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Megbaru Alemu - One of the best experts on this subject based on the ideXlab platform.
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foodborne intestinal Protozoan Infection and associated factors among patients with watery diarrhea in northern ethiopia a cross sectional study
Journal of Health Population and Nutrition, 2018Co-Authors: Birhane Berhe, Gessessew Bugssa, Sena Bayisa, Megbaru AlemuAbstract:Intestinal protozoa are parasites transmitted by consumption of contaminated water and food and mainly affect children and elder people and cause considerable health problems. They are the leading causes of outpatient morbidity due to diarrhea in the developing countries. So, assessing water and food source of diarrheal patients and identifying the main associated factors for transmission of Protozoan parasitic Infections help for effective control measures of Protozoan Infections. Hence, the current study was aimed at determining the prevalence of foodborne intestinal protozoa Infections and associated factors among diarrheic patients in North Ethiopia. A health facility based cross-sectional study was conducted among 223 patients with watery diarrhea in four selected government health facilities in North Ethiopia from November 2016–June 2017. A structured questionnaire was used to collect data on socio-demography of study participants and factors associated with foodborne protozoa Infections. The diarrheic stool samples were collected, transported, and processed using direct wet mount, formal-ether concentration and modified ZiehlNeelson staining methods. The data were analyzed using SPSS version 21 and descriptive statistics, bi-variate, and multivariate logistic regressions were computed. P-value < 0.05 at 95% confidence interval was considered statistically significant. The overall prevalence of foodborne protozoa Infection was 101 (45.3%). The predominant protozoa species identified was Entamoeba histolytica/dispar 55 (24.7%), followed by Giardia intestinalis 25 (11.2%) and Cryptosporidium species 5 (2.2%). The highest proportion of protozoa Infection was observed among males (23.3%) and the age group 15–24 years (13.5%). Statistically significant associations were observed between foodborne Protozoan Infection and not using any type of recipe to decontaminate salads and fruits (AOR = 2.64, 95 CI: 1.34–5.19, P = 0.005) and using vinegar as a decontaminant (AOR = 2.83, 95 CI: 1.24–6.48, P = 0.014). Eating out (meals at a restaurant) on the other hand was found to be protective for foodborne Protozoan Infection (AOR = 0.43, 95 CI: 0.23–0.78, P = 0.006). Our study revealed that foodborne protozoa Infections are of public health significance in the study area. Vinegar, which is frequently used as a recipe for decontaminating salads and fruits, is inversely related to foodborne protozoa parasite Infection .
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Foodborne intestinal Protozoan Infection and associated factors among patients with watery diarrhea in Northern Ethiopia; a cross-sectional study
BMC, 2018Co-Authors: Birhane Berhe, Gessessew Bugssa, Sena Bayisa, Megbaru AlemuAbstract:Abstract Background Intestinal protozoa are parasites transmitted by consumption of contaminated water and food and mainly affect children and elder people and cause considerable health problems. They are the leading causes of outpatient morbidity due to diarrhea in the developing countries. So, assessing water and food source of diarrheal patients and identifying the main associated factors for transmission of Protozoan parasitic Infections help for effective control measures of Protozoan Infections. Hence, the current study was aimed at determining the prevalence of foodborne intestinal protozoa Infections and associated factors among diarrheic patients in North Ethiopia. Methods A health facility based cross-sectional study was conducted among 223 patients with watery diarrhea in four selected government health facilities in North Ethiopia from November 2016–June 2017. A structured questionnaire was used to collect data on socio-demography of study participants and factors associated with foodborne protozoa Infections. The diarrheic stool samples were collected, transported, and processed using direct wet mount, formal-ether concentration and modified ZiehlNeelson staining methods. The data were analyzed using SPSS version 21 and descriptive statistics, bi-variate, and multivariate logistic regressions were computed. P-value
Eric Y Denkers - One of the best experts on this subject based on the ideXlab platform.
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phagocyte responses to Protozoan Infection and how toxoplasma gondii meets the challenge
PLOS Pathogens, 2012Co-Authors: Eric Y Denkers, Anne G Schneider, Sara B Cohen, Barbara A ButcherAbstract:The intracellular Protozoan Toxoplasma gondii is arguably the most successful parasite on the planet. It exploits an uncommonly wide host range that encompasses essentially all warm-blooded animals including both mammalian and avian species. Sexual reproduction in the intestine of the definitive host, the cat, results in fecal shedding of up to 108 highly infectious oocysts. The presence of felines from equatorial latitudes to sub-arctic regions of the globe ensures widespread distribution of the parasite. Moreover, unlike closely related apicomplexans such as the Plasmodia, passage through the definitive host is not obligatory to complete the life-cycle, because T. gondii can be transmitted from one intermediate host to the next through predation and carnivorism [1]. While Toxoplasma causes asymptomatic Infection in most hosts, the parasite may emerge as an opportunistic Infection under immunodeficient conditions such as in AIDS patients and during congenital Infection. This danger underscores the importance of the encounter between T. gondii and the host immune system in determining the success of this particular host-parasite interaction. It is well understood that complete evasion of immunity (or for that matter passive failure to trigger immunity) results in rampant Infection and host death, an outcome undesirable for both host and parasite. At the same time, we are learning in greater detail the mechanisms employed by the host immune system to destroy Toxoplasma. The parasite must obviously avoid this outcome of immunity to ensure persistence. The global success of T. gondii (over 109 asymptomatic Infections in humans alone) suggests that the parasite employs sophisticated molecular strategies to balance evasion versus activation of the host immune response. As summarized in Figure 1, the multiple ways this unifying principle plays out is revealed in studies on Infection in phagocytes of innate immunity, namely dendritic cells (DC), macrophages, and neutrophils. These cells are among the first to encounter and be infected by Toxoplasma after the parasite crosses the intestinal epithelium. The studies together form a platform from which we can further understand the complex relationship between microbial pathogens and cells of the innate immune system. Figure 1 Integrating phagocyte function with T. gondii Infection. Dendritic Cells Are Sentinels and Trojan Horses Early on it was recognized that DC were an early source of IL-12 driving protective Th1 responses to Toxoplasma. Further studies using an intraperitoneal Infection model showed that ablation of CD11c+ DC results in failure to mount protective immunity and death during Infection [2]. With the discovery of Toll-like receptors (TLR) and their ligands in the late 1990s, attention turned to the role of this system in sensing Protozoan pathogens, in particular T. gondii [3]. Indeed, mice lacking MyD88, a central adaptor of TLR signaling, are extremely susceptible to Infection. More specifically, it has been shown using cell-specific gene-deleted mouse strains that MyD88 expression in CD11c+ dendritic cells is required to resist Toxoplasma Infection [4]. There is evidence for involvement of mouse TLR2, TLR4, TLR9, and TLR11 in the innate immune response to T. gondii [3]. Of these receptors, deletion of TLR11 has the most dramatic effect on loss of host resistance [5]. However, Tlr11−/− mice fail to recapitulate the extreme susceptibility phenotype of Myd88−/− mice. This has led to the suggestion that multiple TLR function together to provide optimal resistance, or alternatively that other untested TLR serve as the major MyD88-dependent receptor mediating protective immunity. Toxoplasma profilin (TgPRF), an actin polymerizing molecule, is the ligand recognized by TLR11 [5]. In DC, TgPRF stimulates TLR11-dependent IL-12 production. Interestingly, it was recently found that this response occurs through phagocytic uptake of parasite material followed by TLR11 activation from within the endolysosome [6]. Surface-expressed glycosylphosphatidylinositol moieties purified from tachyzoites have also been found to mediate TLR2 and TLR4 activation [3], although the in vivo importance of this phenomenon is not clear. While the TLR11/TgPRF interaction is significant in the rodent response to Toxoplasma, the importance of TgPRF in human Infection is uncertain since we do not express functional TLR11. In addition to TLR-dependent recognition of Toxoplasma, there is clear evidence for MyD88-independent resistance. This is because Myd88−/− mice develop strong (albeit delayed) Th1 responses during oral Infection, and the same mouse strain develops protective immunity following intraperitoneal Infection with attenuated parasites [7]. In this regard, it was recently shown that release of tachyzoite dense granule protein GRA5 into the host cytoplasm by intracellular parasites bypasses MyD88 to activate NFκB and stimulate IL-12 synthesis [8]. The relative roles that profilin and GRA5 assume during normal Infection have not yet been determined. However, GRA5 IL-12 inducing properties are parasite strain-specific, in that only one lineage (Type II) of the three predominant strains found in Europe and North America possess this activity [8]. On the other hand, there is no evidence that profilin acts in a parasite-strain-dependent manner. Another function of DC during the response to Toxoplasma is to serve as early reservoirs of Infection [9], [10]. It has been suggested that parasites utilize DC in a “Trojan horse” strategy to disseminate throughout the host. Upon in vitro Infection, DC acquire a hypermotility phenotype that is dependent upon host cell G-protein signaling triggered by the parasite. Intraperitoneal inoculation of tachyzoite-harboring DC spreads Infection more rapidly than injection of extracellular parasites alone, suggesting that DC hypermotility promotes dissemination during in vivo Infection, although whether a similar phenomenon occurs during oral Infection is not clear [11]. Interestingly, hypermotility and in vivo dissemination of infected DC occur most efficiently with Type II Toxoplasma, the strain most frequently found in human Infection [12].
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toxoplasma gondii triggers release of human and mouse neutrophil extracellular traps
Infection and Immunity, 2012Co-Authors: Delbert Abi S Abdallah, Changyou Lin, Carissa J Ball, Michael R King, Gerald E Duhamel, Eric Y DenkersAbstract:Neutrophils have recently been shown to release DNA-based extracellular traps that contribute to microbicidal killing and have also been implicated in autoimmunity. The role of neutrophil extracellular trap (NET) formation in the host response to nonbacterial pathogens has received much less attention. Here, we show that the Protozoan pathogen Toxoplasma gondii elicits the production of NETs from human and mouse neutrophils. Tachyzoites of each of the three major parasite strain types were efficiently entrapped within NETs, resulting in decreased parasite viability. We also show that Toxoplasma activates a MEK-extracellular signal-regulated kinase (ERK) pathway in neutrophils and that the inhibition of this pathway leads to decreased NET formation. To determine if Toxoplasma induced NET formation in vivo, we employed a mouse intranasal Infection model. We found that the administration of tachyzoites by this route induced a rapid tissue recruitment of neutrophils with evidence of extracellular DNA release. Taken together, these data indicate a role for NETs in the host innate response to Protozoan Infection. We propose that NET formation limits Infection by direct microbicidal effects on Toxoplasma as well as by interfering with the ability of the parasite to invade target host cells.
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functional aspects of toll like receptor myd88 signalling during Protozoan Infection focus on toxoplasma gondii
Clinical and Experimental Immunology, 2009Co-Authors: Charlotte E Egan, Woraporn Sukhumavasi, Barbara A Butcher, Eric Y DenkersAbstract:Toll-like receptor (TLR)/MyD88 signalling has emerged as a major pathway of pathogen recognition in the innate immune system. Here, we review recent data that begin to show how this pathway controls the immune response to Protozoan Infection, with particular emphasis on the opportunistic pathogen Toxoplasma gondii. The various ways that the parasite activates and suppresses TLR/MyD88 signalling defines several key principals that illuminate the complexities of the host-pathogen interaction. We also speculate how TLR/MyD88 signalling might be exploited to provide protection against Toxoplasma, as well as other protozoa and Infection in general.
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apoptosis and the balance of homeostatic and pathologic responses to Protozoan Infection
Infection and Immunity, 2003Co-Authors: Cristina L Gavrilescu, Eric Y DenkersAbstract:Apoptosis, or programmed cell death (PCD), is a physiological response that eliminates unwanted cells, an evolutionarily ancient process that is present in all multicellular organisms. Apoptosis is used during embryogenesis as a way to shape future adult forms (e.g., limbs, fingers) or to suppress
Ricardo T Gazzinelli - One of the best experts on this subject based on the ideXlab platform.
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role of tlrs myd88 in host resistance and pathogenesis during Protozoan Infection lessons from malaria
Seminars in Immunopathology, 2008Co-Authors: Catherine Ropert, Ricardo T Gazzinelli, Bernardo S FranklinAbstract:Toll-like receptors (TLRs) are important to initiate the innate immune response to a wide variety of pathogens. The protective role of TLRs during Infection with Protozoan parasites has been established. In this regard, malaria represents an exception where activation of TLRs seems to be deleterious to the host. In this article, we review the recent findings indicating the contrasting role of Myeloid Differentiation Primary-Response gene 88 (MyD88) and TLRs during malaria and Infection with other protozoa. These findings suggest that MyD88 may represent an Achilles' heel during Plasmodium Infection.
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activation of toll like receptor 2 by glycosylphosphatidylinositol anchors from a Protozoan parasite
Journal of Immunology, 2001Co-Authors: Marco Antonio Campos, Igor C Almeida, Osamu Takeuchi, Shizuo Akira, Eneida P Valente, Daniela O Procopio, Luiz R Travassos, Jason A Smith, Douglas T Golenbock, Ricardo T GazzinelliAbstract:Glycosylphosphatidylinositol (GPI) anchors and glycoinositolphospholipids (GIPLs) from parasitic protozoa have been shown to exert a wide variety of effects on cells of the host innate immune system. However, the receptor(s) that are triggered by these Protozoan glycolipids has not been identified. Here we present evidence that Trypanosoma cruzi -derived GPI anchors and GIPLs trigger CD25 expression on Chinese hamster ovary-K1 cells transfected with CD14 and Toll-like receptor-2 (TLR-2), but not wild-type (TLR-2-deficient) Chinese hamster ovary cells. The Protozoan-derived GPI anchors and GIPLs containing alkylacylglycerol and saturated fatty acid chains or ceramide were found to be active in a concentration range of 100 nM to 1 μM. More importantly, the GPI anchors purified from T. cruzi trypomastigotes, which contain a longer glycan core and unsaturated fatty acids in the sn-2 position of the alkylacylglycerolipid component, triggered TLR-2 at subnanomolar concentrations. We performed experiments with macrophages from TLR-2 knockout and TLR-4 knockout mice, and found that TLR-2 expression appears to be essential for induction of IL-12, TNF-α, and NO by GPI anchors derived from T. cruzi trypomastigotes. Thus, highly purified GPI anchors from T. cruzi parasites are potent activators of TLR-2 from both mouse and human origin. The activation of TLR-2 may initiate host innate defense mechanisms and inflammatory response during Protozoan Infection, and may provide new strategies for immune intervention during Protozoan Infections.
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signaling of immune system cells by glycosylphosphatidylinositol gpi anchor and related structures derived from parasitic protozoa
Current Opinion in Microbiology, 2000Co-Authors: Catherine Ropert, Ricardo T GazzinelliAbstract:Abstract Glycosylphosphatidylinositol (GPI) anchor and glycoinositolphospholipid (GIPL) are abundant molecules present in the membrane of parasitic protozoa that are common etiologic agents of medical and veterinary diseases. Recent studies have documented the immunostimulatory/ regulatory activity of Protozoan-derived GPI-anchors and related structures. Among the bioactivity displayed by the Protozoan-derived GPI-anchor is the ability to elicit the synthesis of pro-inflammatory cytokines as well as nitric oxide by host macrophages. In contrast, at high concentrations GIPL and lipophosphoglycan (LPG) derived from Protozoan parasites suppress several functions of the host immune system. Additionally, the Protozoan-derived GPI-anchor and GIPL have been shown to serve as targets for both specific B and NK-T lymphocyte responses. This information extends our knowledge about parasite molecules that stimulate/regulate the host immune system during Protozoan Infection. The identification of receptor(s) and signaling pathways triggered by these GPI-related glycolipids may provide new insights for the development of therapies that inhibit detrimental immune responses or potentiate beneficial immune responses observed during Infection with Protozoan parasites.
Birhane Berhe - One of the best experts on this subject based on the ideXlab platform.
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foodborne intestinal Protozoan Infection and associated factors among patients with watery diarrhea in northern ethiopia a cross sectional study
Journal of Health Population and Nutrition, 2018Co-Authors: Birhane Berhe, Gessessew Bugssa, Sena Bayisa, Megbaru AlemuAbstract:Intestinal protozoa are parasites transmitted by consumption of contaminated water and food and mainly affect children and elder people and cause considerable health problems. They are the leading causes of outpatient morbidity due to diarrhea in the developing countries. So, assessing water and food source of diarrheal patients and identifying the main associated factors for transmission of Protozoan parasitic Infections help for effective control measures of Protozoan Infections. Hence, the current study was aimed at determining the prevalence of foodborne intestinal protozoa Infections and associated factors among diarrheic patients in North Ethiopia. A health facility based cross-sectional study was conducted among 223 patients with watery diarrhea in four selected government health facilities in North Ethiopia from November 2016–June 2017. A structured questionnaire was used to collect data on socio-demography of study participants and factors associated with foodborne protozoa Infections. The diarrheic stool samples were collected, transported, and processed using direct wet mount, formal-ether concentration and modified ZiehlNeelson staining methods. The data were analyzed using SPSS version 21 and descriptive statistics, bi-variate, and multivariate logistic regressions were computed. P-value < 0.05 at 95% confidence interval was considered statistically significant. The overall prevalence of foodborne protozoa Infection was 101 (45.3%). The predominant protozoa species identified was Entamoeba histolytica/dispar 55 (24.7%), followed by Giardia intestinalis 25 (11.2%) and Cryptosporidium species 5 (2.2%). The highest proportion of protozoa Infection was observed among males (23.3%) and the age group 15–24 years (13.5%). Statistically significant associations were observed between foodborne Protozoan Infection and not using any type of recipe to decontaminate salads and fruits (AOR = 2.64, 95 CI: 1.34–5.19, P = 0.005) and using vinegar as a decontaminant (AOR = 2.83, 95 CI: 1.24–6.48, P = 0.014). Eating out (meals at a restaurant) on the other hand was found to be protective for foodborne Protozoan Infection (AOR = 0.43, 95 CI: 0.23–0.78, P = 0.006). Our study revealed that foodborne protozoa Infections are of public health significance in the study area. Vinegar, which is frequently used as a recipe for decontaminating salads and fruits, is inversely related to foodborne protozoa parasite Infection .
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Foodborne intestinal Protozoan Infection and associated factors among patients with watery diarrhea in Northern Ethiopia; a cross-sectional study
BMC, 2018Co-Authors: Birhane Berhe, Gessessew Bugssa, Sena Bayisa, Megbaru AlemuAbstract:Abstract Background Intestinal protozoa are parasites transmitted by consumption of contaminated water and food and mainly affect children and elder people and cause considerable health problems. They are the leading causes of outpatient morbidity due to diarrhea in the developing countries. So, assessing water and food source of diarrheal patients and identifying the main associated factors for transmission of Protozoan parasitic Infections help for effective control measures of Protozoan Infections. Hence, the current study was aimed at determining the prevalence of foodborne intestinal protozoa Infections and associated factors among diarrheic patients in North Ethiopia. Methods A health facility based cross-sectional study was conducted among 223 patients with watery diarrhea in four selected government health facilities in North Ethiopia from November 2016–June 2017. A structured questionnaire was used to collect data on socio-demography of study participants and factors associated with foodborne protozoa Infections. The diarrheic stool samples were collected, transported, and processed using direct wet mount, formal-ether concentration and modified ZiehlNeelson staining methods. The data were analyzed using SPSS version 21 and descriptive statistics, bi-variate, and multivariate logistic regressions were computed. P-value
Alon Warburg - One of the best experts on this subject based on the ideXlab platform.
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evaluation of pcr procedures for detecting and quantifying leishmania donovani dna in large numbers of dried human blood samples from a visceral leishmaniasis focus in northern ethiopia
BMC Infectious Diseases, 2013Co-Authors: Ibrahim Abbasi, Samar Aramin, Asrat Hailu, Welelta Shiferaw, Aysheshm Kassahun, Shewaye Belay, Charles L Jaffe, Alon WarburgAbstract:Background: Visceral Leishmaniasis (VL) is a disseminated Protozoan Infection caused by Leishmania donovani parasites which affects almost half a million persons annually. Most of these are from the Indian sub-continent, East Africa and Brazil. Our study was designed to elucidate the role of symptomatic and asymptomatic Leishmania donovani infected persons in the epidemiology of VL in Northern Ethiopia. Methods: The efficacy of quantitative real-time kinetoplast DNA/PCR (qRT-kDNA PCR) for detecting Leishmania donovani in dried-blood samples was assessed in volunteers living in an endemic focus. Results: Of 4,757 samples, 680 (14.3%) were found positive for Leishmania k-DNA but most of those (69%) had less than 10 parasites/ml of blood. Samples were re-tested using identical protocols and only 59.3% of the samples with 10 parasite/ml or less were qRT-kDNA PCR positive the second time. Furthermore, 10.8% of the PCR negative samples were positive in the second test. Most samples with higher parasitemias remained positive upon reexamination (55/59 =93%). We also compared three different methods for DNA preparation. Phenol-chloroform was more efficient than sodium hydroxide or potassium acetate. DNA sequencing of ITS1 PCR products showed that 20/22 samples were Leishmania donovani while two had ITS1 sequences homologous to Leishmania major. Conclusions: Although qRT-kDNA PCR is a highly sensitive test, the dependability of low positives remains questionable. It is crucial to correlate between PCR parasitemia and infectivity to sand flies. While optimal sensitivity is achieved by targeting k-DNA, it is important to validate the causative species of VL by DNA sequencing.
