983 resultados para Diagnostic-tests


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Introduction Dogs play a primary role in the zoonotic cycle of visceral leishmaniasis (VL). Therefore, the accurate diagnosis of infected dogs, primarily asymptomatic dogs, is crucial to the efficiency of VL control programs. Methods We investigated the agreement of four diagnostic tests for canine visceral leishmaniasis (CVL): parasite detection, either after myeloculture or by direct microscopic examination of tissue imprints; kinetoplast-deoxyribonucleic acid-polymerase chain reaction (kDNA-PCR); and an immunochromatographic test (ICT). An enzyme-linked immunosorbent assay (ELISA) and an indirect immunofluorescence test (IFAT), both of which were adopted as part of the screening-culling program in Brazil, were used as reference tests. Our sample set consisted of 44 seropositive dogs, 25 of which were clinically asymptomatic and 19 were symptomatic for CVL according to ELISA-IFAT. Results The highest and lowest test co-positivities were observed for ICT (77.3%) and myeloculture (58.1%), respectively. When analyzed together, the overall percentage of co-positive tests was significantly higher for the symptomatic group compared to the asymptomatic group. However, only ICT was significantly different based on the results of a separate analysis per test for each group of dogs. The majority (93.8%) of animals exhibited at least one positive test result, with an average of 2.66 positive tests per dog. Half of the symptomatic dogs tested positive for all four tests administered. Conclusions The variability between test results reinforces the need for more efficient and reliable methods to accurately diagnose canine VL, particularly in asymptomatic animals.

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Introduction Most studies that have evaluated the stomachs of patients with Chagas disease were performed before the discovery of Helicobacter pylori and used no control groups. This study compared the gastric features of chagasic and non-chagasic patients and assessed whether gastritis could be associated with Chagas disease. Methods Gastric biopsy samples were taken from patients who underwent endoscopy for histological analysis according to the Updated Sydney System. H. pylori infection was assessed by histology, 16S ribosomal ribonucleic acid (rRNA) polymerase chain reaction (PCR), serology and the 13C-urea breath test. Patients were considered H. pylori-negative when all of these diagnostic tests were negative. Clinical and socio-demographic data were obtained by reviewing medical records and using a questionnaire. Results The prevalence of H. pylori infection (70.3% versus 71.7%) and chronic gastritis (92.2% versus 85%) was similar in the chagasic and non-chagasic groups, respectively; such as peptic ulcer, atrophy and intestinal metaplasia. Gastritis was associated with H. pylori infection independent of Chagas disease in a log-binomial regression model. However, the chagasic H. pylori-negative patients showed a significantly higher grade of mononuclear (in the corpus) and polymorphonuclear (PMN) (in the antrum) cell infiltration. Additionally, the patients with the digestive form of Chagas disease showed a significantly lower prevalence of corpus atrophy than those with other clinical forms. Conclusions The prevalence of H. pylori infection and of gastric histological and endoscopic features was similar among the chagasic and non-chagasic patients. Additionally, this is the first controlled study to demonstrate that H. pylori is the major cause of gastritis in patients with Chagas disease.

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Abstract: INTRODUCTION : Molecular analyses are auxiliary tools for detecting Koch's bacilli in clinical specimens from patients with suspected tuberculosis (TB). However, there are still no efficient diagnostic tests that combine high sensitivity and specificity and yield rapid results in the detection of TB. This study evaluated single-tube nested polymerase chain reaction (STNPCR) as a molecular diagnostic test with low risk of cross contamination for detecting Mycobacterium tuberculosis in clinical samples. METHODS: Mycobacterium tuberculosis deoxyribonucleic acid (DNA) was detected in blood and urine samples by STNPCR followed by agarose gel electrophoresis. In this system, reaction tubes were not opened between the two stages of PCR (simple and nested). RESULTS: STNPCR demonstrated good accuracy in clinical samples with no cross contamination between microtubes. Sensitivity in blood and urine, analyzed in parallel, was 35%-62% for pulmonary and 41%-72% for extrapulmonary TB. The specificity of STNPCR was 100% in most analyses, depending on the type of clinical sample (blood or urine) and clinical form of disease (pulmonary or extrapulmonary). CONCLUSIONS: STNPCR was effective in detecting TB, especially the extrapulmonary form for which sensitivity was higher, and had the advantage of less invasive sample collection from patients for whom a spontaneous sputum sample was unavailable. With low risk of cross contamination, the STNPCR can be used as an adjunct to conventional methods for diagnosing TB.

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Cystic fibrosis is a genetic disease usually diagnosed by abnormal sweat testing. We report a case of an 18-year-old female with bronchiectasis, chronic P. aeruginosa infection, and normal sweat chloride concentrations who experienced rapid decrease of lung function and clinical deterioration despite treatment. Given the high suspicion ofcystic fibrosis, broad genotyping testing was performed, showing a compound heterozygous with deltaF508 and 3849+10kb C->T mutations, therefore confirming cystic fibrosis diagnosis. Although the sweat chloride test remains the gold standard for the diagnosis of cystic fibrosis, alternative diagnostic tests such as genotyping and electrophysiologic measurements must be performed if there is suspicion of cystic fibrosis, despite normal or borderline sweat chloride levels.

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Em contextos como o de Moçambique que apresenta uma diversidade linguística, o uso de mais de uma língua no ensino é quase que obrigatório. Assim, urge a necessidade de formalizar a Educação Bilingue (EB) nas escolas moçambicanas. A modalidade de EB em Moçambique é de transição e manutenção, nas primeiras classes (1ª, 2ª e 3ª) usa-se a língua local como meio de instrução e o Português é uma disciplina, a partir da 4ª classe há uma inversão. Dessa estratégia o aluno deve estar em condições na 5ª classe de enfrentar o exame nacional, que é feito em língua oficial Portuguesa, para transitar do 1º para o 2º grau. O trabalho tem como problema esta interrogação: De que modo o programa curricular de Educação Bilingue se traduz nas práticas pedagógicas nas escolas do Ensino Básico que usam a língua Portuguesa e Changana no distrito de Bilene, na província de Gaza? O estudo empírico é de natureza qualitativa e quantitativa, com a utilização de técnicas de recolha de dados como a análise documental, entrevistas, questionário e provas escrita e oral aos alunos. Do estudo conclui-se: i) Não existe um programa de base especificamente para EB; ii) Há incongruência entre o programa e as práticas pedagógicas e iii) Os alunos apresentam maior dificuldades de compreensão, na escrita do que na oralidade, nas provas de conhecimento nas disciplinas básicas (Português e Matemática) em língua Portuguesa.

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We report the case of a 3-year-old female patient, who, since birth, had cyanosis difficult to explain with usual diagnostic tests. The only findings on physical examination were cyanosis and clubbing of her fingers. Chest computerized tomography showed images of excessive attenuation in the right lung, which resembled arteriovenous fistulae that were later confirmed on cardiac catheterization. The fistulous trajectories were then embolized with 7 Gianturco coils, which resulted in an immediate increase in the arterial saturation of blood oxygen.

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BACKGROUND: Capsular fibrosis is a severe complication after breast implantation with an uncertain etiology. Microbial colonization of the prosthesis is hypothesized as a possible reason for the low-grade infection and subsequent capsular fibrosis. Current diagnostic tests consist of intraoperative swabs and tissue biopsies. Sonication of removed implants may improve the diagnosis of implant infection by detachment of biofilms from the implant surface. METHODS: Breast implants removed from patients with Baker grades 3 and 4 capsular contracture were analyzed by sonication, and the resulting sonication fluid was quantitatively cultured. RESULTS: This study investigated 22 breast implants (6 implants with Baker 3 and 16 implants with Baker 4 capsular fibrosis) from 13 patients. The mean age of the patients was 49 years (range, 31-76 years). The mean implant indwelling time was 10.4 years (range, 3 months to 30 years). Of the 22 implants, 12 were used for breast reconstruction and 10 for aesthetic procedures. The implants were located subglandularly (n = 12), submuscularly (n = 6), and subcutaneously (n = 4). Coagulase-negative staphylococci, Propionibacterium acnes, or both were detected in the sonication fluid cultures of nine implants (41%), eight of which grew significant numbers of microorganisms (>100 colonies/ml of sonication fluid). CONCLUSIONS: Sonication detected bacteria in 41% of removed breast implants. The identified bacteria belonged to normal skin flora. Further investigation is needed to determine any causal relation between biofilms and capsular fibrosis.

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Primary ciliary dyskinesia (PCD) is an autosomal recessive disease with an incidence estimated between 1:2,000 and 1:40,000. Ciliated epithelia line the airways, nasal and sinus cavities, Eustachian tube and fallopian tubes. Congenital abnormalities of ciliary structure and function impair mucociliary clearance. As a consequence, patients present with chronic sinopulmonary infections, recurrent glue ear and female subfertility. Similarities in the ultrastructure of respiratory cilia, nodal cilia and sperm result in patients with PCD also presenting with male infertility, abnormalities of left-right asymmetry (most commonly situs inversus totalis) and congenital heart disease. Early diagnosis is essential to ensure specialist management of the respiratory and otological complications of PCD. Diagnostic tests focus on analysis of ciliary function and electron microscopy structure. Analysis is technically difficult and labour intensive. It requires expertise for interpretation, restricting diagnosis to specialist centres. Management is currently based on the consensus of experts, and there is a pressing need for randomised clinical trials to inform treatment.

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In the last years, the knowledge about immunodiagnosis in schistosomiasis has increased considerably. This was due to a better immunologic understanding of the host-parasite interaction and the evolution of the technical procedures by the introduction of new concepts and techniques. The search of more sensitive, specific, practical and less expensive diagnostic tests has led to the development of a great number of immunological tests that could complement the limitations of the parasitological diagnosis. The antigens of differnt life cycle stages of Schistosoma mansoni may be used as target for immunodiagnostic tests and the anti-schistosome antibodies in sera of infected patients can be detected. The research of circulating schistosome antigens, the production of specific antisera and the application of these antibodies in immunodiagnostic tests have also been discussed.

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Rapport de synthèse: Enjeux de la recherche : La pneumonie communautaire chez l'enfant est un problème de santé publique considérable. Elle est responsable de 2 millions de mort par année, 70% survenant dans les pays en voie de développement. Sous nos latitudes son incidence est de 40/1000 enfants par année, ce qui représente une morbidité importante. Deux difficultés surviennent lorsqu'on cherche à diagnostiquer une pneumonie. La première est de distinguer une pneumonie bactérienne d'une virale, particulièrement chez les petits enfants où les infections virales des voies respiratoires inférieures sont fréquentes. L'OMS a définit la pneumonie selon des critères exclusivement cliniques et une étude effectuée à Lausanne en 2000 a montré que ces critères peuvent être utilisés dans nos contrées. La seconde difficulté est de définir l'agent causal de la pneumonie, ceci pour plusieurs raisons : L'aspiration endotrachéale, seul examen fiable, ne peut être obtenue de routine chez l'enfant vu son caractère invasif, la culture des secrétions nasopharyngées reflète la flore physiologique de la sphère ORL et une bactériémie n'est présente que dans moins de 10% des pneumonies. L'étiologie de la pneumonie reste souvent inconnue, et de ce fait plusieurs enfants reçoivent des antibiotiques pour une infection non bactérienne ce qui contribue au développement de résistances. L'objectif de cette étude était d'effectuer une recherche extensive de l'agent causal de la pneumonie et de déterminer quels facteurs pourraient aider le clinicien à différencier une pneumonie virale de bactérienne, en corrélant l'étiologie avec la sévérité clinique et les marqueurs de l'inflammation. Contexte de la recherche : II s'agissait d'une étude prospective, multicentrique, incluant les enfants âgés de 2 mois à 5 ans hospitalisés pour une pneumonie, selon les critères de l'OMS, dans le service de pédiatrie de Lausanne et Genève entre mars 2003 et Décembre 2005, avant l'implantation de la vaccination antipneumococcique de routine. Chaque enfant, en plus des examens usuels, bénéficiait d'une recherche étiologique extensive : Culture virale et bactérienne, PCR (Mycoplasma Pneumoniae, Chlamydia Pneumoniae, Virus Influenza A et B, RSV A et B, Rhinovirus, Parainfluenza 1-3, enterovirus, human metapneumovirus, coronavirus OC43, E229 ; et NL 63) et détection d'AG viraux dans les sécrétions nasopharyngées ; sérologies virales et bactériennes à l'entrée et 3 semaines après la sortie (AG Influenza A et B, Parainfluenza 1,2 et 3, RSV, Adenovirus, M.Pneumoniae et S.Pneumoniae). Conclusions : Un agent pathogène a été découvert chez 86% des 99 patients retenus confirmant le fait que plus la recherche étiologique est étendue plus le pourcentage d'agent causal trouvé est élevé. Une infection bactérienne a été découverte chez 53% des patients dont 45% avaient une infection à S. Pneumoniae confirmant l'importance d'une vaccination antipneumococcique de routine. La déshydratation et les marqueurs de l'inflammation tels que la C-Reactive Protein et la Procalcitonine étaient significativement plus élevés dans les pneumonies bactériennes. Aucune corrélation n'a été trouvée entre le degré de sévérité de la pneumonie et l'étiologie. L'étude a confirmé la haute prévalence d'infections virales (67%) et de co-infection (33%) dans la pneumonie de l'enfant sans que l'on connaisse le rôle réel du virus dans la pathogenèse de la pneumonie. Perspectives : d'autres études à la suite de celle-ci devraient être effectuées en incluant les patients ambulatoires afin de déterminer, avec un collectif plus large de patient, une éventuelle corrélation entre sévérité clinique et étiologie. Abstract : Community-acquired pneumonia (CAP) is a major cause of death in developing countries and of morbidity in developed countries. The objective of the study was to define the causative agents among children hospitalized for CAP defined by WHO guidelines and to correlate etiology with clinical severity and surrogate markers. Investigations included an extensive etiological workup. A potential causative agent was detected in 86% of the 99 enrolled patients, with evidence of bacterial (53%), viral (67%), and mixed (33%) infections. Streptococcus pneumoniae was accounted for in 46% of CAP. Dehydration was the only clinical sign associated with bacterial pneumonia. CRP and PCT were significantly higher in bacterial infections. Increasing the number of diagnostic tests identifies potential causes of CAP in up to 86% of children, indicating a high prevalence of viruses and frequent co-infections. The high proportion of pneumococcal infections re-emphasizes the importance of pneumococcal immunization.

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In the light of emerging and overlooked infectious diseases and widespread drug resistance, diagnostics have become increasingly important in supporting surveillance, disease control and outbreak management programs. In many low-income countries the diagnostic service has been a neglected part of health care, often lacking quantity and quality or even non-existing at all. High-income countries have exploited few of their advanced technical abilities for the much-needed development of low-cost, rapid diagnostic tests to improve the accuracy of diagnosis and accelerate the start of appropriate treatment. As is now also recognized by World Healt Organization, investment in the development of affordable diagnostic tools is urgently needed to further our ability to control a variety of diseases that form a major threat to humanity. The Royal Tropical Institute's Department of Biomedical Research aims to contribute to the health of people living in the tropics. To this end, its multidisciplinary group of experts focuses on the diagnosis of diseases that are major health problems in low-income countries. In partnership we develop, improve and evaluate simple and cheap diagnostic tests, and perform epidemiological studies. Moreover, we advice and support others - especially those in developing countries - in their efforts to diagnose infectious diseases.

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With the availability of new generation sequencing technologies, bacterial genome projects have undergone a major boost. Still, chromosome completion needs a costly and time-consuming gap closure, especially when containing highly repetitive elements. However, incomplete genome data may be sufficiently informative to derive the pursued information. For emerging pathogens, i.e. newly identified pathogens, lack of release of genome data during gap closure stage is clearly medically counterproductive. We thus investigated the feasibility of a dirty genome approach, i.e. the release of unfinished genome sequences to develop serological diagnostic tools. We showed that almost the whole genome sequence of the emerging pathogen Parachlamydia acanthamoebae was retrieved even with relatively short reads from Genome Sequencer 20 and Solexa. The bacterial proteome was analyzed to select immunogenic proteins, which were then expressed and used to elaborate the first steps of an ELISA. This work constitutes the proof of principle for a dirty genome approach, i.e. the use of unfinished genome sequences of pathogenic bacteria, coupled with proteomics to rapidly identify new immunogenic proteins useful to develop in the future specific diagnostic tests such as ELISA, immunohistochemistry and direct antigen detection. Although applied here to an emerging pathogen, this combined dirty genome sequencing/proteomic approach may be used for any pathogen for which better diagnostics are needed. These genome sequences may also be very useful to develop DNA based diagnostic tests. All these diagnostic tools will allow further evaluations of the pathogenic potential of this obligate intracellular bacterium.

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This report gives a comprehensive and up-to-date review of Alzheimer's disease biomarkers. Recent years have seen significant advances in this field. Whilst considerable effort has focused on A�_ and tau related markers, a substantial number of other molecules have been identified, that may offer new opportunities.This Report : Identifies 60 candidate Alzheimer's (AD) biomarkers and their associated studies. Of these, 49 are single species or single parameters, 7 are combinations or panels and 4 involve the measurement of two species or parameters or their ratios. These include proteins (n=34), genes (n=11), image-based parameters (n=7), small molecules (n=3), proteins + genes (n=2) and others (n=3). Of these, 30 (50%) relate to species identified in CSF and 19 (32%) were found in the blood. These candidate may be classified on the basis of their diagnostic utility, namely those which i) may allow AD to be detected when the disease has developed (48 of 75†= 64%), ii) may allow early detection of AD (18 of 75† = 24%) and iii) may allow AD to be predicted before the disease has begun to develop (9 of 75†= 12%). † Note: Of these, 11 were linked to two or more of these capabilities (e.g. allowed both early-stage detection as well as diagnosis after the disease has developed).Biomarkers: AD biomarkers identified in this report show significant diversity, however of the 60 described, 18 (30%) are associated with amyloid beta (A�_) and 9 (15%) relate to Tau. The remainder of the biomarkers (just over half) fall into a number of different groups. Of these, some are associated with other hypotheses on the pathogenesis of AD however the vast majority are individually unique and not obviously linked with other markers. Analysis and discussion presented in this report includes summaries of the studies and clinical trials that have lead to the identification of these markers. Where it has been calculated, diagnostic sensitivity, specificity and the capacity of these markers to differentiate patients with suspected AD from healthy controls and individuals believed to be suffering from other neurodegenerative conditions, have been indicated. These findings are discussed in relation to existing hypotheses on the pathogenesis of the AD and the current drug development pipeline. Many uncertainties remain in relation to the pathogenesis of AD, in diagnosing and treating the disease and many of the studies carried out to identify disease markers are at an early stage and will require confirmation through larger and longer investigations. Nevertheless, significant advances in the identification of AD biomarkers have now been made. Moreover, whilst much of the research on AD biomarkers has focused on amyloid and tau related species, it is evident that a substantial number of other species may provide important opportunities.Purpose of Report: To provide a comprehensive review of important and recently discovered candidate biomarkers of AD, in particular those with potential to reliably detect the disease or with utility in clinical development, drug repurposing, in studies of the pathogenesis and in monitoring drug response and the course of the disease. Other key goals were to identify markers that support current pipeline developments, indicate new potential drug targets or which advance understanding of the pathogenesis of this disease.Drug Repurposing: Studies of the pathogenesis of AD have identified aberrant changes in a number of other disease areas including inflammation, diabetes, oxidative stress, lipid metabolism and others. These findings have prompted studies to evaluate some existing approved drugs to treat AD. This report identifies studies of 9 established drug classes currently being investigated for potential repurposing.Alzheimer’s Disease: In 2005, the global prevalence of dementia was estimated at 25 million, with more than 4 million new cases occurring each year. It is also calculated that the number of people affected will double every 20 years, to 80 million by 2040, if a cure is not found. More than 50% of dementia cases are due to AD. Today, approximately 5 million individuals in the US suffer from AD, representing one in eight people over the age of 65. Direct and indirect costs of AD and other forms of dementia in the US are around $150 billion annually. Worldwide, costs for dementia care are estimated at $315 billion annually. Despite significant research into this debilitating and ultimately fatal disease, advances in the development of diagnostic tests for AD and moreover, effective treatments, remain elusive.Background: Alzheimer's disease is the most common cause of dementia, yet its clinical diagnosis remains uncertain until an eventual post-mortem histopathology examination is carried out. Currently, therapy for patients with Alzheimer disease only treats the symptoms; however, it is anticipated that new disease-modifying drugs will soon become available. The urgency for new and effective treatments for AD is matched by the need for new tests to detect and diagnose the condition. Uncertainties in the diagnosis of AD mean that the disease is often undiagnosed and under treated. Moreover, it is clear that clinical confirmation of AD, using cognitive tests, can only be made after substantial neuronal cell loss has occurred; a process that may have taken place over many years. Poor response to current therapies may therefore, in part, reflect the fact that such treatments are generally commenced only after neuronal damage has occurred. The absence of tests to detect or diagnose presymptomatic AD also means that there is no standard that can be applied to validate experimental findings (e.g. in drug discovery) without performing lengthy studies, and eventual confirmation by autopsy.These limitations are focusing considerable effort on the identification of biomarkers that advance understanding of the pathogenesis of AD and how the disease can be diagnosed in its early stages and treated. It is hoped that developments in these areas will help physicians to detect AD and guide therapy before the first signs of neuronal damage appears. The last 5-10 years have seen substantial research into the pathogenesis of AD and this has lead to the identification of a substantial number of AD biomarkers, which offer important insights into this disease. This report brings together the latest advances in the identification of AD biomarkers and analyses the opportunities they offer in drug R&D and diagnostics.��

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The hepatitis A virus (HAV) HAF-203 strain was isolated from an acute case of HAV infection. The primary isolation of HAF-203 in Brazil and its adaptation to the FRhK-4 cell lineage allowed the production of large amounts of viral particles enabling molecular characterization of the first HAV isolate in Brazil. The aim of our study was to determine the nucleotide sequence of the HAF-203 strain genome, compare it to other HAV genomes and highlight its genetic variability. The complete nucleotide sequence of the HAF-203 strain (7472 nucleotides) was compared to those obtained earlier by others for other HAV isolates. These analyses revealed 19 HAF-specific nucleotide sequence differences with 10 amino acid substitutions. Most of the non-conservative changes were located at VP1, 2C, and 3D genes, but the 3B region was the most variable. The availability of HAF-203 complementary DNA was useful for the production of the recombinant VP1 protein, which is a major determinant of viral infectivity. This recombinant protein was shown by enzyme-linked immunoassay and blotting, to be immunogenic and resemble the native protein, therefore suggesting its value as a reagent for incorporation into diagnostic tests.

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The circumsporozoite protein (CSP), a major antigen of Plasmodium falciparum, was expressed in the slime mold Dictyostelium discoideum. Fusion of the parasite protein to a leader peptide derived from Dictyostelium contact site A was essential for expression. The natural parasite surface antigen, however, was not detected at the slime mold cell surface as expected but retained intracellularly. Removal of the last 23 amino acids resulted in secretion of CSP, suggesting that the C-terminal segment of the CSP, rather than an ectoplasmic domain, was responsible for retention. Cell surface expression was obtained when the CSP C-terminal segment was replaced by the D. discoideum contact site A glycosyl phosphatidylinositol anchor signal sequence. Mice were immunized with Dictyostelium cells harboring CSP at their surface. The raised antibodies recognized two different regions of the CSP. Anti-sporozoite titers of these sera were equivalent to anti-peptide titers detected by enzyme-linked immunosorbent assay. Thus, cell surface targeting of antigens can be obtained in Dictyostelium, generating sporozoite-like cells having potentials for vaccination, diagnostic tests, or basic studies involving parasite cell surface proteins.