Molecular characterization of Taenia multiceps isolates from Gansu Province, China by sequencing of mitochondrial cytochrome C oxidase subunit 1

Genetic diversity and haplotypes of Cysticercus tenuicollis isolates from slaughtered sheep and goats in Elazig and Bingol provinces of Turkey

BACKGROUND

The cestode Taenia hydatigena uses canids, primarily dogs, as definitive hosts, whereas the metacestode larval stage cysticercus infects a range of intermediate hosts, including domestic animals such as goats, sheep and pigs.

OBJECTIVES

In this study, we aimed to determine the genetic differences and haplotypes of Cysticercus tenuicollis isolates obtained from sheep and goats slaughtered in the Bingol and Elazig provinces of Turkey.

METHODS

C. tenuicollis isolates were collected from 44 sheep and 26 goats slaughtered in slaughterhouses in Bingol and Elazig. After the isolation of total genomic DNA from C. tenuicollis isolates, the genetic characterization of the partial mitochondrial cytochrome oxidase 1 (CO1) gene region (866 bp) was amplified using specific primers by polymerase chain reaction (PCR), the products were then sequenced, and haplotype and genetic diversity analyses were carried out.

RESULTS

As a result of the haplotype network analyses, 34 different haplotypes were detected around the main haplotype (Hap02) arranged in a star-like configuration and separated from other haplotypes by 1-28 mutation steps and covering 22.85% (16/70) of all isolates. Twenty-seven polymorphic fields were detected, 77.77% (21/27) of which were parsimony-informative, and secondary haplotype and nucleotide diversity were observed. Additionally, we detected high intraspecies haplotype diversity (hd: 0.933) and high nucleotide diversity (π: 0.00383), with 27 different nucleotide variation positions among the haplotypes of the isolates. Tajima's D value was negative, indicating population expansion and/or selection purification. The significantly negative Fu's Fs values indicated recent population expansion or the presence of expected rare haplotypes.

CONCLUSION

The results of this study confirmed that C. tenuicollis isolates clustered in one lineage and were closely related to the relevant reference sequences in different countries, confirming the circulation of C. tenuicollis in different geographical regions.

Genetic Variation of Taenia Saginata Cyst Isolates from Iraq Based on Mitochondrial COX1 Sequences

The zoonotic parasite disease of economic and public health relevance is bovine cysticercosis, resulting from the larval stage of Taenia saginata. The presented research aims to identify intraspecific variation in T. saginata isolated from cattle in Iraq's Sulaymaniyah province using the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene. Sequence analysis of the COX1 gene revealed that five distinct haplotypes were identified in 37 T. saginata specimens from Iraq. Four of the five T. saginata haplotypes may have been identified for the first time in the world. Phylogenetic research revealed that all T. saginata haplotypes had been clustered in a single clade, with Korean and Iranian isolates sharing a high degree of closeness. In addition, individual haplotypes related to COX1 had a pairwise evolutionary divergence of 0.005- 0.013, whereas the overall evolutionary divergence regarding all five haplotypes ranged between 0.000-0.018. It was concluded that added newly recorded data on T. saginata genetic variation could have substantial implications for taeniasis epidemiology and control.

Comparison of mitochondrial genetic variation of Taenia hydatigena cysticerci from China and Mongolia

Parasitic infection is one of the many challenges facing livestock production globally. Cysticercosis tenuicollis is a common parasitic disease in domestic and wild ruminants (intermediate host) caused by the larval stage of Taenia hydatigena that primarily infects dogs (definitive host). Although genetic studies on this parasite exist, only a few describe the genetic variation of this parasite in Mongolia. Our aim was thus, to identify the mitochondrial differences in ovine isolates of Cysticercus tenuicollis entering China from Mongolia and comparison with existing Chinese isolates from sheep and goats based on the recently described PCR-RFLP method and mitochondrial genes of NADH dehydrogenase subunit 4 (nad4) and the NADH dehydrogenase subunit 5 (nad5). Sixty-nine isolates were collected during routine veterinary meat inspections from sheep that originated from Mongolia, at the modern slaughterhouses in Erenhot City, Inner Mongolia. Additional 114 cysticerci were also retrieved from sheep and goats from northern (Inner Mongolia Autonomous Region, Ningxia Hui Autonomous Region, and Gansu Province), western (Tibet Autonomous Region), and southern (Jiangxi Province and Guangxi Province) China. The PCR-RFLP approach of the nad5 showed nine mitochondrial subclusters A1, A2, A3, A5, A8, A9, A10, A11, and B of T. hydatigena isolates from sheep and goats from Mongolia and China. Meanwhile, haplogroup A1 RFLP profile was more widespread than other variants. These data supplements existing information on the molecular epidemiology of T. hydatigena in China and Mongolia and demonstrate the occurrence of similar genetic population structures in both countries.

Taenia multiceps coenurosis: a review

Taenia multiceps is a taeniid cestode that inhabits the small intestines of both wild and domestic carnivores. The larval stage, Coenurus cerebralis, is typically found in the central nervous system (CNS) of a wide range of livestock and, to a lesser extent, in the extra-cerebral tissues of sheep and goats. This review covers all aspects of the life cycle of T. multiceps and its epidemiology, molecular characterization, pathogenesis, diagnosis, therapy, control and zoonotic potential. Coenurosis caused by the larval stage of T. multiceps has a worldwide distribution and is often fatal in intermediate hosts, which can result in substantial economic losses in livestock farming. Molecular characterization using the mitochondrial genes cytochrome c oxidase subunit 1 and nicotinamide adenine dinucleotide dehydrogenase subunit 1 of different T. multiceps populations has revealed significant genetic variation and the presence of three major haplotypes. The disease mostly affects young sheep and is referred to as either acute or chronic coenurosis. Acute coenurosis occurs as a result of oncospheres migrating through the CNS, while chronic coenurosis occurs as a consequence of the coenurus maturing, which causes displacement and pressure atrophy of brain tissue. Non-cerebral coenurosis has been most commonly reported in goats. The best diagnostic method for cerebral coenurosis involves the interpretation of clinical signs with accurate localization of the cyst using diagnostic imaging techniques. A vaccine based on recombinant oncosphere antigens has proved to be an effective tool against T. multiceps infection in sheep. Additionally, use of anthelmintics during the parasite's migration stages reduces the development of cysts in the sheep brain. Surgery is considered the most effective method for the treatment of cerebral coenurosis in small ruminants, but is often not carried out because of the limited finances of many sheep and goat breeders. However, coenurosis can also be controlled effectively through preventative measures, such as anthelmintic treatment of dogs and the proper disposal of intermediate host carcasses. The parasite is also zoonotic, and cases of coenurosis have been reported in humans with coenuri located in the brain, spinal cord and eyes.

First Report on Molecular Characterization of Taenia multiceps Isolates From Sheep and Goats in Faisalabad, Pakistan

Coenurus cerebralis is the larval stage of Taenia multiceps commonly found in the brain (cerebral form), intramuscular and subcutaneous tissues (non-cerebral form) of ungulates. Globally, few reports exist on the molecular characterization and genetic diversity of C. cerebralis with none available for Pakistan. The current study molecularly characterized 12 C. cerebralis isolates surgically recovered from sheep (n = 4) and goats (n = 8) from a total of 3,040 small ruminants using a portion of the cytochrome c oxidase subunit 1 (cox1) mitochondrial (mt) gene. NCBI BLAST search confirmed the identity of each isolate. A high haplotype and a low nucleotide diversity with three haplotypes from the 12 isolates were observed. The findings suggest the existence of unique haplotypes of C. cerebralis in Pakistan. The negative value of Tajima's D and the positive value of Fu's Fs were inconsistent with population expansion, however, the sample size was small. Bayesian phylogeny revealed that all Pakistani isolates alongside the Chinese sequences (obtained from GenBank) constituted a cluster while sequences from other regions constituted another cluster. This is the first molecular study to determine the genetic diversity of C. cerebralis in Pakistan and serves as a foundation for prospective studies on the prevalence and population structure of C. cerebralis in the country. Furthermore, in this study, we amplified only a partial segment of the cox1 gene from a limited sample size. This could have implications on the interpretation of the actual population structure in reality. Thus, we recommend future studies to consider a larger sample size in a massive epidemiological survey for further insights.

Molecular and phylogenetic studies of Taenia hydatigena cysts in native sheep in Sulaimani Province, Iraq

This study aimed to determine the strain(s) of Taenia hydatigena parasite in native breed of sheep in Sulaimani province of Iraq by using polymerase chain reaction, DNA sequencing and phylogenetic analysis. Sheep isolates (20) of T. hydatigena cysts were collected from native breed of sheep at Modern SulaimaniSlaughterhouse. Following DNA extraction, fragment of cytochrome c oxidase 1 (cox1) gene was amplified by the polymerase chain reaction using specific primer and 4 highly concentrated amplicons were subjected to partial sequencing. All isolates were 100% identical, indicating no genetic variation in isolates. Phylogenetic analysis computed by neighbor joining (NJ) from the partial cox1 gene nucleotide sequences revealed that the Iraqi T. hydatigena isolates identified in this study were clustered in one clade, along with isolates from Mongolia and China. It can be concluded that the identified strain from sheep isolates was similar to the Mongolian and Chinese strains, and closely related to strains of neighboring countries especially Iran and Turkey.

Coenurosis of Yak, Bos grunniens, caused by Taenia multiceps: A Case Report with Molecular Identification in Qinghai Tibetan Plateau Area, China

Coenurosis is an important zoonotic helminthic disease caused by the larval stage of the tapeworm Taenia multiceps. This parasite typically infects the brain of the intermediate hosts, including sheep, goat, cattle and even humans. We report a case of T. multiceps infection in a yak confirmed by clinical symptoms, morphological characteristics, and molecular and phylogenetic analyses. The coenurus was thin-walled, whitish, and spherical in shape with a diameter of 10 cm. The parasite species was identified as T. multiceps by PCR amplification and sequencing of the 18S rRNA, cox1 and nad1 genes. Three gene sequences all showed high homology (all above 97%) with the reference sequences from different hosts. Moreover, phylogenetic reconstructions with the 3 published Taenia gene sequences confirmed that the Qinghai yak isolate was closely related to T. multiceps. Although there are advanced diagnosis and treatment methods for coenurosis, early infection is difficult to diagnose. Importantly, the findings of yak infection case should not be ignored due to its zoonotic potential.

Histopathological and Molecular Evaluation of the Experimentally Infected Goats by the Larval Forms of Taenia multiceps

BACKGROUND

Introduction of Taenia multiceps and T. gaigeri as two separate species have been recognized mainly on morphological grounds. This experimental study was conducted to test whether cerebral and non-cerebral forms of Coenurus cerebralis belong to one origin or they are originated from two different tape worms.

METHODS

Two groups of dogs were infected with the cerebral and muscular sources of the coenuri cysts. About two months later the eggs were collected from the fecal samples to be used to experimentally infect other healthy goats. Histopathological and molecular evaluation was conducted in two groups of goats that were challenged with T. multiceps eggs obtained from the infected dogs by brain and muscular sources of coenuri cysts in School of Veterinary Medicine of Shiraz University, Shiraz, Iran in 2015. All aberrant sites of predilection of the metacestode in goats were muscles, heart, diaphragm and lungs. The brain and spinal cord were carefully dissected and examined but the cysts were not found in these locations. In addition, the molecular genetic markers of mitochondrial DNA (CO1 and ND1) were applied to resolve the questionable relationship between T. multiceps and T. gaigeri.

RESULTS

The larval stages of T. multiceps in brain and in other aberrant sites, which showed similar morphological criteria, were monophyletic species.

CONCLUSION

Therefore, T. gaigeri must be considered taxonomically invalid.

Molecular characterization and phylogenetic analysis of Taenia multiceps from China

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.

Molecular Characterization of Annexin B2, B3 and B12 in Taenia multiceps

Coenurus cerebralis, the metacestode of Taenia multiceps, causes coenurosis, a disease severely affecting goat, sheep, cattle and yak farming and resulting in huge economic losses annually. Annexins bind calcium ions and play an important role in flatworm parasite development. To explore potential functions of annexins in T. multiceps, three homologous genes, namely, TmAnxB2, TmAnxB3 and TmAnxB12, were screened from the transcriptome dataset, amplified from C. cerebralis cDNA and subjected to bioinformatics analysis. Then, polyclonal antibodies recognizing the recombinant TmAnxB2 (rTmAnxB2) and rTmAnxB3 were prepared for localization of TmAnxB2 and TmAnxB3 in different tissues and developmental stages by immunofluorescence. The transcription of all three genes was also measured by relative fluorescent quantitative PCR. The sizes of rTmAnxB2, rTmAnxB3 and rTmAnxB12 were 58.00, 53.06 and 53.51 kDa, respectively, and rTmAnxB12 was unstable. Both rTmAnxB2 and rTmAnxB3 were recognized by goat-positive T. multiceps sera in Western blots. Immunofluorescence revealed that TmAnxB2 and TmAnxB3 were localized in the protoscolex and cyst wall and TmAnxB3 was also detected in adult cortex. TmAnxB2 and TmAnxB12 mRNA levels were determined to be highest in oncospheres and protoscolex, whereas transcription of TmAnxB3 was highest in scolex and immature segments. Taken together, these findings indicate that TmAnxB2 and TmAnxB12 may play critical roles in T. multiceps larvae, while TmAnxB3 may have important functions in adults. These results will lay the foundation for functional research of annexins in T. multiceps.

Genetic characterization of three mitochondrial gene sequences of goat/sheep-derived coenurus cerebralis and cysticercus tenuicollis isolates in Inner Mongolia, China

Taenia multiceps and Taenia hydatigena are widely distributed tapeworms of canids. Due to a lack of genetic information on these two parasites in China, in this study we analyzed six coenurus cerebralis and two cysticercus tenuicollis cysts from goats or sheep in Inner Mongolia, northern China by amplifying three mitochondrial genes (cox1, nad4, and cytb). Two haplotypes were obtained at each locus for either of the two Taenia cestode species, with ten nucleotide sequences being novel. The degrees of genetic variations were 1.18%, 0.61% and 0.52% for coenurus cerebralis, and 0.24%, 0.46% and 0.35% for cysticercus tenuicollis at the cox1, nad4 and cytb loci, respectively. This is the first molecular description of animal-derived metacestodes of T. multiceps and T. hydatigena in Inner Mongolia, China. Novel nucleotide sequences might reflect endemic genetic characterization of the two cestodes. The present data are useful to explore the biological and epidemiological significance of intra-specific variations within both Taenia cestodes.

Prevalence and Identity of Taenia multiceps cysts "Coenurus cerebralis" in Sheep in Egypt

Coenurosis is a parasitic disease caused by the larval stage (Coenurus cerebralis) of the canids cestode Taenia multiceps. C. cerebralis particularly infects sheep and goats, and pose a public health concerns. The present study aimed to determine the occurrence and molecular identity of C. cerebralis infecting sheep in Egypt. Infection rate was determined by postmortem inspection of heads of the cases that showed neurological manifestations. Species identification and genetic diversity were analyzed based on PCR-sequence analysis of nuclear ITS1 and mitochondrial cytochrome oxidase (COI) and nicotinamide adenine dinucleotide dehydrogenase (ND1) gene markers. Out of 3668 animals distributed in 50 herds at localities of Ashmoun and El Sadat cities, El Menoufia Province, Egypt, 420 (11.45%) sheep showed neurological disorders. Postmortem examination of these animals after slaughter at local abattoirs indicated to occurrence of C. cerebralis cysts in the brain of 111 out of 420 (26.4%), with overall infection rate 3.03% of the involved sheep population. Molecular analysis of representative samples of coenuri at ITS1 gene marker showed extensive intra- and inter-sequence diversity due to deletions/insertions in the microsatellite regions. On contrast to the nuclear gene marker, considerably low genetic diversity was seen in the analyzed mitochondrial gene markers. Phylogenetic analysis based on COI and ND1 gene sequences indicated that the generated sequences in the present study and the reference sequences in the database clustered in 4 haplogroups, with more or less similar topologies. Clustering pattern of the phylogenetic tree showed no effect for the geographic location or the host species.

GP50 as a promising early diagnostic antigen for Taenia multiceps infection in goats by indirect ELISA

Background

Coenurosis is caused by coenurus, the metacestode of Taenia multiceps, which mainly parasitizes the brain and spinal cord of cattle, sheep and goats. To date, no widely-approved methods are available to identify early coenurus infection.

Methods

In this study, we identified a full-length cDNA that encodes GP50 (TmGP50) from the transcriptome of T. multiceps, and then cloned and expressed in E. coli. The native proteins in adult stage and coenurus were located via immunofluorescence assays, while the potential of recombinant TmGP50 protein (rTmGP50) for indirect ELISA-based serodiagnostics was assessed using native goat sera. In addition, we orally infected 20 goats with mature T. multiceps eggs. Praziquantel (10%) was given to 10 of the goats 45 days post-infection (p.i.). Blood samples were collected for 17 weeks p.i. from the 20 goats and anti-rTmGP50 antibodies were evaluated using the indirect ELISA established here.

Results

The TmGP50 contains an 897 bp open reading frame, in which signal sequence resides in 1 ~ 48 sites and mature polypeptide consists of 282 amino acid residues. Immunofluorescence staining showed that native TmGP50 was localized to the microthrix and parenchymatous zone of the adult parasite and coenurus, and the coenurus cystic wall. The indirect ELISA based on rTmGP50 exhibited a sensitivity of 95.0% and a specificity of 92.6% when detecting GP50 antibodies in sera of naturally infected goats and sheep. In goats experimentally infected with T. multiceps, anti-TmGP50 antibody was detectable from 2 to 17 weeks p.i. in the control group, while the antibody fell below the cut-off value about 3 weeks after praziquantel treatment.

Conclusion

Our results indicate that recombinant TmGP50 is a suitable early diagnostic antigen for coenurus infection in goats.

Genetic characterisation of Taenia multiceps cysts from ruminants in Greece

This study was designed to genetically characterise the larval stage (coenurus) of Taenia multiceps from ruminants in Greece, utilising DNA regions within the cytochrome c oxidase subunit 1 (partial cox1) and NADH dehydrogenase 1 (pnad1) mitochondrial (mt) genes, respectively. A molecular-phylogenetic approach was used to analyse the pcox1 and pnad1 amplicons derived from genomic DNA samples from individual cysts (n=105) from cattle (n=3), goats (n=5) and sheep (n=97). Results revealed five and six distinct electrophoretic profiles for pcox1 and pnad1, respectively, using single-strand conformation polymorphism. Direct sequencing of selected amplicons representing each of these profiles defined five haplotypes each for pcox1 and pnad1, among all 105 isolates. Phylogenetic analysis of individual sequence data for each locus, including a range of well-defined reference sequences, inferred that all isolates of T. multiceps cysts from ruminants in Greece clustered with previously published sequences from different continents. The present study provides a foundation for future large-scale studies on the epidemiology of T. multiceps in ruminants as well as dogs in Greece.

Comparison of cerebral and non-cerebral coenurosis by genetic markers of glycolytic enzyme (enolase) and mitochondrial sequences in sheep and goats

Coenurosis is a debilitating disease caused by the larval stage of Taenia multiceps. The larval stage of T. multiceps appears in two cerebral and non-cerebral forms known as Coenurus cerebralis and Coenurus gaigeri,respectively. This leads to the hypothesis that there are genetic intraspecific variabilities within this species. Molecular analysis in the present study showed that C. cerebralis and C. gaigeri were 100% genetically identical based on exonic region of enolase (ENO) gene and both mitochondrial (cox1 and nad1) markers. In addition, an intronic mutation at ENO gene (position: 1171) was detected in the Iranian C. cerebralis. The phylogenetic analyses based on the ENO, cox1, nad1 sequence data also suggest that T. gaigeri may not be distinct from T. multiceps and there is only one single valid species within T. multiceps.

Application of polymerase chain reaction on cerebrospinal fluid for diagnosis of cerebral coenurosis in small ruminants

Sheep and goats serve as intermediate hosts for the canine tapeworm Taenia multiceps. The cysts produced by the intermediate stage of parasite are usually found in the cerebral hemispheres of small ruminants, and the resulting disease is commonly known as coenurosis. Coenurosis is clinically manifested in the form of various nervous symptoms, depending on the exact location of the cyst. The variety of neurological symptoms contributes to the complexity of clinical diagnosis and reinforces the need for a more specific and acceptable diagnostic approach. We demonstrated here, for the first time, that the T. multiceps DNA is present in the cerebrospinal fluid (CSF) of the infected sheep and goats. In addition, the molecular genetic marker of the mitochondrial DNA was applied phylogenetically to show that our isolates together with other T. multiceps strains comprised a monophyletic group that is a sister to Taenia krabbei. Pairwise comparison between the cox1 sequences of our study and other T. multiceps genotypes existing in the GenBank showed similarity ranging from 98 to 100%. Accordingly, the polymerase chain reaction (PCR) can be used for amplification of DNA of the parasite originated from the CSF and provides a valuable method for accurate identification of coenurosis cases.

Preliminary Analysis of Taenia multiceps Metacestode Antigens by Two-Dimensional Electrophoresis

BACKGROUND

Taenia multiceps is a cestode parasite with its larval stage (metacestode), Coenurus cerebralis, mainly encysts in the central nervous system of sheep and other livestock causing cerebralis coenurosis. Since, treatment of coenurosis with chemotherapy showed little effect and surgical removal of cysts is not advisable in field conditions, vaccination is useful to control coenurosis. Previous study indicated that immunization with T. multiceps metacestode antigens could induce protection in sheep against coenurosis, so the aim of this study was to identify T. multiceps metacestode antigens in order to find potential vaccine development candidates for further study.

METHODS

The protein extracts from the larval T. multiceps were analyzed by two-dimensional electrophoresis (2-DE) and characterized by mass spectrometry.

RESULTS

A total of 150 protein spots were detected with isoelectric point (pI) value from 4.97 to 9.65 and molecular weight from 14 to 98 kDa. Twenty-two protein identities were determined by mass spectrometry and 15 unique proteins were obtained. Functional annotation revealed that some of these proteins are involved in catalytic activity, binding, metabolic, cellular process and stress response. Among these molecules are antioxidant proteins (peroxiredoxin and glutathione-S-transferase), glycolytic enzymes (malate dehydrogenase and enolase), proteins with chaperone activity (heat shock protein 70 and small heat shock protein), and structural proteins (actin, actin modulator protein and paramyosin).

CONCLUSION

The identification of T. multiceps metacestode protein will provide valuable information to elucidate their specific roles in the parasitism and screen new targets for vaccine development.