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1.
Acta Trop ; 231: 106433, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35364046

RESUMO

Schistosomes are blood-dwelling parasites that are constantly exposed to high-level oxidative stress arising from parasite-intrinsic and host defense mechanisms. To survive in their hosts, schistosomes require an antioxidant system to minimize with oxidative stress. Several schistosome antioxidant enzymes have been identified and have been suggested to play indispensable antioxidant roles for the parasite. In addition to antioxidant enzymes, non-enzymatic antioxidants including small molecules, peptides, and proteins have been identified and characterized. Neuroglobin (Ngb), a nervous system-specific heme-binding protein, has been classified as a non-enzymatic antioxidant and is capable of scavenging a variety of free radical species. The antioxidant activity of Ngb has been well-studied in humans. Ngb is involved in cellular oxygen homeostasis and reactive oxygen/nitrogen scavenging in the central and peripheral nervous systems, but its functions in schistosome parasites have not yet been characterized. In this study, we aimed to characterize the molecular properties and functions of Schistosoma mekongi Ngb (SmeNgb) using bioinformatic, biochemical, and molecular biology approaches. The amino acid sequence of Ngb was highly conserved among schistosomes as well as closely related trematodes. SmeNgb was abundantly localized in the gastrodermis, vitelline, and ovary of adult female S. mekongi worms as well as in the tegument of adult male worms. Assessment of antioxidant activity demonstrated that recombinant SmeNgb had Fe2+ chelating and hydrogen peroxide scavenging activities. Intriguingly, siRNA silencing of SmeNgb gene expression resulted in tegument pathology. Understanding the properties and functions of SmNgb will help in future development of effective treatments and vaccines against S. mekongi, other schistosome parasites, and other platyhelminths.

2.
Parasit Vectors ; 14(1): 352, 2021 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-34217359

RESUMO

BACKGROUND: Phlebotomine sand flies are vectors of Leishmania spp. At least 27 species of sand flies have been recorded in Thailand. Although human leishmaniasis cases in Thailand are mainly imported, autochthonous leishmaniasis has been increasingly reported in several regions of the country since 1999. Few studies have detected Leishmania infection in wild-caught sand flies, although these studies were carried out only in those areas reporting human leishmaniasis cases. The aim of this study was therefore to identity sand fly species and to investigate Leishmania infection across six provinces of Thailand. METHODS: Species of wild-caught sand flies were initially identified based on morphological characters. However, problems identifying cryptic species complexes necessitated molecular identification using DNA barcoding in parallel with identification based on morphological characters. The wild-caught sand flies were pooled and the DNA isolated prior to the detection of Leishmania infection by a TaqMan real-time PCR assay. RESULTS: A total of 4498 sand flies (1158 males and 3340 females) were caught by trapping in six provinces in four regions of Thailand. The sand flies were morphologically classified into eight species belonging to three genera (Sergentomyia, Phlebotomus and Idiophlebotomus). Sergentomyia iyengari was found at all collection sites and was the dominant species at most of these, followed in frequency by Sergentomyia barraudi and Phlebotomus stantoni, respectively. DNA barcodes generated from 68 sand flies allowed sorting into 14 distinct species with 25 operational taxonomic units, indicating a higher diversity (by 75%) than that based on morphological identification. Twelve barcoding sequences could not be assigned to any species for which cytochrome c oxidase subunit I sequences are available. All tested sand flies were negative for Leishmania DNA. CONCLUSIONS: Our results confirm the presence of several sand fly species in different provinces of Thailand, highlighting the importance of using DNA barcoding as a tool to study sand fly species diversity. While all female sand flies tested in this study were negative for Leishmania, the circulation of Leishmania spp. in the investigated areas cannot be ruled out.


Assuntos
Insetos Vetores/parasitologia , Leishmania/genética , Leishmania/isolamento & purificação , Leishmaniose/transmissão , Psychodidae/parasitologia , Animais , DNA de Protozoário/análise , Feminino , Leishmaniose/prevenção & controle , Masculino , Tailândia
3.
Parasit Vectors ; 13(1): 416, 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32787935

RESUMO

BACKGROUND: Under-regulated national borders in Southeast Asia represent potential regions for enhanced parasitic helminth transmission and present barriers to helminthiasis disease control. METHODS: Three Thailand border regions close to Myanmar, Laos and Cambodia were surveyed for clinical parasitic helminth disease. In-field microscopy was performed on stools from 567 individuals. Sub-samples were transported to Bangkok for molecular analysis comprising three multiplex qPCR assays. RESULTS: The overall helminth infection prevalence was 17.99% as assessed by Kato-Katz and 24.51% by qPCR. The combined prevalence of the two methods was 28.57%; the most predominant species detected were Opisthorchis viverrini (18.34%), hookworm (6.88%; Ancylostoma spp. and Necator americanus), Ascaris lumbricoides (2.29%) and Trichuris trichiura (1.76%). CONCLUSIONS: These data demonstrate the value of molecular diagnostics for determining more precise prevalence levels of helminthiases in Southeast Asia. Availability of such accurate prevalence information will help guide future public health initiatives and highlights the need for more rigorous surveillance and timely intervention in these regions.


Assuntos
Helmintíase/epidemiologia , Helmintos/isolamento & purificação , Prevalência , Ancylostoma/isolamento & purificação , Ancylostomatoidea/isolamento & purificação , Animais , Ascaris lumbricoides/isolamento & purificação , Ásia Sudeste/epidemiologia , Fezes/parasitologia , Feminino , Humanos , Masculino , Necator americanus/isolamento & purificação , Opisthorchis/isolamento & purificação , Patologia Molecular , Reação em Cadeia da Polimerase em Tempo Real , Tailândia/epidemiologia , Trichuris/isolamento & purificação
4.
Korean J Parasitol ; 58(1): 57-60, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32145728

RESUMO

During the mobile clinic activities in Tak Province, Thailand, Paragonimus sp. eggs were found in a fecal sample of a 72-year-old Karen resident. Paragonimus DNA was amplified from the stool sample and identified to P. heterotremus. The patient did not have any symptoms. Apparent pulmonary lesion was not found on the chest X-ray. The patient admitted habitual consumption of semi-cooked or roasted waterfall crabs for several years. The waterfall crabs collected from stream near the village were found negative for Paragonimus metacercariae. In northern Thailand, paragonimiasis remains as one of the public health concerns and should be ruled out for asymptomatic pulmonary patients.


Assuntos
Infecções Assintomáticas , Paragonimíase/parasitologia , Idoso , Animais , Fezes/parasitologia , Humanos , Masculino , Paragonimus/isolamento & purificação , Tailândia
5.
Acta Trop ; 204: 105288, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31811864

RESUMO

Gnathostoma spinigerum is a causative agent of human gnathostomiasis and infects people residing in endemic areas as well as travelers. Cutaneous and visceral larval migrants cause clinical manifestations, resulting in severe morbidity and mortality. To survive in hosts, these parasites have evolved various immune evasion mechanisms, including the release of regulatory molecules. Serine protease inhibitors (serpins) that are present in many parasitic helminths are proteins suspected of suppressing host serine protease-related digestion and immune responses. In this study, the serpin secreted by G. spinigerum (GsSerp) was characterized using bioinformatics and molecular biology techniques. The bioinformatics revealed that GsSerp contains 9 helices, 3 ß-sheets, and a reactive central loop, which are conserved structures of the serpin superfamily. Recombinant GsSerp (rGsSerp) was expressed in E. coli (molecular weight, 39 kDa) and could inhibit chymotrypsin. Mouse polyclonal antibody against GsSerp could detect the native GsSerp in crude worm antigen but not the excretory-secretory product (ES) of infective-stage larva (aL3Gs). Moreover, the expression of GsSerp in the aL3Gs tissue was located in the hemolymph and intestinal tissue, indicating its role in parasite homeostasis. Our findings may help develop effective strategies for preventing and controlling gnathostomiasis.


Assuntos
Clonagem Molecular , Gnathostoma/metabolismo , Proteínas de Helminto/metabolismo , Inibidores de Serino Proteinase/metabolismo , Animais , Anticorpos , Biologia Computacional , Escherichia coli , Regulação da Expressão Gênica , Proteínas de Helminto/genética , Proteínas de Helminto/farmacologia , Humanos , Larva/imunologia , Camundongos , Inibidores de Serino Proteinase/genética
6.
Acta Trop ; 202: 105247, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31672487

RESUMO

Schistosoma mekongi is a causative agent of human schistosomiasis. There is limited knowledge of the molecular biology of S. mekongi and very few studies have examined drug targets, vaccine candidates and diagnostic biomarkers for S. mekongi. To explore the biology of S. mekongi, computational as well as experimental approaches were performed on S. mekongi males and females to identify excretory-secretory (ES) proteins and proteins that are differentially expressed between genders. According to bioinformatic prediction, the S. mekongi ES product was approximately 4.7% of total annotated transcriptome sequences. The classical secretory pathway was the main process to secrete proteins. Mass spectrometry-based quantification of male and female adult S. mekongi proteins was performed. We identified 174 and 156 differential expression of proteins in male and female worms, respectively. The dominant male-biased proteins were involved in actin filament-based processes, microtubule-based processes, biosynthetic processes and homeostatic processes. The major female-biased proteins were related to biosynthetic processes, organelle organization and signal transduction. An experimental approach identified 88 proteins in the S. mekongi secretome. The S. mekongi ES proteins mainly contributed to nutrient uptake, essential substance supply and host immune evasion. This research identifies proteins in the S. mekongi secretome and provides information on ES proteins that are differentially expressed between S. mekongi genders. These findings will contribute to S. mekongi drug and vaccine development. In addition, the study enhances our understanding of basic S. mekongi biology.


Assuntos
Proteínas de Helminto/metabolismo , Schistosoma/metabolismo , Esquistossomose/parasitologia , Via Secretória/genética , Animais , Antígenos de Helmintos/metabolismo , Biologia Computacional , Desenvolvimento de Medicamentos , Eletroforese em Gel Bidimensional , Feminino , Identidade de Gênero , Ontologia Genética , Genoma Helmíntico , Proteínas de Helminto/genética , Proteínas de Helminto/imunologia , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/imunologia , Masculino , Espectrometria de Massas , Camundongos , Proteômica , Schistosoma/genética , Esquistossomose/metabolismo , Transcriptoma
7.
Acta Trop ; 202: 105244, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31669533

RESUMO

Mekong schistosomiasis caused by Schistosoma mekongi is a public health problem that occurs along the border between southern Laos and northern Cambodia. Given its restricted distribution and low prevalence, eventual eradication via an effective control program can be expected to be successful. To achieve this goal detailed knowledge of its basic biology, molecular biology, biochemistry, and pathology is urgently required. In this regard, recent studies on transcriptome analysis of adult male and female S. mekongi worms, and proteome analysis of developmental stages have been reported and are discussed here. The biology, habitat, and distribution of the snail intermediate host Neotricula aperta, which are factors in disease transmission, are discussed in this review. These have initiated renewed interest in S. mekongi research and contributed promising data that will be utilized in the generation of effective control and prevention strategies.


Assuntos
Reservatórios de Doenças/parasitologia , Schistosoma/parasitologia , Esquistossomose , Caramujos/parasitologia , Animais , Camboja/epidemiologia , Ecossistema , Perfilação da Expressão Gênica , Humanos , Laos/epidemiologia , Estágios do Ciclo de Vida , Prevalência , Proteômica , Esquistossomose/diagnóstico , Esquistossomose/prevenção & controle , Esquistossomose/transmissão
8.
Parasit Vectors ; 12(1): 383, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31362766

RESUMO

BACKGROUND: Schistosoma mekongi, which causes schistosomiasis in humans, is an important public health issue in Southeast Asia. Treatment with praziquantel is the primary method of control but emergence of praziquantel resistance requires the development of alternative drugs and vaccines. Calcium-dependent cysteine protease (calpain) is a novel vaccine candidate that has been studied in S. mansoni, S. japonicum, and protozoans including malaria, leishmania and trypanosomes. However, limited information is available on the properties and functions of calpain in other Schistosoma spp., including S. mekongi. In this study, we functionally characterized calpain 1 of S. mekongi (SmeCalp1). RESULTS: Calpain 1 of S. mekongi was obtained from transcriptomic analysis of S. mekongi; it had the highest expression level of all isoforms tested and was predominantly expressed in the adult male. SmeCalp1 cDNA is 2274 bp long and encodes 758 amino acids, with 85% to 90% homology with calpains in other Schistosoma species. Recombinant SmeCalp1 (rSmeCalp1), with a molecular weight of approximately 86.7 kDa, was expressed in bacteria and stimulated a marked antibody response in mice. Native SmeCalp1 was detected in crude worm extract and excretory-secretory product, and it was mainly localized in the tegument of the adult male; less signal was detected in the adult female worm. Thus, SmeCalp1 may play a role in surface membrane synthesis or host-parasite interaction. We assessed the protease activity of rSmeCalp1 and demonstrated that rSmeCalp1 could cleave the calpain substrate N-succinyl-Leu-Leu-Val-Tyr-7-amino-4-methylcoumarin, that was inhibited by calpain inhibitors (MDL28170 and E64c). Additionally, rSmeCalp1 could degrade the biological substrates fibronectin (blood clotting protein) and human complement C3, indicating important roles in the intravascular system and in host immune evasion. CONCLUSIONS: SmeCalp1 is expressed on the tegumental surface of the parasite and can cleave host defense molecules; thus, it might participate in growth, development and survival during the entire life-cycle of S. mekongi. Information on the properties and functions of SmeCalp1 reported herein will be advantageous in the development of effective drugs and vaccines against S. mekongi and other schistosomes.


Assuntos
Antígenos de Helmintos/imunologia , Calpaína/genética , Calpaína/metabolismo , Schistosoma/enzimologia , Animais , Antígenos de Helmintos/genética , Cumarínicos/metabolismo , Cisteína Proteases/genética , Cisteína Proteases/metabolismo , Feminino , Imunização , Masculino , Camundongos , Camundongos Endogâmicos ICR , Oligopeptídeos/metabolismo , Schistosoma/genética , Esquistossomose/imunologia , Esquistossomose/parasitologia , Análise de Sequência de DNA
9.
Parasite ; 26: 34, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31166909

RESUMO

BACKGROUND: Gnathostoma spinigerum is a harmful parasitic nematode that causes severe morbidity and mortality in humans and animals. Effective drugs and vaccines and reliable diagnostic methods are needed to prevent and control the associated diseases; however, the lack of genome, transcriptome, and proteome databases remains a major limitation. In this study, transcriptomic and secretomic analyses of advanced third-stage larvae of G. spinigerum (aL3Gs) were performed using next-generation sequencing, bioinformatics, and proteomics. RESULTS: An analysis that incorporated transcriptome and bioinformatics data to predict excretory-secretory proteins (ESPs) classified 171 and 292 proteins into classical and non-classical secretory groups, respectively. Proteins with proteolytic (metalloprotease), cell signaling regulatory (i.e., kinases and phosphatase), and metabolic regulatory function (i.e., glucose and lipid metabolism) were significantly upregulated in the transcriptome and secretome. A two-dimensional (2D) immunomic analysis of aL3Gs-ESPs with G. spinigerum-infected human sera and related helminthiases suggested that the serine protease inhibitor (serpin) was a promising antigenic target for the further development of gnathostomiasis immunodiagnostic methods. CONCLUSIONS: The transcriptome and excretory-secretory proteome of aL3Gs can facilitate an understanding of the basic molecular biology of the parasite and identifying multiple associated factors, possibly promoting the discovery of novel drugs and vaccines. The 2D-immunomic analysis identified serpin, a protein secreted from aL3Gs, as an interesting candidate for immunodiagnosis that warrants immediate evaluation and validation.


Assuntos
Gnathostoma/genética , Proteínas de Helminto/genética , Testes Imunológicos , Larva/genética , Proteoma , Transcriptoma , Animais , Antígenos de Helmintos/genética , Biologia Computacional/métodos , Gnatostomíase/tratamento farmacológico , Proteínas de Helminto/isolamento & purificação , Humanos
10.
Parasit Vectors ; 11(1): 504, 2018 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-30201055

RESUMO

BACKGROUND: Schistosoma mekongi is one of five major causative agents of human schistosomiasis and is endemic to communities along the Mekong River in southern Lao People's Democratic Republic (Laos) and northern Cambodia. Sporadic cases of schistosomiasis have been reported in travelers and immigrants who have visited endemic areas. Schistosoma mekongi biology and molecular biology is poorly understood, and few S. mekongi gene and transcript sequences are available in public databases. RESULTS: Transcriptome sequencing (RNA-Seq) of male and female S. mekongi adult worms (a total of three biological replicates for each sex) were analyzed and the results demonstrated that approximately 304.9 and 363.3 million high-quality clean reads with quality Q30 (> 90%) were obtained from male and female adult worms, respectively. A total of 119,604 contigs were assembled with an average length of 1273 nt and an N50 of 2017 nt. From the contigs, 20,798 annotated protein sequences and 48,256 annotated transcript sequences were obtained using BLASTP and BLASTX searches against the UniProt Trematoda database. A total of 4658 and 3509 transcripts were predominantly expressed in male and female worms, respectively. Male-biased transcripts were mostly involved in structural organization while female-biased transcripts were typically involved in cell differentiation and egg production. Interestingly, pathway enrichment analysis suggested that genes involved in the phosphatidylinositol signaling pathway may play important roles in the cellular processes and reproductive systems of S. mekongi worms. CONCLUSIONS: We present comparative transcriptomic analyses of male and female S. mekongi adult worms, which provide a global view of the S. mekongi transcriptome as well as insights into differentially-expressed genes associated with each sex. This work provides valuable information and sequence resources for future studies of gene function and for ongoing whole genome sequencing efforts in S. mekongi.


Assuntos
Doenças Endêmicas , Schistosoma/genética , Esquistossomose/parasitologia , Transcriptoma , Animais , Camboja/epidemiologia , Feminino , Perfilação da Expressão Gênica , Biblioteca Gênica , Humanos , Laos/epidemiologia , Masculino , Esquistossomose/epidemiologia , Análise de Sequência de RNA
11.
Parasitol Res ; 115(12): 4457-4470, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27562899

RESUMO

Cathepsin L is a cysteine protease belonging to the papain family. In parasitic trematodes, cathepsin L plays essential roles in parasite survival and host-parasite interactions. In this study, cathepsin L of the lung fluke Paragonimus pseudoheterotremus (PpsCatL) was identified and its molecular biological and immunological features characterized. A sequence analysis of PpsCatL showed that the gene encodes a 325-amino-acid protein that is most similar to P. westermani cathepsin L. The in silico three-dimensional structure suggests that PpsCatL is a pro-enzyme that becomes active when the propeptide is cleaved. A recombinant pro-PpsCatL lacking the signal peptide (rPpsCatL), with a molecular weight of 35 kDa, was expressed in E. coli and reacted with P. pseudoheterotremus-infected rat sera. The native protein was detected in crude worm antigens and excretory-secretory products and was localized in the cecum and in the lamellae along the intestinal tract of the adult parasite. Enzymatic activity of rPpsCatL showed that the protein could cleave the fluorogenic substrate Z-Phe-Arg-AMC after autocatalysis but was inhibited with E64. The immunodiagnostic potential of the recombinant protein was evaluated with an enzyme-linked immunosorbent assay (ELISA) and suggested that rPpsCatL can detect paragonimiasis with high sensitivity and specificity (100 and 95.6 %, respectively). This supports the further development of an rPpsCatL-ELISA as an immunodiagnostic tool.


Assuntos
Antígenos de Helmintos/imunologia , Catepsina L/genética , Catepsina L/imunologia , Proteínas de Helminto/genética , Proteínas de Helminto/imunologia , Paragonimíase/parasitologia , Paragonimus/enzimologia , Sequência de Aminoácidos , Animais , Antígenos de Helmintos/química , Antígenos de Helmintos/genética , Sequência de Bases , Catepsina L/química , Ensaio de Imunoadsorção Enzimática/métodos , Escherichia coli/genética , Escherichia coli/metabolismo , Feminino , Proteínas de Helminto/química , Humanos , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Paragonimíase/diagnóstico , Paragonimus/classificação , Paragonimus/genética , Paragonimus/isolamento & purificação , Ratos , Ratos Wistar , Alinhamento de Sequência
12.
Artigo em Inglês | MEDLINE | ID: mdl-24968666

RESUMO

Ascaris lumbricoides, Trichuris trichiura, and Necator americanus are medically important soil-transmitted helminths (STHs) occurring frequently worldwide including Thailand. Fecal examination using a microscope has been recommended as the gold standard for diagnosis of STH infections, but suffers from low sensitivity. Recently, highly sensitive and specific assays, such as multiplex quantitative PCR, has been established, but the high cost and need for special instruments are still barriers limiting their applications in routine diagnosis. Therefore, a conventional multiplex PCR assay, with its lower cost and greater simplicity, was developed, for the simultaneous detection of STHs in fecal samples. The multiplex PCR assay was species-specific to the three STHs, and could detect one copy of DNA target. Compared with microscopic examination of fecal samples, sensitivity and specificity of the multiplex PCR was 87% and 83%, respectively. This multiplex PCR assay provides an alternative method for routine diagnosis of STHs infection, and might be applied for epidemiological studies of STHs in endemic areas.


Assuntos
Ascaríase/diagnóstico , Reação em Cadeia da Polimerase Multiplex , Necatoríase/diagnóstico , Solo/parasitologia , Tricuríase/diagnóstico , Animais , Ascaríase/parasitologia , Ascaris lumbricoides/isolamento & purificação , Fezes/parasitologia , Humanos , Necator americanus/isolamento & purificação , Necatoríase/patologia , Sensibilidade e Especificidade , Tailândia , Tricuríase/parasitologia , Trichuris/isolamento & purificação
13.
J Parasitol Res ; 2013: 310605, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23864933

RESUMO

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.

14.
Korean J Parasitol ; 51(1): 55-9, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23467439

RESUMO

Twelve 924 bp cytochrome c oxidase subunit 1 (cox1) mitochondrial DNA sequences from Taenia asiatica isolates from Thailand were aligned and compared with multiple sequence isolates from Thailand and 6 other countries from the GenBank database. The genetic divergence of T. asiatica was also compared with Taenia saginata database sequences from 6 different countries in Asia, including Thailand, and 3 countries from other continents. The results showed that there were minor genetic variations within T. asiatica species, while high intraspecies variation was found in T. saginata. There were only 2 haplotypes and 1 polymorphic site found in T. asiatica, but 8 haplotypes and 9 polymorphic sites in T. saginata. Haplotype diversity was very low, 0.067, in T. asiatica and high, 0.700, in T. saginata. The very low genetic diversity suggested that T. asiatica may be at a risk due to the loss of potential adaptive alleles, resulting in reduced viability and decreased responses to environmental changes, which may endanger the species.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/genética , Variação Genética , Filogeografia , Taenia/classificação , Taenia/genética , Teníase/epidemiologia , Teníase/parasitologia , Animais , Ásia/epidemiologia , Análise por Conglomerados , Genótipo , Humanos , Dados de Sequência Molecular , Subunidades Proteicas/genética , Análise de Sequência de DNA , Taenia/isolamento & purificação
15.
Acta Trop ; 126(1): 37-42, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23318934

RESUMO

There have been few studies on human trichostrongyliasis in Southeast Asia, information on its clinical manifestations is also sparse. Trichostrongyliasis occurs predominantly in areas where poor hygiene is common especially where human/animal feces are used as a fertilizer, thereby contaminating vegetables and stream water. The intimate coexistence of domestic animals and humans explains the prevalence of Trichostrongylus infection in such areas. The goal of the current study was to determine the prevalence of trichostrongyliasis among villagers in Thakamrien village, Sonkon district, Savannakhet province, Laos, and to investigate potential relationships between clinical features, laboratory data, and severity of infection. Of 272 villagers examined, 160 (58.8%) were determined positive for helminthic infections by fecal examination, and 59 (36.9%) of these were infected with Trichostrongylus. Only 58 cases were in the inclusion criteria of the study and then underwent further assessment, including a questionnaire on personal behaviors, physical examination, and laboratory tests. Villagers in the trichostrongyliasis group were more likely than the control group to have consumed fresh vegetables, not washed their hands before meals or after using the toilet, and to have had close contact with herbivorous animals (goats and cows). Similarly, villagers in the trichostrongyliasis group were more likely than the control group to have a history of loose feces, rash, or abdominal pain; however, no obvious clinical symptoms were observed during physical examination of the trichostrongyliasis patients. The degree of infection was determined by both fecal egg counts and quantification of adult worms after deworming. Laboratory data were evaluated for any relationship with severity of infection. No significant differences were found in laboratory values between the trichostrongyliasis and control groups, with most values being within normal limits; however, both groups had high eosinophil counts. This study demonstrated that the useful clinical characteristics of trichostrongyliasis patients include history of loose feces, rashes, and abdominal pain, as well as in personal behaviors, such as the regular consumption of fresh vegetables, lack of hand washing, and close contact with cattle.


Assuntos
Tricostrongilose/epidemiologia , Tricostrongilose/patologia , Trichostrongylus/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Fezes/parasitologia , Feminino , Humanos , Laos/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , População Rural , Inquéritos e Questionários , Adulto Jovem
16.
Parasitol Int ; 60(4): 503-6, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21946336

RESUMO

Six species of heterophyid intestinal flukes (HIFs) constitute the major endemic zoonotic fish-borne pathogens in Asia: Haplorchis taichui, H. pumilio, H. yokogawai, Procerovum varium, Stellantchasmus falcatus, and Centrocestus formosanus. Several different species of these parasites are often found co-infecting the same second intermediate fish host. Because of their morphological similarities, differentiating between species of HIF metacercariae is difficult, time-consuming, and frequently results in misidentification. In this study, we aimed to develop an efficient and accurate method of identifying metacercariae of these 6 HIFs. Metacercariae were roughly grouped together, based on morphological characteristics seen under a stereomicroscope. Then, PCR-restriction fragment length polymorphism (PCR-RFLP) was used to identify the exact species of each metacercaria, using the 28S ribosomal RNA gene as the genetic marker and MboII as the restriction enzyme. Using a combination of morphological and molecular methods eliminates the need for DNA sequencing and infecting animal subjects to obtain adult worms, increases accuracy, and decreases the need for laborious morphological identification. Because the method is simple, rapid, and relatively cheap compared with PCR-sequencing, it may be an effective tool for epidemiological studies of HIFs in endemic areas.


Assuntos
Doenças dos Peixes/diagnóstico , Heterophyidae/genética , Intestinos/parasitologia , Metacercárias/genética , Polimorfismo de Fragmento de Restrição , Infecções por Trematódeos/diagnóstico , Infecções por Trematódeos/veterinária , Animais , Ásia/epidemiologia , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Peixes , Água Doce/parasitologia , Heterophyidae/classificação , Heterophyidae/isolamento & purificação , Heterophyidae/patogenicidade , Humanos , Metacercárias/classificação , Metacercárias/isolamento & purificação , Metacercárias/patogenicidade , Microscopia , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 28S/análise , RNA Ribossômico 28S/genética , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia
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