Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-02-07T12:40:29Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_EstudoEpidemiologicoAmebiase.pdf: 672147 bytes, checksum: c79be901d2d8e5217f47c8d1f43d0318 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2014-02-07T15:11:58Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_EstudoEpidemiologicoAmebiase.pdf: 672147 bytes, checksum: c79be901d2d8e5217f47c8d1f43d0318 (MD5) / Made available in DSpace on 2014-02-07T15:11:58Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_EstudoEpidemiologicoAmebiase.pdf: 672147 bytes, checksum: c79be901d2d8e5217f47c8d1f43d0318 (MD5) Previous issue date: 2005 / CESUPA - Centro Universitário do Pará / A epidemiologia da amebíase está sendo reavaliada desde que a E. histolytica (patogênica) foi considerada espécie distinta de E. dispar (não patogênica). Neste estudo, investigou-se a freqüência da amebíase em uma amostra de residentes do Pará por diferentes técnicas de diagnóstico e avaliou-se a patogenia do parasito. Os participantes (n = 845) forneceram material fecal e destes, 191 foram entrevistados quanto aos sintomas de diarréia, cólicas intestinais, constipação, náuseas e vômito. Foram também analisados 8 exsudatos de pacientes com suspeita de amebíase hepática. As amostras foram observadas sob microscopia de luz e a confirmação de E. histolytica feita a partir da pesquisa de antígenos. Um total de 98 amostras fecais e todos os exsudatos foram semeados em meio Pavlova para isolamento e posterior caracterização bioquímica e molecular (identificação de espécie e genotipagem). Isolados de outras regiões do Brasil foram também genotipados. A positividade obtida foi de 29,35% (248/845) e não houve correlação com a faixa etária. A microscopia revelou baixa sensibilidade (45,26%; 74/334), porém elevada especificidade (87,03%; 260/334) quando comparada ao ELISA. Houve relação significativa (OR 4,4026) entre a presença de sintomas e a positividade no ELISA, sendo a diarréia (58,82%) e a cólica intestinal (58,82%) os sintomas mais relatados. Nenhum exsudato foi positivo no exame a fresco, porém 7 foram positivos no ELISA. Obteve-se 22 isolados de material fecal e a caracterização da HE foi possível em 13, dos quais 7 E. histolytica e 6 E. dispar. O DNA de 22 isolados e dos exsudatos foram testados para identificação molecular de espécie e genotipagem. Do total, 16 cultivos (9 cepas mistas, 4 E. dispar e 3 E. histolytica) e 5 exsudatos (todos E. histolytica) amplificaram na PCR. A genotipagem identificou adicional positividade para E. histolytica em um exsudato e revelou diferentes polimorfismos de comprimento para o locus 1-2 de E. histolytica e E. dispar do Pará e de outras regiões do Brasil e um caso de co-infecção por diferentes genótipos de E. dispar. Nossos resultados revelam que a amebíase invasiva é um importante problema de saúde pública em nossa população e grande variedade de genótipos de E. histolytica contribuem para a doença no Brasil. / The amebiasis epidemiology had been evaluated since the E. histolytica (pathogenic) was differentiated from E. dispar (non-pathogenic). In this study, it had investigated the amebiasis frequency in residents from Pará using different diagnostic techniques and evaluated the parasite pathogenesis. All participants (n = 845) had given their fecal material and from them, 191 were asked about the symptoms of diarrhea, abdomen pain, constipation, nausea and vomit. We had also analyzed 8 liver exudates from patients suspected of hepatic amebiasis. All samples were examined by microscopy and the E. histolytica confirmation was done by antigen detection (E. histolytica Test. TechLab). Of the total, 98 fecal samples and all exudates were cultured in Pavlova medium for parasite isolation and biochemical characterization and molecular (species identification and genotyping of the locus 1-2). Strains from other Brazil regions were also genotyped. The positive rate for E. histolytica found was 29.35% (248/845) and there was no correlation with age. The sensitivity of the microscopy method was low (45.26% - 74/334) and the specificity high (87.03% - 260/334) when compared to the ELISA test. The correlation between presence of symptoms and ELISA positive results was significant (OR 4.4026) with the diarrhea and abdominal pain being the most reported. None of the exudate samples was positive under the microscopy, but 7 of them were ELISA positive. We had success in culturing only 22 fecal samples. The characterization of HE was possible only for 13 isolates, from which, 7 were E. histolytica and 6 E. dispar. The DNA of the 22 isolates and all exudates were tested by PCR for the species identification and genotyping. Of the total, 16 strains (9 mixed, 4 E. dispar and 3 E. histolytica) and 5 exudate had amplified at the PCR. The genotyping had identified additional positivity for E. histolytica in one exudate and showed different length polymorphisms for the locus 1-2 de E. histolytica and E. dispar of Pará and other Brazil regions and one case of co-infection by different genotypes of the E. dispar. Our results had showed that the invasive amebiasis is an important public health problem within the Amazonian population and that the high genotype variability of E. histolytica contribute for the maintenance of this disease in Brazil.

Underdiagnosis of intestinal parasites in patients with diarrhea A compilation from the Swedish public health authority indicates that infections caused by Cryptosporidium spp. increased in Sweden from 47 cases in 2004 to 594 cases in 2016 and Giardia intestinalis causes around 1300 infections per year. The primary aim of this study was to investigate the prevalence of parasites in patients with diarrhea. Furthermore, the study investigated whether samples taken with E-swab could be analyzed with real-time polymerase chain reaction (PCR) for detection of Cryptosporidium spp., Dientamoeba fragilis, Entamoeba histolytica/dispar and G. intestinalis rather than Sodium acetate-acetic acid-formaline fixative (SAF-fixative). Prevalence of parasites in fecal samples was collected from 200 samples from patients with bacterial issue ordered. For evaluation of E-swab, 22 frozen, unfixed samples that were positive for intestinal parasites was used. Twelve positive E-swab samples was used as comparative positive controls. This was analyzed using real-time PCR. Bacteria was counted for 9.5% of the infections whilst parasites counted for 14% of the infections. The conclusion was that E-swab could replace SAF-fixative in the diagnosis of intestinal parasites and that there is that an underdiagnosis of intestinal parasites. Keywords: Cryptosporidium spp, Dientamoeba fragilis, Entamoeba histolytica, Entamoeba dispar, Giardia intestinalis, real-time PCR, E-swab, prevalence.

MSc (Microbiology) / Department of Microbiology

No description available.

Coyotes (Canis latrans) have inhabited Florida (USA) since the 1960s and are currently found throughout the state. The purpose of the present study was to obtain information on enteric parasites and diet of Florida coyotes from two different habitat types. Seasonal variation in diet was also examined. Fresh coyote fecal samples were collected from protected and urban habitats in Pinellas County, Florida (USA; 27°54' n, 82°41'w) from may 2005 to march 2007. A standard fecal flotation examination and formalin-ethyl acetate sedimentation were utilized on fecal samples collected from the protected (n=40) and urban (n=50) habitats. Five novel (newly documented) parasites of coyotes were discovered; one cestode (Hymenolepis spp.), one nematode (Ascaris spp.), and three protozoa (Balantidium coli, Blastocystis spp., and Entamoeba histolytica). Novel parasites of Florida coyotes were also discovered two cestodes (diphyllobothrium latum and dipylidium caninum), two nematodes (toxocara canis and uncinaria stenocephala), one trematode (paragonimus spp.), and four protozoa (cryptosporidium spp., giardia canis, isospora spp., and sarcocystis cruzi). One cestode (Taenia spp.), three nematodes (Ancylostoma caninum, Physaloptera spp., and Trichurus vulpis), and one trematode (Alaria spp.) were also recovered, all of which have previously been documented in Florida coyotes. Diet items were identified to the lowest possible taxonomic level by gross morphological characteristics and medullary configurations of dorsal guard hairs. A poisson regression was utilized to determine the relation between diet items and habitat, season, and interaction. In the protected habitat (n=49), vegetative matter (96%), Insecta (53%), and Rodentia (45%) were recovered most often, as opposed to berries (56%) and Lagomorpha (32%) in the urban habitats (n=71). Overall, vegetative matter, berries, and Lagomorpha were recovered most often from Florida coyote fecal samples. Odocoileus virginianus, Lagomorpha, and berries varied the most between wet and dry seasons. It is suggested that Florida coyotes are more susceptible to reinfection by novel parasites because of their rapid range expansion and lack of acquired immunity. Rapid habitat loss in Florida (i.e., urbanization) lowers survival of adult coyotes, increases the probability of transmission of disease between wild and domestic canids, and alters the diet of coyotes by lowering biological diversity of available prey items.

Interleukin-8 is a chemokine which is chemotactic for neutrophils and T-lymphocytes and plays a crucial role in the pathogenesis of inflammatory bowel disease. Intestinal mucosal epithelial cells produce IL-8 in response to pathogens which mediates bidirectional communication between pathogen and host. The objective of this study was to investigate the molecular mechanisms involved in IL-8 gene regulation in T84 human colonic epithelial cells. To determine if IL-8 plays a role in the pathogenesis of intestinal amebiasis, the effect of Entamoeba histolytica on IL-8 gene expression was investigated. E. histolytica secreted components enhanced IL-8 mRNA expression and protein production in the absence of amebae-enterocyte contact. The proinflammatory cytokines IL-1beta and TNF-alpha were not involved in IL-8 protein production. As PGE2 is central in mucosal inflammation, the effect of PGE2 on IL-8 gene expression was determined. Using purified PGE2 and PGE2 receptor agonists, it was shown that PGE2 coupled to the EP4 receptor and triggered cAMP-dependent PKA signaling which upregulated IL-8 mRNA expression at the posttranscriptional level. Elevation of [Ca 2+]i from intracellular Ca2+ stores by A23187 or thapsigargin stimulated IL-8 mRNA transcription and IL-8 protein production through the activation of calcineurin. Moreover, IL-8 3'-UTR had a strong suppressive effect on CAT reporter gene expression in COS7 cells by reducing its mRNA level. A unique fragment (nt 2387-2743) containing AU rich elements was shown to attenuate CAT mRNA expression by destabilizing the transcripts. Secondary structure but not AU rich elements played a major role in CAT mRNA turnover.

Charles University, Faculty of Science Department of parasitology Doctoral study programme: Parasitology Abstract (en) Analysis of the genome of a free-living amoeba Mastigamoeba balamuthi and its comparison with pathogenic Entamoeba histolytica Mgr. Vojtěch Žárský Supervisor: prof. RNDr. Jan Tachezy, Ph.D. Praha, 2020 Abstract Examination and comparison of organisms have been tremendously important for the study of life's history on earth. The progress of our understanding of the genetic basis of heredity and the recent boom of sequencing technologies allows us to continue in this exciting field of research from the perspective of genes and genomes. In this work, I focus on the study of an anaerobic amoeba Mastigamoeba balamuthi, which is related to an important human pathogen Entamoeba histolytica. Comparative analysis allows us to draw some conclusions about the nature of the common ancestor of Mastigamoeba and E. histolytica, how it adapted to the anaerobic lifestyle, and about the way the Entamoeba lineage evolved to become a successful parasite. Surprisingly we also noticed that besides hydrogenosomes (hydrogen-producing organelles related to mitochondria), M. balamuthi also harbors peroxisomes - organelles thought to be absent in anaerobic organisms. This finding motivated us to inquire more about...

Der Intestinalparasit Entamoeba histolytica exprimiert während seines gesamten Lebenszyklus zwei Cysteinpeptidase-Inhibitoren der Chagasin-Familie (EhICP1 und EhICP2). Beide EhICPs inhibieren die peptidolytische Aktivität von E. histolytica-Zellextrakten und der humanen Peptidasen Cathepsin B und L unterschiedlich effektiv. Innerhalb der Trophozoiten von E. histolytica sind die EhICPs in verschiedenen Kompartimenten lokalisiert, EhICP1 im Cytosol und EhICP2 in Vesikeln, wo es mit verschiedenen lysosomalen Hydrolasen und mit phagocytierten Partikeln kolokalisiert. Im Vergleich zu den amöbialen Peptidasen liegen die EhICPs im molaren Unterschuss innerhalb der Zellen vor. Außerdem ist die Produktion und Lokalisationen der Peptidasen sowie der verschiedenen physiologische Prozesse, an denen die EhCPs beteiligt sind, unabhängig von der Expression der ehicp-Gene. Die erhaltenen Ergebnisse lassen darauf schließen, dass EhICP1 die Zelle vor versehentlich aus undicht gewordenen Lysosomen freigesetzten Peptidasen schützt, während EhICP2 an housekeeping-Prozessen, wie der Kontrolle der Prozessierung von Peptidasen, beteiligt sein könnte. Neben der Charakterisierung der Cysteinpeptidase-Inhibitoren aus E. histolytica bildeten Untersuchungen an einem Annexin-homologen Protein aus Giardia lamblia, einem anderen Intestinalparasiten, einen weiteren Schwerpunkt der hier vorgestellten Arbeit. Das Annexin-homologe alpha-19-Giardin nimmt unter allen Annexinen eine Sonderstellung dahingehend ein, als dass es als bisher einzig bekanntes Annexin ein N-terminales Signal für eine Doppelacylierung besitzt. Mit Hilfe von verschiedenen Expressionssystemen konnte hier experimentell belegt werden, dass alpha-19-Giardin tatsächlich als Substrat für eine Myristoyl- sowie für eine Palmitoyltransferase fungiert, und diese Modifikation die Membranassoziation des Proteins bewirkt.

Gastrointestinal parasites impose a great and often silent burden of morbidity and mortality on poor populations in developing countries. Veron, Dominican Republic (DR), is a rural city in the southeastern corner of the country where many Dominicans and Haitians migrate to for work in support and expansion of the tourist industry of Punta Cana. Few studies of the prevalence of gastrointestinal (GI) parasitic infections have been published in the DR. Presently, there is a high prevalence of gastrointestinal parasitic infections throughout the poorest areas of the DR and Haiti. This study investigated the prevalence of GI protozoan and helminth parasites from children at the Rural Clinic of Veron during 2008. Participants provided a fecal sample that was examined microscopically for protozoan and helminth parasites using the fecal flotation technique to concentrate and isolate helminth ova and protozoan cysts. Of 108 fecal samples examined, 107 were positive for one or more parasites. Participant ages ranged from 2 to 15 years; 52 were males and 56 were females. Percent infection rates were 48.2% for Ascaris lumbricoides, 13.9% for Enterobius vermicularis, 24.1% for Entamoeba histolytica, and 22.2% for Giardia intestinalis. 9.3% had double infections. A survey of subject characteristics and risk factors was completed by each parent/guardian. Any plan to reduce GI parasites in children of this region will require a determined effort between international, national, and local health authorities combined with improved education of schools, child care providers, food handlers, and agricultural workers. A special effort must be made to reach out to immigrants and those not part of the public education system and to address microbial water quality. / Ph. D.

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2015-06-22T17:06:27Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_InvestigacaoPrevalenciaAmebiase.pdf: 998371 bytes, checksum: 9fbcc3b63ed1bd45a04c6848805b8dc9 (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2015-06-25T13:29:11Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_InvestigacaoPrevalenciaAmebiase.pdf: 998371 bytes, checksum: 9fbcc3b63ed1bd45a04c6848805b8dc9 (MD5) / Made available in DSpace on 2015-06-25T13:29:11Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_InvestigacaoPrevalenciaAmebiase.pdf: 998371 bytes, checksum: 9fbcc3b63ed1bd45a04c6848805b8dc9 (MD5) Previous issue date: 2012 / A amebíase é uma infecção causada pela Entamoeba histolytica e considerada uma importante causa de morbi-mortalidade no mundo. Estudos relatam uma prevalência elevada da amebíase em regiões tropicais, principalmente em comunidades que vivem em precárias condições sanitárias. O estudo epidemiológico da amebíase tem sido reavaliado desde que a E. histolytica, forma patogênica, foi distinta da E. dispar, forma não patogênica. O objetivo desta pesquisa foi estimar a prevalência de E. histolytica na população de escolares da rede municipal da cidade de Imperatriz (MA). Realizou-se um estudo de corte transversal que envolveu 405 escolares. As amostras foram analisadas através de exame parasitológico, pelo método de sedimentação espontânea, para triagem das amostras positivas para o complexo E. histolytica/E .dispar. Os exames positivos para o complexo E. histolytica/E. dispar foram posteriormente submetidos à reação em cadeia da polimerase (PCR) para diferenciação das espécies. Na PCR foi utilizado para amplificação inicial de um fragmento de 1076 pb, um conjunto de primers externo E1 e E2, seguida por uma PCR Multiplex usando os primers Eh-L/Eh-R e Ed-L/Ed-R para amplificação da E. histolytica e E. dispar, respectivamente. Não foi diagnosticado pela PCR amostras positivas para E.histolytica. A prevalência da E. dispar na população de escolares foi de 2,7% (11/405). A PCR se mostrou importante ferramenta para o diagnóstico diferencial das Entamoebas. Porém, estudos de prevalência da amebíase devem ser impulsionados em população com características diferenciadas, a fim de contribuir de forma efetiva para definir a situação epidemiológica desta infecção na cidade de Imperatriz. / Amoebiasis is an infection caused by Entamoeba histolytica and an important cause of morbidity and mortality worldwide. Studies have reported a high prevalence of in tropic amebiasis al regions, especially in communities living in poor sanitary conditions. The epidemiological study of amoebiasis has been reevaluated since E. histolytica, pathogenic form, was distinct from E. dispar, non-pathogenic form. The aim of this study was to estimate the prevalence of E. histolytica in the population of the municipal city Imperatriz (MA). We conducted a cross-sectional study involving 405 students. By the screening of the complex E. histolytica / E.dispar parasitological examination was performed using the sedimentation method. The positive samples for E.histolytica/ E.dispar complex were subjected to polymerase chain reaction (PCR) for species differentiation. For initial amplification by the PCR we used a outer primer set E1 and E2 that amplified a 1076 bp fragment and followed by a multiplex PCR using inner primer set Ed-L/Ed-R and Eh-L/Eh-R E.histolytica and E.dispar respectively. No sample showing positivity for E. histolytica The prevalence of E.dispar in the population was 2.7% (11/405). The PCR proved important tool for the differential diagnosis of Entamoebas. However, studies on the prevalence of amoebiasis should be conducted in population with different characteristics, in order to contribute effectively to define the epidemiological situation of this infection in Imperatriz city.