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2.
PLoS One ; 13(11): e0207495, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30440026

RESUMO

Relocation is one of the mitigating measures taken by either local people or related officers to reduce the human-bonnet macaque Macaca radiata conflict in India. The review on relocations of primates in India indicates that monkeys are unscreened for diseases or gastrointestinal parasites (henceforth endoparasites) before relocation. We collected 161 spatial samples from 20 groups of bonnet macaque across their distribution range in south India and 205 temporal samples from a group in Chiksuli in the central Western Ghats. The isolation of endoparasite eggs/cysts from the fecal samples was by the centrifugation flotation and sedimentation method. All the sampled groups, except one, had an infection of at least one endoparasite taxa, and a total of 21 endoparasite taxon were recorded. The number of helminth taxon (16) were more than protozoan (5), further, among helminths, nematodes (11) were more common than cestodes (5). Although the prevalence of Ascaris sp. (26.0%), Strongyloides sp. (13.0%), and Coccidia sp. (13.0%) were greater, the load of Entamoeba coli, Giardia sp., Dipylidium caninum and Diphyllobothrium sp. were very high. Distant groups had more similarity in composition of endoparasites taxon than closely located groups. Among all the variables, the degree of provisioning was the topmost determinant factor for the endoparasite taxon richness and their load. Temporal sampling indicates that the endoparasite infection remains continuous throughout the year. Monthly rainfall and average maximum temperature in the month did not influence the endoparasite richness. A total of 17 taxon of helminths and four-taxon of protozoan were recorded. The prevalence of Oesophagostomum sp., and Strongyloides sp., and mean egg load of Spirurids and Trichuris sp. was higher than other endoparasite taxon. The overall endoparasite load and helminth load was higher in immatures than adults, where, adult females had the highest protozoan load in the monsoon. The findings indicate that relocation of commensal bonnet macaque to wild habitat can possible to lead transmission of novel endoparasites that can affect their population. Thus, we suggest avoidance of such relocations, however, if inevitable the captured animals need to be screened and treated for diseases and endoparasites before relocations.


Assuntos
Trato Gastrointestinal/parasitologia , Helmintos/patogenicidade , Enteropatias Parasitárias/parasitologia , Doenças dos Macacos/parasitologia , Animais , Ascaris/isolamento & purificação , Ascaris/patogenicidade , Cestoides/isolamento & purificação , Cestoides/patogenicidade , Fezes/parasitologia , Feminino , Trato Gastrointestinal/fisiopatologia , Giardia/isolamento & purificação , Giardia/patogenicidade , Helmintos/classificação , Helmintos/isolamento & purificação , Humanos , Índia , Enteropatias Parasitárias/veterinária , Macaca radiata/parasitologia , Doenças dos Macacos/epidemiologia , Nematoides/isolamento & purificação , Nematoides/patogenicidade
3.
Georgian Med News ; (279): 171-175, 2018 Jun.
Artigo em Russo | MEDLINE | ID: mdl-30035741

RESUMO

One of the most poorly studied areas of protozoology is metabolic processes of parasitic protozoa. Study of the biochemistry of parasites required for the development of effective chemotherapy of protozoal diseases. Some amitochondrial parasites of humans, such as Giardia intestinalis, Entamoeba histolytica, Trichomonas sp., living in an environment with low oxygen content, have specialized cellular organelles-hydrogenosomes (like mitochondria provide cells with simple energy). The study of the functioning of these organelles allows us to consider them as targets for the development of аntiprotozoal drugs. The target for chemotherapy in the treatment of trypanosomiasis can be processes related to the characteristics of the glycolytic pathway or a decrease in the level of energy substrate, such as glucose. This leads to a rapid decrease in ATP levels in the cell of the parasite, an overall loss of mobility and disappearance of trypanosomes from the bloodstream of the infected host. Also, glucose transporters located in the membrane of the parasite can be targets for drugs.


Assuntos
Antiprotozoários/farmacologia , Entamoeba/metabolismo , Giardia/metabolismo , Trichomonas/metabolismo , Trypanosoma/metabolismo , Animais , Antiprotozoários/química , Entamoeba/efeitos dos fármacos , Entamoeba/patogenicidade , Giardia/efeitos dos fármacos , Giardia/patogenicidade , Humanos , Trichomonas/efeitos dos fármacos , Trichomonas/patogenicidade , Trypanosoma/efeitos dos fármacos , Trypanosoma/patogenicidade
4.
Gigascience ; 7(3): 1-13, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29385462

RESUMO

Background: Giardia is a protozoan parasite of public health relevance that causes gastroenteritis in a wide range of hosts. Two genetically distinct lineages (assemblages A and B) are responsible for the human disease. Although it is clear that differences in virulence occur, the pathogenesis and virulence of Giardia remain poorly understood. Results: The genome of Giardia is believed to contain open reading frames that could encode as many as 6000 proteins. By successfully applying quantitative proteomic analyses to the whole parasite and to the supernatants derived from parasite culture of assemblages A and B, we confirm expression of ∼1600 proteins from each assemblage, the vast majority of which are common to both lineages. To look for signature enrichment of secreted proteins, we considered the ratio of proteins in the supernatant compared with the pellet, which defined a small group of enriched proteins, putatively secreted at a steady state by cultured growing trophozoites of both assemblages. This secretome is enriched with proteins annotated to have N-terminal signal peptide. The most abundant secreted proteins include known virulence factors such as cathepsin B cysteine proteases and members of a Giardia superfamily of cysteine-rich proteins that comprise variant surface proteins, high-cysteine membrane proteins, and a new class of virulence factors, the Giardia tenascins. We demonstrate that physiological function of human enteric epithelial cells is disrupted by such soluble factors even in the absence of the trophozoites. Conclusions: We are able to propose a straightforward model of Giardia pathogenesis incorporating key roles for the major Giardia-derived soluble mediators.


Assuntos
Gastroenterite/genética , Giardia/genética , Giardíase/genética , Tenascina/metabolismo , Animais , Linhagem da Célula/genética , Proteínas da Matriz Extracelular/genética , Gastroenterite/parasitologia , Genoma/genética , Genótipo , Giardia/patogenicidade , Giardíase/parasitologia , Humanos , Proteínas do Tecido Nervoso/genética , Filogenia , Proteômica , Tenascina/genética
5.
BMC Infect Dis ; 17(1): 486, 2017 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-28693557

RESUMO

BACKGROUND: Giardia is a leading but neglected cause of infectious gastroenteritis worldwide and is treatable. There is a substantial burden of undetected Giardia in the UK and for every one case of Giardia reported to national surveillance there are 14 cases in the community. We aimed to ascertain the prevalence of, and risk factors associated with secondary household Giardia infections to assess the burden of infection and inform control measures. METHODS: We identified all giardiasis cases notified in nine local authorities in Lancashire between June 2014 and June 2015, and invited their household contacts to submit faecal specimens for Giardia testing and complete a risk factor questionnaire. We estimated the proportion of households with additional Giardia infection. We compared household risk factors between households with and without additional Giardia using Fisher's exact test. We used multivariable logistic regression to identify independent risk factors for additional Giardia infections. RESULTS: We identified additional Giardia infections in 30% (27/91) of included households. A total of 41 infections were found from 212 household members, of which 37 were asymptomatic. The majority of infections were assemblage B (57%) but there were also a high number of mixed infections (20%). Risk factors significantly associated with additional household infections were; having children under 5 years in the household (odds ratio 42; 95% confidence intervals 10-178) and the presence of gastrointestinal illness in the household before the onset of the index case (odds ratio 9; 95% confidence intervals 1.5-48). CONCLUSIONS: Our finding of a high household prevalence of asymptomatic infection has raised the public health question of whether treatment of asymptomatic household contacts may be justified in preventing Giardia re-infection of the index case or in preventing secondary cases and household clusters. We recommend the communication of this risk in household contacts of Giardia and reinforcement of standard hygiene controls.


Assuntos
Giardíase/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Coinfecção/epidemiologia , Estudos Transversais , Inglaterra/epidemiologia , Características da Família , Giardia/patogenicidade , Giardíase/transmissão , Humanos , Lactente , Recém-Nascido , Modelos Logísticos , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Adulto Jovem
6.
Am J Clin Nutr ; 105(5): 1132-1138, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28381477

RESUMO

Background: Early exposure to enteropathogens has been associated with malnutrition in children in low-resource settings. However, the contribution of individual enteropathogens remains poorly defined. Molecular diagnostics offer an increase in sensitivity for detecting enteropathogens but have not been comprehensively applied to studies of malnutrition.Objective: We sought to identify enteropathogens associated with malnutrition in Bangladesh.Design: Malnourished children [weight-for-age z score (WAZ) <-2] aged 6-23 mo in Dhaka, Bangladesh, and identified by active community surveillance were enrolled as cases, and normal-weight children (WAZ >-1) of the same age and from the same community were enrolled as controls. Stools were collected at enrollment and, for cases, after a 5-mo nutritional intervention. Enrollment and follow-up stools were tested by quantitative polymerase chain reaction for 32 enteropathogens with the use of a custom-developed TaqMan Array Card.Results: Enteropathogen testing was performed on 486 cases and 442 controls upon enrollment and 365 cases at follow-up. At enrollment, the detection of enteroaggregative Escherichia coli (OR: 1.39; 95% CI: 1.05, 1.83), Campylobacter spp. (OR: 1.46; 95% CI: 1.11, 1.91), heat-labile enterotoxin-producing E. coli (OR: 1.55; 95% CI: 1.04, 2.33), Shigella/enteroinvasive E. coli (OR: 1.65; 95% CI: 1.10, 2.46), norovirus genogroup I (OR: 1.66; 95% CI: 1.23, 2.25), and Giardia (OR: 1.73; 95% CI: 1.20, 2.49) were associated with malnourished cases, and the total burden of these pathogens remained associated with malnutrition after adjusting for sociodemographic factors. The number of these pathogens at follow-up was negatively associated with the change in WAZ during the intervention (-0.10 change in WAZ per pathogen detected; 95% CI: -0.14, -0.06), whereas the number at enrollment was positively associated with the change in WAZ (0.05 change in WAZ per pathogen detected; 95% CI: 0.00, 0.10).Conclusions: A subset of enteropathogens was associated with malnutrition in this setting. Broad interventions designed to reduce the burden of infection with these pathogens are needed. This trial was registered at clinicaltrials.gov as NCT02441426.


Assuntos
Campylobacter , Transtornos da Nutrição Infantil/etiologia , Escherichia coli , Giardia , Desnutrição/etiologia , Norovirus , Shigella , Bangladesh , Peso Corporal , Campylobacter/genética , Campylobacter/patogenicidade , Estudos de Casos e Controles , Transtornos da Nutrição Infantil/microbiologia , Transtornos da Nutrição Infantil/parasitologia , Transtornos da Nutrição Infantil/virologia , Pré-Escolar , Diarreia/etiologia , Diarreia/microbiologia , Diarreia/parasitologia , Diarreia/virologia , Escherichia coli/genética , Escherichia coli/patogenicidade , Feminino , Giardia/genética , Giardia/patogenicidade , Humanos , Lactente , Masculino , Desnutrição/microbiologia , Desnutrição/parasitologia , Desnutrição/virologia , Norovirus/genética , Norovirus/patogenicidade , Reação em Cadeia da Polimerase , Shigella/genética , Shigella/patogenicidade
7.
Trends Parasitol ; 33(7): 561-576, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28336217

RESUMO

Intestinal protozoa are important etiological agents of diarrhea, particularly in children, yet the public health risk they pose is often neglected. Results from the Global Enteric Multicenter Study (GEMS) showed that Cryptosporidium is among the leading causes of moderate to severe diarrhea in children under 2 years. Likewise, Giardia infects approximately 200 million individuals worldwide, and causes acute diarrhea in children under 5 years. Despite this recognized role as pathogens, the question is why and how these parasites cause disease in some individuals but not in others. This review focuses on known pathogenic mechanisms of Cryptosporidium and Giardia, and infection progress towards disease.


Assuntos
Criptosporidiose/fisiopatologia , Giardíase/fisiopatologia , Fatores Etários , Criptosporidiose/parasitologia , Cryptosporidium/patogenicidade , Giardia/patogenicidade , Giardíase/parasitologia , Humanos
8.
Curr Opin Microbiol ; 34: 47-52, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27501461

RESUMO

Giardia intestinalis is a non-invasive protozoan parasite infecting the upper small intestine causing acute, watery diarrhea or giardiasis in 280 million people annually. Asymptomatic infections are equally common and recent data have suggested that infections even can be protective against other diarrheal diseases. Most symptomatic infections resolve spontaneously but infections can lead to chronic disease and treatment failures are becoming more common world-wide. Giardia infections can also result in irritable bowel syndrome (IBS) and food allergies after resolution. Until recently not much was known about the mechanism of giardiasis or the cause of post-giardiasis syndromes and treatment failures, but here we will describe the recent progress in these areas.


Assuntos
Giardia/fisiologia , Giardíase , Animais , Diarreia/parasitologia , Gastroenteropatias/parasitologia , Giardia/isolamento & purificação , Giardia/patogenicidade , Giardíase/complicações , Giardíase/tratamento farmacológico , Giardíase/parasitologia , Interações Hospedeiro-Parasita , Humanos , Síndrome do Intestino Irritável/parasitologia , Falha de Tratamento
9.
Infect Genet Evol ; 44: 157-161, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27370572

RESUMO

Two genetic assemblages (A and B) of the protozoan parasite species, Giardia duodenalis, infect humans, domestic animals and wildlife. In New South Wales, Australia, over 2000 sporadic human giardiasis cases are reported annually, but parasite sources and links between sporadic cases are unknown. This study describes G. duodenalis assemblages contributing to human and cattle cases in NSW, and examines demographic, spatial, and temporal distributions of NSW human infections and G. duodenalis assemblages. Genotyping by PCR-restriction fragment length polymorphism of the glutamate dehydrogenase (gdh) gene identified G. duodenalis assemblage B as the most common (86%) cause of infection among human cases (n=165). Approximately 37% of cattle DNA samples were PCR positive (18S rRNA, gdh), and G. duodenalis assemblages E (69%) or B (31%) were identified from these samples. Human assemblage A was more common among older age groups, and seasonality in the geographic dispersal of human assemblage A was observed. The results of this study indicate G. duodenalis assemblage B is highly prevalent among humans in NSW, and the potential for cross-species transmission exists between humans and cattle in this region. Spatio-temporal and demographic distributions of human assemblage A and B are highlighted, and risk factors associated with these dispersal patterns warrants further research.


Assuntos
Giardia/genética , Giardia/patogenicidade , Giardíase/epidemiologia , Adolescente , Adulto , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/parasitologia , Criança , Pré-Escolar , Fazendas , Fezes/parasitologia , Feminino , Giardíase/veterinária , Humanos , Lactente , Recém-Nascido , Masculino , New South Wales/epidemiologia , Polimorfismo de Fragmento de Restrição , Fatores de Risco , Estações do Ano
10.
Sci Rep ; 6: 27564, 2016 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-27282464

RESUMO

Luminescent lanthanide chelates have been used to label antibodies in time-gated luminescence (TGL) bioimaging. However, it is a challenging task to label directly an antibody with lanthanide-binding ligands and achieve control of the target ligand/protein ratios whilst ensuring that affinity and avidity of the antibody remain uncompromised. We report the development of a new indirect detection reagent to label antibodies with detectable luminescence that circumvents this problem by labelling available lysine residues in the linker portion of the recombinant fusion protein Linker-Protein G (LPG). Succinimide-activated lanthanide chelating ligands were attached to lysine residues in LPG and Protein G (without Linker) and the resulting Luminescence-Activating (LA-) conjugates were compared for total incorporation and conjugation efficiency. A higher and more efficient incorporation of ligands at three different molar ratios was observed for LPG and this effect was attributed to the presence of eight readily available lysine residues in the linker region of LPG. These Luminescence-Activating (LA-) complexes were subsequently shown to impart luminescence (upon formation of europium(III) complexes) to cell-specific antibodies within seconds and without the need for any complicated bioconjugation procedures. The potential of this technology was demonstrated by direct labelling of Giardia cysts and Cryptosporidium oocysts in TGL bioimaging.


Assuntos
Quelantes/química , Elementos da Série dos Lantanídeos/química , Luminescência , Proteínas Recombinantes de Fusão/química , Quelantes/farmacologia , Cryptosporidium/isolamento & purificação , Cryptosporidium/patogenicidade , Európio/química , Giardia/isolamento & purificação , Giardia/patogenicidade , Elementos da Série dos Lantanídeos/farmacologia , Ligantes , Medições Luminescentes/métodos , Proteínas Recombinantes de Fusão/farmacologia
11.
São Paulo; s.n; 2016. 147 p.
Tese em Português | LILACS | ID: biblio-868416

RESUMO

O uso das águas costeiras para fins recreacionais está associado com benefícios à saúde e bem-estar, todavia eventuais impactos negativos podem diminuir estes benefícios. Esses usos variam de acordo com o tipo de atividade desenvolvida, sendo que a recreação de contato primário requer contato direto e prolongado com a água, durante a qual pode ocorrer ingestão acidental. A Resolução CONAMA nº 274/2000 dispõe sobre os critérios de balneabilidade e reza que as condições da qualidade das águas recreacionais devem ser avaliadas através de indicadores microbiológicos de contaminação fecal, e ainda recomenda que seja realizada pesquisa de organismos patogênicos em praias sistematicamente impróprias. Dada a escassez de dados da ocorrência de patógenos em águas costeiras, no período de 2010 a 2012, a CETESB realizou o Estudo de microrganismos patogênicos nas praias do Litoral Paulista pesquisando enterovírus, adenovírus, vírus da hepatite A, Cryptosporidium sp e Giardia sp, no intuito de preencher esta lacuna e gerar dados primários. Assim, o objetivo deste trabalho foi estimar a probabilidade de infecção por Cryptosporidium sp e Giardia sp após exposição a águas recreacionais costeiras usando como ferramenta a Avaliação Quantitativa de Risco Microbiológico (AQRM), como também o risco de doença. As concentrações de (oo)cistos nas águas das praias são oriundas dos relatórios de Qualidade das Praias Litorâneas no Estado de São Paulo da CETESB dos anos de 2011 e 2012. Nesse período foram analisadas 203 amostras coletadas de 12 praias na 1ª fase e de cinco praias na 2ª fase para a pesquisa de ocorrência de (oo)cistos. As amostras de água foram coletadas na isóbata de um metro, com frequência mensal. Giardia sp foi o microrganismo mais frequente, presente em 43 por cento das amostras e Cryptosporidium sp em 13 por cento . O cenário de exposição considerou tipos de atividade, tipos de usuários (crianças, adultos e esportistas), concentração de (oo)cistos, volume de ingestão, duração e frequência da exposição. A probabilidade de infecção foi maior em praias com mais amostras positivas para oocistos e cistos, no grupo dos esportistas e para Giardia sp. Em alguns casos os valores de risco de doença ultrapassaram o risco tolerável pela U.S. EPA (2012) de 3,6 por cento casos de gastroenterite, assim como ultrapassaram os resultados de incidência acumulada encontradas por LAMPARELLI et al. (2015). Os resultados apontaram a necessidade de melhoria nos sistemas de tratamento de efluentes no Litoral Paulista. A AQRM é uma ferramenta capaz de estimar a probabilidade de infecção no cenário das águas recreacionais e pode auxiliar no gerenciamento dos riscos


The use of coastal water for recreational purposes has been associated with benefits to health and well-being; however some negative impacts can diminish such benefits. The usages can vary according to the type of activity but the primary contact demands physical contact resulting in a high probability in accidental ingestion of water. Brazilian legislation for coastal recreational waters CONAMA 274/2000 establishes criteria for fecal indicator bacteria and furthermore recommends investigation of pathogenic organisms for beaches which classification is systematically as improper. Given the scarcity of data referring to pathogenic presence in beaches´ waters, CETESB carried out a study, in 2010 and 2012, for quantifying enterovirus, adenovirus, hepatitis A virus, Cryptosporidium sp and Giardia sp in coastal waters of São Paulo state in order to obtain data about their occurrence of these pathogens in coastal waters. The objective of this study was to estimate the annual risk of infection and disease for Giardia sp and Cryptosporidium sp by ingestion of water during primary contact recreation using QMRA approach. Concentrations of both parasites were taken from the annual report entitled Quality of coastal beaches in São Paulo state by CETESB (2011 and 2012). In these years were analyzed 203 samples of water for quantifying (oo)cysts of Giardia and Cryptosporidium from 12 beaches in the first year and five beaches in the second year of research. The samples were collected at one meter isobaths, with monthly frequency. Giardia was the most frequent parasite present in 43 per cent of samples and Cryptosporidium sp in 13 per cent . Exposure scenario was built considering types of activity, beach goers (children, adults and athletes), concentration of parasites, ingestion rate, duration and frequency of exposure. The probability of annual infection was higher in beaches in which there were more positive results for parasites for athletes and for Giardia infection. The tolerable risk for gastroenteritis by USEPA, which is 3.6 per cent , was overpassed in some cases. Though the results found in this study overpassed the cumulative incidence reported by LAMPARELLI et al. (2015). The results indicate the need for improvements in wastewater treatment systems in the coastal area of São Paulo. As QMRA is a tool capable in estimating the probability of infection it can help to highlight crucial issues in risk management


Assuntos
Cryptosporidium/patogenicidade , Ingestão de Líquidos , Giardia/patogenicidade , Água para Recreação , Medição de Risco , Água do Mar/microbiologia , Doenças Transmissíveis/transmissão , Microbiologia
12.
Antimicrob Agents Chemother ; 59(11): 6749-54, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26282413

RESUMO

Enteric protozoan parasites, which are spread by the fecal-oral route, are important causes of diarrhea (Giardia duodenalis) and amebic dysentery (Entamoeba histolytica). Cyst walls of Giardia and Entamoeba have a single layer composed of fibrils of ß-1,3-linked GalNAc and ß-1,4-linked GlcNAc (chitin), respectively. The goal here was to determine whether hand sanitizers that contain ethanol or isopropanol as the active microbicide might reduce transmission of these parasites. We found that treatment with these alcohols with or without drying in a rotary evaporator (to model rapid evaporation of sanitizers on hands) kills 85 to 100% of cysts of G. duodenalis and 90 to 100% of cysts of Entamoeba invadens (a nonpathogenic model for E. histolytica), as shown by nuclear labeling with propidium iodide and failure to excyst in vitro. Alcohols with or without drying collapsed the cyst walls of Giardia but did not collapse the cyst walls of Entamoeba. To validate the in vitro results, we showed that treatment with alcohols eliminated oral infection of gerbils by 1,000 G. duodenalis cysts, while a commercial hand sanitizer (Purell) killed E. invadens cysts that were directly applied to the hands. These results suggest that expanded use of alcohol-based hand sanitizers might reduce the transmission of Giardia and Entamoeba.


Assuntos
Entamoeba/patogenicidade , Giardia/patogenicidade , Higienizadores de Mão/uso terapêutico , 2-Propanol/farmacocinética , 2-Propanol/uso terapêutico , Animais , Entamoeba/efeitos dos fármacos , Etanol/farmacologia , Etanol/uso terapêutico , Feminino , Gerbillinae , Giardia/efeitos dos fármacos , Giardíase/tratamento farmacológico , Giardíase/fisiopatologia , Higienizadores de Mão/farmacologia
13.
PLoS Pathog ; 10(4): e1003908, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24722548

RESUMO

An abundant literature dealing with the population genetics and taxonomy of Giardia duodenalis, Cryptosporidium spp., Pneumocystis spp., and Cryptococcus spp., pathogens of high medical and veterinary relevance, has been produced in recent years. We have analyzed these data in the light of new population genetic concepts dealing with predominant clonal evolution (PCE) recently proposed by us. In spite of the considerable phylogenetic diversity that exists among these pathogens, we have found striking similarities among them. The two main PCE features described by us, namely highly significant linkage disequilibrium and near-clading (stable phylogenetic clustering clouded by occasional recombination), are clearly observed in Cryptococcus and Giardia, and more limited indication of them is also present in Cryptosporidium and Pneumocystis. Moreover, in several cases, these features still obtain when the near-clades that subdivide the species are analyzed separately ("Russian doll pattern"). Lastly, several sets of data undermine the notion that certain microbes form clonal lineages simply owing to a lack of opportunity to outcross due to low transmission rates leading to lack of multiclonal infections ("starving sex hypothesis"). We propose that the divergent taxonomic and population genetic inferences advanced by various authors about these pathogens may not correspond to true evolutionary differences and could be, rather, the reflection of idiosyncratic practices among compartmentalized scientific communities. The PCE model provides an opportunity to revise the taxonomy and applied research dealing with these pathogens and others, such as viruses, bacteria, parasitic protozoa, and fungi.


Assuntos
Cryptosporidium/genética , Variação Genética , Giardia/genética , Desequilíbrio de Ligação , Pneumocystis/genética , Cryptosporidium/patogenicidade , Giardia/patogenicidade , Pneumocystis/patogenicidade
14.
Orv Hetil ; 154(46): 1836-42, 2013 Nov 17.
Artigo em Húngaro | MEDLINE | ID: mdl-24212044

RESUMO

INTRODUCTION: Many species of Cryptosporidium, and two assemlages of Giardia duodenalis cause typically acute diaorrhoea in human. The oocysts and cysts of these parasites excreted in faeces are capable of infecting other hosts and those are environmentally stable. AIM: The aims of the study were to evaluate the prevalence and genotypes of Cryptosporidium and Giardia species from different water sources as well as to monitor and characterize the (oo)cyst contamination sources in watersheds. In addition, an epidemiological study was performed in three selected settlements. METHOD: Wide range of modern epidemiological and molecular detection methods have been applied. RESULTS: (Oo)cysts densities were associated with water receiving effluents of sewage treatment plants or originating from a forest environment. It was confirmed, that cattle can be a source of Cryptosporidium oocysts at watersheds and aquatic birds can play a role in the environmental dissemination of these protozoa. The epidemiological study demonstrated a specific epidemiological situation, giving essential evidence about giardiasis in asymptomatic carriers. The applied novel detection technology was found to be cost effective and simple procedure for screening catchments to identify those that require further treatment and more detailed microscopic counts. CONCLUSIONS: The presented results contribute to a better understanding the epidemiology and relevance of waterborne parasites, their surveillance and performance of future control measures to prevent waterborne infections in Hungary.


Assuntos
Criptosporidiose/parasitologia , Cryptosporidium/isolamento & purificação , Giardia/isolamento & purificação , Giardíase/parasitologia , Poluição da Água , Água/parasitologia , Animais , Aves/parasitologia , Cryptosporidium/patogenicidade , Fezes/parasitologia , Giardia/patogenicidade , Humanos , Hungria/epidemiologia , Oocistos/parasitologia , Esgotos/parasitologia , Poluição da Água/análise , Poluição da Água/estatística & dados numéricos , Abastecimento de Água/análise , Abastecimento de Água/estatística & dados numéricos
15.
Water Res ; 47(14): 5282-97, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23863377

RESUMO

This study is the first to report a quantitative microbial risk assessment (QMRA) on pathogens detected in stormwater discharges-of-concern, rather than relying on pathogen measurements in receiving waters. The pathogen concentrations include seven "Reference Pathogens" identified by the U.S. EPA: Cryptosporidium, Giardia, Salmonella, Norovirus, Rotavirus, Enterovirus, and Adenovirus. Data were collected from 12 sites representative of seven discharge types (including residential, commercial/industrial runoff, agricultural runoff, combined sewer overflows, and forested land), mainly during wet weather conditions during which times human health risks can be substantially elevated. The risks calculated herein therefore generally apply to short-term conditions (during and just after rainfall events) and so the results can be used by water managers to potentially inform the public, even for waters that comply with current criteria (based as they are on a 30-day mean risk). Using an example waterbody and mixed source, pathogen concentrations were used in QMRA models to generate risk profiles for primary and secondary water contact (or inhalation) by adults and children. A number of critical assumptions and considerations around the QMRA analysis are highlighted, particularly the harmonization of the pathogen concentrations measured in discharges during this project with those measured (using different methods) during the published dose-response clinical trials. Norovirus was the most dominant predicted health risk, though further research on its dose-response for illness (cf. infection) is needed. Even if the example mixed-source concentrations of pathogens had been reduced 30 times (by inactivation and mixing), the predicted swimming-associated illness rates - largely driven by Norovirus infections - can still be appreciable. Rotavirus generally induced the second-highest incidence of risk among the tested pathogens while risks for the other Reference Pathogens (Giardia, Cryptosporidium, Adenovirus, Enterovirus and Salmonella) were considerably lower. Secondary contact or inhalation resulted in considerable reductions in risk compared to primary contact. Measurements of Norovirus and careful incorporation of its concentrations into risk models (harmonization) should be a critical consideration for future QMRA efforts. The discharge-based QMRA approach presented herein is particularly relevant to cases where pathogens cannot be reliably detected in receiving waters with detection limits relevant to human health effects.


Assuntos
Medição de Risco/métodos , Microbiologia da Água , Cryptosporidium/patogenicidade , Monitoramento Ambiental/métodos , Giardia/patogenicidade , Humanos , Modelos Teóricos , Norovirus/patogenicidade , Saúde Pública , Recreação , Rotavirus/patogenicidade , Salmonella/patogenicidade , Estados Unidos
16.
Cell Microbiol ; 15(6): 860-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23437821

RESUMO

Some water-borne protozoan parasites induce diseases through their membrane-associated functional structures and virulence factors that hijack the host cellular molecules and signalling pathways leading to structural and functional lesions in the intestinal barrier. In this Microreview we analyse the insights on the mechanisms of pathogenesis of Entamoeba intestinalis, Giardia and Cryptosporidium observed in the human colon carcinoma fully differentiated colon cancer cell lines, cell subpopulations and clones expressing the structural and functional characteristics of highly specialized fully differentiated epithelial cells lining the intestinal epithelium and mimicking structurally and functionally an intestinal barrier.


Assuntos
Permeabilidade da Membrana Celular/fisiologia , Colo/fisiopatologia , Colo/parasitologia , Neoplasias do Colo/fisiopatologia , Neoplasias do Colo/parasitologia , Linhagem Celular Tumoral , Colo/patologia , Neoplasias do Colo/patologia , Cryptosporidium/patogenicidade , Cryptosporidium/fisiologia , Entamoeba/patogenicidade , Entamoeba/fisiologia , Giardia/patogenicidade , Giardia/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Humanos , Mucosa Intestinal/parasitologia , Mucosa Intestinal/patologia , Mucosa Intestinal/fisiopatologia , Microvilosidades/parasitologia , Microvilosidades/patologia , Microvilosidades/fisiologia
17.
Environ Sci Pollut Res Int ; 20(2): 778-89, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23001759

RESUMO

Toxoplasma gondii, Cryptosporidium parvum, and Giardia duodenalis are human waterborne protozoa. These worldwide parasites had been detected in various watercourses as recreational, surface, drinking, river, and seawater. As of today, water protozoa detection was based on large water filtration and on sample concentration. Another tool like aquatic invertebrate parasitism could be used for sanitary and environmental biomonitoring. In fact, organisms like filter feeders could already filtrate and concentrate protozoa directly in their tissues in proportion to ambient concentration. So molluscan shellfish can be used as a bioindicator of protozoa contamination level in a site since they were sedentary. Nevertheless, only a few researches had focused on nonspecific parasitism like protozoa infection on aquatic invertebrates. Objectives of this review are twofold: Firstly, an overview of protozoa in worldwide water was presented. Secondly, current knowledge of protozoa parasitism on aquatic invertebrates was detailed and the lack of data of their biological impact was pointed out.


Assuntos
Monitoramento Ambiental/métodos , Invertebrados/parasitologia , Água/parasitologia , Animais , Organismos Aquáticos/parasitologia , Cryptosporidium/fisiologia , Giardia/patogenicidade , Giardia/fisiologia , Água Subterrânea/parasitologia , Frutos do Mar/parasitologia , Toxoplasma/patogenicidade , Toxoplasma/fisiologia
18.
Clin Microbiol Rev ; 25(3): 420-49, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22763633

RESUMO

Several enteric protozoa cause severe morbidity and mortality in both humans and animals worldwide. In developed settings, enteric protozoa are often ignored as a cause of diarrheal illness due to better hygiene conditions, and as such, very little effort is used toward laboratory diagnosis. Although these protozoa contribute to the high burden of infectious diseases, estimates of their true prevalence are sometimes affected by the lack of sensitive diagnostic techniques to detect them in clinical and environmental specimens. Despite recent advances in the epidemiology, molecular biology, and treatment of protozoan illnesses, gaps in knowledge still exist, requiring further research. There is evidence that climate-related changes will contribute to their burden due to displacement of ecosystems and human and animal populations, increases in atmospheric temperature, flooding and other environmental conditions suitable for transmission, and the need for the reuse of alternative water sources to meet growing population needs. This review discusses the common enteric protozoa from a public health perspective, highlighting their epidemiology, modes of transmission, prevention, and control. It also discusses the potential impact of climate changes on their epidemiology and the issues surrounding waterborne transmission and suggests a multidisciplinary approach to their prevention and control.


Assuntos
Controle de Doenças Transmissíveis/métodos , Cryptosporidium/patogenicidade , Promoção da Saúde/métodos , Infecções por Protozoários/epidemiologia , Saúde Pública , Clima , Cyclospora/patogenicidade , Países Desenvolvidos , Transmissão de Doença Infecciosa/prevenção & controle , Entamoeba/patogenicidade , Giardia/patogenicidade , Humanos , Prevalência , Infecções por Protozoários/diagnóstico , Infecções por Protozoários/prevenção & controle
19.
Am J Epidemiol ; 176(5): 387-95, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22842722

RESUMO

In developing countries where diarrheal disease is a leading cause of morbidity and mortality in children under 5 years of age, enteric coinfection is common. There is little understanding, however, of the biologic interaction between coinfecting pathogens. The authors investigated the potential for synergistic interaction between coinfecting pathogens on diarrhea pathogenesis using an epidemiologic framework. They conducted community-based, case-control studies in 22 communities in northwestern Ecuador between 2003 and 2008. Risk ratios of diarrhea associated with single infections and coinfections were estimated. Interaction between coinfecting pathogens was assessed through departure from risk ratio additivity and multiplicativity after adjustment for age. On the additive scale, the authors found departure from the null value of 0 for rotavirus-Giardia coinfections (interaction contrast ratio = 8.0, 95% confidence interval: 3.1, 18.9) and for rotavirus-Escherichia coli coinfections (interaction contrast ratio = 9.9, 95% confidence interval: 2.6, 28.4). On the multiplicative scale, they found departure from the value of 1 for rotavirus-Giardia coinfections (multiplicative interaction = 3.6, 95% confidence interval: 1.3, 8.7). This research provides epidemiologic evidence for synergism between rotavirus and other enteric pathogens. During coinfection, the pathogenic potential of each organism appears to be enhanced. The potential for pathogenesis to be more severe in the presence of a rotavirus coinfection amplifies the need for rotavirus vaccination.


Assuntos
Coinfecção/complicações , Diarreia/microbiologia , Infecções por Escherichia coli/complicações , Giardíase/complicações , Infecções por Rotavirus/complicações , Adolescente , Adulto , Estudos de Casos e Controles , Criança , Pré-Escolar , Coinfecção/diagnóstico , Coinfecção/epidemiologia , Diarreia/epidemiologia , Equador/epidemiologia , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Infecções por Escherichia coli/diagnóstico , Infecções por Escherichia coli/epidemiologia , Giardia/isolamento & purificação , Giardia/patogenicidade , Giardíase/diagnóstico , Giardíase/epidemiologia , Humanos , Lactente , Recém-Nascido , Razão de Chances , Prevalência , Rotavirus/isolamento & purificação , Rotavirus/patogenicidade , Infecções por Rotavirus/diagnóstico , Infecções por Rotavirus/epidemiologia , Virulência , Adulto Jovem
20.
Adv Parasitol ; 78: 57-95, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22520441

RESUMO

In this review, the current status of genomic and proteomic research on Giardia is examined in terms of evolutionary biology, phylogenetic relationships and taxonomy. The review also describes how characterising genetic variation in Giardia from numerous hosts and endemic areas has provided a better understanding of life cycle patterns, transmission and the epidemiology of Giardia infections in humans, domestic animals and wildlife. Some progress has been made in relating genomic information to the phenotype of Giardia, and as a consequence, new information has been obtained on aspects of developmental biology and the host-parasite relationship. However, deficiencies remain in our understanding of pathogenesis and host specificity, highlighting the limitations of currently available genomic datasets.


Assuntos
Genoma de Protozoário , Giardia/genética , Giardíase/parasitologia , Proteoma , Animais , Variação Genética , Giardia/metabolismo , Giardia/patogenicidade , Giardíase/patologia , Giardíase/transmissão , Interações Hospedeiro-Parasita , Humanos , Filogenia
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