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1.
PLoS Negl Trop Dis ; 16(6): e0010491, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35675339

RESUMO

BACKGROUND: Previous reports show altered gut bacterial profiles are associated with helminth infected individuals. Our recently published molecular survey of clinical helminthiases in Thailand border regions demonstrated a more comprehensive picture of infection prevalence when Kato Katz microscopy and copro-qPCR diagnostics were combined. We revealed that Opisthorchis viverrini, hookworm, Ascaris lumbricoides and Trichuris trichiura were the most predominant helminth infections in these regions. In the current study, we have profiled the faecal and saliva microbiota of a subset of these helminth infected participants, in order to determine if microbial changes are associated with parasite infection. METHODS: A subset of 66 faecal samples from Adisakwattana et al., (2020) were characterised for bacterial diversity using 16S rRNA gene profiling. Of these samples a subset of 24 participant matched saliva samples were also profiled for microbiota diversity. Sequence data were compiled, OTUs assigned, and diversity and abundance analysed using the statistical software Calypso. RESULTS: The data reported here indicate that helminth infections impact on both the host gut and oral microbiota. The profiles of faecal and saliva samples, irrespective of the infection status, were considerably different from each other, with more alpha diversity associated with saliva (p-value≤ 0.0015). Helminth infection influenced the faecal microbiota with respect to specific taxa, but not overall microbial alpha diversity. Conversely, helminth infection was associated with increased saliva microbiota alpha diversity (Chao 1 diversity indices) at both the genus (p-value = 0.042) and phylum (p-value = 0.026) taxa levels, compared to uninfected individuals. Elevated individual taxa in infected individuals saliva were noted at the genus and family levels. Since Opisthorchis viverrini infections as a prominent health concern to Thailand, this pathogen was examined separately to other helminths infections present. Individuals with an O. viverrini mono-infection displayed both increases and decreases in genera present in their faecal microbiota, while increases in three families and one order were also observed in these samples. DISCUSSION: In this study, helminth infections appear to alter the abundance of specific faecal bacterial taxa, but do not impact on overall bacterial alpha or beta diversity. In addition, the faecal microbiota of O. viverrini only infected individuals differed from that of other helminth single and dual infections. Saliva microbiota analyses of individuals harbouring active helminth infections presented increased levels of both bacterial alpha diversity and abundance of individual taxa. Our data demonstrate that microbial change is associated with helminthiases in endemic regions of Thailand, and that this is reflected in both faecal and saliva microbiota. To our knowledge, this is the first report of an altered saliva microbiota in helminth infected individuals. This work may provide new avenues for improved diagnostics; and an enhanced understanding of both helminth infection pathology and the interplay between helminths, bacteria and their host.

2.
PLoS Negl Trop Dis ; 15(7): e0009597, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34310596

RESUMO

Soil-transmitted helminths, such as roundworms (Ascaris lumbricoides), whipworms (Trichuris trichiura) and hookworms (Necator americanus and Ancylostoma spp.), are gastrointestinal parasites that occur predominantly in low- to middle-income countries worldwide and disproportionally impact children. Depending on the STH species, health status of the host and infection intensity, direct impacts of these parasites include malnutrition, anaemia, diarrhoea and physical and cognitive stunting. The indirect consequences of these infections are less well understood. Specifically, gastrointestinal infections may exert acute or chronic impacts on the natural gut microfauna, leading to increased risk of post-infectious gastrointestinal disorders, and reduced gut and overall health through immunomodulating mechanisms. To date a small number of preliminary studies have assessed the impact of helminths on the gut microbiome, but these studies are conflicting. Here, we assessed STH burden in 273 pre-school and school-aged children in Tha Song Yang district, Tak province, Thailand receiving annual oral mebendazole treatment. Ascaris lumbricoides (107/273) and Trichuris trichiura (100/273) were the most prevalent species and often occurred as co-infections (66/273). Ancylostoma ceylanicum was detected in a small number of children as well (n = 3). All of these infections were of low intensity (<4,999 or 999 eggs per gram for Ascaris and Trichuris respectively). Using this information, we characterised the baseline gut microbiome profile and investigated acute STH-induced alterations, comparing infected with uninfected children at the time of sampling. We found no difference between these groups in bacterial alpha-diversity, but did observe differences in beta-diversity and specific differentially abundant OTUs, including increased Akkermansia muciniphila and Bacteroides coprophilus, and reduced Bifidobacterium adolescentis, each of which have been previously implicated in STH-associated changes in the gut microfauna.


Assuntos
Anti-Helmínticos/uso terapêutico , Microbioma Gastrointestinal/efeitos dos fármacos , Helmintíase/tratamento farmacológico , Mebendazol/uso terapêutico , Solo/parasitologia , Anti-Helmínticos/administração & dosagem , Criança , Pré-Escolar , Fezes/parasitologia , Feminino , Helmintíase/epidemiologia , Humanos , Masculino , Administração Massiva de Medicamentos , Mebendazol/administração & dosagem , Tailândia/epidemiologia
3.
Int J Parasitol ; 51(9): 741-748, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33774039

RESUMO

Molecular studies of gastrointestinal infections or microbiotas require either rapid sample processing or effective interim preservation. This is difficult in remote settings in low-income countries, where the majority of the global infectious disease burden exists. Processing or freezing of samples immediately upon collection is often not feasible and the cost of commercial preservatives is prohibitive. We compared fresh freezing (the 'gold standard' method), with low-cost chemical preservation in (i) a salt-based buffer consisting of DMSO, EDTA and NaCl (DESS) or (ii) 2.5% potassium dichromate (PD), for soil-transmitted helminth detection and microbiota characterisation in pre-school and school-aged children from north-western Thailand. Fresh frozen samples were frozen at -20°C on collection and maintained at -80°C within ~3 days of collection until molecular analysis, with international shipping on dry ice. In contrast, chemically preserved samples were collected and stored at ~4°C, transported on wet ice and only stored at -20°C on arrival in Australia ~8 weeks after collection, with international shipping on wet ice. DESS and PD provided better sensitivity for STH diagnosis, estimating higher infection rates (>80% for Ascaris lumbricoides and >60% for Trichuris trichiura; versus 56% and 15% for these parasites in fresh frozen samples) and egg abundance (inferred as gene copy number estimates). All methods performed similarly for microbiota preservation, showing no significant differences in alpha-diversity based on overall richness or inverted Simpson's Index. All three methods performed similarly for RNA and protein preservation in a small subset of samples. Overall, DESS provided the best performance, with the added benefit of being non-toxic, compared with PD, hence making it particularly applicable for studies in remote and resource-poor settings.


Assuntos
Helmintos , Microbiota , Animais , Criança , Fezes , Humanos , Solo , Trichuris
4.
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
5.
Parasitology ; 147(9): 972-984, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32364103

RESUMO

Gastrointestinal helminth infection likely affects the gut microbiome, in turn affecting host health. To investigate the effect of intestinal parasite status on the gut microbiome, parasitic infection surveys were conducted in communities in Nan Province, Thailand. In total, 1047 participants submitted stool samples for intestinal parasite examination, and 391 parasite-positive cases were identified, equating to an infection prevalence of 37.3%. Intestinal protozoan species were less prevalent (4.6%) than helminth species. The most prevalent parasite was the minute intestinal fluke Haplorchis taichui (35.9%). Amplicon sequencing of 16S rRNA was conducted to investigate the gut microbiome profiles of H. taichui-infected participants compared with those of parasite-free participants. Prevotella copri was the dominant bacterial operational taxonomic unit (OTU) in the study population. The relative abundance of three bacterial taxa, Ruminococcus, Roseburia faecis and Veillonella parvula, was significantly increased in the H. taichui-infected group. Parasite-negative group had higher bacterial diversity (α diversity) than the H. taichui-positive group. In addition, a significant difference in bacterial community composition (ß diversity) was found between the two groups. The results suggest that H. taichui infection impacts the gut microbiome profile by reducing bacterial diversity and altering bacterial community structure in the gastrointestinal tract.


Assuntos
Bactérias/isolamento & purificação , Microbioma Gastrointestinal , Enteropatias Parasitárias/complicações , População Rural , Trematódeos/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Tailândia , Adulto Jovem
6.
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
7.
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
8.
Artigo em Inglês | MEDLINE | ID: mdl-29644815

RESUMO

Taenia solium, T. saginata, and T. asiatica are cestode pathogens causing taeniasis in humans. Houseflies can transfer Taenia eggs to food. However, houseflies are thought to carry only small numbers of Taenia eggs, sometimes fewer than 10. Although several PCR-based methods have been developed to detect Taenia DNA, these require more than 10 eggs for adequate detection. We developed a multiplex PCR method with high specificity for the discrimination among the eggs of the three Taenia species, T. solium, T. saginata, and T. asiatica, using 18S ribosomal DNA (rDNA) as a genetic marker. This technique was found to be highly sensitive, capable of identifying the Taenia species from only one egg. This multiplex PCR technique using 18S rDNA specific primers should be suitable to diagnose Taenia eggs.


Assuntos
Moscas Domésticas/parasitologia , Reação em Cadeia da Polimerase Multiplex/métodos , Óvulo/classificação , Taenia/isolamento & purificação , Animais , DNA de Helmintos/genética , Marcadores Genéticos , Humanos , RNA de Helmintos/genética , RNA Ribossômico 18S/genética , Sensibilidade e Especificidade
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