◽

Cited By ~ 2

Author(s):

Oleg N. Shchepin ◽

Martin Schnittler ◽

Nikki H.A. Dagamac ◽

Dmitry V. Leontyev ◽

Yuri K. Novozhilov

Keyword(s):

New Species ◽

18S Rdna ◽

Sequence Similarity ◽

Phylogenetic Analyses ◽

Environmental Dna ◽

Full Length ◽

Detection Techniques ◽

Rdna Sequences ◽

18S Rdna Sequences ◽

Environmental Sequences

Background and aims – Recent studies showed the position of two slime mould species with microscopic sporocarps, Echinosteliopsis oligospora and Echinostelium bisporum, within the class Myxomycetes. These minute species are seldom seen in studies based on detection of sporocarps and can easily be confused with protosteloid amoebozoans.Methods – We searched all published ePCR data sets that targeted myxomycete 18S rDNA for the presence of environmental sequences similar to E. oligospora and Echinosteliales in traditional circumscription, and performed phylogenetic analyses that included short environmental sequences and full-length 18S rDNA sequences representing all the major groups of myxomycetes.Key results – We report 19 unique sequences which are closely related to E. bisporum or E. oligospora based on sequence similarity (73.1–95.2% similarity) and which form well-supported monophyletic clades with these species in phylogenetic analyses. They may represent new species that are not yet described. Our phylogeny based on full-length 18S rDNA sequences further confirms the position of E. bisporum and E. oligospora within myxomycetes and the paraphyly of the order Echinosteliales in its traditional circumscription.Conclusions – Our results show that ePCR-based studies can reveal myxomycete taxa that often escape detection by traditional approaches, including potentially new species, and thus provide valuable new data on diversity and ecology of myxomycetes. As such, strategies for studying myxomycetes biodiversity should be revised, focusing also on molecular detection techniques in addition to the sporocarp-based ones.

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