Estudio histopatológico de tejido cardiaco de roedores infectados con Trypanosoma cruzi capturados en barrios suburbanos de Mérida, México / Histopathological study in cardiac tissue of rodents infected with Trypanosoma cruzi, captured in suburbs of Mérida, México

Resumen Introducción. Trypanosoma cruzi es el agente causal de la tripanosomiasis americana, enfermedad endémica en México. Los roedores Mus musculus y Rattus rattus son reservorios del parásito, el cual invade las fibras cardiacas y desarrolla nidos parasitarios produciendo diversas lesiones. Los estudios histopatológicos en roedores naturalmente infectados son escasos. Objetivo. Describir los tipos y las frecuencias de las lesiones microscópicas en muestras de tejido cardiaco de M. musculus y R. rattus infectados con T. cruzi capturados en Mérida, México. Materiales y métodos. Los roedores se capturaron en los barrios suburbanos de Mérida. Se extrajo el tejido cardiaco y se procesó por la técnica de inclusión en parafina y tinción con hematoxilina y eosina. Su examen se hizo con un microscópico convencional y se determinaron todas las lesiones y su grado de afección. Resultados. Se trabajaron ocho muestras de tejido de M. musculus y siete de R. rattus. Se encontraron nidos parasitarios en siete del total de las muestras: en 3 de las 8 de M. musculus y en 4 de las 7 de R. rattus. Se observaron infiltrados inflamatorios en todas las muestras. Otras lesiones fueron la degeneración de las fibras cardiacas (8/15), la congestión de los vasos sanguíneos (6/15) y la necrosis (5/15). Discusión. Las lesiones observadas están descritas en los modelos animales experimentales y en los humanos con tripanosomiasis americana. Los infiltrados inflamatorios se han descrito como la lesión más significativa en los humanos y en los reservorios en la etapa crónica de la enfermedad. Conclusión. Las lesiones observadas están asociadas con la infección con T. cruzi, lo cual confirma que los roedores estudiados son reservorios de este parásito.

Abstract Introduction: Trypanosoma cruzi is the causal agent of the American trypanosomiasis, an endemic disease in México. The commensal rodents Mus musculus and Rattus rattus are reservoirs of this parasite, which invades cardiac fibers and develops parasite nests causing various lesions. Histopathological studies in naturally infected rodents are scarce. Objective: To describe the types and frequencies of microscopic lesions in cardiac tissue of M. musculus and R. rattus infected with T. cruzi captured in Mérida, México. Materials and methods: The rodents were captured in suburban environments of Mérida. Cardiac tissue was extracted and processed by the paraffin inclusion technique and hematoxylin and eosin stained. The observation was made with a conventional microscope and all the lesions, as well as their degree, were identified. Results: Eight tissue samples of M. musculus and seven of R. rattus were studied. Parasite nests were found in 7/15, specifically 3/8 in M. musculus and 4/7 in R. rattus. The inflammatory infiltrate was the most frequent lesion. Other lesions were: Degeneration of cardiac fibers (8/15), congestion of blood vessels (6/15), and necrosis (5/15). Discussion: The lesions we observed have been described in experimental animal models and in humans with American trypanosomiasis. The inflammatory infiltrate has been identified as the most significant lesion in humans and reservoirs in the chronic stage of the disease. Conclusion: The lesions we described are associated with T. cruzi infection, which confirms that the rodents studied are reservoirs of this parasite.

Antibodies against Apicomplexa protozoa and absence sarcocysts in heart tissues from horses in southern Brazil / Anticorpos contra protozoários do filo Apicomplexa e ausência de sarcocistos no miocárdio de equinos no sul do Brasil

Abstract Sarcocystis spp., Neospora spp., and Toxoplasma gondii are Apicomplexa protozoa that can infect horses. This study aimed to investigate the occurrence of antibodies against Sarcocystis spp., Neospora spp., and T. gondii in horses slaughtered in southern Brazil. The presence of histological lesions, tissue cysts, and Sarcocystis spp. DNA in the hearts of these horses was also investigated. A total of 197 paired serum and heart samples were evaluated by serology and direct microscopic examination; 50 of these samples were subjected to histopathological and PCR analyses. Antibodies against at least one of the protozoa were detected in 146 (74.1%) of the serum samples. The frequencies of positive serology were: 36% (71/197) against Sarcocystis spp., 39.1% (77/197) against Neospora spp., and 47.2% (93/197) against T. gondii. No cysts, Sarcocystis spp. DNA, or histopathological lesions were observed in myocardial tissue samples. The frequencies of antibody seropositivity against Sarcocystis spp., Neospora spp., and T. gondii showed that horses are frequently infected by these parasites in southern Brazil. The absence of sarcocysts in horse tissues is compatible with their role as aberrant/accidental hosts in the life cycle of Sarcocystis spp..

Resumo Sarcocystis spp., Neospora spp. e Toxoplasma gondii são protozoários que pertencem ao filo Apicomplexa e que podem afetar equinos. O objetivo deste estudo foi investigar a ocorrência de anticorpos contra Sarcocystis spp., Neospora spp. e T. gondii. A presença de lesões histológicas, cistos teciduais e DNA de Sarcocystis spp. no miocárdio de equinos abatidos no sul do Brasil também foi investigado. Um total de 197 amostras de soro juntamente com as respectivas amostras de coração, foram avaliadas por sorologia e exame microscópico direto. Destas amostras, 50 foram selecionadas e submetidas a análise histopatológica e PCR. Anticorpos contra pelo menos um dos protozoários foi detectado em 146 (74,1%) das amostras de soro. As frequências de sorologia positiva foram: 36% (71/197) para Sarcocystis spp., 39,1% (77/197) para Neospora spp. e 47,2% (93/197) para T. gondii. Não foram encontradas lesões histopatológicas, cistos e DNA de Sarcocystis spp. nas amostras de miocárdio dos equinos. As frequências de soropositividade para Sarcocystis spp., Neospora spp. e T. gondii mostra que os equinos podem ser frequentemente infectados por estes parasitas no sul do Brasil. A ausência de sarcocistose no coração dos equinos é compatível com seu papel como hospedeiro errático/acidental no ciclo de vida deste protozoário.

New host, geographic records, and histopathologic studies ofAngiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment

To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis andAngiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylusspecies parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.

Trypanosoma cruzi -infected Triatoma gerstaeckeri (Hemiptera: Reduviidae) from Nuevo León, México, and pathogenicity of the regional strain / Triatoma gerstaeckeri (Hemiptera: Reduviidae) infectada con Trypanosoma cruzi en Nuevo León, México, y capacidad patógena de la cepa regional

Introduction: Four species of triatomines have been reported in Nuevo León, northeast (NE) México, but Triatoma gerstaeckeri has only been recorded from a peridomestic dwelling. Objectives: To assess the natural infection index (NII) of Trypanosoma cruzi in triatomines and the infestation index (II) of T. gerstaeckeri collected in a suburban locality, and to collect histopathological data to understand tissue tropism of the regional T. cruzi strain (strain NE) obtained from the vectors collected after an experimental inoculation in Mus musculus . Materials and methods: Triatomines were collected from 85 houses and peridomiciles in Allende, Nuevo León. Stool samples were obtained to determine the T. cruzi NII and were used in an experimental mice infection. Results: A total of 118 T . gerstaeckeri were captured, and 46 (adults and nymphs) were collected inside the same house (II=1.17%). Thirty-seven reduvids were infected with T. cruzi (NII=31.3%). Tissue tropism of the T. cruzi NE strain was progressive in skeletal muscle, myocardial, and adipose tissues and was characterized by the presence of intracellular amastigotes and destruction of cardiac myocells. Conclusions: The presence of naturally infected domiciliary vectors is an important risk factor for public health in the region considering that these vectors are the principal transmission mechanism of the parasite. The T. cruzi NE strain has similar virulence to that of other Mexican and Texan strains and caused chagasic infections in 11 of 12 mice.

Introducción. En Nuevo León, localizado en el noreste de México, existen cuatro especies de triatominos, de las cuales Triatoma gerstaeckeri ha sido la única reportada en peridomicilios. Objetivos. Evaluar el índice de infección natural de Trypanosoma cruzi en los triatominos y el índice de infestación de T. gerstaeckeri en una localidad suburbana, y obtener datos histopatológicos para comprender el tropismo tisular de la cepa regional (cepa NE) de T. cruzi obtenida de los vectores recolectados después de la infección experimental en Mus musculus. Materiales y métodos. La recolección de triatominos se llevó a cabo en 85 casas y peridomicilios de Allende, Nuevo León, México. Se obtuvieron muestras de las deyecciones para conocer el índice de infección natural por T. cruzi y, con estas, se hicieron inoculaciones experimentales en ratones. Resultados. Se capturaron 118 especímenes de T. gerstaeckeri , 46 (adultos y ninfas) en el mismo domicilio (índice de infestación=1,17 %). Treinta y siete redúvidos estaban infectados con T. cruzi (índice de infección natural, 31,3). El tropismo tisular de la cepa NE de T. cruzi fue progresivo en músculo esquelético, miocardio y tejido adiposo, y se caracterizó por la presencia de amastigotes intracelulares con destrucción de células cardiacas. Conclusiones. La presencia de vectores domiciliarios naturalmente infectados con T. cruzi , es un factor de riesgo importante para la salud pública de la región, considerando que este es el principal mecanismo de la transmisión del parásito y que la cepa NE de T. cruzi tiene una virulencia similar a la de otras cepas mexicanas y texanas, y causó infección chagásica en 11 de los 12 ratones inoculados.

Metallothionein-1 and nitric oxide expression are inversely correlated in a murine model of Chagas disease

Chagas disease, caused by Trypanosoma cruzi, represents an endemic among Latin America countries. The participation of free radicals, especially nitric oxide (NO), has been demonstrated in the pathophysiology of seropositive individuals with T. cruzi. In Chagas disease, increased NO contributes to the development of cardiomyopathy and megacolon. Metallothioneins (MTs) are efficient free radicals scavengers of NO in vitro and in vivo. Here, we developed a murine model of the chronic phase of Chagas disease using endemic T. cruzi RyCH1 in BALB/c mice, which were divided into four groups: infected non-treated (Inf), infected N-monomethyl-L-arginine treated (Inf L-NAME), non-infected L-NAME treated and non-infected vehicle-treated. We determined blood parasitaemia and NO levels, the extent of parasite nests in tissues and liver MT-I expression levels. It was observed that NO levels were increasing in Inf mice in a time-dependent manner. Inf L-NAME mice had fewer T. cruzi nests in cardiac and skeletal muscle with decreased blood NO levels at day 135 post infection. This affect was negatively correlated with an increase of MT-I expression (r = -0.8462, p < 0.0001). In conclusion, we determined that in Chagas disease, an unknown inhibitory mechanism reduces MT-I expression, allowing augmented NO levels.

Estudo do controle autonômico do coração na doença de chagas / Study of control autonômicodo heart in Chagas' disease

O comprometimento do sistema nervoso autônomo do coração na enfermidade chagasica crônica:referência ao envolvimento do sistema nervoso na Doença de Chagas foi inicialmente feita por Carlos Chagas, em 1913 ; "Relativement à la frequence des formes nerveuses de la trypanos- somiase, nous possedons des observations nombreuses, qui nous au torisent à affirmer que cette maladie est celle qui? peut-être, provoque, en pathologic humaine, la plus grand nombre d'affec tions organiques du systéme nerveux central" (01). Embora Carlos Chagas, nesta época, se referisse apenas a manifestações decorren tes do comprometimento do sistema nervoso central, ja em 1921, su geriu a possibilidade de "lesões dos nervos sensitivos intracar- díacos", ou de um "augmento do tonus sympathico", para esclarecer este "capítulo novo da pathologia humana"A relevância emprestada pelos diversos autores à lesão neuronal, como fator patogênico, tem variado bastante. Koborle (02) postulou ser a moléstia de Chagas uma enfermidade exclusiva do sistema nervoso parassimpãtico ("cardiopatia parassimpatico- priva"), em qu9 as ’“patias" chagásicas —cardiopatia, bronqui- ectasia, megas etc— representariam tão-somente sequelas das lesões neuronais ocorridas na fase aguda. Por outro lado, Andrade e Andrade (0 3), embora admitindo a ocorrência de intensa destruição neuronal no coração de chagãsicos brasileiros, a qual comunicaria certas peculiaridades ã miocardiopatia em nosso meio, acreditam que a lesão autonômica não á fundamental na cardiopatia.

Alteration of Cytokine Production during Visceral Larva Migrans by Toxascaris leonina in Mice

To determine alteration of immune responses during visceral larva migrans (VLM) caused by Toxascaris leonina at several time points, we experimentally infected mice with embryonated eggs of T. leonina and measured T-helper (Th) cell-related serial cytokine production after infection. At day 5 post infection (PI), most larvae were detected from the lungs, spleen, intestine, and muscle. Expression of thymic stromal lymphopoietin (TSLP) and CCL11 (eotaxin) showed a significant increase in most infected organs, except the intestine. However, expression of the CXCL1 (Gro-alpha) gene was most highly enhanced in the intestine at day 14 PI. Th1-related cytokine secretion of splenocytes showed increases at day 28 PI, and the level showed a decrease at day 42 PI. Th2-related cytokine secretion of splenocytes also showed an increase after infection; in particular, IL-5 level showed a significant increase at day 14 PI, and the level showed a decrease at day 28 PI. However, levels of Th17-related cytokines, IL-6 and IL-17A, showed gradual increases until day 42 PI. In conclusion, Th1, Th2, and Th17-related cytokine production might be important in immune responses against T. leonina VLM in experimental mice.

Heart involvement in Kala Azar

Leishmaniasis is a vector-borne disease. About 30 species of sandflies are proven vectors of leishmania, the usual reservoir host includes human and domestic/wild animals. In addition, acquisition of visceral leishmaniasis as a result of blood transfusion has been documented. Visceral leishmaniasis presents in various forms. We report a three year old girl with visceral leishmaniasis and pericardial effusion. Meglumine antimoniate was prescribed for her and all her signs and symptoms plus her pericardial effusion were resolved

Sarcocystis and Its Complications in Camels (Camelus dromedarius) of Eastern Provinces of Iran

The prevalence of Sarcocystis spp. was investigated by gross and histopathological examinations in 250 camels (Camelus dromedarius) slaughtered from 2002 to 2005 in the Mashhad Slaughterhouse, eastern Iran. Samples were taken from the diaphragm, heart, tongue, esophagus and masseter muscles for histopathological studies. No macroscopic sarcocysts were found in the samples at gross inspection. Sarcocysts were detected in 209 of 250 (83.6%) examined camels at histopathological level. The infection rate of the esophagus, heart, masseter muscles, diaphragm, and tongue was 58.8%, 48.0%, 46.8%, 41.6%, and 28.0%, respectively. There was no significant difference in the rate of infection between male (85.8%) and female (81.0%) camels. The tissue response to vital cysts was minimal; however, reaction to the degenerating cysts was severe and caused tissue damages resulting in hyperemia, hemorrhages, mononuclear cell infiltration, necrotic changes, and fibrosis. The wild and domestic carnivores especially dogs may be the final hosts of Sarcocystis spp. in this area.

A serological survey of Dirofilaria immitis infection in pet dogs of Busan, Korea, and effects of chemoprophylaxis

The status of Dirofilaria immitis infection was assessed in pet dogs of Busan, Korea, and chemoprophylactic effects of microfilaricidal medication were evaluated. A total of 294 pet dogs older than 6 mo were examined, 217 of which had been maintained indoors, and 77 had been kept outdoors. The Snap(R) kit and direct microscopic examinations of the peripheral blood were used. The mean overall parasite positive rates were 10.2% and 6.5%, respectively. Outdoor dogs evidenced adult worm infection rate of 31.2% and microfilaria infection rate of 18.2%. The indoor dogs, however, evidenced adult worm infection rate of 2.8% and microfilaria infection rate of 2.3%. The prevalence in males was more than 2 times that of females. The changing pattern of infection rates by age evidenced a gradual increase, from 2- to 6-year-old dogs, after which, a decrease in infection rates was noted. With regard to chemoprophylaxis, the infection rates of complete and incomplete chemoprophylaxis groups were found to be 2-3 times lower than that of the non-chemoprophylaxis group. The results of the present study indicate that the risk of exposure to D. immitis in pet dogs is quite high, particularly in male outdoor dogs, and chemoprophylactic measures were quite effective.

Prevalence of Toxocara canis, Toxascaris leonina and Dirofilaria immitis in dogs in Chuncheon, Korea (2004)

The intestines and hearts of dogs were examined for Toxocara canis, Toxascaris leonina, and Dirofilaria immitis, after necropsy between June 26 and September 29, 2004 in Chuncheon, Korea. Of the 662 dogs examined, 6 were infected with T. canis (0.9%), 86 with T. leonina (13.0%). Fifty dogs were infected with D. immitis among 500 dogs examined (10.0%). Five were co-infected with T. canis and T. leonina, and three were co-infected with T. leonina and D. immitis. The cumulative positive infection rate for three species was 134/662 (20.2%). Considering previously reported seropositive rates of T. canis excretory-secretory antigen, i.e., 5% in the adult population in Korea, the possibility of toxocariasis caused by T. leonina should be reevaluated.

Niveles de parasitemia y alteraciones histopatológicas en Mus musculus BALB/c infectado con Trypanosoma cruzi obtenido de Panstrongylus chinai del Valle Chamán, La Libertad - Perú / Parasitemia levels and histopathologycal changes in Mus musculus balb/c infected with Typanosoma cruzi obtained from Panstrongylus chinai of Chaman Valley, la libertad - Peru

Se determinó los niveles de parasitemia y las alteraciones histopatológicas en el corazón y el encéfalo de Mus musculus cepa BALB/c infectado experimentalmente con Trypanosoma cruzi obtenido de Panstrongyius chinai capturados en el valle de Chamán, La Libertad-Perú. El trabajo se hizo en 10 ejemplares de M. musculus machos (nueve experimentales y un control) de 20 días de edad. A cada uno de los ejemplares del grupo experimental se les inoculó intraperitonealmente 5x104 tripomastigotes (0,1 mL inoculo original) suspendidos en sangre, y al control 0,1 mL de solución salina fisiológica estéril. La parasitemia se inició a partir del quinto día de la inoculación del T. cruzi, elevándose hasta niveles comprendidos entre 2,5x106 y 7,0x106 tripomastigotes/mL, antes de la muerte de los animales (18 días como máximo). El corazón y encéfalo fueron separados y conservados en formol al 10 por ciento para realizar cortes y colorearlos con la técnica H/E. Todos los ratones parasitados presentaron: erizamiento de pelo, incontinencia urinaria, parálisis de extremidades posteriores y convulsiones. A nivel histopatológico, tanto en el corazón como en el encéfalo, se observaron áreas de edema, congestión vascular, hipercromasia y nidos de amastigota. En el encéfalo se presentó, además, focos de inflamación crónica y difusa y en el corazón infiltrado inflamatorio linfocitario.

Prevalence of Sarcocystis infection in horses in Mongolia.

Sarcocystis infection was detected in 93% of horses in Mongolia. Using the compress method, sarcocysts were found in the muscles of the diaphragm, heart and tongue in 40 of the 43 horses that were slaughtered at the Makh Impex Meat Company in Ulaan Baatar in July 1998. The muscle of the tongue showed the highest rate (97.5%) of infection. The distribution of sarcocysts in the muscles was positively correlated with horse age; the rate of detection was significantly lower (p=0.01) in the under 10 year old group than the older group. All horses were apparently healthy and were slaughtered for human consumption.

Acute Chagas' cardiopathy in a polar bear (Ursus maritimus) in Guadalajara, Mexico

Relatamos o caso de uma ursa polar (Ursus maritimus) de 24 anos de idade, que contraiu a infecção chagásica no Zoológico de Guadalajara, em Jalisco, no México, e morreu de cardite chagásica aguda 15 dias após o início da sintomatologia. Os achados histopatológicos são descritos, bem como a presença de triatomíneos (Triatoma longipennis Usinger) infectados por Trypanosoma cruzi coletados a 5 metros do local onde o animal vivia, na cidade de Guadalajara.

We report a 24-year-old female polar bear (Ursus maritimus) who contracted Chagas' infection at the Guadalajara Zoo, in Jalisco, México, and died of acute Chagas' carditis 15 days later. The histopathological findings are described, as well as the presence of triatomids (Triatoma longipennis Usinger) infected with Trypanosoma cruzi collected within 5 meters from the place where the animal lived in the city of Guadalajara.

Contribuiçäo ao conhecimento da cardiopatia chagásica aguda: estudo sistematizado dos sistemas excito-condutor e nervoso autônomo intracardíaco em caso autóctone do Acre / A contribution to the knowledge of acute chagasic cardiopathy: a systematized study of the conducting system and the autonomic intracardiac nervous system in an autochthonous case in Acre

The histopathology of the heart is described in an acute case of Chagas' disease (DC). Lesions involving the conducting system (SC) and the autonomic intracardiac nervous system (SNAIC) are emphasized. Light microscopy showed acute pan-carditis with plenty of Trypanosoma cruzi amastigotes within heart muscle cells. Multiple inflammatory foci were found in the SC with parasitic nests within the atrioventricular node and left his bundle. There were also severe atrial periganglionitis and perineuritis with or without peripheral involvement of those structures. Apparently there was no cardiac neuronal depopulation. The epidemiological study suggested transmission through Rhodnius pictipes. To the best of our knowledge, this is the first reported case of acute DC from the Amazonian basin with systematized microscopy study of the SC and SNAIC.

Estudo sobre a participação das proteínas de fase aguda alfa-2-macroglobulina e proteína C reativa na infecção por Trypanosoma cruzi / Study on participation of proteins of acute phase alpha-2-macroglobulina and protein C reactive in infection for Trypanosoma cruzi

Alfa-2-macroglobulina (A2M), proteína inibidora de protease, é encontrada no plasma e tecidos de mamíferos. Camundongos e humanos infectados por T. cruzi apresentaram aumento nos níveis de A2M durante a fase aguda da doença. Examinou-se por citometria de fluxo (CF) a ligação de A2M-protease (A2M-P) a macrófagos peritoneais de camundongos C3H e C57/B/6 infectados com T. cruzi observando que o receptor para A2M está mais expresso em C57/B1/6 do que em C3H e é positivamente modulado em ambas as cepas durante a fase aguda da infecção. Pela técnica de imunofluorescência (IF), A2M foi detectada no coração de camundongos Swiss durante a fase aguda da infecção por T. cruzi. Geralmente A2M co-localizava com os ninhos de amastigotas e com antígenos do parasita espalhados no miocárdio inflamado. A marcação mais intensa de A2M no tecido cardíaco foi correlacionada com o dia de pico do parasitismo tissular nos animais infectados. Análises de IF indireta sugeriram que A2M++liga-se in vivo à superfície de T. cruzi. Estudos através das técnicas de ELISA e de CF caracterizaram a ligação in vitro de A2M nativa (A2M-N) e A2M-P a formas tripomastigotas obtidos por cultivo em meio definido. A ligação de A2M-N ao parasita foi mais forte em pH 5.0 e inibidores de cisteíno- e serino-proteinases interferiram nesta ligação. Aproximadamente 80 dos parasitas ligaram A2M-P conjugada a FITC com alta afinidade, em processo dependente da concentração e revertido pela adição de A2M-P não marcada, de EDTA, ou ainda pela incubação em pH ácido, sugerindo a presença de um receptor para A2M. Experimentos de IF indireta destinados a detectar a ligação de proteína C reativa (CRP), proteína de fase aguda em humanos, a formas circulantes de T. cruzi foram prejudicados, pois soros anti-CRP humana se ligavam ao parasita. Ensaios de ELISA, de CF e de "western blot" mostraram que três soros policlonais monoespecíficos e dois anticorpos monoclonais anti-CRP humana se ligavam à superfíciede metacíclicos de T. cruzi obtidos por cultivo em meio definido. Essa ligação é específica, dose-dependente e saturável. O uso de EDTA impede o reconhecimento antigênico pelos anti-soros. Em análises de "western blot" de extratos do parasita, uma banda proteica em torno de 20 kDa é reconhecida pelos anti-soros. Os resultados indicam que uma possível molécula "CRP-like" é expressa na superfície de T. cruzi.

Sialoglycoconjugates in Trypanosoma cruzi-host cell interaction: possible biological model - a review

A number of glycoconjugates, including glycolipids and glycoproteins, participate in the process of host-cell invasion by Trypanosoma cruzi and one of the most important carbohydrates involved on this interaction is sialic acid. It is known that parasite trans-sialidase participates with sialic acid in a coordinated fashion in the initial stages of invasion. Given the importance of these sialogycoconjugates, this review sets out various possible biological models for the interaction between the parasite and mammalian cells that possess a sialylated receptor/ligand system