Cardiac abnormalities in Trypanosoma cruzi seropositive patients in the State of Querétaro, México / Alteraciones cardiacas en una población seropositiva a Trypanosoma cruzi en Querétaro, México

Abstract: Background: Chagas disease is an endemic illness in the Americas and therefore constitutes a public health problem. An estimated 8 million people are infected and over 20 million live in areas at risk. In Mexico, the problem is under reported and no epidemiological data by the different States indicating true prevalence for this infection is available. During the chronic phase, 30% of infected patients may develop chagasic cardiomyopathy (CCM), characterized by different types of alterations of cardiac function. Objective: To describe cardiac abnormalities in Trypanosoma cruzi seropositive subjects in the endemic areas. Material and methods: This is a descriptive cross-sectional study with non-random sampling. In our project the endemic area was considered for Trypanosoma cruzi using the Epi Info statistical program (Stat Calc) to calculate the number of subjects to study by means of a sample of 1 033 subjects aged 2-90 years. Prior informed consent or parental consent, implementation of a survey, a 5 mL of blood sample free from anticoagulant was taken from the cubital vein to detect anti-Trypanosoma cruzi by ELISA, recombinant ELISA, hemagglutination indirect (HAI), indirect immunofluorescence (IFI) and Western blot (using the enzyme superoxide dismutase iron as antigen). Those subjects who were positive in two or more tests were chosen for electrocardiogram (EKG) and an echocardiogram (ECO) with portable devices. Results: Of the 1 033 participants, 84 between 6 and 88 years tested positive for Trypanosoma cruzi. In the analysis of data with echocardiograms and electrocardiograms, 47 subjects over 26 years (56%), presented right bundle branch block or left bundle block (RBBB/LBBB), changes in the diameters of the right ventricle or left ejection fraction accounting of 70%. In subjects under 26 years there were electrocardiographic changes (RBBB/LBBB). Conclusion: 8.13% were seropositive for Trypanosoma cruzi with ventricular conduction system and morphological alterations.

Resumen: Antecedentes: La enfermedad de Chagas es una patología endémica en las Américas, donde representa un problema de salud pública. Se estima que aproximadamente 8 millones de personas están infectadas y 20 millones viven en áreas de riesgo de infectarse. En México el problema está subestimado y se carece de datos epidemiológicos por estado del país que indiquen una prevalencia real de este padecimiento. Durante la fase crónica, el 30% de los pacientes infectados pueden desarrollar miocardiopatía chagásica (MCC), que se caracteriza por presentar diferentes alteraciones de la función cardiaca. Objetivo: Describir las alteraciones cardiacas en sujetos seropositivos para Trypanosoma cruzi de áreas endémicas. Material y métodos: Es un estudio con diseño transversal descriptivo, con muestra no probabilística. En nuestro proyecto, se consideró una zona endémica a Trypanosoma cruzi, mediante el programa estadístico Epi Info (Stat Calc), para estimar el número de sujetos a estudiar, obteniéndose una muestra de 1 033 sujetos de edades entre 2 a 90 años. Previo consentimiento informado, y aplicación de una encuesta, se puncionó la vena cubital, obteniéndose una muestra sanguínea de 5 mL, sin anticoagulante, para buscar anticuerpos anti-Trypanosoma cruzi mediante, ELISA, ELISA recombinante, hemaglutinación indirecta (HAI), inmunofluorescencia indirecta (IFI) y Western-Blot (usando la enzima superóxido dismutasa de hierro como antígeno). Los sujetos reactivos a dos o más pruebas fueron seleccionados para la realización de un electrocardiograma (EKG) y un ecocardiograma (ECO) con equipos portátiles Resultados: De los 1 033 participantes, 84 entre 6 a 88 años resultaron positivos para Trypanosoma cruzi. En el análisis de los hallazgos ecocardiográficos y electrocardiográficos en los 47 sujetos mayores de 26 años (56%) presentaron bloqueo de rama derecha o izquierda del haz de His (BRDHH/BRIHH). Conclusión: El 8.13% fueron seropositivos para Trypanosoma cruzi con cambios morfológicos ventriculares y del sistema de conducción del haz de His.

Comparative serology techniques for the diagnosis of Trypanosoma cruzi infection in a rural population from the state of Querétaro, Mexico

Immunological diagnostic methods for Trypanosoma cruzi depend specifically on the presence of antibodies and parasitological methods lack sensitivity during the chronic and “indeterminate” stages of the disease. This study performed a serological survey of 1,033 subjects from 52 rural communities in 12 of the 18 municipalities in the state of Querétaro, Mexico. We detected anti-T. cruzi antibodies using the following tests: indirect haemagglutination assay (IHA), indirect immunofluorescence assay (IFA), ELISA and recombinant ELISA (rELISA). We also performed Western blot (WB) analysis using iron superoxide dismutase (FeSOD), a detoxifying enzyme excreted by the parasite, as the antigen. Positive test results were distributed as follows: ELISA 8%, rELISA 6.2%, IFA and IHA 5.4% in both cases and FeSOD 8%. A comparative study of the five tests was undertaken. Sensitivity levels, specificity, positive and negative predictive values, concordance percentage and kappa index were considered. Living with animals, trips to other communities, gender, age, type of housing and symptomatology at the time of the survey were statistically analysed using SPSS software v.11.5. Detection of the FeSOD enzyme that was secreted by the parasite and used as an antigenic fraction in WBs showed a 100% correlation with traditional ELISA tests.

Lagochilascaris minor Leiper, 1909 (Nematoda: Ascarididae) in Mexico: three clinical cases from the Peninsula of Yucatan / Lagochilascaris minor Leiper, 1909 (Nematoda: Ascarididae) en México: tres casos clínicos de la Península de Yucatán

Human lagochilascariasis (HL) is a parasite produced by Lagochilascaris minor Leiper 1909 that also can be found in cats and dogs. HL is considered an emerging zoonosis in the Americas, spreading from Mexico to Argentina, and the Caribbean Islands. The present paper describes three HL cases from the Peninsula of Yucatan, Mexico, recorded in the last decade. It describes the characteristics of the lesions and discusses the route of transmission in humans and particularly in the observed patients.

La Lagochilascariasis humana (HL) es producida por Lagochilascaris minor Leiper, 1909; el cual es un parásito que puede ser encontrado también en gatos y perros. HL es considerada una zoonosis emergente en América distribuida desde México hasta Argentina y las islas del Caribe. El presente artículo describe tres casos de HL en la Península de Yucatán, México registrados en la última década. Se describen las características de las lesiones y se discute la ruta de transmisión en humanos y particularmente en los pacientes observados.

In vitro evaluation of new terpenoid derivatives against Leishmania infantum and Leishmania braziliensis

The activity of five (1-5) abietane phenol derivatives against Leishmania infantum and Leishmania braziliensis was studied using promastigotes and axenic and intracellular amastigotes. Infectivity and cytotoxicity tests were performed with J774.2 macrophage cells using Glucantime as a reference drug. The mechanisms of action were analysed by performing metabolite excretion and transmission electron microscopy ultrastructural studies. Compounds 1-5 were more active and less toxic than Glucantime. The infection rates and mean number of parasites per cell observed in amastigote experiments showed that derivatives 2, 4 and 5 were the most effective against both L. infantum and L. braziliensis. The ultrastructural changes observed in the treated promastigote forms confirmed that the greatest cell damage was caused by the most active compound (4). Only compound 5 caused changes in the nature and amounts of catabolites excreted by the parasites, as measured by ¹H nuclear magnetic resonance spectroscopy. All of the assayed compounds were active against the two Leishmania species in vitro and were less toxic in mammalian cells than the reference drug.

Purification and biochemical characterization of four iron superoxide dismutases in Trypanosoma cruzi

Four superoxide dismutase (SOD) activities (SOD I, II, III, and IV) have been characterized in the epimastigote form of Trypanosoma cruzi. The total extract was subjected to two successive ammonium sulphate additions between 35 and 85 percent, and the resulting fraction was purified using two continuous chromatography processes (ion exchange and filtration). Enzymes were insensitive to cyanide but sensitive to hydrogen peroxide, properties characteristic of iron-containing SODs. The molecular masses of the different SODs were 20 kDa (SOD I), 60 kDa (SOD II), 50 kDa (SOD III) and 25 kDa (SOD IV), whereas the isoelectric points were 6.9, 6.8, 5.2 and 3.8, respectively. Subcellular location and digitonin experiments have shown that these SODs are mainly cytosolic, with small amounts in the low-mass organelles (SOD II and SOD I) and the mitochondrion (SOD III), where these enzymes play an important role in minimizing oxidative damage.

Identification of excreted iron superoxide dismutase for the diagnosis of Phtytomonas

An excreted iron superoxide dismutase (FeSODe) of pI 3.6 with a molecular weight of 28-30 kDa was detected in the in vitro culture of Phytomonas isolated from Euphorbia characias (SODeCHA) and from Lycopersicon esculentum (SODeTOM), in Grace's medium without serum. These FeSODe excreted into the medium had immunogenic capacity: the positivity of the anti-SODeCHA serum persisted to a dilution of 1/30,000, and for the anti-SODeTOM to 1/10,000 by Western blot. In addition, cross reaction was detected between the anti-SODe serum of Phytomonas isolated from E. characias against SODeTOM, and the anti-SODe serum from L. esculentum with SODeCHA. This characteristic offers the possibility of its use to diagnose plant trypanosomatids. The validation of the test was confirmed by experimental inoculation of tomato fruits with Phytomonas isolated from L. esculentum. At 7, 10, 15, and 21 days post infection, it was possible to detect the presence of the parasites with the anti-SODe serum of Phytomonas isolated from L. esculentum at a dilution of 1/250. These serological results were confirmed by visualization of the parasites by optical microscopy. The data of this study confirm that the SOD is sufficient to identify a trypanosomatid isolated from plants as belonging to the genus Phytomonas.

Procesamiento de muestras fecales en el estudio de Cryptosporidium sp. mediante PCR

El presente trabajo describe un protocolo aplicado a muestras de heces de ganado bovino para el aislamiento y purificación de ooquistes de Cryptosporidium sp. y el eventual uso de los mismos para estudios genéticos mediante PCR.

The present paper describes a protocol applied to fecal samples of cattle for the isolation and purification of Cryptosporidium sp. oocysts and the possible use of the same ones for genetic studies by means of PCR.

Cytotoxicity of three new triazolo-pyrimidine derivatives against the plant trypanosomatid: Phytomonas sp. isolated from Euphorbia characias

There is no effective chemotherapy against diseases caused by Phytomonas sp., a plant trypanosomatid responsible for economic losses in major crops. We tested three triazolo-pyrimidine complexes [two with Pt(II), and another with Ru(III)] against promastigotes of Phytomonas sp. isolated from Euphorbia characias. The incorporation of radiolabelled precursors, ultrastructural alterations and changes in the pattern of metabolite excretion were examined. Different degrees of toxicity were found for each complex: the platinun compound showed an inhibition effect on nucleic acid synthesis, provoking alterations on the levels of mitochondria, nucleus and glycosomes. These results, together with others reported previously in our laboratory about the activity of pyrimidine derivatives, reflect the potential of these compounds as agents in the treatment of Phytomonas sp.

Antigen incorporation on Cryptosporidium parvum oocyst walls

Cryptosporidium parvum oocysts are the infective stages responsible for transmission and survival of the organism in the environment. In the present work we show that the oocyst wall, far from being a static structure, is able to incorporate antigens by a mechanism involving vesicle fusion with the wall, and the incorporation of the antigen to the outer oocyst wall. Using immunoelectron microscopy we show that the antigen recognized by a monoclonal antibody used for diagnosis of cryptosporidiosis (Merifluor®, Meridian Diagnostic Inc.) could be found associated with vesicles in the space between the sporozoites and the oocysts wall, and incorporated to the outer oocyst wall by an unknown mechanism

Biochemical characterization of a trypanosomatid isolated from the plant Amaranthus retroflexus

A protozoan flagelate has recently been isolated from Amaranthus retroflexus. This plant grows near economically important crops in southeastern Spain, which are known to be parasitized by Phytomonas spp. The present study focuses on the characterization of the energy metabolism of this new isolate. These flagellates utilize glucose efficiently as their primary energy source, although they are unable to completely degrade it. They excrete ethanol, acetate, glycine, and succinate in lower amount, as well as ammonium. The presence of glycosomes was indicated by the early enzymes of the glycolytic pathway, one enzyme of the glycerol pathway (glycerol kinase), and malate dehydrogenase. No evidence of a fully functional citric-acid cycle was found. In the absence of catalase activity, these flagellates showed significant superoxide dismutase activity located in the glycosomal and cytosolic fractions. These trypanosomes, despite being morphologically and metabolically similar to other Phytomonas isolated from the same area, showed significant differences, suggesting that they are phylogenetically different species.