Morphological and molecular characterization of Sarcocystis wenzeli in chickens (Gallus gallus) in China

Abstract Background: There has been considerable confusion concerning the number and classification of Sarcocystis spp. in chickens. Scarce nucleotide data of Sarcocystis spp. from chickens are provided in GenBank. The study aimed to investigate the morphological and molecular characteristics of Sarcocystis spp. found in chickens in China.Methods: Tissues from 33 chickens were collected in 2019. Sarcocysts were observed using light (LM) and transmission electron microscopy (TEM). Individual sarcocysts from different chickens were selected for DNA extraction, and five loci, 18S rDNA, 28S rDNA, ITS1 region, the mitochondrial cox1 gene and the apicoplastic rpoB gene, were amplified from each sarcocyst, sequenced and analyzed.Results: Only S. wenzeli was found in 14 of 33 (42.4%) chickens. Under LM, the sarcocysts were microscopic and exhibited palisade-like villar protrusions measuring 1.5–2.8 μm. Ultrastructurally, the sarcocyst wall contained numerous stubby hill-like villar protrusions. The protrusions included scattered microtubules, which extended from the tips of the protrusions into the ground substance. The five loci were successfully sequenced and the sequences deposited in GenBank. At 18S rDNA, ITS1 and cox1, the most similar sequences in GenBank were those of Sarcocystis sp. obtained from the brains of chickens, i.e. 99.9–100%, 98.1–98.5% and 99.3% identity, respectively. The five loci (18S rDNA, 28S rDNA, ITS1, cox1 and rpoB) showed different levels of interspecific sequence similarity with other closely related species of Sarcocystis (e.g. 99.8%, 99.0–99.2%, 89.3-89.7%, 98.5%, and 97.5%, respectively, with S. anasi). Phylogenetic analysis based on four of the loci (18S rDNA, cox1, rpoB and ITS1) revealed that S. wenzeli formed an independent clade with Sarcocystis spp. that utilize geese or ducks as intermediate hosts and canines as the known or presumed definitive host.Conclusions: To our knowledge, the sequences of 28S rDNA and rpoB reported here constitute the first records of genetic markers of Sarcocystis spp. in chickens. Based on molecular analysis, S. wenzeli might be responsible for the neurological disease in chickens, and ITS1 and rpoB are more suitable for discriminating it from closely related Sarcocystis spp. Phylogenetic analysis revealed that S. wenzeli presents a close relationship with Sarcocystis spp. in geese or ducks.

Download Full-text

Morphological and molecular characterization of Sarcocystis wenzeli in chickens (Gallus gallus) in China

10.21203/rs.3.rs-49974/v2 ◽

2020 ◽

Author(s):

Jing Pan ◽

Chunli Ma ◽

Zhumei Huang ◽

Yulong Ye ◽

Hongxia Zeng ◽

...

Keyword(s):

Phylogenetic Analysis ◽

18S Rdna ◽

Sequence Similarity ◽

28S Rdna ◽

Ground Substance ◽

Molecular Characteristics ◽

Cox1 Gene ◽

Intermediate Hosts ◽

Rdna Its ◽

Sarcocystis Spp

Abstract Background: There has been considerable confusion concerning the number and classification of Sarcocystis spp. in chickens. Scarce nucleotide data of Sarcocystis spp. from chickens are provided in GenBank. The study aimed to investigate the morphological and molecular characteristics of Sarcocystis spp. found in chickens in China. Methods: Tissues from 33 chickens were collected in 2019. Sarcocysts were observed using light (LM) and transmission electron microscopy (TEM). Individual sarcocysts from different chickens were selected for DNA extraction, and five loci, 18S rDNA, 28S rDNA, the ITS-1 region ( ITS-1 ), the mitochondrial cox1 gene ( cox1 ), and the apicoplastic rpoB gene ( rpoB ), were amplified from each sarcocyst, sequenced and analyzed. Results: Only S . wenzeli was found in 14 of 33 (42.4%) chickens. Under LM, the sarcocysts were microscopic and exhibited palisade-like villar protrusions measuring 1.5–2.8 μm. Ultrastructurally, the sarcocyst wall contained numerous stubby hill-like villar protrusions. The protrusions included scattered microtubules, which extended from the tips of the protrusions into the ground substance. The five loci were successfully sequenced and deposited in GenBank. At 18S rDNA, ITS-1 and cox1 , the most similar sequences in GenBank were those of Sarcocystis sp. obtained from the brains of chickens, i.e., 99.9–100%, 98.1–98.5%, and 99.3% identity, respectively. The five loci (18S rDNA, 28S rDNA, ITS-1 , cox1 and rpoB ) showed different levels of interspecific sequence similarity with other closely related species of Sarcocystis (e.g., 99.8%, 99.0–99.2%, 89.3-89.7%, 98.5%, and 97.5%, respectively, with S . anasi ). Phylogenetic analysis based on three of the loci (18S rDNA, cox1 , and rpoB ) revealed that S . wenzeli formed an independent clade with Sarcocystis spp. that employ geese or ducks as intermediate hosts and canines as the known or presumed definitive host. Conclusions: The sequences of 28S rDNA and rpoB reported here constitute the first records of genetic markers of Sarcocystis spp. in chickens. Based on molecular analysis, S . wenzeli might be responsible for the neurological disease in chickens, and ITS-1 and rpoB are more suitable for discriminating it from closely related Sarcocystis spp. Phylogenetic analysis revealed that S . wenzeli presents a close relationship with Sarcocystis spp. in geese or ducks.

Download Full-text

Morphological and molecular characterization of Sarcocystis wenzeli in chickens (Gallus gallus) in China

10.21203/rs.3.rs-49974/v3 ◽

2020 ◽

Author(s):

Jing Pan ◽

Chunli Ma ◽

Zhumei Huang ◽

Yulong Ye ◽

Hongxia Zeng ◽

...

Keyword(s):

Phylogenetic Analysis ◽

18S Rdna ◽

Sequence Similarity ◽

Rpob Gene ◽

28S Rdna ◽

Ground Substance ◽

Molecular Characteristics ◽

Cox1 Gene ◽

Intermediate Hosts ◽

Rdna Its

Abstract Background: There has been considerable confusion concerning the number and classification of Sarcocystis spp. in chickens. Scarce nucleotide data of Sarcocystis spp. from chickens are provided in GenBank. The study aimed to investigate the morphological and molecular characteristics of Sarcocystis spp. found in chickens in China.Methods: Tissues from 33 chickens were collected in 2019. Sarcocysts were observed using light (LM) and transmission electron microscopy (TEM). Individual sarcocysts from different chickens were selected for DNA extraction, and five loci, 18S rDNA, 28S rDNA, ITS-1 region (ITS-1), the mitochondrial cox1 gene (cox1), and the apicoplastic rpoB gene (rpoB) , were amplified from each sarcocyst, sequenced and analyzed.Results: Only S. wenzeli was found in 14 of 33 (42.4%) chickens. Under LM, the sarcocysts were microscopic and exhibited palisade-like villar protrusions measuring 1.5–2.8 μm. Ultrastructurally, the sarcocyst wall contained numerous stubby hill-like villar protrusions. The protrusions included scattered microtubules, which extended from the tips of the protrusions into the ground substance. The five loci were successfully sequenced and deposited in GenBank. At 18S rDNA, ITS-1 and cox1, the most similar sequences in GenBank were those of Sarcocystis sp. obtained from the brains of chickens, i.e., 99.9–100%, 98.1–98.5% and 99.3% identity, respectively. The five loci (18S rDNA, 28S rDNA, ITS-1, cox1and rpoB) showed different levels of interspecific sequence similarity with other closely related species of Sarcocystis (e.g., 99.8%, 99.0–99.2%, 89.3-89.7%, 98.5%, and 97.5%, respectively, with S. anasi). Phylogenetic analysis based on four of the loci (18S rDNA, cox1, rpoB and ITS-1) revealed that S. wenzeli formed an independent clade with Sarcocystis spp. that employ geese or ducks as intermediate hosts and canines as the known or presumed definitive host.Conclusions: The sequences of 28S rDNA and rpoB reported here constitute the first records of genetic markers of Sarcocystis spp. in chickens. Based on molecular analysis, S. wenzeli might be responsible for the neurological disease in chickens, and ITS-1 and rpoB are more suitable for discriminating it from closely related Sarcocystis spp. Phylogenetic analysis revealed that S. wenzeli presents a close relationship with Sarcocystis spp. in geese or ducks.

Download Full-text

Morphological and Molecular Characterization of Sarcocystis Wenzeli in Chickens (Gallus gallus) in China

10.21203/rs.3.rs-49974/v1 ◽

2020 ◽

Author(s):

Jing Pan ◽

Chunli Ma ◽

Zhumei Huang ◽

Yulong Ye ◽

Hongxia Zeng ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Related Species ◽

18S Rdna ◽

Sequence Similarity ◽

28S Rdna ◽

Ground Substance ◽

Molecular Characteristics ◽

Cox1 Gene ◽

Intermediate Hosts ◽

Closely Related Species

Abstract Background: There has been considerable confusion concerning the number and classification of Sarcocystis spp. found in chickens. To date, no nucleotide sequences of Sarcocystis spp. from chickens have been provided in GenBank. The present study aimed to investigate the morphological and molecular characteristics of Sarcocystis spp. in chickens in China.Methods: Tissues from 33 chickens were collected in 2019. Sarcocysts were observed using light (LM) and transmission electron microscopy (TEM). Individual sarcocysts from different chickens were selected for DNA extraction, and five loci, 18S rDNA, 28S rDNA, the ITS-1 region (ITS-1), the mitochondrial cox1 gene (cox1), and the apicoplastic rpoB gene (rpoB), were amplified from each sarcocyst, cloned, sequenced and analyzed.Results: Only S. wenzeli was found in 14 of 33 (42.4%) chickens. Under LM, the sarcocysts were microscopic and exhibited palisade-like villar protrusions measuring 1.5–2.8 μm. The bradyzoites were lancet-shaped, measuring 9.2–12.6 × 1.5–3.5 μm. Ultrastructurally, the sarcocyst wall contained numerous stubby hill-like villar protrusions that were up to 1.2 μm long and 1.0 μm wide. The protrusions included scattered microtubules, which extended from the tips of the protrusions into the ground substance. The intraspecific similarity of the five loci (18S rDNA, 28S rDNA, ITS-1, cox1, and rpoB) among the newly obtained sequences ranged from 99.8–100%, 99.7–100%, 99.0–99.9%, 100% and 98.9–100%, respectively. The five loci showed different levels of interspecific sequence similarity with closely related species of Sarcocystis (e.g., 99.8%, 99.0–99.2%, 89.3-89.7%, 98.5%, and 97.5%, respectively, with S. anasi). Phylogenetic analysis based on three of the loci (18S rDNA, cox1, and rpoB) revealed that S. wenzeli formed an independent clade with Sarcocystis spp. that employ geese or ducks as intermediate hosts and canines as the known or presumed definitive host.Conclusions: The sequences of 18S rDNA, 28S rDNA, ITS-1, cox1 and rpoB from S. wenzeli reported here constitute the first records of genetic markers of Sarcocystis from chickens made available in GenBank. Based on sequence analysis, ITS-1 and rpoB are more suitable for discriminating S. wenzeli from closely related species of Sarcocystis. Phylogenetic analysis revealed that S. wenzeli presents a close relationship with Sarcocystis spp. from geese or ducks.

Download Full-text

Morphological and molecular characterization of Sarcocystis wenzeli in chickens (Gallus gallus) in China

Parasites & Vectors ◽

10.1186/s13071-020-04390-x ◽

2020 ◽

Vol 13 (1) ◽

Author(s):

Jing Pan ◽

Chunli Ma ◽

Zhumei Huang ◽

Yulong Ye ◽

Hongxia Zeng ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Sequence Similarity ◽

Ground Substance ◽

Molecular Characteristics ◽

Intermediate Hosts ◽

Transmission Electron ◽

Close Relationship ◽

Nucleotide Data

Abstract Background There has been considerable confusion concerning the number and classification of Sarcocystis spp. in chickens. Scarce nucleotide data of Sarcocystis spp. from chickens are provided in GenBank. The study aimed to investigate the morphological and molecular characteristics of Sarcocystis spp. found in chickens in China. Methods Tissues from 33 chickens were collected in 2019. Sarcocysts were observed using light (LM) and transmission electron microscopy (TEM). Individual sarcocysts from different chickens were selected for DNA extraction, and five loci, 18S rDNA, 28S rDNA, ITS1 region, the mitochondrial cox1 gene and the apicoplastic rpoB gene, were amplified from each sarcocyst, sequenced and analyzed. Results Only S. wenzeli was found in 14 of 33 (42.4%) chickens. Under LM, the sarcocysts were microscopic and exhibited palisade-like villar protrusions measuring 1.5–2.8 μm. Ultrastructurally, the sarcocyst wall contained numerous stubby hill-like villar protrusions. The protrusions included scattered microtubules, which extended from the tips of the protrusions into the ground substance. The five loci were successfully sequenced and the sequences deposited in GenBank. At 18S rDNA, ITS1 and cox1, the most similar sequences in GenBank were those of Sarcocystis sp. obtained from the brains of chickens, i.e. 99.9–100%, 98.1–98.5% and 99.3% identity, respectively. The five loci (18S rDNA, 28S rDNA, ITS1, cox1 and rpoB) showed different levels of interspecific sequence similarity with other closely related species of Sarcocystis (e.g. 99.8%, 99.0–99.2%, 89.3–89.7%, 98.5%, and 97.5%, respectively, with S. anasi). Phylogenetic analysis based on four of the loci (18S rDNA, cox1, rpoB and ITS1) revealed that S. wenzeli formed an independent clade with Sarcocystis spp. that utilize geese or ducks as intermediate hosts and canines as the known or presumed definitive host. Conclusions To our knowledge, the sequences of 28S rDNA and rpoB reported here constitute the first records of genetic markers of Sarcocystis spp. in chickens. Based on molecular analysis, S. wenzeli might be responsible for the neurological disease in chickens, and ITS1 and rpoB are more suitable for discriminating it from closely related Sarcocystis spp. Phylogenetic analysis revealed that S. wenzeli presents a close relationship with Sarcocystis spp. in geese or ducks.

Download Full-text

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

10.21203/rs.3.rs-907878/v1 ◽

2021 ◽

Author(s):

junjie hu ◽

Jun Sun ◽

Yanmei Guo ◽

Hongxia Zeng ◽

Yunzhi Zhang ◽

...

Keyword(s):

Host Specificity ◽

Definitive Host ◽

18S Rdna ◽

Common Species ◽

Molecular Characteristics ◽

Intermediate Hosts ◽

Parasite Life Cycle ◽

Rdna Sequences ◽

Transmission Electron ◽

18S Rdna Sequences

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.

Download Full-text

Molecular characterization and phylogenetic analysis of Taenia multiceps from China

Acta Parasitologica ◽

10.1515/ap-2018-0085 ◽

2018 ◽

Vol 63 (4) ◽

pp. 721-727 ◽

Cited By ~ 1

Author(s):

L. Tan ◽

A.B. Wang ◽

S.Q. Zheng ◽

X.L. Zhang ◽

C.J. Huang ◽

...

Keyword(s):

Phylogenetic Analysis ◽

Dna Sequences ◽

Hunan Province ◽

Biological Study ◽

Economic Losses ◽

Molecular Characteristics ◽

12S Rrna ◽

Intermediate Hosts ◽

Taenia Multiceps ◽

Coenurus Cerebralis

Abstract Taenia multiceps, one of the most widely distributed zoonotic tapeworm parasites, is able to parasitize the small intestine of canids. The metacestode of T.multiceps is fatal to ruminants and causes important economic losses in livestock. However, molecular characteristics of T.multiceps and coenurus in China are still unclear. In this study, 36 goat isolates of the coenurus stage and 18 dog isolates of the adult stage of T.multiceps were obtained from three geographical areas in China and the isolated parasite above were analyzed by amplifying the partial of cytochrome coxidase subunit 1(pcox1), 12S ribosomal RNA (12S rRNA) from mitochondrial DNA (mtDNA) regions and an internal transcribed spacer (ITS) of ribosomal DNA (rDNA). These DNA sequences obtained from T.multiceps and coenurus were employed to evaluate the nucleotide diversity and confirm the relationship between T.multiceps and coenurus. Sequences variation were 0–1.4%, 0–1.5%, 0–4.2% for pcox1, 12S rRNA and ITS, respectively, among T.multiceps and coenurus isolates obtained in this study. In Sichuan province, sequence variations for Coenurus cerebralis isolated from Yaan city were 0–1.4% for pcox1, 0–1.0% for 12S rRNA and 0–2.1% for ITS. In Hunan province, variations were 0–1.0%, 0–1.5% and 0–3.3% for corresponding genes for non-coenurus cerebralis isolated from Changsha city, while variations of T.multiceps isolates from Xiangxi autonomous prefecture were 0–1.0%, 0–1.1% and 0–3.4% for pcox1, 12S rRNA and ITS, respectively. Phylogenetic analysis based on pcox1 sequences indicated that all cerebral and noncerebral metacestodes belong to T.multiceps. These results provide reference values for future molecular epidemiological and biological study on T.multiceps in dogs and intermediate hosts.

Download Full-text

Morphological and molecular characterization of three Helicotylenchus species from Iran

Zootaxa ◽

10.11646/zootaxa.4388.2.4 ◽

2018 ◽

Vol 4388 (2) ◽

pp. 207 ◽

Cited By ~ 6

Author(s):

EBRAHIM SHOKOOHI ◽

MARIETTE MARAIS ◽

HENDRIKA FOURIE ◽

HADI PANAHI

Keyword(s):

Phylogenetic Analysis ◽

Molecular Characterization ◽

28S Rdna ◽

Molecular Characteristics ◽

Monophyletic Clade ◽

Morphological And Molecular Characterization

Three Helicotylenchus species, namely Helicotylenchus digonicus, Helicotylenchus pseudorobustus and Helicotylenchus vulgaris were identified during a nematode survey conducted in Iran. The morphological and molecular characteristics of the species were defined. In addition, phylogenetic analysis of five Iranian Helicotylenchus populations based on 28S rDNA were done and showed the unresolved position of molecularly identified H. pseudorobustus and H. digonicus. However, populations of H. vulgaris and H. digonicus were placed close to each other. Phylogenetic analysis confirmed that molecularly characterized Helicotylenchus species formed a monophyletic clade. A detailed revision of the species is, however, needed. Illustrations and measurements for all species are provided.

Download Full-text

The Role of Mustelids in the Transmission of Sarcocystis spp. Using Cattle as Intermediate Hosts

Animals ◽

10.3390/ani11030822 ◽

2021 ◽

Vol 11 (3) ◽

pp. 822

Author(s):

Petras Prakas ◽

Linas Balčiauskas ◽

Evelina Juozaitytė-Ngugu ◽

Dalius Butkauskas

Keyword(s):

American Mink ◽

Single Species ◽

Meles Meles ◽

Cox1 Gene ◽

Intermediate Hosts ◽

Specific Pcr ◽

Sarcocystis Spp ◽

Species Specific ◽

Pcr Targeting

There is a lack of research on the role of mustelids in the transmission of various Sarcocystis spp. In the present study we tested the hypothesis that widespread mustelids in Lithuania could be involved in the transmission of Sarcocystis spp. using cattle as intermediate hosts. In 2016–2020, intestinal samples of 84 mustelids were examined. Sarcocystis spp. were identified by species-specific PCR targeting the cox1 gene and subsequent sequencing. Under a light microscope, oocysts/sporocysts of Sarcocystis spp. were observed in 40 samples (47.6%), while using molecular methods, they were detected in 75 animals (89.3%). Four Sarcocystis spp. were identified in the intestinal samples of American mink (Neovisonvison), Beech marten (Martes foina), European pine marten (Martes martes), European badger (Meles meles) and European polecat (Mustela putorius). The prevalence of predominant Sarcocystis spp., S. bovifelis (89.3%) and S. cruzi (73.8%) was significantly higher than that of S. hirsuta (3.6%) and S. hominis (1.2%). In an individual sample, most frequently two Sarcocystis spp. were identified (69.0%), then a single species (15.5%) and three species (4.8%). The present study provides strong evidence that mustelids serve as definitive hosts for Sarcocystis spp. using cattle as intermediate hosts.

Download Full-text

Description of Calcaridorylaimus heynsi n. sp. (Nematoda: Dorylaimidae) from Potchefstroom, South Africa

Nematology ◽

10.1163/15685411-00003346 ◽

2020 ◽

Vol 22 (8) ◽

pp. 855-865

Author(s):

Antoinette Swart ◽

Hendrika Fourie ◽

Louwrens R. Tiedt ◽

Milad Rashidifard

Keyword(s):

South Africa ◽

Phylogenetic Analysis ◽

New Species ◽

18S Rdna ◽

Molecular Techniques ◽

28S Rdna ◽

Median Line ◽

Rdna Sequences ◽

28S Rdna Sequences ◽

Short Body

Summary Calcaridorylaimus heynsi n. sp. is the second species of the genus to be described by both morphological and molecular techniques. Morphologically, it can be distinguished from all known species of Calcaridorylaimus by a combination of the following characters: presence of advulval ornamentations, short body (0.90-1.33 mm), slightly anteriorly positioned vulva (V = 47.6 (45.8-49.8)), short odontostyle in females and males (13.1 (11.5-14.5) μm and 13.5 (12.0-18.0) μm, respectively), number of supplements (2 + 9-11), short spicules when measured along the median line (40.4 (38-42) μm) and pore-like vulval opening. It is closest to C. sirgeli, especially in the presence of advulval ornamentations and the pore-like vulva. Phylogenetic analysis based on partial D2-D3 segment of 28S rDNA sequences showed that C. heynsi n. sp. is in a well-supported sister relation with Mesodorylaimus sp. in a clade with C. cignatus and Mesodorylaimus spp. In the Bayesian tree, using partial sequences 18S rDNA, M. japonicus was the closest taxon to the new species.

Download Full-text

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

Download Full-text