Spurious infection by Calodium hepaticum (Bancroft, 1983) Moravec, 1982 and intestinal parasites in forest reserve dwellers in Western Brazilian Amazon

ABSTRACT Subsistence hunting is the main source of protein for forest reserve dwellers, contributing to the development of spurious infections by Calodium hepaticum, frequently associated with the consumption of the liver from wild mammals. The prevalence of infections by soil-transmitted helminths (STHs) and intestinal protozoa is considered an indicator of the social vulnerability of a country, besides providing information on habits, customs and quality of life of a given population. Intestinal parasites mostly affect poor rural communities with limited access to clean water and adequate sanitation. This study reports the results of a parasitological survey carried out in 2017 and 2019, in two municipalities (Xapuri and Sena Madureira) in Acre State. Stool samples were collected from 276 inhabitants. Upon receipt, each sample was divided into two aliquots. Fresh samples without preservative were processed and examined by the Kato-Katz technique. Samples fixed in 10% formalin were processed by the spontaneous sedimentation and the centrifugal sedimentation techniques. Calodium hepaticum eggs were found in three stool samples. The overall STH prevalence was 44.9%. The hookworm prevalence (19.2%) was higher than that of Ascaris lumbricoides (2.5%) and Trichuris trichiura (0.7%), an unexpected finding for municipalities belonging to the Western Brazilian Amazon. When considering parasites transmitted via the fecal-oral route, Endolimax nana and Entamoeba coli showed the highest positivity rates, of 13% and 10.9%, respectively. This study is the first report of spurious infection by C. hepaticum among forest reserve dwellers that consume undercooked liver of lowland pacas. Additionally, this is the first report of Blastocystis sp. in Acre State.

Effects of multiple doses of simvastatin and artesunate monotherapy on SCHISTOSOMA MANSONI adult worms during infection in hyperlidemic mice / Efectos de múltiples dosis de simvastatina y artesunato en monoterapia en gusanos adultos de SCHISTOSOMA MANSONI durante la infección en ratones hiperlidémicos / Efeitos de doses múltiplas de monoterapia com sinvastatina e artesunato em vermes adultos SCHISTOSOMA MANSONI durante a infecção em camundongos hiperlidêmicos

A single dose of simvastatin and of artesunate monotherapy cause damage to the reproductive system of schistosomes as well as severe tegumental damage in male worms recovered from mice fed high-fat chow. This study aims to investigate whether treatment with multipledose regimes may offer more antischistosomal activity advantages than single daily dosing in mice fed high-fat chow. For this purpose, nine weeks post-infection, Swiss Webster mice were gavaged with simvastatin (200 mg/kg) or artesunate (300 mg/kg) for five consecutive days and euthanized two weeks post-treatment. Adult worms were analyzed using brightfield microscopy, confocal microscopy and scanning electron microscopy, presenting damages caused by simvastatin and artesunate to the reproductive system of males and females as well as tegument alterations, including peeling, sloughing areas, loss of tubercles, tegumental bubbles and tegument rupture exposing subtegumental tissue. The overall findings in this study revealed the potential antischistosomal activity of simvastatin and artesunate against Schistosoma mansoni adult worms, in addition to showing that multiple doses of either monotherapy caused severe damage to the tegument.

Una sola dosis de simvastatina y de artesunato en monoterapia causa daño al sistema reproductivo de los esquistosomas, así como daño tegumental severo en gusanos machos recuperados de ratones alimentados con comida rica en grasas. Este estudio tiene como objetivo investigar si el tratamiento con regímenes de dosis múltiples puede ofrecer más ventajas de actividad antiesquistosomal que la dosis única diaria en ratones alimentados con comida rica en grasas. Para este propósito, nueve semanas después de la infección, los ratones Swiss Webster se alimentaron por sonda con simvastatina (200 mg / kg) o artesunato (300 mg / kg) durante cinco días consecutivos y se sacrificaron dos semanas después del tratamiento. Los gusanos adultos se analizaron utilizando campo claro microscopía, microscopía confocal y microscopía electrónica de barrido, presentando daños causados ​​por simvastatina y artesunato en el sistema reproductivo de machos y hembras, así como alteraciones del tegumento, incluyendo descamación, desprendimiento, pérdida de tubérculos, burbujas tegumentales y rotura del tegumento exponiendo tejido subtegumental. Los hallazgos generales de este estudio revelaron la posible actividad antiesquistosomal de la simvastatina y el artesunato contra los gusanos adultos de Schistosoma mansoni, además de mostrar que dosis múltiples de cualquiera de las dos monoterapia causaron daños graves al tegumento.

Uma única dose de sinvastatina e de monoterapia com artesunato causa danos ao sistema reprodutivo dos esquistossomos, bem como danos graves ao tegumento em vermes machos recuperados de camundongos alimentados com ração rica em gordura. Este estudo tem como objetivo investigar se o tratamento com regimes de múltiplas doses pode oferecer mais vantagens da atividade anti-esquistossomótica do que uma única dose diária em ratos alimentados com ração rica em gordura. Para tanto, nove semanas após a infecção, camundongos Swiss Webster foram inoculados com sinvastatina (200 mg / kg) ou artesunato (300 mg / kg) por cinco dias consecutivos e sacrificados duas semanas após o tratamento. Vermes adultos foram analisados ​​usando campo claro microscopia, microscopia confocal e microscopia eletrônica de varredura, apresentando danos causados ​​pela sinvastatina e artesunato ao sistema reprodutivo de homens e mulheres, bem como alterações do tegumento, incluindo descamação, áreas de descamação, perda de tubérculos, bolhas tegumentais e ruptura do tegumento com exposição de tecido subtegumentar. Os achados gerais deste estudo revelaram a potencial atividade anti-esquistossomótica da sinvastatina e do artesunato contra vermes adultos do Schistosoma mansoni, além de mostrar que doses múltiplas de ambas as monoterapias causaram danos graves ao tegumento.

Schistosoma mansoni specimens first described by Pirajá da Silva in Brazil (1908) re-examined by confocal laser scanning microscopy / Espécimes de Schistosoma mansoni descritos por Pirajá da Silva no Brasil (1908) reexaminados pela técnica de microscopia de varredura a laser confocal

INTRODUCTION: Pirajá da Silva made a seminal contribution to helminthology by demonstrating both schistosome eggs in feces of patients from the State of Bahia and the morphology of Schistosoma mansoni adult worms. METHODS: In this study, a microscopic investigation of the whole-mounts deposited at the Helminthological Collection of the Oswaldo Cruz Institute is presented. Confocal laser scanning microscopy was used as the main investigation technique. RESULTS: At the anterior end of the adult male, suckers with well-developed musculature and germinative cells inside the testicular lobes were observed, as well as spines located in the mid region of the male gynecophoric canal. Tegumental tubercles and transversal and longitudinal muscular bundles were observed at the dorsal surface. The female reproductive system presented a uterus lacking eggs and an elongated ovary with germinative cells. The vitellaria were restricted to the extreme posterior end of each female connected to a short vitelline duct. CONCLUSIONS: The results reported in this study demonstrate that the characteristic studied here are similar to those previously reported, using fresh worms. Moreover, this study also highlights the importance of deposits of specimens in helminthological collections, which further permit revisiting whole-mounts in such institutions.

INTRODUÇÃO: Pirajá da Silva fez contribuição magnífica à helmintologia ao descrever ovos de Schistosoma mansoni nas fezes de um paciente, no Estado da Bahia e a morfologia de vermes adultos. MÉTODOS: Neste estudo, apresentamos uma avaliação microscópica das lâminas montadas e depositadas na Coleção Helmintológica do Instituto Oswaldo Cruz. A técnica empregada nesta nova análise foi a microscopia de varredura a laser confocal. RESULTADOS: Na parte anterior dos vermes adultos machos, observamos ventosas com musculatura bem desenvolvida e células germinativas dentro dos lobos testiculares. Visualizamos, também, espinhos localizados na região mediana do canal ginecóforo. Na superfície dorsal, encontramos tubérculos e feixes musculares transversais e longitudinais. Em relação ao aparelho reprodutivo feminino, pudemos distinguir um ovo no interior do útero e o ovário alongado com células germinativas. As glândulas vitelínicas estavam restritas à parte posterior das fêmeas conectadas por um ducto vitelínico curto. CONCLUSÕES: As características morfológicas são similares as estudadas anteriormente por Pirajá da Silva com vermes frescos. Além disso, este estudo demonstra a importância de se depositar espécimes nas coleções helmintológicas abrindo possibilidade de novos estudos com estas lâminas.

Hepatic stereology of acute schistosomiasis mansoni infection in C57BL/10 and CBA mice

Estudos prévios mostraram que o curso da infecção esquistossomótica experimental depende da constituição genética do hospedeiro. A fim de testar se linhagens de camundongos infectados por Schistosoma mansoni apresentam diferenças nos padrões de patologia durante a fase aguda, examinamos possíveis alterações nos hepatócitos, sinusóides e quantidade de fibrose, utilizando uma abordagem estereológica. As mudanças na organização hepática de camundongos fêmeas, adultas, das linhagens C57BL/10 e CBA, foram examinadas oito semanas após a infecção. A densidade de volume de hepatócitos Vv(h), sinusóides Vv(s) e fibrose Vv(fh) foram examinadas por determinação do ponto de contagem (sitema-teste M42) e video microscopia, por microscopia de luz. Em ambas linhagens de camundongo, Vv(h) e Vc(s) foram significamente reduzidas (p menor que 0,05) em relação ao grupo controle. Os maiores valores de Vv(fh) foram encontradas na linhagem C57BL/10. Demonstramos que a infecção esquistossomótica reduziu acentuadamente hepatócitos (linhagem CBA) sinusóides (linhagem C57BL10), enquanto a fibrose foi maior em C57BL10 do que CBA.

High fat diet has a prominent effect upon the course of chronic schistosomiasis mansoni in mice

This study investigated whether a long-term high-fat diet has an effect on the outcome of chronic murine schistosomiasis mansoni compared to a standard diet. Swiss Webster female mice (3 weeks old) were fed each diet for up to six months and were then infected with 50 Schistosoma mansoni cercariae. Their nutritional status was assessed by monitoring total serum cholesterol and body mass. Infected mice were examined 6-17 weeks post infection to estimate the number of eggs in faeces. Mice were euthanised the next day. Total serum cholesterol was lower in infected mice in comparison to uninfected controls (p = 0.0055). In contrast, body mass (p = 0.003), liver volume (p = 0.0405), spleen volume (p = 0.0124), lung volume (p = 0.0033) and faecal (p = 0.0064) and tissue egg density (p = 0.0002) were significantly higher for infected mice fed a high-fat diet. From these findings, it is suggested that a high-fat diet has a prominent effect on the course of chronic schistosomiasis mansoni in mice.

Biological implications of the phenotypic plasticity in the Schistosoma mansoni - Nectomys squamipes model / Implicações biológicas da plasticidade fenotípica no modelo Schistosoma mansoni - Nectomys squamipes

The water-rat Nectomys squamipes is mostly important non-human host in schistosomiasis mansoni transmission in Brazil, due to its susceptibility, high abundance and water-contact pattern. During experimental infection of N. squamipes with Schistosoma mansoni, adult worms show phenotypic plasticity. This finding led us to investigate whether biological behavior is also affected. This was assessed comparing the biological characteristics of four S. mansoni strains: BE (State of Belém do Pará), CE (State of Pernambuco), CMO (State of Rio Grande do Norte) and SJ (State of São Paulo) using laboratory-bred N. squamipes. The infection was monitored by determination of the pre-patent period, fecal egg output, egg viability, intestinal egg count and, infectivity rate. No biological modification was observed in these parameters. Overall results highlight that N. squamipes was susceptible to several S. mansoni strains, suggesting that it might contribute to the maintenance of schistosomiasis mansoni in Brazil.

O rato d´água Nectomys squamipes é importante transmissor não-humano da esquistossomose. Durante a infecção experimental em N. squamipes, os vermes adultos apresentam plasticidade fenotípica. Esses achados levaram-nos a investigar se os aspectos biológicos também são afetados. Foram comparadas as características biológicas de quatro cepas de S. mansoni: BE (Estado de Belém do Pará), CM (Estado de Pernambuco), CMO (Estado do Rio Grande do Norte) e SJ (Estado de São Paulo), utilizando como modelo experimental N. squamipes criados e mantidos em laboratório. A infecção foi monitorada para a determinação do período pré-patente, eliminação de ovos nas fezes, viabilidade dos ovos, contagem de ovos retidos no intestino e infectividade. Nenhuma modificação biológica foi observada nesses parâmetros. Os resultados sugerem que o N. squamipes é susceptível a várias cepas de S. mansoni, contribuindo para a manutenção da esquistossomose no Brasil.

Somatic, Biochemical and Hepatic Alterations in Wild Type Mice Chronically Fed High Fat Diet / Alteraciones Somáticas Bioquímicas y hepáticas en un Tipo de Ratas Alimentadas Crónicamente con Dieta Alta en Grasas

This study evaluated whether a high fat diet (HFC group) induces overweight, hepatic steatosis and plasma lipoproteins level alteration compared to standard chow diet (SC group). Female mice were submitted to each diet over 6 months. Body mass and food intake were evaluated weekly throughout the experiment. Total cholesterol, TG, LDL-c, HDL-c and VLDL-c were analyzed. Mice were sacrificed to remove liver, spleen, heart and intestine. The volume of the organs was determined according to the submersion method. Fixed livers were embedded in paraffin and stained with hematoxylin and eosin and Masson's trichrome. The analysis used a video microscope system and a test-system with 42 test-points. The volume density was estimated for hepatocytes, steatosis and sinusoids. Animals fed HFC had smaller chow intake than SC group. HFC group presented body mass greater than SC. Animals fed HFC showed heavier liver and spleen and lighter intestine than SC (p<0.05), heart mass was not significant between groups. Plasma lipoproteins differed between groups (p<0.05) except VLDL-c and TG fractions. The liver structure was without major alteration in SC group however, HFC mice group showed different degrees of fatty degeneration with micro- and macrovesicular steatosis dispersed in all liver with typical peri-cellular/peri-sinusoidal fibrosis. The quantitative study showed significant (p<0.05) volume density reduction for hepatocytes and sinusoids. In conclusion, our results clearly show that hepatic steatosis can be induced in mouse by such a fat-rich diet without any toxin ingestion, alimentary deficiency and genes depletion.

Este estudio evaluó cómo una dieta de alta densidad energética (grupo ADE) induce sobrepeso, esteatosis hepática y altera los niveles de las lipoproteínas plasmáticas cuando son comparados con la dieta patrón (grupo SC). Hembras de camundongos fueron sometidas a cada una de las dietas durante 6 meses. La masa corporal y la ingestión de alimento fueron evaluadas semanalmente durante el experimento. Además fueron medidos el colesterol total, TG, LDL-c, HDL-c e VLDL-c. Los animales fueron sacrificados y el hígado, bazo, corazón e intestinos fueron removidos para estudio. El volumen de los órganos fue medido por el método de la sumersión. Fragmentos de hígado fueron preparados para el estudio en microscopía de luz, teñidos con hematoxilina-eosina y tricrómico de Masson. El análisis fue realizado con video microscopía y sistema test M42. La densidad de volumen fue estimada para hepatocitos, esteatosis y sinusoides. Los animales alimentados con dieta ADE presentaron menor ingestión de alimento y tuvieron masa corporal mayor que los animales con dieta patrón. Animales ADE mostraron también hígado y bazo más pesados e intestino más liviano que animales SC (p<0.05). Para la masa del corazón no hubo diferencia significativa entre los dos grupos. Las lipoproteínas plasmáticas fueron diferentes entre los grupos (p<0.05) excepto VLDL-c y fracciones de TG. La estructura hepática no presentó grandes alteraciones en el grupo SC; sin embargo, animales del grupo ADE presentaron diferentes grados de degeneración adiposa con esteatosis macro y microvesicular dispersas en todo el hígado con típica fibrosis pericelular y perisinusoidal, y significativa reducción de la densidad de volumen de hepatocitos y sinosoides. En conclusión, los resultados muestran que la esteatosis hepática puede ser inducida experimentalmente en camundongos, a través de dieta ADE, sin ingestión de cualquier toxina, deficiencia alimentaria o depleción genética.

Hepatic stereology of schistosomiasis mansoni infected-mice fed a high-fat diet

High-fat diets induce weight gain and fatty liver in wild-type mice. Schistosomiasis mansoni infection also promotes hepatic injury. This study was designed to quantify hepatic alterations in schistosomiasis mansoni-infected mice fed a high fat-rich chow compared to mice fed a standard rodent chow, using stereology. Female SW mice fed each either high-fat diet (29 percent lipids) or standard chow (12 percent lipids) over 8 months, and then were infected with Schistosoma mansoni cercariae. Four experimental groups were studied: infected mice fed a high-fat diet (IHFC) or standard chow (ISC), uninfected mice fed a high-fat diet (HFC) or standard chow (SC). Mice were sacrificed during early infection (9 weeks from exposure). The following hepatic biometry and the stereology parameters were determined: volume density (hepatocytes [h], sinusoids [s], steatosis [st] and hepatic fibrosis [hf]); numerical density (hepatocyte nuclei - Nv[h]); absolute number of total hepatocyte N[h], normal hepatocyte N[nh], and binucleated hepatocyte N[bh], percentage of normal hepatocyte P[nh] and binucleated hepatocyte P[bh]. IHFC and HFC groups exhibited TC, HDL-C, LDL-C, and body mass significantly greater (p < 0.05) than control group. No significant differences were found regards liver volume (p = 0.07). Significant differences were observed regards P[nh] (p = 0.0045), P[bh] (p = 0.0045), Nv[h] (p = 0.0006), N[h] (p = 0.0125), N[bh] (p = 0.0164) and N[nh] (p = 0.0078). IHFC mice group presented 29 percent of binucleated hepatocytes compared to HFC group (19 percent), ISC group (17 percent) and SC (6 percent). Volume density was significantly different between groups: Vv[h] (p = 0.0052), Vv[s] (p = 0.0025), Vv[st] (p = 0.0004), and Vv[hf] (p = 0.0007). In conclusion, schistosomiasis mansoni infection with concurrent high-fat diet promotes intensive quantitative changes in hepatic structure, contributing to an increasing on hepatic regeneration.

Development of Schistosoma mansoni worms in mice analyzed by bright field and confocal microscopy

The blood flukes of mammals (Digenea: Schistosomatidae) are among trematodes unique whose adult worms have separeted sexes which are dissimilar in appearance. The developmental features, growth and organogenesis of Schistosoma mansoni were studied in Swiss Webster mice by a digital system for image analysis and confocal microscopy. Data so far obtained showed two phases with significative morphological changes at 3-4 weeks post-infection, and a gradual similar development onwards in the reproductive system and tegument. Our male-dependent phase demonstrated that mating occurs before sexual maturing. At week three, the majority of male worms (59 percent) had formed the gynaecophoric canal although testicular lobes and tegumental tubercles were absent. By this time, 33 percent females had an incipient ovary (without cellular differentiation). At week four, 77.2 percent males presented testicular lobes with few germinative cells while 26 percent had developing tegumental tubercles. The immature ovary was observed in 69 percent females. Suckers followed different pattern of growth between male and females. The size of oral and ventral suckers from six-week-old male worms grew abruptly (3.0 fold) more than that of three-week-old. In female worms, maximum growth was attained at week four, reducing in size thereafter. From sixth week onwards, all specimens showed the fully developed reproductive system. Probably, these features are morphological traits which schistosome has experienced from hermaphrodite to dioecy.

Avaliação do papel da dieta rica em colesterol na esquistossomíase mansônica experimental de Mus musculus Swiss Webster / Evaluation of the paper of the rich diet in cholesterol in experimental schistosomiasis of mus musculus swiss webster

Na tentativa de estudar os efeitos de uma dieta rica em gordura no curso da esquistossomíase mansônica, foi estebelecido um modelo experimental em camundongos. Foram realizados estudos bioquímicos, parasitológicos, histológicos e estereológicos. Camundongos Swiss Webster fêmeas foram submetidos ou a dieta hiperlipídica (29 por cento de lipídios)ou dieta padrão(12 por cento de lipídios)por mais de 5 meses,e então infectados com ~50 cercárias de Schistosoma mansoni. Os animais foram divididos em 4 grupos :camundongos infectados alimentados com dieta hiperlipídica (IHFC)ou padrão (ISC), camundongos não infectados alimentados com dieta hiperlipídica (HFC) ou padrão (SC). O peso corporal, a ingestão de ração, o colesterol total, TG, LDL-c, HDL-c, VLDL-c foram avaliados. Os animais foram sacrificados para remover o fígado, baço,coração e intestino. As lipoproteínas plasmáticas estavam aumentadas no HFC se comparadas ao SC. Apesar do colesterol total não ser significativamente menor no ISC, estes valores foram significativamente reduzidos no IHFC. O HFC apresentou menor ingestão de ração, maior massa corporal, fígado e baço mais pesados, e intestino mais leve do que o SC. No HFC observou-se a presença de micro e macro esteatoses por todo o fígado com típica fibrose peri-celular/peri-sinusoidal. O IHFC mostrou granulomas hepáticos dos tipos: exsudativo, exsudativo/exsudativo-produtivo, exsudativo-produtivo, produtivo, e algum grau de esteatose hepática e necrose focal. O ISC não apresentou granulomas produtivos nem esteatose hepática. A respeito do nºe da porcentagem do total de hepatócitos, hepatócitos normais e hepatócitos binucleados observamos diferenças significativas entre os grupos. O IHFC apresentou maior percentual de hepatócitos binucleados (29por cento) se comparados ao HFC (19por cento), ISC(17por cento)e SC (6por cento). A densidade de volume era significativamente diferente entre grupos...

In an attempt to study the effects of a high-fat chow on schistosomiasis outcome, an experimental model in mice was established. Biochemical, parasitological, histological, and stereological analyses were performed. Weaning female SW mice were submittedto each diet (high-fat diet -29% lipids) or standard chow (12% lipids) over 5 months, and then were infected with ~ 50 Schistosoma mansoni cercariae. Animals were divided into four groups: infected mice fed a high-fat diet (IHFC) or standard chow (ISC), uninfected mice fed a high-fat diet (HFC) or standard chow (SC). Body mass and food intake were evaluated weekly throughout the experiment. Total cholesterol, TG, LDL-c,HDL-c and VLDL-c were analyzed. Mice were sacrificed to remove liver, spleen, heart and intestine. The volume of the organs was determined according to the submersion method. Plasma lipoproteins levels were increased from normally fed animals to animals fed HFC. Despite the plasma total cholesterol did not significantly decrease in ISC group, these values were significantly reduced in IHFC mice group. HFC group presented smaller chow intake, greater body mass, heavier liver and spleen, and lighter intestine than SC group. HFC mice group showed different degrees of fatty degeneration with micro- and macrovesicular steatosis dispersed in all liver with typicalperi-cellular/peri-sinusoidal fibrosis, whereas no major alteration in SC group was seen. Livers from IHFC group showed exudative, exudative/exudative-productive, exudativeproductive,productive granulomas, and some degree of hepatic steatosis and focal necrosis. ISC group did not present productive granulomas and hepatic steatosis.Regarding the absolute number and percentage of total hepatocyte, normal hepatocyte and binucleated hepatocyte significant differences (p<0.05) were observed. IHFC mice group presented 29% of binucleated hepatocytes compared to HFC group (19%), ISCgroup (17%) and SC (6%)...

Avaliação do papel da dieta rica em colesterol na esquistossomíase mansônica experimental de Mus musculus Swiss Webster / Evaluation of the paper of the rich diet in cholesterol in experimental schistosomiasis of mus musculus swiss webster

Na tentativa de estudar os efeitos de uma dieta rica em gordura no curso da esquistossomíase mansônica,foi estebelecido um modelo experimental em camundongos.Foram realizados estudos bioquímicos,parasitológicos, histológicos e estereológicos.Camundongos Swiss Webster fêmeas foram submetidos ou a dieta hiperlipídica(29por cento de lipídios)ou dieta padrão(12por cento de lipídios)por mais de 5 meses,e então infectados com~50 cercárias de Schistosoma mansoni.Os animais foram divididos em 4 grupos:camundongos infectados alimentados com dieta hiperlipídica(IHFC)ou padrão(ISC),camundongos não infectados alimentados com dieta hiperlipídica(HFC)ou padrão(SC).O peso corporal,a ingestão de ração,o colesterol total,TG,LDL-c,HDL-c,VLDL-c foram avaliados. Os animais foram sacrificados para remover o fígado, baço,coração e intestino.As lipoproteínas plasmáticas estavam aumentadas no HFC se comparadas ao SC.Apesar do colesterol total não ser significativamente menor no ISC,estes valores foram significativamente reduzidos no IHFC.O HFC apresentou menor ingestão de ração,maior massa corporal,fígado e baço mais pesados,e intestino mais leve do que o SC.No HFC observou-se a presença de micro e macro esteatoses por todo o fígado com típica fibrose peri-celular/peri-sinusoidal.O IHFC mostrou granulomas hepáticos dos tipos:exsudativo,exsudativo/exsudativo-produtivo,exsudativo-produtivo,produtivo,e algum grau de esteatose hepática e necrose focal.O ISC não apresentou granulomas produtivos nem esteatose hepática.A respeito do nºe da porcentagem do total de hepatócitos,hepatócitos normais e hepatócitos binucleados observamos diferenças significativas entre os grupos.O IHFC apresentou maior percentual de hepatócitos binucleados(29por cento)se comparados ao HFC(19por cento),ISC(17por cento)e SC(6por cento).A densidade de volume era significativamente diferente entre grupos.O IHFC apresentou maior nºde ovos viáveis,maior maturação e nºde ovos nas fezes se comparado ao ISC. Os vermes...

Phenotypic plasticity in adult worms of Schistosoma mansoni (Trematoda: Schistosomatidae) evidenced by brightfield and confocal laser scanning microscopies

A comparative morphometric study was performed to identify host-induced morphological alterations in Schistosoma mansoni adult worms. A wild parasite population was obtained from a naturally infected rodent (Nectomys squamipes)and then recovered from laboratory infected C3H/He mice. Furthermore, allopatric worm populations maintained for long-term under laboratory conditions in Swiss Webster mice were passed on to N. squamipes. Suckers and genital system (testicular lobes, uterine egg, and egg spine) were analyzed by a digital system for image analysis. Confocal laser scanning microscopy (CLSM) showed details of the genital system (testicular lobes, vitelline glands, and ovary) and the tegument just below the ventral sucker. Significant morphological changes (p < 0.05) were detected in male worms in all experimental conditions, with no significant variability as assessed by CLSM. Significant changes (p < 0.05) were evident in females from the wild population related to their ovaries and vitelline glands, whereas allopatric females presented differences only in this last character. We conclude that S. mansoni worms present the phenotypic plasticity induced by modifications in the parasite's microenvironment, mainly during the first passage under laboratory conditions.

Caracterização de cepas de Schistosoma mansoni por morfometria de vermes adultos provenientes de infecção unissexual / Characterization of Schistosoma mansoni strains by morphometry of adult worms derived from single-sex infection

Camundongos foram infectados com cercárias, de um único sexo, de cepas simpátricas do Schistosoma mansoni. Nos vermes adultos, foram encontradas diferenças significativas (p<0,05) nas ventosas, lobos testiculares, ovário e espessura do tegumento. O experimento demonstra que a morfometria de vermes isolados de infecção unissexual também é uma ferramenta na identificação de cepas do Schistosoma mansoni.

Características biológicas e morfológicas de cepas brasileiras de Schistosoma mansoni em Mus musculus / Parasitological and morphological characteristics of Brazilian strains of Schistosoma mansoni in Mus musculus

A fim de verificar diferenças biológicas e morfológicas entre cepas brasileiras (CMO, CM e BE) de Schistosoma mansoni foram estudados os seguintes parâmetros: período pré-patente, cinética de eliminaçäo de ovos nas fezes, contagem de ovos no intestino, infectividade e as características fenotípicas dos vermes adultos. O período pré-patente foi de 42 a 44 dias. A recuperaçäo de vermes adultos variou de 26 por cento a 29 por cento, sem diferenças significativas (p>0,05) nestes parâmetros. Todas as cepas apresentaram maior quantidade de ovos no intestino delgado do que no grosso (p<0,05). Diferenças significativas foram observadas no aparelho reprodutor e ventosas dos adultos machos. Todas as medidas foram menores na cepa CMO. As fêmeas apresentaram diferenças significativas no maior diâmetro do ovo, área e perímetro do espinho do ovo e na área da ventosa oral. Concluímos que as diferenças entre cepas podem ser expressas mesmo quando estas säo mantidas por várias geraçöes em condiçöes de laboratório

Morphometric study of Schistosoma mansoni adult worms recovered from undernourished infected mice

Some unfavourable effects of malnutrition of the host on Schistosoma mansoni worm biology and structure have been reported based upon brigthfield microscopy. This paper aims to study by morphometric techniques, some morphological parameters in male and female adult worms recovered from undernourished albino mice in comparison with parasites recovered from well-fed infected mice. Undernourished animals were fed a multideficient and essentially low protein diet (RBD diet) and compared to well-fed control mice fed with the commercial diet NUVILAB. Seventy-five days post-infection with 80 cercarie (BL strain) animals were sacrificed. All adult worms were fixed in 10 percent formalin and stained with carmine chloride. One hundred male and 60 female specimens from each group (undernourished and control) were examined using an image system analysis Leica Quantimet 500C and the Sigma Scan Measurement System. The following morphometrical parameters were studied: body length and width, oral and ventral suckers, number and area of testicular lobes, length and width of ovary and uterine egg. For statistical analysis, the Student's t test for unpaired samples was applied. Significant differences (p < 0.05) were detected in body length and width, in parameters of suckers, uterine egg width, ovary length and area of testicular lobes, with lower values for specimens from undernourished mice. The nutritional status of the host has negative influence on S. mansoni adult worms, probably through unavailability of essential nutrients to the parasites

Ocorrência de Cryptosporidium sp em amostras fecais de crianças, menores de 10 anos de idade, com indicaçäo clínica de Rotavírus / Occurrence of Cryptosporidium sp in fecal samples of children less than 10 years old with clinical indication of Rotavirus

A partir da indicaçäo clínica de Rotavírus em fezes de 485 crianças, investigou-se a presença de oocistos de Cryptosporidium sp. Näo houve diferenças significativas entre a positividade de Cryptosporidium sp e rotavírus com a consistência das fezes. Cryptosporidium sp deve ser incluído na investigaçäo diagnóstica dos quadros diarréicos em crianças

Reproductive system abnormalities in Schistosoma mansoni adult worms isolated from Nectomys squamipes (Muridae: Sigmodontinae): brightfield and confocal laser scanning microscopy analysis

Schistosoma mansoni adult worms with genital anomalies isolated from Nectomys squamipes (Muridae: Sigmodontinae) were studied by confocal laser scanning microscopy under the reflected mode. One male without testicular lobes (testicular agenesia/anorchism) and two females, one with an atrophied ovary and another with 17 uterine eggs, were identified. The absence of testicular lobes occurred in a worm presenting otherwise normal male adult characteristics: tegument, tubercles and a gynaecophoric canal with spines. In both female specimens the digestive tube showed a vacuolated appearance, and the specimen with supernumerary uterine eggs exhibited a developing miracidium and an egg with a formed shell. The area of the ventral sucker was similar in both specimens however the tegument thickness, ovary and vitelline glands of the specimen with the atrophied ovary were smaller than those of the one with supernumerary eggs. These reported anomalies in the reproductive system call attention to the need to improve our understanding of genetic regulation and the possible role of environmental influences upon trematode development

Parasitological characteristics of Schistosoma mansoni infection in swiss mice with underlying malnutrition

The effects of a protein-restricted diet (8 percent protein, 81 percent carbohydrate and 11 percent lipids) on Schistosoma mansoni infectivity, fecal egg excretion and intestinal egg distribution in Swiss (SW) mice were studied. Pregnant mice received a deficient diet from the middle of gestation until delivery. Seven-days-old mice were exposed to 50 cercariae (BH strain, Brazil). Offspring mice had a free access to the deficient diet since lactation until adulthood. The controls were fed with a commercial mice diet. A parasitological examination was performed between six and eight weeks post-infection while both groups were necropsied one week later. Mice on the experimental diet showed a significant loss in body weight. There was no significant difference (p > 0.05) in pre-patent period, kinetics of egg excretion and worm recovery from mice on either diet. Significant differences (p < 0.05) were found concerning to the percentage of deposited eggs in the distal segment of the small intestine from hosts on the experimental diet.Our data suggest that experimental malnutrition induced for a long term has no detrimental effect on the acute schistosomiais infection in SW mice

Natural Schistosoma mansoni infection in Nectomys squamipes: histopathological and morphometric analysis in comparison to experimentally infected N. squamipes and C3H/He mice

Histopathologic and morphometric (area, perimeter, major and minor diameters) analysis of hepatic granulomas isolated from twelve naturally infected Nectomys squamipes were compared to four experimentally infected ones and six C3H/He mice. Liver paraffin sections were stained for cells and extracellular matrix. Both groups of N. squamipes presented peculiar granulomas consisting predominantly of large macrophages, full of schistosome pigment, characterizing an exudative-macrophage granuloma type, smaller than the equivalent granuloma type in mouse. Naturally infected animals exhibited granulomas in different stages of development, including large number of involutional types. Morphometric analysis showed that all measurements were smaller in naturally infected animals than in other groups. The results demonstrated that both N. squamipes groups reproduced, with small variations, the hepatic granuloma aspects already described in cricetidium (Calomys callosus), showing a genetic tendency to set up strong macrophage responses and small granulomas. Unexpectedly, natural infection did not engender distinguished histopathological characteristics distinct from those derived from experimental single infection, showing changes predominantly secondary to the duration of infection. It appears that the variability of the inocula (and the number of infections?) interfere more with the quantity than with the quality of the pathological changes, denoting some morpho-functional determinism in the response to schistosomal infection dependent on the animal species

Morphological aspects of Schistosoma mansoni adult worms isolated from nourished and undernourished mice: a comparative analysis by confocal laser scanning microscopy

Malnutrition hampers the course of schistosomiasis mansoni infection just as normal growth of adult worms. A comparative morphometric study on adult specimens (male and female) recovered from undernourished (fed with a low protein diet - regional basic diet) and nourished (rodent commercial laboratory food, NUVILAB) white mice was performed. Tomographic images and morphometric analysis of the oral and ventral suckers, reproductive system and tegument were obtained by means of confocal laser scanning microscopy. Undernourished male specimens presented smaller morphometric values (length and width) of the reproductive system (first, third and last testicular lobes) and thickness of the tegument than controls. Besides that, it was demonstrated that the dorsal surface of the male worms bears large tubercles unevenly distributed, but kept grouped and flat. At the subtegumental region, vacuolated areas were detected. It was concluded that the inadequate nutritional status of the vertebrate host has a negative influence mainly in the reproductive system and topographical somatic development of male adult Schistosoma mansoni, inducing some alterations on the structure of the parasite