Sympatric occurrence of Taenia solium, T. saginata, and T. asiatica, Thailand.
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ABSTRACT:
PROVIDER: S-EPMC2857269 | BioStudies |
REPOSITORIES: biostudies
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Project description:Most part of Southeast Asia is considered endemic for human-infecting Taenia tapeworms; Taenia solium, T. saginata, and T. asiatica. However, until now there was no report of the occurrence of human cases of T. asiatica in Lao PDR. This study, conducted in Savannakhet Province, Lao PDR, microscopically examined a total of 470 fecal samples by Kato Katz method and found 86% of people harboring at least one helminth. Hookworms were detected in 56% of the samples besides Opisthorchis like eggs (42%), Trichuris trichiura (27%), Ascaris spp. (14%), and Taenia spp. (4%) eggs. Serology for cysticercosis showed 6.8% positives with results varying from 3% to 14.3% in Ethnic School students and Kalouk Kao village respectively. Species-specific PCR targeting mitochondrial DNA (mtDNA) of 28 tapeworms, recovered from 16 patients, revealed T. solium (n = 2), T. saginata (n = 21), and T. asiatica (n = 5). Two patients were confirmed to be coinfected with T. saginata and T. asiatica, indicating the endemicity of the 3 human Taenia in Lao PDR. However, nucleotide sequencing of a nuclear DNA gene, DNA polymerase delta (pold) revealed that all the tapeworms identified as T. asiatica using mtDNA had T. saginata type allele at pold locus, demonstrating that they are not "pure T. asiatica" but the hybrid descendants between the two species, confirming the wide distribution of hybrids of T. saginata/ T. asiatica in Southeast Asia. The high prevalence of several helminthic NTDs in east Savannakhet area even with conventional control measures indicates the importance to establish wide and multifaceted health programs to sustainably improve the quality of life of the populations living in these communities.
| S-EPMC5821399 | BioStudies
Project description:A previously described Taenia saginata HDP2 DNA sequence, a 4-kb polymorphic fragment, was previously used as the basis for developing PCR diagnostic protocols for the species-specific discrimination of T. saginata from T. solium and for the differentiation of T. saginata from T. asiatica. The latter was shown subsequently to lack the required specificity, so we undertook genetic studies of the HDP2 sequence from T. saginata and T. asiatica to determine why, and to develop a novel HDP2-PCR protocol for the simultaneous unambiguous identification of human taeniids. Sequencing and further analysis of the HDP2 DNA fragments of 19 Asiatic isolates of T. saginata and T. asiatica indicated that the HDP2 sequences of both species exhibited clear genomic variability, due to polymorphic variable fragments, that could correspond to the non-transcribed region of ribosomal DNA. This newly observed polymorphism allowed us to develop a novel, reproducible and reliable HDP2-PCR protocol which permitted the simultaneous discrimination of all T. saginata and T. asiatica isolates examined. This species-specific identification was based on, and facilitated by, the clear size difference in amplicon profiles generated: fragments of 1300 bp, 600 bp and 300 bp were produced for T. asiatica, amplicons of 1300 bp and 300 bp being obtained for T. saginata. Control T. solium samples produced one amplicon of 600 bp with the HDP2-PCR protocol. The assay has the potential to prove useful as a diagnostic tool in areas such as South East Asia where T. saginata, T. asiatica and T. solium coexist.
| S-EPMC2906438 | BioStudies
Project description:Geographical information of Taenia asiatica is reviewed together with that of T. solium and T. saginata. Current distribution of T. asiatica was found to be mostly from Asian countries: the Republic of Korea, China, Taiwan, Indonesia, and Thailand. Molecular genotypic techniques have found out more countries with T. asiatica from Japan, the Philippines, and Vietnam. Specimens used in this paper were collected from around the world and mostly during international collaboration projects of Korean foundations for parasite control activities (1995-2009) in developing countries.
| S-EPMC2769216 | BioStudies
Project description:We have designed species-specific oligonucleotides which permit the differential detection of two species of cestodes, Taenia saginata and Taenia solium. The oligonucleotides contain sequences established for two previously reported, noncoding DNA fragments cloned from a genomic library of T. saginata. The first, which is T. saginata specific (fragment HDP1), is a repetitive sequence with a 53-bp monomeric unit repeated 24 times in direct tandem along the 1, 272-bp fragment. From this sequence the two oligonucleotides that were selected (oligonucleotides PTs4F1 and PTs4R1) specifically amplified genomic DNA (gDNA) from T. saginata but not T. solium or other related cestodes and had a sensitivity down to 10 pg of T. saginata gDNA. The second DNA fragment (fragment HDP2; 3,954 bp) hybridized to both T. saginata and T. solium DNAs and was not a repetitive sequence. Three oligonucleotides (oligonucleotides PTs7S35F1, PTs7S35F2, and PTs7S35R1) designed from the sequence of HDP2 allowed the differential amplification of gDNAs from T. saginata, T. solium, and Echinococcus granulosus in a multiplex PCR, which exhibits a sensitivity of 10 pg.
| S-EPMC86191 | BioStudies
Project description:Human infection with Taenia asiatica or a hybrid between Taenia saginata and T. asiatica has not been reported in Cambodia. We detected for the first time a hybrid form between T. saginata and T. asiatica in Preah Vihear Province, Cambodia. An adult tapeworm specimen, i.e., 75 cm long strobila without scolex, was expelled from a 27-year-old man after praziquantel medication and purging. It was morphologically indistinguishable between T. saginata and T. asiatica. Several proglottids were molecularly analyzed to confirm the tapeworm species. The mitochondrial gene encoding cytochrome c oxidase subunit 1 (cox1) and nuclear genes encoding elongation factor-1α (ef1) and ezrin-radixin-moesin (ERM)-like protein (elp) were sequenced, and a single-allele analysis was performed to confirm the haploid genotype. The results revealed that our sample showed a discrepancy between the mitochondrial and 2 nuclear genes. It possessed homozygous sequences typical of T. saginata at cox1 and ef1 loci. However, it was heterozygous at the elp locus, with 1 allele in T. asiatica (elpA) and 1 in T. saginata (elpC), which indicates that it is a hybrid between T. saginata and T. asiatica. The present results confirmed the presence of a hybrid between T. saginata and T. asiatica in Cambodia and strongly suggest the existence of also 'pure' T. asiatica in Cambodia.
| S-EPMC8106985 | BioStudies
Project description:Taenia saginata is the most common human Taenia in Thailand. By cox1 sequences, 73 isolates from four localities in north and northeast were differentiated into 14 haplotypes, 11 variation sites and haplotype diversity of 0.683. Among 14 haplotypes, haplotype A was the major (52.1%), followed by haplotype B (21.9%). Clustering diagram of Thai and GenBank sequences indicated mixed phylogeny among localities. By MJ analysis, haplotype clustering relationships showed paired-stars-like network, having two main cores surrounded by minor haplotypes. Tajima's D values were significantly negative in T. saginata world population, suggesting population expansion. Significant Fu's F s values in Thai, as well as world population, also indicate that population is expanding and may be hitchhiking as part of selective sweep. Haplotype B and its dispersion were only found in populations from Thailand. Haplotype B may evolve and ultimately become an ancestor of future populations in Thailand. Haplotype A seems to be dispersion haplotype, not just in Thailand, but worldwide. High genetic T. saginata intraspecies divergence was found, in contrast to its sister species, T. asiatica; among 30 samples from seven countries, its haplotype diversity was 0.067, while only 2 haplotypes were revealed. This extremely low intraspecific variation suggests that T. asiatica could be an endangered species.
| S-EPMC3707265 | BioStudies
Project description:Taenia solium is known to cause human cysticercosis while T. saginata does not. Comparative in vitro and in vivo studies on the oncosphere and the postoncospheral (PO) forms of T. solium and T. saginata may help to elucidate why cysticercosis can occur from one and not the other. The aim of this study was to use in vitro culture assays and in vivo models to study the differences in the development of the T. solium and T. saginata oncosphere. Furthermore, this study aimed to evaluate the expression of cytokines and metalloproteinases (MMPs) in human peripheral blood mononuclear cells (PBMCs), which were stimulated by these oncospheres and PO antigens. T. solium and T. saginata activated oncospheres (AO) were cultured in INT-407 and HCT-8 intestinal cells for 180 days. The T. solium began to die while the T. saginata grew for 180 days and developed to cysticerci in INT-407 cells. Rats were inoculated intracranially with AO and PO forms of either T. saginata or T. solium. Rats infected with T. solium AO and PO forms developed neurocysticercosis (NCC), while those infected with the T. saginata did not. Human PMBCs were stimulated with antigens of AO and PO forms of both species, and the production of cytokines and metalloproteinases (MMPs) was measured. The T. solium AO antigen stimulated a higher production of IL-4, IL-5, IL-13, IFN-?, and IL-2 cytokines compared to T. saginata AO. In the PO form, the T. saginata PO antigen increased the production of IL-4, IL-5, IL-13, IFN-?, IL-1?, IL-6, IL-10, TNF-? and IL-12 cytokines compared to T. solium, suggesting that this global immune response stimulated by different forms could permit survival or destruction of the parasite depending of their life-cycle stage. Regarding MMPs, T. solium AO antigen stimulated a higher production of MMP-9 compared to T. saginata AO antigen, which may be responsible for altering the permeability of intestinal cells and facilitating breakdown of the blood-brain barrier during the process of invasion of host tissue.
| S-EPMC6435196 | BioStudies
Project description:BACKGROUND: The Taenia solium cysticercosis-taeniasis complex is a Neglected Tropical Disease of significant public health importance in many impoverished communities worldwide. The parasite is suspected to be endemic in Lao PDR as a result of widespread risk factors including open human defecation, free ranging pigs and weak systems for meat inspection and carcass condemnation. Reported prevalences of human taeniasis throughout the country have ranged from 0-14%, although few of these have definitively diagnosed T. solium, grossly indistinguishable from Taenia saginata (beef tapeworm) and Taenia asiatica. This short communication details the suspicion of a hyper endemic "hotspot" of T. solium in a remote Tai Dam village in northern Lao PDR. FINDINGS: Initial antibody serosurveillance of four provinces in Lao PDR in 2011 indicated human taeniasis and cysticercosis prevalences of 46.7% and 66.7% respectively, in the village of Om Phalong in the north of the country. Subsequent copro-antigen ELISA on 92 human faecal samples from this same village, representing a total 27.9% of the target community, indicated a taeniasis prevalence of 26.1% (95% CI?=?18.2-35.9). Subsequent PCR and sequencing of samples (n?=?5) all identified as T. solium; the other human tapeworms T. saginata and T. asiatica were not detected in any of the samples genotyped. CONCLUSION: This is potentially one of the highest documented prevalences of T. solium taeniasis to date in Lao PDR, if not the Southeast Asia region. This result raises suspicion that other "hotspots" of T. solium hyper endemicity may exist in the region, particularly in communities where the consumption of raw pork is commonplace as a result of cultural practices.
| S-EPMC3986602 | BioStudies
Project description:BACKGROUND:Due to the relative short life span and the limited spatial movement, porcine cysticercosis is an excellent indicator of current local active transmission. The aim of this study was to map at province-level, the occurrence of T. solium and T. asiatica in pigs and areas at risk of transmission to pigs in East and Southeast Asia, based on the density of extensive pig production systems and confirmed reports of porcine cysticercosis. METHODS:This study covered East and Southeast Asia, which consist of the following countries: Brunei, Cambodia, China, East Timor, Indonesia, Japan, Laos, Malaysia, Mongolia, Myanmar, North Korea, Philippines, Singapore, South Korea, Thailand and Vietnam. Literature searches were carried out to identify current epidemiological data on the occurrence of porcine cysticercosis caused by T. solium and T. asiatica infections. Modelled densities of pigs in extensive production systems were mapped and compared to available data on porcine cysticercosis. RESULTS:Porcine cysticercosis was confirmed to be present during the period 2000 to 2018 in eight out of the 16 countries included in this study. Taenia solium porcine cysticercosis was confirmed from all eight countries, whereas only one country (Laos) could confirm the presence of T. asiatica porcine cysticercosis. Province-level occurrence was identified in five countries (Cambodia, Indonesia, Laos, Myanmar, and Vietnam) across 19 provinces. Smallholder pig keeping is believed to be widely distributed throughout the region, with greater densities predicted to occur in areas of China, Myanmar, Philippines and Vietnam. CONCLUSIONS:The discrepancies between countries reporting taeniosis and the occurrence of porcine cysticercosis, both for T. solium and T. asiatica, suggests that both parasites are underreported. More epidemiological surveys are needed to determine the societal burden of both parasites. This study highlights a straightforward approach to determine areas at risk of porcine cysticercosis in the absence of prevalence data.
2018-01-01 | S-EPMC6267083 | BioStudies
Project description:From October 2015 to August 2018, tapeworm proglottids were obtained from 10 patients who were residents of Daegu and Gyeongbuk provinces and had a history of raw beef consumption. Most of them had no overseas travel experience. The gravid proglottids obtained from the 10 cases had 15-20 lateral uterine branches. A part of internal transcribed spacer 1 (ITS1) DNA of the 10 cases, amplified by polymerase chain reaction (PCR) and digested with AleI restriction enzyme, produced the same band pattern of Taenia saginata, which differentiated from T. asiatica and T. solium. Sequences of ITS1 and cytochrome c oxidase subunit 1 (cox1) showed higher homology to T. saginata than to T. asiatica and T. solium. Collectively, these 10 cases were identified as T. saginata human infections. As taeniasis is one of the important parasitic diseases in humans, it is necessary to maintain hygienic conditions during livestock farming to avoid public health concerns.
| S-EPMC6753295 | BioStudies