Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 864
Filtrar
1.
Parasitol Res ; 119(9): 3053-3059, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32638102

RESUMO

Intestinal parasitic infections (IPIs) can be a severe threat to immunocompromised patients. This is particularly true for those undergoing chemotherapy and hemodialysis. The present research is aimed at identifying intestinal parasites that might be present in immunocompromised patients. In this cross-sectional study 1040 stool samples were collected from March to September 2017. Six hundred and forty-one stool samples from immunocompromised patients (279 samples from hemodialysis patients and 362 samples from chemotherapy patients) and 399 samples from the control group were collected in Guilan province, Iran. The samples were tested by direct, formalin-ether methods for protozoa and ova of intestinal parasites and Ziehl-Neelsen staining methods for coccidian parasites such as Cryptosporidium species. The overall parasitic infection rate was highest (15%) in hemodialysis patients and 11.3% in chemotherapy patients, whereas the lowest rate was observed (7.3%) in the control group. The infectivity rates were statistically significant (P = 0.008) when compared with the control group. The parasites found were Blastocystis hominis (8.9% of the cases), Entamoeba coli (1.6%), Iodamoeba butschlii (0.8%), Endolimax nana (0.6%), Chilomastix mesnili (0.5%), Strongyloides stercoralis (0.5%), and Taenia species (0.15%), whereas Giardia lamblia was detected only in the control group. There was not a correlation between prevalence of parasites with age or education levels of the infected individuals. Results of the present study suggest that periodic stool examinations in special parasitological laboratories should be included as part of routine and general medical care.


Assuntos
Infecção Hospitalar/parasitologia , Helmintíase/parasitologia , Helmintos/isolamento & purificação , Intestinos/parasitologia , Neoplasias/parasitologia , Parasitos/isolamento & purificação , Diálise Renal/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Estudos Transversais , Fezes/parasitologia , Feminino , Helmintíase/imunologia , Helmintos/classificação , Humanos , Hospedeiro Imunocomprometido , Enteropatias Parasitárias/parasitologia , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Neoplasias/imunologia , Parasitos/classificação , Parasitos/genética , Prevalência , Adulto Jovem
2.
Parasitol Res ; 119(8): 2623-2629, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32591865

RESUMO

Shotgun metagenomics with high-throughput sequencing (HTS) techniques is increasingly used for pathogen identification and characterization. While many studies apply targeted amplicon sequencing, here we used untargeted metagenomics to simultaneously identify protists and helminths in pre-diagnosed faecal and tissue samples. The approach starts from RNA and operates without an amplification step, therefore allowing the detection of all eukaryotes, including pathogens, since it circumvents the bias typically observed in amplicon-based HTS approaches. The generated metagenomics datasets were analysed using the RIEMS tool for initial taxonomic read assignment. Mapping analyses against ribosomal reference sequences were subsequently applied to extract 18S rRNA sequences abundantly present in the sequence datasets. The original diagnosis, which was based on microscopy and/or PCR, could be confirmed in nearly all cases using ribosomal RNA metagenomics. In addition to the pre-diagnosed taxa, we detected other intestinal eukaryotic parasites of uncertain pathogenicity (of the genera Dientamoeba, Entamoeba, Endolimax, Hymenolepis) that are often excluded from routine diagnostic protocols. The study clearly demonstrates the applicability of untargeted RNA metagenomics for the parallel detection of parasites.


Assuntos
Enteropatias Parasitárias/diagnóstico , Metagenômica , Técnicas de Diagnóstico Molecular/métodos , Parasitos/isolamento & purificação , Animais , Fezes/parasitologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Parasitos/classificação , Parasitos/genética , RNA Ribossômico 18S/genética , Análise de Sequência de DNA
3.
Acta Trop ; 207: 105516, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32371221

RESUMO

INTRODUCTION: A test comparison of in-house and commercial real-time PCR (qPCR) kits for the detection of human parasites and microsporidia in stool samples was conducted without a gold standard. Three different commercial kits were included in the comparison, with a range of 3-15 different PCR targets, while 14 targets were covered by in-house testing, so not all 16 target pathogens were covered by all assays. METHODS: Residual materials from nucleic acid extractions of stool samples with very high likelihood of being colonized or infected by at least one enteric parasite species or microsporidia were tested. In all, 500 DNA samples were analyzed, but due to limited sample volume, only 250 of the 500 samples were tested per assay. Each sample was assessed with the qPCR platforms being compared and cycle threshold (Ct) values were included in a descriptive comparison. RESULTS: Depending on the assay applied, qPCR detected per 250 tested samples Giardia duodenalis (184-205), Blastocystis spp. (174-183), Trichuris trichiura (118-120), Ascaris lumbricoides (79-96), Necator americanus (78-106), Hymenolepis nana (40-42), Cryptosporidium spp. (27-36), Dientamoeba fragilis (26-28), Schistosoma spp. (13-23), Enterobius vermicularis (8-14), Entamoeba histolytica (7-16), Strongyloides stercoralis (6-38), Cyclospora spp. (6-13), Taenia spp. (1-4), microsporidia (1-5), and Ancylostoma spp. (1-2). Inter-assay agreement kappa was almost perfect (0.81-1) for Dientamoeba fragilis, Hymenolepis nana, Cryptosporidium spp., and Ascaris lumbricoides, substantial (0.61-0.8) for Necator americanus, Blastocystis spp., Ancylostoma spp., Giardia duodenalis, Schistosoma spp., Trichuris trichiura, and Enterobius vermicularis, moderate (0.41-0.6) for Entamoeba histolytica, fair (0.21-0.4) for microsporidia, slight (0-0.2) for Cyclospora spp. and Strongyloides stercoralis, and poor (<0) for Taenia spp. CONCLUSIONS: Varying inter-assay agreement makes interpretation of microsporidia and parasite PCR in stool samples challenging. Intra-assay agreement had been controlled during the developing of the assays. Future studies, e.g., with optimized nucleic acid procedures and including microscopically characterized samples, are advisable.


Assuntos
Fezes/parasitologia , Microsporídios/isolamento & purificação , Parasitos/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Animais , Fezes/microbiologia , Humanos , Enteropatias Parasitárias/diagnóstico , Microsporídios/genética , Parasitos/genética
4.
Parasit Vectors ; 13(1): 200, 2020 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-32306993

RESUMO

BACKGROUND: Approximately 30% of children worldwide are infected with gastrointestinal parasites. Depending on the species, parasites can disrupt intestinal bacterial microbiota affecting essential vitamin biosynthesis. METHODS: Stool samples were collected from 37 asymptomatic children from a previous cross-sectional Argentinian study. A multi-parallel real-time quantitative PCR was implemented for Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Trichuris trichiura, Cryptosporidium spp., Entamoeba histolytica and Giardia duodenalis. In addition, whole-genome sequencing analysis was conducted for bacterial microbiota on all samples and analyzed using Livermore Metagenomic Analysis Toolkit and DIAMOND software. Separate analyses were carried out for uninfected, Giardia-only, Giardia + helminth co-infections, and helminth-only groups. RESULTS: For Giardia-only infected children compared to uninfected children, DNA sequencing data showed a decrease in microbiota biodiversity that correlated with increasing Giardia burden and was statistically significant using Shannon's alpha diversity (Giardia-only > 1 fg/µl 2.346; non-infected group 3.253, P = 0.0317). An increase in diversity was observed for helminth-only infections with a decrease in diversity for Giardia + helminth co-infections (P = 0.00178). In Giardia-only infections, microbiome taxonomy changed from Firmicutes towards increasing proportions of Prevotella, with the degree of change related to the intensity of infection compared to uninfected (P = 0.0317). The abundance of Prevotella bacteria was decreased in the helminths-only group but increased for Giardia + helminth co-infections (P = 0.0262). Metagenomic analysis determined cobalamin synthesis was decreased in the Giardia > 1 fg/µl group compared to both the Giardia < 1 fg/µl and the uninfected group (P = 0.0369). Giardia + helminth group also had a decrease in cobalamin CbiM genes from helminth-only infections (P = 0.000754). CONCLUSION: The study results may provide evidence for an effect of parasitic infections enabling the permissive growth of anaerobic bacteria such as Prevotella, suggesting an altered capacity of vitamin B12 (cobalamin) biosynthesis and potential impact on growth and development in children .


Assuntos
Coinfecção , Microbioma Gastrointestinal/genética , Intestinos , Parasitos/genética , Vitamina B 12/genética , Animais , Criança , Pré-Escolar , Coinfecção/microbiologia , Coinfecção/parasitologia , Estudos Transversais , DNA de Helmintos , DNA de Protozoário , Feminino , Genes Bacterianos , Giardia lamblia/classificação , Giardia lamblia/genética , Giardia lamblia/isolamento & purificação , Helmintos/classificação , Helmintos/genética , Helmintos/isolamento & purificação , Humanos , Intestinos/microbiologia , Intestinos/parasitologia , Masculino , Metagenômica , Parasitos/classificação , Parasitos/isolamento & purificação , Projetos Piloto , Reação em Cadeia da Polimerase em Tempo Real , Vitamina B 12/metabolismo , Sequenciamento Completo do Genoma
5.
Adv Parasitol ; 108: 175-229, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32291085

RESUMO

In the past two decades, significant progress has been made in the sequencing, assembly, annotation and analyses of genomes and transcriptomes of parasitic worms of socioeconomic importance. This progress has somewhat improved our knowledge and understanding of these pathogens at the molecular level. However, compared with the free-living nematode Caenorhabditis elegans, the areas of functional genomics, transcriptomics, proteomics and metabolomics of parasitic nematodes are still in their infancy, and there are major gaps in our knowledge and understanding of the molecular biology of parasitic nematodes. The information on signalling molecules, molecular pathways and microRNAs (miRNAs) that are known to be involved in developmental processes in C. elegans and the availability of some molecular resources (draft genomes, transcriptomes and some proteomes) for selected parasitic nematodes provide a basis to start exploring the developmental biology of parasitic nematodes. Indeed, some studies have identified molecules and pathways that might associate with developmental processes in related, parasitic nematodes, such as Haemonchus contortus (barber's pole worm). However, detailed information is often scant and 'omics resources are limited, preventing a proper integration of 'omic data sets and comprehensive analyses. Moreover, little is known about the functional roles of pheromones, hormones, signalling pathways and post-transcriptional/post-translational regulations in the development of key parasitic nematodes throughout their entire life cycles. Although C. elegans is an excellent model to assist molecular studies of parasitic nematodes, its use is limited when it comes to explorations of processes that are specific to parasitism within host animals. A deep understanding of parasitic nematodes, such as H. contortus, requires substantially enhanced resources and the use of integrative 'omics approaches for analyses. The improved genome and well-established in vitro larval culture system for H. contortus provide unprecedented opportunities for comprehensive studies of the transcriptomes (mRNA and miRNA), proteomes (somatic, excretory/secretory and phosphorylated proteins) and lipidomes (e.g., polar and neutral lipids) of this nematode. Such resources should enable in-depth explorations of its developmental biology at a level, not previously possible. The main aims of this review are (i) to provide a background on the development of nematodes, with a particular emphasis on the molecular aspects involved in the dauer formation and exit in C. elegans; (ii) to critically appraise the current state of knowledge of the developmental biology of parasitic nematodes and identify key knowledge gaps; (iii) to cover salient aspects of H. contortus, with a focus on the recent advances in genomics, transcriptomics, proteomics and lipidomics as well as in vitro culturing systems; (iv) to review recent advances in our knowledge and understanding of the molecular and developmental biology of H. contortus using an integrative multiomics approach, and discuss the implications of this approach for detailed explorations of signalling molecules, molecular processes and pathways likely associated with nematode development, adaptation and parasitism, and for the identification of novel intervention targets against these pathogens. Clearly, the multiomics approach established recently is readily applicable to exploring a wide range of interesting and socioeconomically significant parasitic worms (including also trematodes and cestodes) at the molecular level, and to elucidate host-parasite interactions and disease processes.


Assuntos
Biologia Computacional , Nematoides/crescimento & desenvolvimento , Nematoides/genética , Infecções por Nematoides/parasitologia , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Interações Hospedeiro-Parasita/fisiologia , Humanos , Parasitos/genética , Parasitos/crescimento & desenvolvimento
6.
BMC Infect Dis ; 20(1): 190, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32131754

RESUMO

BACKGROUND: In the Republic of Congo, hot temperature and seasons distortions observed may impact the development of malaria parasites. We investigate the variation of malaria cases, parasite density and the multiplicity of Plasmodium falciparum infection throughout the year in Brazzaville. METHODS: From May 2015 to May 2016, suspected patients with uncomplicated malaria were enrolled at the Hôpital de Mfilou, CSI « Maman Mboualé¼, and the Laboratoire National de Santé Publique. For each patient, thick blood was examined and parasite density was calculated. After DNA isolation, MSP1 and MSP2 genes were genotyped. RESULTS: A total of 416, 259 and 131 patients with suspected malaria were enrolled at the CSI «Maman Mboualé¼, Hôpital de Mfilou and the Laboratoire National de Santé Publique respectively. Proportion of malaria cases and geometric mean parasite density were higher at the CSI «Maman Mboualé¼ compared to over sites (P-value <0.001). However the multiplicity of infection was higher at the Hôpital de Mfilou (P-value <0.001). At the Laboratoire National de Santé Publique, malaria cases and multiplicity of infection were not influenced by different seasons. However, variation of the mean parasite density was statistically significant (P-value <0.01). Higher proportions of malaria cases were found at the end of main rainy season either the beginning of the main dry season at the Hôpital de Mfilou and the CSI «Maman Mboualé¼; while, lowest proportions were observed in September and January and in September and March respectively. Higher mean parasite densities were found at the end of rainy seasons with persistence at the beginning of dry seasons. The lowest mean parasite densities were found during dry seasons, with persistence at the beginning of rainy seasons. Fluctuation of the multiplicity of infection throughout the year was observed without significance between seasons. CONCLUSION: The current study suggests that malaria transmission is still variable between the north and south parts of Brazzaville. Seasonal fluctuations of malaria cases and mean parasite densities were observed with some extension to different seasons. Thus, both meteorological and entomological studies are needed to update the season's periods as well as malaria transmission intensity in Brazzaville.


Assuntos
Malária Falciparum/epidemiologia , Malária Falciparum/genética , Parasitos/genética , Plasmodium falciparum/genética , Animais , Antígenos de Protozoários/genética , Criança , Pré-Escolar , Congo/epidemiologia , Testes Diagnósticos de Rotina , Feminino , Genótipo , Humanos , Malária Falciparum/parasitologia , Malária Falciparum/transmissão , Masculino , Proteína 1 de Superfície de Merozoito/genética , Plasmodium falciparum/isolamento & purificação , Prevalência , Proteínas de Protozoários/genética , Chuva , Estações do Ano
7.
Parasit Vectors ; 13(1): 141, 2020 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-32188497

RESUMO

BACKGROUND: Enteric parasites are transmitted in households but few studies have sampled inside households for parasites and none have used sensitive molecular methods. METHODS: We collected bed and living room dust samples from households of children participating in a clinical trial of anthelmintic treatment in rural coastal Ecuador. Dust was examined for presence of DNA specific for 11 enteric parasites (Ascaris lumbricoides, Trichuris trichiura, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Toxocara canis and T. cati, Giardia lamblia, Blastocystis hominis, Cryptosporidium spp., and Entamoeba histolytica) by quantitative PCR (qPCR). RESULTS: Of the 38 households sampled, 37 had positive dust for at least one parasite and up to 8 parasites were detected in single samples. Positivity was greatest for B. hominis (79% of household samples) indicating a high level of environmental fecal contamination. Dust positivity rates for individual pathogens were: S. stercoralis (52%), A. lumbricoides (39%), G. lamblia (39%), Toxocara spp. (42%), hookworm (18%) and T. trichiura (8%). DNA for Cryptosporidium spp. and E. histolytica was not detected. Bed dust was more frequently positive than floor samples for all parasites detected. Positivity for A. lumbricoides DNA in bed (adjusted OR: 10.0, 95% CI: 2.0-50.1) but not floor dust (adjusted OR: 3.6, 95% CI: 0.3-37.9) was significantly associated with active infections in children. CONCLUSIONS: To our knowledge, this is the first use of qPCR on environmental samples to detect a wide range of enteric pathogen DNA. Our results indicate widespread contamination of households with parasite DNA and raise the possibility that beds, under conditions of overcrowding in a humid tropical setting, may be a source of transmission.


Assuntos
Leitos/parasitologia , DNA/análise , Poeira/análise , Características da Família , Enteropatias Parasitárias/transmissão , Parasitos/genética , Adolescente , Animais , Criança , Ensaios Clínicos Controlados como Assunto , Meio Ambiente , Fezes/parasitologia , Feminino , Humanos , Masculino , Reação em Cadeia da Polimerase em Tempo Real , População Rural
8.
Parasit Vectors ; 13(1): 104, 2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32103784

RESUMO

BACKGROUND: Blood parasites belonging to the Apicomplexa, Trypanosomatidae and Filarioidea are widespread in birds and have been studied extensively. Microscopical examination (ME) of stained blood films remains the gold standard method for the detection of these infections in birds, particularly because co-infections predominate in wildlife. None of the available molecular tools can detect all co-infections at the same time, but ME provides opportunities for this to be achieved. However, fixation, drying and staining of blood films as well as their ME are relatively time-consuming. This limits the detection of infected hosts during fieldwork when captured animals should be released soon after sampling. It is an obstacle for quick selection of donor hosts for parasite experimental, histological and other investigations in the field. This study modified, tested and described the buffy coat method (BCM) for quick diagnostics (~ 20 min/sample) of avian blood parasites. METHODS: Blood of 345 birds belonging to 42 species was collected, and each sample was examined using ME of stained blood films and the buffy coat, which was examined after centrifugation in capillary tubes and after being transferred to objective glass slides. Parasite detection using these methods was compared using sensitivity, specificity, positive and negative predictive values and Cohen's kappa index. RESULTS: Haemoproteus, Leucocytozoon, Plasmodium, microfilariae, Trypanosoma and Lankesterella parasites were detected. BCM had a high sensitivity (> 90%) and specificity (> 90%) for detection of Haemoproteus and microfilariae infections. It was of moderate sensitivity (57%) and high specificity (> 90%) for Lankesterella infections, but of low sensitivity (20%) and high specificity (> 90%) for Leucocytozoon infections. Trypanosoma and Plasmodium parasites were detected only by BCM and ME, respectively. According to Cohen's kappa index, the agreement between two diagnostic tools was substantial for Haemoproteus (0.80), moderate for Lankesterella (0.46) and fair for microfilariae and Leucocytozoon (0.28) infections. CONCLUSIONS: BCM is sensitive and recommended as a quick and reliable tool to detect Haemoproteus, Trypanosoma and microfilariae parasites during fieldwork. However, it is not suitable for detection of species of Leucocytozoon and Plasmodium. BCM is a useful tool for diagnostics of blood parasite co-infections. Its application might be extended to studies of blood parasites in other vertebrates during field studies.


Assuntos
Doenças das Aves/diagnóstico , Doenças das Aves/parasitologia , Buffy Coat/parasitologia , Parasitos/isolamento & purificação , Parasitologia/métodos , Coloração e Rotulagem/métodos , Animais , Animais Selvagens/sangue , Animais Selvagens/parasitologia , Doenças das Aves/sangue , Aves/sangue , Aves/classificação , Aves/parasitologia , Parasitos/classificação , Parasitos/genética , Especificidade da Espécie
9.
Int J Parasitol ; 50(3): 195-208, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32087247

RESUMO

The Manila clam (Ruditapes philippinarum) is the bivalve species with the highest global production from both fisheries and aquaculture, but its production is seriously threatened by perkinsosis, a disease caused by the protozoan parasite Perkinsus olseni. To understand the molecular mechanisms underlying R. philippinarum-P. olseni interactions, we analysed the gene expression profiles of in vitro challenged clam hemocytes and P. olseni trophozoites, using two oligo-microarray platforms, one previously validated for R. philippinarum hemocytes and a new one developed and validated in this study for P. olseni. Manila clam hemocytes were in vitro challenged with trophozoites, zoospores, and extracellular products from P. olseni in vitro cultures, while P. olseni trophozoites were in vitro challenged with Manila clam plasma along the same time-series (1 h, 8 h, and 24 h). The hemocytes showed a fast activation of the innate immune response, particularly associated with hemocyte recruitment, in the three types of challenges. Nevertheless, different immune-related pathways were activated in response to the different parasite stages, suggesting specific recognition mechanisms. Furthermore, the analyses provided useful complementary data to previous in vivo challenges, and confirmed the potential of some proposed biomarkers. The combined analysis of gene expression in host and parasite identified several processes in both the clam and P. olseni, such as redox and glucose metabolism, protease activity, apoptosis and iron metabolism, whose modulation suggests cross-talk between parasite and host. This information might be critical to determine the outcome of the infection, thus highlighting potential therapeutic targets. Altogether, the results of this study aid understanding the response and interaction between R. philippinarum and P. olseni, and will contribute to developing effective control strategies for this threatening parasitosis.


Assuntos
Alveolados , Bivalves/parasitologia , Alveolados/genética , Alveolados/metabolismo , Animais , Bivalves/genética , Bivalves/metabolismo , Células Sanguíneas/metabolismo , Interações Hospedeiro-Parasita/imunologia , Imunidade Inata , Técnicas In Vitro/métodos , Parasitos/genética , Parasitos/metabolismo , Frutos do Mar/parasitologia , Transcriptoma , Trofozoítos/genética , Trofozoítos/metabolismo
10.
Parasitol Res ; 119(2): 385-394, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31901105

RESUMO

Ticks are important parasites from economic and public health points of view because of their ability to reduce farm animals' productivity and transmit zoonotic diseases. We conducted this cross-sectional study between January and March 2016 and between March and April 2017 to identify tick species in West Darfur, Al-Jazeera, and the River Nile states in the Sudan and to investigate whether these ticks carry Rickettsia spp. and Crimean-Congo hemorrhagic fever (CCHF) virus. In total, 1593 ticks were collected from 207 animals and identified based on morphology or 16S rRNA gene and tested for Rickettsia spp. and CCHF virus either individually or as pools containing 2 to 10 pooled ticks using molecular methods. Overall, 14 tick species belonging to three genera, namely Amblyomma, Hyalomma, and Rhipicephalus, were identified. Hyalomma anatolicum and Rhipicephalus evertsi evertsi were the most frequent ticks. A total of 561 tests comprised of individual or pooled ticks were conducted and 13.7% (77/561) were positive for Rickettsia spp. which were mostly Rickettsia aeschlimannii and R. africae. The highest positivity was noticed among H. rufipes collected from cattle and camels in West Darfur. However, none of the screened Hyalomma ticks harbored CCHF viral RNA. These findings suggest that there might be a risk of zoonotic transmission of Rickettsia spp. by ticks but zoonotic transmission of CCHF virus is apparently doubtful. An in-depth and a country-wide epidemiological study is needed to better understand the dynamic of Rickettsia spp. and CCHF virus in the Sudan.


Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo/isolamento & purificação , Febre Hemorrágica da Crimeia/transmissão , Ixodidae/microbiologia , Infecções por Rickettsia/transmissão , Rickettsia/isolamento & purificação , Doenças Transmitidas por Carrapatos/microbiologia , Animais , Camelus , Bovinos , Estudos Transversais , Vírus da Febre Hemorrágica da Crimeia-Congo/genética , Parasitos/genética , RNA Ribossômico 16S/genética , Rickettsia/genética , Sudão , Zoonoses/transmissão
11.
PLoS One ; 15(1): e0227810, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31999735

RESUMO

The pre-Columbian Huecoid and Saladoid cultures were agricultural ethnic groups that supplemented their diets by fishing, hunting and scavenging. Archaeological deposits associated to these cultures contained a variety of faunal osseous remains that hinted at the cultures' diets. The present study identified zoonotic parasites that may have infected these two cultures as a result of their diets. We used metagenomic sequencing and microscopy data from 540-1,400 year old coprolites as well as the zooarchaeological data to recreate the possible interactions between zoonotic parasites and their hosts. Microscopy revealed Diphyllobothrium spp. and Dipylidium caninum eggs along with unidentified cestode and trematode eggs. DNA sequencing together with functional prediction and phylogenetic inference identified reads of Cryptosporidium spp., Giardia intestinalis and Schistosoma spp. The complimentary nature of the molecular, microscopy and zooarchaeology data provided additional insight into the detected zoonotic parasites' potential host range. Network modeling revealed that rodents and canids living in close proximity to these cultures were most likely the main source of these zoonotic parasite infections.


Assuntos
Parasitos/isolamento & purificação , Zoonoses/história , Animais , Dieta/efeitos adversos , História do Século XV , História Medieval , Interações Hospedeiro-Parasita , Humanos , Estilo de Vida , Metagenômica , Parasitos/genética , Parasitos/fisiologia , Porto Rico/epidemiologia , Análise de Sequência de DNA , Zoonoses/epidemiologia , Zoonoses/parasitologia
12.
BMC Evol Biol ; 20(1): 8, 2020 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-31931696

RESUMO

BACKGROUND: Red Queen dynamics are defined as long term co-evolutionary dynamics, often with oscillations of genotype abundances driven by fluctuating selection in host-parasite systems. Much of our current understanding of these dynamics is based on theoretical concepts explored in mathematical models that are mostly (i) deterministic, inferring an infinite population size and (ii) evolutionary, thus ecological interactions that change population sizes are excluded. Here, we recall the different mathematical approaches used in the current literature on Red Queen dynamics. We then compare models from game theory (evo) and classical theoretical ecology models (eco-evo), that are all derived from individual interactions and are thus intrinsically stochastic. We assess the influence of this stochasticity through the time to the first loss of a genotype within a host or parasite population. RESULTS: The time until the first genotype is lost ("extinction time"), is shorter when ecological dynamics, in the form of a changing population size, is considered. Furthermore, when individuals compete only locally with other individuals extinction is even faster. On the other hand, evolutionary models with a fixed population size and competition on the scale of the whole population prolong extinction and therefore stabilise the oscillations. The stabilising properties of intra-specific competitions become stronger when population size is increased and the deterministic part of the dynamics gain influence. In general, the loss of genotype diversity can be counteracted with mutations (or recombination), which then allow the populations to recurrently undergo negative frequency-dependent selection dynamics and selective sweeps. CONCLUSION: Although the models we investigated are equal in their biological motivation and interpretation, they have diverging mathematical properties both in the derived deterministic dynamics and the derived stochastic dynamics. We find that models that do not consider intraspecific competition and that include ecological dynamics by letting the population size vary, lose genotypes - and thus Red Queen oscillations - faster than models with competition and a fixed population size.


Assuntos
Evolução Biológica , Deriva Genética , Interações Hospedeiro-Parasita , Modelos Genéticos , Animais , Ecologia , Teoria do Jogo , Parasitos/genética , Densidade Demográfica , Dinâmica Populacional
13.
Parasit Vectors ; 13(1): 1, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900233

RESUMO

BACKGROUND: Ticks and tick-borne pathogens (TTBP) are a major constraint to livestock production in Pakistan; despite a high prevalence of TTBPs, knowledge on the capacity of Pakistani ticks to carry pathogens and endosymbionts is limited. Furthermore, mixed infections with multiple microorganisms further complicate and limit the detection potential of traditional diagnostic methods. The present study investigated the tick-borne microorganisms in bovine ticks in Pakistan, employing a high-throughput microfluidic real-time PCR based technique. METHODS: Ticks were collected from clinically healthy cattle (n = 116) and water buffaloes (n = 88) from 30 villages across six districts located in five agro-ecological zones (AEZs) of Pakistan from September to November 2017. The microfluidic real-time PCR was used to test the genomic DNA of individual ticks for the presence of 27 bacterial and eight parasitic microorganisms. Phylogenetic methods were used to assess the genetic relationship of DNA sequences determined herein. RESULTS: PCR detected DNA of at least one microorganism in each of 221 ticks tested (94.4%, 221/234). DNA-based detection inferred that single pathogens/endosymbionts were the most common (43.4%, 96/221) followed by double (38.9%, 86/221), triple (14.5%, 32/221), quadruple (2.3%, 5/221) and quintuple (0.9%, 2/221) mixed infections. Piroplasms (Babesia/Theileria spp.) were the most prevalent (31.6%, 74/234), followed by Ehrlichia spp. (20%, 47/234) and Anaplasma marginale (7.7%, 18/234). Anaplasma phagocytophilum, A. ovis, A. centrale, Babesia ovis, Borrelia spp., Rickettsia spp., R. massiliae, Bartonella spp. and Hepatozoon spp. were also detected. Endosymbionts such as Francisella-like (91.5%, 214/234) and Coxiella-like (1.3%, 3/234) organisms were also detected in ticks. The highest diversity of microorganisms was detected in Hyalomma anatolicum ticks (test-positive for 14/14 microorganisms), followed by Rhipicephalus microplus (4/14), Hy. hussaini (3/14) and Rh. annulatus (2/14). Ticks collected from cattle carried significantly more frequently piroplasms (41.2%, 54/131; P < 0.05) than those from buffaloes (19.4%, 20/103). However, the overall prevalence of microorganisms did not vary significantly among ticks from the two host species as well as across different AEZs. CONCLUSIONS: To our knowledge, this is the first study to investigate a wide range of tick-borne microorganisms in bovine ticks using a high-throughput diagnostic method from different AEZs in Pakistan. These findings will aid in establishing the distribution patterns and the control of tick-borne pathogens of bovines in Pakistan.


Assuntos
Búfalos/parasitologia , Bovinos/parasitologia , Parasitos/isolamento & purificação , Carrapatos/microbiologia , Carrapatos/parasitologia , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Reservatórios de Doenças/microbiologia , Reservatórios de Doenças/parasitologia , Paquistão , Parasitos/classificação , Parasitos/genética , Filogenia , Carrapatos/classificação
14.
Int J Parasitol ; 50(1): 1-18, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31857072

RESUMO

Second and third generation sequencing methods are crucial for population genetic studies, and variant detection is a popular approach for exploiting this sequence data. While mini- and microsatellites are historically useful markers for studying important Protozoa such as Toxoplasma and Plasmodium spp., detecting non-repetitive variants such as those found in genes can be fundamental to investigating a pathogen's biology. These variants, namely single nucleotide polymorphisms and insertions and deletions, can help elucidate the genetic basis of an organism's pathogenicity, identify selective pressures, and resolve phylogenetic relationships. They also have the added benefit of possessing a comparatively low mutation rate, which contributes to their stability. However, there is a plethora of variant analysis tools with nuanced pipelines and conflicting recommendations for best practise, which can be confounding. This lack of standardisation means that variant analysis requires careful parameter optimisation, an understanding of its limitations, and the availability of high quality data. This review explores the value of variant detection when applied to non-model organisms such as clinically important protozoan pathogens. The limitations of current methods are discussed, including special considerations that require the end-users' attention to ensure that the results generated are reproducible, and the biological conclusions drawn are valid.


Assuntos
Biologia Computacional/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Parasitos/genética , Infecções por Protozoários/genética , Animais , DNA de Protozoário , Resistência a Medicamentos/genética , Variação Genética , Genética Populacional , Genoma de Protozoário , Humanos , Leishmania/genética , Filogenia , Plasmodium/genética , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Toxoplasma/genética , Trypanosoma cruzi/genética
15.
Int J Nanomedicine ; 14: 7593-7607, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31802863

RESUMO

Background: Amphotericin B (Amp) and Betulinic acid (BA) as antileishmanial agents have negligible water solubility and high toxicity. To solve these problems, for the first time, chitosan nanoparticles and Anionic Linear Globular Dendrimer (D) were synthesized for the treatment of Leishmania major (L. major). Method: Chitosan and dendrimer nanoparticles were synthesized, and Amp and BA were loaded into the nanoparticles. The particles were then characterized using various methods and their efficacy was evaluated in vitro and in vivo environments (parasite burden was confirmed using pathological studies and real-time PCR methods). Result: The results of docking showed that Amp and BA can be loaded into chitosan and dendrimer nanoparticles. The results of physically drug loading efficiency for AK (Amphotericin B-chitosan), BK (Betulinic acid-chitosan), AD (Amphotericin B-Dendrimer) and BD (Betulinic acid- Dendrimer) were 90, 93, 84 and 96 percent, respectively. The characterization results indicated that the drugs were loaded into nanoparticles physically. Moreover, the increased solubility rate for AD=478, BD=790, AK=80 and BK=300 folds. Furthermore, the results of the drug delivery system showed the slow controlled drug release pattern with cellular uptake of more than 90%. The treatment results showed a 100 percent decrease of toxicity for the all nanodrugs was observed in vivo and in vitro environments. Moreover, AK10 and BK20 mg/kg reduced parasite burden by 83 percent (P<0.001), while AD50 and BD40 mg/kg reduced it to a lesser extent compared to glucantime. Conclusion: All the synthesized nanodrugs were completely succeeded by 100% to recovery the L. major induced pathological effects in the infected footpad. Also, the results of present study were confirmed with real-time PCR and the results showed that AK and BK were succeeded in a large extent to the treatment of L. major infection (P<0.001), therefore AK and BK could be considered as proper alternatives of choices drugs.


Assuntos
Anfotericina B/farmacologia , Quitosana/química , Dendrímeros/química , Leishmania major/efeitos dos fármacos , Leishmania major/genética , Nanopartículas/química , Reação em Cadeia da Polimerase em Tempo Real/métodos , Triterpenos/química , Anfotericina B/química , Animais , Antiprotozoários/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Simulação de Acoplamento Molecular , Nanopartículas/uso terapêutico , Nanopartículas/toxicidade , Parasitos/efeitos dos fármacos , Parasitos/genética , Solubilidade , Termodinâmica
16.
Nat Commun ; 10(1): 5615, 2019 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-31819062

RESUMO

Novel interventions that leverage the heterogeneity of parasite transmission are needed to achieve malaria elimination. To better understand spatial and temporal dynamics of transmission, we applied amplicon next-generation sequencing of two polymorphic gene regions (csp and ama1) to a cohort identified via reactive case detection in a high-transmission setting in western Kenya. From April 2013 to July 2014, we enrolled 442 symptomatic children with malaria, 442 matched controls, and all household members of both groups. Here, we evaluate genetic similarity between infected individuals using three indices: sharing of parasite haplotypes on binary and proportional scales and the L1 norm. Symptomatic children more commonly share haplotypes with their own household members. Furthermore, we observe robust temporal structuring of parasite genetic similarity and identify the unique molecular signature of an outbreak. These findings of both micro- and macro-scale organization of parasite populations might be harnessed to inform next-generation malaria control measures.


Assuntos
Malária/epidemiologia , Malária/transmissão , Parasitos/fisiologia , Análise Espaço-Temporal , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Haplótipos/genética , Humanos , Quênia/epidemiologia , Pessoa de Meia-Idade , Parasitos/genética , Plasmodium falciparum/genética , Plasmodium falciparum/fisiologia , Adulto Jovem
17.
N Engl J Med ; 381(26): 2569-2580, 2019 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-31881145

RESUMO

Rapid advances in DNA sequencing technology ("next-generation sequencing") have inspired optimism about the potential of human genomics for "precision medicine." Meanwhile, pathogen genomics is already delivering "precision public health" through more effective investigations of outbreaks of foodborne illnesses, better-targeted tuberculosis control, and more timely and granular influenza surveillance to inform the selection of vaccine strains. In this article, we describe how public health agencies have been adopting pathogen genomics to improve their effectiveness in almost all domains of infectious disease. This momentum is likely to continue, given the ongoing development in sequencing and sequencing-related technologies.


Assuntos
Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Influenza Humana/epidemiologia , Saúde Pública , Tuberculose/epidemiologia , Animais , Bactérias/genética , Doenças Transmitidas por Alimentos/diagnóstico , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/parasitologia , Humanos , Influenza Humana/diagnóstico , Influenza Humana/microbiologia , Metagenômica , Parasitos/genética , Tuberculose/diagnóstico , Vírus/genética
18.
BMC Evol Biol ; 19(1): 230, 2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856710

RESUMO

BACKGROUND: Coevolution is a selective process of reciprocal adaptation in hosts and parasites or in mutualistic symbionts. Classic population genetics theory predicts the signatures of selection at the interacting loci of both species, but not the neutral genome-wide polymorphism patterns. To bridge this gap, we build an eco-evolutionary model, where neutral genomic changes over time are driven by a single selected locus in hosts and parasites via a simple biallelic gene-for-gene or matching-allele interaction. This coevolutionary process may lead to cyclic changes in the sizes of the interacting populations. RESULTS: We investigate if and when these changes can be observed in the site frequency spectrum of neutral polymorphisms from host and parasite full genome data. We show that changes of the host population size are too smooth to be observable in its polymorphism pattern over the course of time. Conversely, the parasite population may undergo a series of strong bottlenecks occurring on a slower relative time scale, which may lead to observable changes in a time series sample. We also extend our results to cases with 1) several parasites per host accelerating relative time, and 2) multiple parasite generations per host generation slowing down rescaled time. CONCLUSIONS: Our results show that time series sampling of host and parasite populations with full genome data are crucial to understand if and how coevolution occurs. This model provides therefore a framework to interpret and draw inference from genome-wide polymorphism data of interacting species.


Assuntos
Interações Hospedeiro-Parasita , Modelos Genéticos , Parasitos/genética , Adaptação Biológica , Animais , Evolução Biológica , Genética Populacional , Genômica , Doenças Parasitárias/parasitologia , Polimorfismo Genético , Densidade Demográfica , Dinâmica Populacional , Simbiose
19.
Parasit Vectors ; 12(1): 610, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31881926

RESUMO

With a global population of about 35 million in 47 countries, dromedary camels play a crucial role in the economy of many marginal, desert areas of the world where they survive under harsh conditions. Nonetheless, there is scarce knowledge regarding camels' parasite fauna which can reduce their milk and meat productions. In addition, only scattered information is available about zoonotic parasites transmitted to humans via contamination (e.g. Cryptosporidium spp., Giardia duodenalis, Balantidium coli, Blastocystis spp. and Enterocytozoon bieneusi), as foodborne infections (e.g. Toxoplasma gondii, Trichinella spp. and Linguatula serrata) or by arthropod vectors (Trypanosoma spp.). Herein, we draw attention of the scientific community and health policy-making organizations to the role camels play in the epidemiology of parasitic zoonotic diseases also in the view of an increase in their farming in desert areas worldwide.


Assuntos
Camelus/parasitologia , Parasitos/fisiologia , Doenças Parasitárias em Animais/parasitologia , Doenças Parasitárias/parasitologia , Zoonoses/parasitologia , Animais , Humanos , Parasitos/classificação , Parasitos/genética , Parasitos/isolamento & purificação , Doenças Parasitárias/transmissão , Doenças Parasitárias em Animais/transmissão , Zoonoses/transmissão
20.
PLoS Pathog ; 15(12): e1008216, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31887217

RESUMO

Eukaryotes of the genus Plasmodium cause malaria, a parasitic disease responsible for substantial morbidity and mortality in humans. Yet, the nature and abundance of any viruses carried by these divergent eukaryotic parasites is unknown. We investigated the Plasmodium virome by performing a meta-transcriptomic analysis of blood samples taken from patients suffering from malaria and infected with P. vivax, P. falciparum or P. knowlesi. This resulted in the identification of a narnavirus-like sequence, encoding an RNA polymerase and restricted to P. vivax samples, as well as an associated viral segment of unknown function. These data, confirmed by PCR, are indicative of a novel RNA virus that we term Matryoshka RNA virus 1 (MaRNAV-1) to reflect its analogy to a "Russian doll": a virus, infecting a parasite, infecting an animal. Additional screening revealed that MaRNAV-1 was abundant in geographically diverse P. vivax derived from humans and mosquitoes, strongly supporting its association with this parasite, and not in any of the other Plasmodium samples analyzed here nor Anopheles mosquitoes in the absence of Plasmodium. Notably, related bi-segmented narnavirus-like sequences (MaRNAV-2) were retrieved from Australian birds infected with a Leucocytozoon-a genus of eukaryotic parasites that group with Plasmodium in the Apicomplexa subclass hematozoa. Together, these data support the establishment of two new phylogenetically divergent and genomically distinct viral species associated with protists, including the first virus likely infecting Plasmodium parasites. As well as broadening our understanding of the diversity and evolutionary history of the eukaryotic virosphere, the restriction to P. vivax may be of importance in understanding P. vivax-specific biology in humans and mosquitoes, and how viral co-infection might alter host responses at each stage of the P. vivax life-cycle.


Assuntos
Malária Vivax/parasitologia , Parasitos/genética , Plasmodium vivax/genética , Plasmodium/genética , Vírus de RNA/genética , Animais , Anopheles/parasitologia , Doenças das Aves , Humanos , Malária Falciparum/parasitologia , Plasmodium falciparum/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA