Morphological and molecular characterization of Austrodiplostomum compactum metacercariae in the eyes and brains of fishes from the Ivaí River, Brazil / Caracterização morfológica e molecular de metacercárias de Austrodiplostomum compactum em olhos e cérebros de peixes do Rio Ivaí, Brasil

Abstract Austrodiplostomum spp. (Platyhelminthes: Digenea) are endoparasites with a broad geographic distribution in South America. During the larval stage, they parasitize the eyes, brains, muscles, gill, kidneys and swim bladder of a wide variety of fishes. The metacercariae of Austrodiplostomum spp. have several morphological characteristics during development, but are very similar among species, which makes it necessary to use molecular tools to contribute to the elucidation during the larval stage. The objective of this study was to perform morphological and molecular analyses of Austrodiplostomum sp. found in specimens of Hypostomus sourced from the Ivaí River in the state of Paraná, Brazil. Of the 93 analyzed specimens (H. hermanni [n = 50], H. albopunctatus [n = 9], Hypostomus sp. 1 [n = 24], and Hypostomus sp. 2 [n = 10]), 60 were parasitized. A total of 577 Austrodiplostomum sp. metacercariae was collected from the infected hosts; DNA from seven of these samples was extracted, amplified, and sequenced. The morphological data associated with the genetic distance values and the relationships observed in the COI gene tree, indicate that all metacercariae were A. compactum. This is the first record of A. compactum parasitizing H. hermanni, H. albopunctatus, Hypostomus sp. 1, and Hypostomus sp. 2 in the Ivaí River.

Resumo Austrodiplostomum spp. (Platyhelminthes: Digenea) são endoparasitos com uma ampla distribuição geográfica na América do Sul. Durante a fase larval, parasitam os olhos, cérebros, músculos, brânquias, rins e bexiga natatória de uma grande variedade de peixes. As metacercárias de Austrodiplostomum spp. apresentam várias características morfológicas durante o desenvolvimento, as quais são muito semelhantes entre as espécies, o que torna necessário o uso de ferramentas moleculares para contribuir para a elucidação durante a fase larval. O objetivo deste estudo foi realizar análises morfológicas e moleculares de Austrodiplostomum sp. encontradas em espécimes de Hypostomus provenientes do rio Ivaí, no Paraná, Brasil. Dos 93 espécimes analisados (H. hermanni [n = 50], H. albopunctatus [n = 9], Hypostomus sp. 1 [n = 24], e Hypostomus sp. 2 [n = 10]), 60 foram parasitados. Um total de 577 metacercárias de Austrodiplostomum foram coletadas dos hospedeiros infectados; o DNA de sete dessas amostras foi extraído, amplificado e sequenciado. Os dados morfológicos, associados aos valores de distância genética e as relações observadas na árvore gênica do COI, indicam que todas as metacercárias são A. compactum. Este é o primeiro registo de A. compactum parasitando H. hermanni, H. albopunctatus, Hypostomus sp. 1, e Hypostomus sp. 2 no rio Ivaí.

Histopathology of murine toxoplasmosis under treatment with dialyzable leukocyte extract

BACKGROUND Dialyzable leukocyte extracts (DLEs) contain molecules smaller than 10 kDa with biological activity in receptor organisms. Primarily, they participate in the regulation of the Th1 immune response, which is essential for the control of several intracellular infections, such as toxoplasmosis. This disease is associated with congenital infection, encephalitis or systemic infections in immunocompromised individuals. The clinical course of this infection fundamentally depends on a well-regulated immune response and timely treatment with the appropriate drugs. OBJECTIVE The aim of this study was to evaluate the effect of treatment with a leukocyte extract, derived from crocodile lymphoid tissue, on the histopathology and brain parasite load in NIH mice that had been infected with cysts of Toxoplasma gondii (ME-49 strain). METHODS The treatment was applied during the acute and chronic stages of the infection. Histopathological changes were evaluated in the ileum, liver and spleen at one, four and eight weeks after infection and in the brain at week 8. The parasite load was evaluated by counting the cysts of T. gondii found in the brain. FINDINGS Compared to the control mouse group, the mice infected with T. gondii and under treatment with DLE showed less tissue damage, mainly at the intestinal, splenic and hepatic levels. In addition, a greater percentage of survival was observed, and there was a considerable reduction in the parasite load in the brain. CONCLUSIONS The results suggest that DLE derived from crocodile is a potential adjunctive therapy in the conventional treatment of toxoplasmosis.

Experimental neurocysticercosis: absence of IL-4 induces lower encephalitis / Neurocisticercose experimental: ausência de IL-4 induz menos encefalite

ABSTRACT Neurocysticercosis (NCC) is the most severe clinical manifestation of cysticercosis. One of the factors responsible for its symptomatology is the host inflammatory response. Therefore the influence of interleukin 4 (IL-4) on the induction of encephalitis in experimental NCC was evaluated. Methods BALB/c (WT) and BALB/c (IL-4-KO) mice were inoculated intracranially with Taenia crassiceps cysticerci and euthanized at 7, 30, 60 and 90 days later, the encephala removed and histopathologically analyzed. Results The absence of IL-4 induced greater parasitism. In the initial phase of the infection, IL-4-KO showed a lower intensity in the inflammatory infiltration of polimorphonuclear cells in the host-parasite interface and intra-parenquimatous edema. The IL-4-KO animals, in the late phase of the infection, showed lower intensity of ventriculomegaly, encephalitis, and meningitis, and greater survival of the parasites in comparison with the WT animals. Conclusion The absence of IL-4 induced lower inflammatory infiltration, ventriculomegaly and perivasculitis in experimental NCC.

RESUMO A Neurocisticercose (NCC) é a manifestação clínica mais severa da cisticercose, e um dos fatores responsáveis pela sintomatologia é a resposta inflamatória do hospedeiro. Desta forma avaliou-se a influência da interleucina 4 (IL-4) na indução de encefalite na NCC experimental. Métodos Camundongos das linhagens BALB/c (WT) e BALB/c (IL-4-KO) foram inoculados intracranialmente com cisticercos de Taenia crassiceps e eutanasiados aos 7, 30, 60 e 90 dias após a infecção, os encéfalos foram removidos e analisados histopatologicamente. Resultados A ausência da IL-4 induziu um maior parasitismo nos animais. Na fase inicial da infecção os animais IL-4-KO apresentaram menor intensidade tanto de infiltrado inflamatório de polimorfonucleares na interface parasito-hospedeiro quanto de edema intraparenquimatoso. Os animais IL-4-KO, na fase tardia, apresentaram menor intensidade de ventriculomegalia, encefalite, meningite e maior sobrevivência dos cisticercos em relação aos animais WT. Conclusão A ausência da IL-4 induz menos infiltrado inflamatório, ventriculomegalia e perivasculite na NCC experimental.

Isolation and Genotyping of Toxoplasma gondii Strains in Ovine Aborted Fetuses in Khorasan Razavi Province, Iran

Toxoplasmosis is an important zoonotic disease that can cause abortion in humans and animals. The aim of this study was isolation and subsequent genotyping of Toxoplasma gondii isolates in ovine aborted fetuses. During 2012-2013, 39 ovine aborted fetuses were collected from sheep flocks in Khorasan Razavi Province, Iran. The brain samples were screened for detection of the parasite DNA by nested PCR. The positive brain samples were bioassayed in Webster Swiss mice. The serum samples of mice were examined for T. gondii antibodies by IFAT at 6 weeks post inoculation, and T. gondii cysts were searched in brain tissue samples of seropositive mice. The positive samples were genotyped by using a PCR-RLFP method. Subsequently, GRA6 sequences of isolates were analyzed using a phylogenetic method. The results revealed that T. gondii DNA was detected in 54% (20/37, 95% CI 38.4-69.0%) brain samples of ovine aborted fetuses. In bioassay of mice, only 2 samples were virulent and the mice were killed at 30 days post inoculation, while the others were non-virulent to mice. The size of cysts ranged 7-22 µm. Complete genotyping data for GRA6 locus were observed in 5 of the 20 samples. PCR-RLFP results and phylogenetic analysis revealed that all of the isolated samples were closely related to type I. For the first time, we could genotype and report T. gondii isolates from ovine aborted fetuses in Khorasan Razavi Province, Iran. The results indicate that the T. gondii isolates are genetically related to type I, although most of them were non-virulent for mice.

Application of different techniques to detect Toxoplasma gondii in slaughtered sheep for human consumption / Utilização de diferentes técnicas para detecção de Toxoplasma gondii em ovinos abatidos para consumo humano

Abstract The aim of this study was to investigate occurrence of Toxoplasma gondii in sheep slaughtered in the state of Alagoas, Brazil, by means of different diagnosis techniques. Serum samples and tissues from 100 slaughtered sheep were used. To detect antibodies, the indirect immunofluorescence antibody test (IFAT) was used, and tissues from seropositive animals (cut-off ≥1:64) were submitted to Polymerase Chain Reaction (PCR) and immunohistochemistry (IHC). To assess the concordance between the direct techniques, the kappa test was used. In the IFAT, it was observed that 14% (14/100) of the ovine samples were serum-positive. In the PCR, 21.43% (3/14) of the animals were positive and in IHC, it was observed that 7.14% (1/14) were positively stained for T. gondii in cerebral tissue. Histopathologically, the predominant finding was the presence of mononuclear cell infiltrate in the heart and a perivascular cuff in the cerebrum and cerebellum. The concordance between the direct diagnosis techniques was moderate (k=0.44). Thus, it is important to use different direct techniques in diagnosing toxoplasmosis in naturally infected sheep.

Resumo O objetivo deste estudo foi pesquisar a ocorrência de Toxoplasma gondii em ovinos abatidos no Estado de Alagoas, Brasil por meio de diferentes técnicas de diagnóstico. Foram utilizadas amostras de soros e tecidos de 100 ovinos abatidos. Para a pesquisa de anticorpos foi utilizada a Reação de Imunofluorescência Indireta (RIFI), e os tecidos dos animais soropositivos (ponto de corte ≥1:64) foram submetidos às técnicas de Reação de Cadeia da Polimerase (PCR) e Imunohistoquímica (IHQ). Para o estudo da concordância entre as técnicas diretas foi empregado o teste Kappa. Na RIFI, 14% (14/100) das amostras foram soro-positivas. Na PCR, 21,43% (3/14) dos animais foram positivos e, na IHC, 7,14% (1/14) apresentaram marcação positiva para T. gondii no tecido cerebral. Na histopatologia, o achado predominante foi o infiltrado celular mononuclear no coração e manguito perivascular no cérebro e cerebelo. A concordância entre as técnicas diretas de diagnóstico foi moderada (K= 0,44). Desse modo, é importante utilizar diferentes técnicas diretas no diagnóstico da toxoplasmose em ovinos naturalmente infectados.

Epidemiological aspects of Toxoplasma gondii infection in riverside communities in the Southern Brazilian Amazon

INTRODUCTION: Toxoplasma gondii infection is widely prevalent in humans and other animals worldwide. Information on the prevalence of T. gondii infection is scarce in some regions of Brazil, including riverside communities along the Amazon River basin. M METHODS: The prevalence of T. gondii in 231 people, aged 1-85 years, who were living in four riverside communities along the Purus River, Lábrea, State of Amazonas, Brazil, was determined. Antibodies against T. gondii were assayed using a commercial enzyme-linked immunosorbent assay (ELISA) kit. The hearts and brains of 50 chickens, which were raised free-range in the communities, were pooled according to the community of origin and bioassayed in mice. The isolates were genotyped using polymorphisms at 12 nuclear markers (SAG1, 5' and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3). RESULTS: The overall seroprevalence of T. gondii was 56.7% (131/231). IgG antibodies were presented by 117 (89.3%) and IgM by 14 (10.7%) of the 131 positive individuals. No association between age group and gender with prevalence was observed (chi-square test, p > 0.05); however, the comparison between localities showed that the seroprevalence of T. gondii was significantly lower among the individuals living in the Boca do Ituxi (p < 0.05) community. Five isolates of T. gondii were obtained in the mouse bioassay, and genotyping revealed two complete genotypes that had not been described previously and three mixed isolates. CONCLUSIONS: These results support previous findings that T. gondii population genetics are highly diverse in Brazil and that T. gondii infection is active in these riverside communities. .

Detection of Acute Toxoplasmosis in Pigs Using Loop-Mediated Isothermal Amplification and Quantitative PCR

A loop-mediated isothermal amplification (LAMP) assay allows rapid diagnosis of Toxoplasma gondii infection. In the present study, the LAMP assay was evaluated using blood from both naturally and experimentally infected pigs. The sensitivity of the LAMP assay was compared with that of Q-PCR. Both assays detected T. gondii in the blood of experimentally infected pigs, with 100% agreement. In infected blood samples, the parasite was detected as early as 2 days post-infection and reached a peak in 3-5 days. In 216 field serum samples, the detection rates of LAMP and Q-PCR assays were 6.9% and 7.8%, respectively. This result indicates that the sensitivity of the LAMP assay was slightly lower than that of the Q-PCR assay. However, the LAMP may be an attractive diagnostic method in conditions where sophisticated and expensive equipment is unavailable. This assay could be a powerful supplement to current diagnostic methods.

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.

Real-Time RT-PCR on SAG1 and BAG1 Gene Expression during Stage Conversion in Immunosuppressed Mice Infected with Toxoplasma gondii Tehran Strain

Toxoplasmic encephalitis is caused by reactivation of bradyzoites to rapidly dividing tachyzoites of the apicomplexan parasite Toxoplasma gondii in immunocompromised hosts. Diagnosis of this life-threatening disease is problematic, because it is difficult to discriminate between these 2 stages. Toxoplasma PCR assays using gDNA as a template have been unable to discriminate between an increase or decrease in SAG1 and BAG1 expression between the active tachyzoite stage and the latent bradyzoite stage. In the present study, real-time RT-PCR assay was used to detect the expression of bradyzoite (BAG1)- and tachyzoite-specific genes (SAG1) during bradyzoite/tachyzoite stage conversion in mice infected with T. gondii Tehran strain after dexamethasone sodium phosphate (DXM) administration. The conversion reaction was observed in the lungs and brain tissues of experimental mice, indicated by SAG1 expression at day 6 after DXM administration, and continued until day 14. Bradyzoites were also detected in both organs throughout the study; however, it decreased at day 14 significantly. It is suggested that during the reactivation period, bradyzoites not only escape from the cysts and reinvade neighboring cells as tachyzoites, but also converted to new bradyzoites. In summary, the real-time RT-PCR assay provided a reliable, fast, and quantitative way of detecting T. gondii reactivation in an animal model. Thus, this method may be useful for diagnosing stage conversion in clinical specimens of immunocompromised patients (HIV or transplant patients) for early identification of tachyzoite-bradyzoite stage conversion.

The Return of an Old Worm: Cerebral Paragonimiasis Presenting with Intracerebral Hemorrhage

Paragonimiasis is caused by ingesting crustaceans, which are the intermediate hosts of Paragonimus. The involvement of the brain was a common presentation in Korea decades ago, but it becomes much less frequent in domestic medical practices. We observed a rare case of cerebral paragonimiasis manifesting with intracerebral hemorrhage. A 10-yr-old girl presented with sudden-onset dysarthria, right facial palsy and clumsiness of the right hand. Brain imaging showed acute intracerebral hemorrhage in the left frontal area. An occult vascular malformation or small arteriovenous malformation compressed by the hematoma was initially suspected. The lesion progressed for over 2 months until a delayed surgery was undertaken. Pathologic examination was consistent with cerebral paragonimiasis. After chemotherapy with praziquantel, the patient was monitored without neurological deficits or seizure attacks for 6 months. This case alerts practicing clinicians to the domestic transmission of a forgotten parasitic disease due to environmental changes.

The Return of an Old Worm: Cerebral Paragonimiasis Presenting with Intracerebral Hemorrhage

Paragonimiasis is caused by ingesting crustaceans, which are the intermediate hosts of Paragonimus. The involvement of the brain was a common presentation in Korea decades ago, but it becomes much less frequent in domestic medical practices. We observed a rare case of cerebral paragonimiasis manifesting with intracerebral hemorrhage. A 10-yr-old girl presented with sudden-onset dysarthria, right facial palsy and clumsiness of the right hand. Brain imaging showed acute intracerebral hemorrhage in the left frontal area. An occult vascular malformation or small arteriovenous malformation compressed by the hematoma was initially suspected. The lesion progressed for over 2 months until a delayed surgery was undertaken. Pathologic examination was consistent with cerebral paragonimiasis. After chemotherapy with praziquantel, the patient was monitored without neurological deficits or seizure attacks for 6 months. This case alerts practicing clinicians to the domestic transmission of a forgotten parasitic disease due to environmental changes.

Presence of amastigotes in the central nervous system of hamsters infected with Leishmania sp. / Presença de amastigotas em sistema nervoso central de hamster infectado com Leishmania sp.

Visceral leishmaniasis (VL) is a severe chronic disease caused by Leishmania (Leishmania) infantum chagasi. Better knowledge on the effects caused by this disease can help develop adequate clinical management and treatment. Parasitological and immunohistochemical studies were performed golden hamsters Mesocricetus auratus infected with bone marrow from individuals with VL in the State of Mato Grosso do Sul, central-west Brazil. The effects of parasitism in the spleen, liver, kidneys, lungs, heart and brain of the animals were examined. Eighteen hamsters were inoculated intraperitoneally, and six healthy animals were used as negative controls. The animals were kept in the animal house and checked for clinical signs. Specimens of each organ were examined for the presence of amastigotes. Immunohistochemical technique was performed in all brain specimens and organs negative on the direct examination of parasites. Direct examination of amastigotes was positive in the spleen and liver of all infected animals; 33.3 percent showed the parasite in the kidneys and lungs, and 16.7 percent in the heart. Parasitic forms were seen in 83.3 percent (15/18) of the brain examined. Immunohistochemistry confirmed the results of the direct examination, except in two specimens of lung tissue and in the brain specimens. Other studies are needed to further clarify the effect of the parasite in the central nervous system.

A leishmaniose visceral (LV) é uma doença crônica grave, causada pelo parasito Leishmania (Leishmania) infantum chagasi. Esclarecer as alterações provocadas pela doença é fundamental para que se adotem condutas clínicas e de tratamento adequadas. Com o objetivo de analisar a infecção experimental em hamsters da linhagem golden, Mesocricetus auratus, infectados com tecido de medula óssea de pacientes com LV no Estado de Mato Grosso do Sul, foram realizados estudos parasitológicos e de imunomarcação. Foi verificada a distribuição do parasitismo no baço, fígado, rim, pulmão, coração e encéfalo desses animais. Foram utilizados 18 hamsters experimentalmente inoculados via intra-peritoneal, e seis animais sadios como controles negativos. Os animais foram mantidos em biotério de experimentação e observados, em busca de alterações clínicas. Com fragmentos de cada órgão, procedeu-se a confecção de lâminas por aposição para pesquisa de amastigotas. Nos órgãos com resultado negativo na pesquisa direta do parasito, e em todas as amostras de encéfalo, foi realizada a técnica de imunohistoquímica. A pesquisa direta de amastigotas foi positiva no baço e fígado de todos os animais infectados; 33,3 por cento apresentaram o parasito em rim e pulmão, e 16,7 por cento no coração. Quando realizada a pesquisa em encéfalo, formas parasitárias foram observadas em 83,3 por cento (15/18) dos animais. A imunomarcação confirmou os resultados da pesquisa direta, exceto em duas amostras de tecido pulmonar e nas amostras de encéfalo. Mais estudos são necessários, para esclarecer o real papel do parasito no sistema nervoso central.

A rare case of disseminated cysticercosis: Case report and literature review.

Cysticercosis is a common tropical disease. One of the uncommon manifestations of cysticercosis and a rare complication is its disseminated form. We report an immunocompetent patient with disseminated cysticercosis who had involvement of the brain, subcutaneous tissues, lungs and skeletal muscles and presented with arthritis. He was otherwise asymptomatic in spite of the extensive involvement of multiple organs. A planned approach to therapy is necessary to prevent complications.

Cerebral Paragonimiasis and Bo Sung Sim's Hemispherectomy in Korea in 1950s-1960s / 의사학

This paper deals with cerebral paragonimiasis and cerebral hemispherectomy conducted as a treatment of cerebral paragonimiasis by Bo Sung Sim in Korea in 1950s-1960s. He demonstrated that cerebral hemispherectomy could be used for unilateral diffuse cerebral paragonimiasis. Sim learned cerebral hemispherectomy from Dr. L. A. French. at the University of Minnesota from 1955 to 1957 in America. The authors argues that Bo Sung Sim's introduction of cerebral hemispherectomy to Korea was not a simple application of an advanced medical technology, but a complicated and active process in that Sim used the technique to intervene intractable complications from cerebral paragonimiasis such as generalized convulsions, spastic hemiplegia and mental deterioration. Bo Sung Sim, one of the neurosurgeons of the first generation in Korea, was trained in neurology, neuropathology, neuroradiology and animal experiments as well as in neurosurgery at the University of Minnesota. After returning to Korea, Sim faced parasitic diseases, one of the most serious public health problems at that time, which were far different from what he learned in America. As a neurosurgeon, Sim tackled with parasitic diseases of the central nervous system with various diagnostics and therapeutics. In 1950s, more than one million populations suffered from pulmonary paragonimiasis acquired by eating raw crabs or by feeding juice of crushed crayfish for the treatment of measles in Korea. About 26.6 percent of people with paragonimiasis had cerebral paragonimiasis. Before bithionol therapy was introduced in 1962, neurosurgery was the only available treatment to control increased intracranial pressures, intractable epilepsy, paralysis and mental deterioration. Between 1958 to 1962, Bo Sung Sim operated on 24 patients of cerebral paragonimiasis. In two of them, he performed cerebral hemispherectomy to control intractable convulsions when he found diffuse cerebral paragonimiasis and cerebral atrophy at the operating table. The two patients were recovered dramatically after the operation. The first patient became a part of medical campus for 20 years after hemispherectomy, doing chores at the hospital and helping Bo Sung Sim for his teaching neuroanatomy. The presence of the hemispherectomized patient in the classroom impressed the students deeply. Furthermore, the hemispherectomized patient stimulated Sim and his school to perform research upon the neuroanatomy and neurophysiology of the brain with hemispherectomized animals.

Molecular and pathological study of bovine aborted fetuses and placenta from Neospora caninum infected dairy cattle

The objective of the study was to evaluate the presence of Neospora caninum organisms in the brain of aborted fetuses and placentas of full-term calves born of seropositive cows. During 2006-2007, 12 brains of aborted calves from Neospora seropositive cattle and 7 placentas from seropositive dams giving birth to full-term calves, from four dairy cattle farms located around Tehran province, Iran were examined by Nested-PCR and histopathology techniques. The Nested-PCR demonstrated that all of 12 aborted fetal brain samples and 5 of 7 placentas were infected by N. caninum. Mild to severe placentitis was observed in 5 placentas. Severe hyperemia and perivascular and perineuronal edema revealed in all fetal brain. In 3 out of 12 brains, scattered foci of hemorrhages, neuropilar necrosis and gliosis were present. In addition, nonpurulent encephalitis with severe lymphohistiocytic perivascular cuffing in one case and a small tissue cyst like Neospora caninum cyst in other calf were observed. Our results confirmed the molecular and histopathologic findings of other studies about Neospora caninum infection and it seems to support the hypothesis that Neospora infection is associated with bovine abortion in Iran

Anatomopathological study in BALB/c mice brains experimentally infected with Toxoplasma gondii

Toxoplasmosis is one of the most important diseases of the nervous central system, leading to severe symptoms and, many times, irreversible sequelae. This work demonstrated the main anatomopathological lesions caused by Toxoplasma gondii in brains from experimentally infected BALB/c mice. We analyzed 51 cases of mice that developed toxoplasmosis after experimental infection by intraperitoneal inoculation of blood, amniotic liquid and cerebrospinal fluid from fetuses, newly born children and pregnant women with clinical and laboratory signals of toxoplasmosis. In all experiments where we detected the parasite in mice we also detected pathological lesions in the animal brains with great polymorphism between experiments. Edema was the most found lesion in all cases. Besides, it was possible to demonstrate the inflammatory process in 82.4 percent of cases and necrosis in 64.7 percent of cases, in agreement with the literature that describes severe neurological damage in its hosts.

Immunohistochemical characterization of mononuclear cells and MHC II expression in the brain of horses with experimental chronic Trypanosoma evansi infection / Caracterização imunoistoquímica de células mononucleares e expressão de CMH II no sistema nervoso central de eqüinos com infecção crônica experimental por Trypanosoma evansi

An histochemical and immunohistochemical study was carried out to evaluate the mechanisms of immune response of horses experimentally infected by Trypanosoma evansi. For this purpose the HE histochemical stain and the avidin biotin peroxidase method were used. To determine the presence and immunoreactivity of immune cells we used anti-major histocompatibility complex II antibodies. Cellular infiltration fenotype was characterized with the aid of anti-CD3 antibody for T lymphocytes and by anti-BLA 36 antibodies for B lymphocytes. Macrophages were marked with an antibody against myeloid/histyocites antigen (clone Mac387). Lesions in the CNS of experimentally infected horses were those of a wide spread non suppurative encephalomyelitis and meningomyelitis. The severity of lesions varied in different parts of the nervous system, reflecting an irregular distribution of inflammatory vascular changes. Lymphoid perivascular cuffs and meningeal infiltrations were of predominantly composed of T and B cells. The parasite, T. evansi, was not identified in these horses tissues.

Este estudo objetivou caracterizar a resposta imune celular no sistema nervoso central (SNC) de eqüinos com infecção crônica experimental por Trypanosoma evansi. Para este propósito, foram utilizados os métodos histoquímicos (HE) e imunoistoquímicos do complexo avidina-biotina peroxidase (ABC). O fenótipo do infiltrado celular foi caracterizado com o auxílio de anticorpos anti - CD3, para linfócitos T e antiBLA36 para linfócitos B. Os macrófagos foram marcados com anticorpo antiantígenos da linhagem mielóide/histiócitos (Clone Mac387). A lesão no sistema nervoso central (SNC) dos eqüinos infectados com T. evansi foi caracterizada como meningoencefalite e meningomielite não supurativa. A gravidade das lesões variou em diferentes segmentos do SNC, refletindo distribuição irregular das alterações vasculares. A distribuição de células T e B e antígenos do complexo maior de histocompatibilidade classe II foram avaliados dentro do SNC de eqüinos cronicamente infectados com T. evansi. O infiltrado perivascular e meníngeo eram constituídos predominantemente por células T e B. Macrófagos foram raramente visualizados. T.evansi não foi identificado no parênquima do SNC dos eqüinos.

Anatomopathological aspects of neurocysticercosis in autopsied patients

The aim of this paper was to describe the occurrence and morphology of neurocysticercosis (NCC) in autopsies. We revised 2218 autopsies performed at the School Hospital from Federal Unversity of Triangulo Mineiro, 1970-2003. Data referring to age, gender and color of patients were reported and NCC was microscopically and macroscopically analyzed. We found 53 (2.4 percent) NCC cases. The mean age was 50 years old, 34 (64.1 percent) individuals were male and 36 (67.9 percent) white. Macroscopically, 17 cysticerci were analyzed. The most frequent location was meningocortical in 12 (70.6 percent) cases. Microscopically, the cysticerci presented an ovoid shape, containing the larvae preserved in 4 (23.5 percent) cases or in destruction degrees in 13 (76.5 percent) cases. Therefore, in NCC was found several general pathologic processes (necrosis, interstitial deposits, fibrosis, gliosis, inflammation) amongst which are highlighted beta-fibrillose in 13 (76.5 percent) cases associated to inflammatory process in 16 (94.1 percent) cases caused by the parasite, not yet related to NCC, and calcification present in viable and destruction parasites.

O objetivo desse trabalho foi descrever ocorrência e morfologia da neurocisticercose (NCC) autópsias. Revisou-se 2218 autópsias realizadas no Hospital Escola da Universidade Federal do Triângulo Mineiro (UFTM), 1970-2003. Registrou-se idade, gênero e cor dos pacientes, analisou-se macroscopia e microscopia da NCC. Encontrou-se 53 (2,4 por cento) casos de NCC. A média das idades foi 50 anos, sendo 34 (64,1 por cento) do sexo masculino e 36 (67,9 por cento) brancos, não havendo diferença significante na comparação da idade, gênero e cor dos pacientes. Analisou-se macroscopicamente 17 cisticercos. A localização mais comum foi a meningo-cortical em 12 (70,6 por cento) casos. Microscopicamente, os cisticercos apresentaram forma oval contendo a larva íntegra em 4 (23,5 por cento) casos ou em grau de destruição em 13 (76,5 por cento) casos. Portanto, na NCC foram verificados vários processos patológicos gerais (necrose, depósitos intersticiais, fibrose, gliose, inflamação) destacando-se: beta-fibrilose em 13 (76,5 por cento) casos associada ao processo inflamatório em 16(94,1 por cento) casos causado pelo parasito, ainda não relatada na NCC, e calcificação presente no parasito viável e em destruição.

Immunohistochemical study of acute and chronic toxoplasmosis in experimentally infected mice.

Acute and chronic Toxoplasma infections were evaluated in mice using stage specific antibodies and immunocytochemistry. Mice with acute toxoplasmosis were less active, had erectile body hair and seldom took food or water resulting in weight loss. All mice died within 7 days post-inoculation. The immunohistochemical technique enhanced visualization of parasites allowing their distribution to be accurately followed. Following intraperitoneal infection, tachyzoites were initially identified on the surface of the liver and spleen. There was a rapid increase in the number of tachyzoites associated with invasion from the surrounding connective tissue into the organs with formation of inflammatory lesions in the liver. The focal inflammatory lesions showed increasing numbers of tachyzoites with the period post-inoculation. Similar increases in tachyzoites were observed for the spleen. In contrast, only a few individual tachyzoites were seen in the brain at the final time point. In chronic infections, the mice were asymptomatic but tissue cysts containing large numbers of bradyzoites were observed in all brains with the average number of 295 tissue cysts per half brain and the average cystic size of 46.02 +/- 5.08 microm. By histology and immunostaining, the tissue cysts were readily identifiable along with a mild inflammatory cell infiltration into the meninges and perivascular cuffing. Double immunocytochemical labelling confirmed the exclusive presence of tachyzoites during the acute phase and bradyzoites during the chronic phase.

Loss of infectivity of Neospora caninum oocysts maintained for a prolonged time

The purpose of this study was to investigate whether sporulated Neospora caninum oocysts, which had been stored for 46 mo in a 2% sulfuric acid solution at 4 degrees C, remain morphologically viable and infective to gerbils (Meriones unguiculatus). Six gerbils were orally inoculated with doses of 400 or 1,200 oocysts. Two mo after inoculation, the animals did not show any clinical signs, had no histological lesions, and were seronegative for N. caninum at 1: 50 in an immunofluorescent antibody test. PCR using the brain from each gerbil did not reveal N. caninum specific DNA. We conclude that oocysts preserved for 46 mo are not infective, despite being morphologically intact.