RESUMO
Eurytrema coelomaticum is a digenean flatworm of ruminants that is the causative agent of eurytrematosis, a disease of veterinary health concern. Although modern techniques of morphological analysis have provided new insights about the morphology and anatomy of parasitic helminths, most studies on E. coelomaticum adults are based on conventional light microscopy. In the present study, a combined approach using brightfield, fluorescence, confocal and scanning electron microscopies (SEMs), together with the cryofracture technique, have updated morphological data on E. coelomaticum recovered from cattle in Rio de Janeiro State, Brazil. Light microscopy confirmed the presence of several structures present in the current description, such as suckers, pharynx, oesophagus, intestinal bifurcation and the cirrus-sac. Fluorescence stereomicroscopy revealed for the first time the cubic crystal protein inclusions in the forebody, which were further detailed by confocal and SEMs. Confocal microscopy provided detailed information of the muscular architecture associated with the attachment structures (suckers), digestive system (pharynx and oesophagus), egg-forming complex (ovary, Mehlis' gland and Laurer's canal) and male reproductive system, which are similar to those found in other digenean flukes. SEM images of cryofractured parasites showed mucus and developing eggs within uterine loops. It was demonstrated that the combination of advanced tools generated complementary information, confirming the importance of experimental morphology in parasitology. Therefore, the knowledge of the adult structural organization of E. coelomaticum was improved and this work has contributed to propose new morphological criteria to evaluate the effects of antiparasitic drugs on flukes of medical and veterinary importance.
Assuntos
Heterophyidae/anatomia & histologia , Heterophyidae/ultraestrutura , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Ovos , Feminino , Genitália/anatomia & histologia , Genitália/ultraestrutura , Masculino , Microscopia Confocal , Microscopia Eletrônica de Varredura , Platelmintos , Infecções por Trematódeos/veterináriaRESUMO
Polycystic echinococcosis, caused by the larval stage (metacestode) of the small-sized tapeworm, Echinococcus vogeli, is an emerging parasitic zoonosis of great public health concern in the humid tropical rainforests of South and Central America. Because morphological and morphometric characteristics of the metacestode are not well known, hydatid cysts from the liver and the mesentery were examined from patients following surgical procedures. Whole mounts of protoscoleces with rostellar hooks were examined under light and confocal laser scanning microscopy. Measurements were made of both large and small hooks, including the total area, total length, total width, blade area, blade length, blade width, handle area, handle length and handle width. The results confirmed the 1:1 arrangement of hooks in the rostellar pad and indicated, for the first time, that the morphometry of large and small rostellar hooks varies depending upon the site of infection. Light and confocal microscopy images displayed clusters of calcareous corpuscles in the protoscoleces. In conclusion, morphological features of large and small rostellar hooks of E. vogeli are adapted to a varied environment within the vertebrate host and such morphological changes in calcareous corpuscles occur at different stages in the maturation of metacestodes.
Assuntos
Equinococose/parasitologia , Echinococcus/anatomia & histologia , Adolescente , Adulto , Animais , Brasil/epidemiologia , Criança , Pré-Escolar , Equinococose/epidemiologia , Echinococcus/classificação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
The helminth fauna of Agouti paca (Linnaeus, 1766) has seldom been studied. In this paper, we report an unusual mixed infection of Echinococcus vogeli Rausch & Bernstein, 1972 and Calodium hepaticum (syn. Capillaria hepatica Bancroft, 1863) in free-ranging paca from a forested region in Acre (Brazil). Gross morphological examination revealed that paca liver contained multiple spherical to subspherical white or translucent lesions, which were isolated or frequently contiguous and partially covered by Glisson's capsule. Microscopic examination revealed unilocular cystic structures that contained abundant brood capsules in which numerous protoscolices budded from the inner surface. The protoscolices possessed rostellar hooks (33-41 µm in length), a morphological characteristic of the blade and calcareous corpuscles that is consistent with the metacestode E. vogeli. The diagnosis of C. hepaticum infection was based on the morphology and morphometry of the egg-shaped ellipsoids with bipolar plugs (44.8 ± 1.9 µm (length) × 24.4 ± 2.0 µm (width)) and liver histopathology. This finding expands the known range of C. hepaticum hosts in South America and, to the best of our knowledge, it is the first case of a mixed infection of E. vogeli and C. hepaticum. Furthermore, our data provide evidence that wild animal meat may be a source of C. hepaticum infection.
Assuntos
Coinfecção/parasitologia , Equinococose/veterinária , Echinococcus/isolamento & purificação , Nematoides/isolamento & purificação , Infecções por Nematoides/veterinária , Doenças dos Roedores/parasitologia , Animais , Brasil , Equinococose/complicações , Equinococose/parasitologia , Fígado/parasitologia , Microscopia , Infecções por Nematoides/complicações , Infecções por Nematoides/parasitologia , Roedores , ÁrvoresRESUMO
This study aimed to investigate myocardial injuries in mice infected with Schistosoma mansoni and fed a high-fat chow. Sections of myocardial tissue from S. mansoni-infected mice, and controls that had been killed 9 and 17 weeks post-infection, were stained with H&E and Picrosirius red. Histopathological examination, stereological design-based method (optical disector) and morphometry (vessels, cardiomyocytes and an amount of collagen) were used. Data were analysed using two-way ANOVA. Regardless of time of infection, myocardial tissue from the infected mice fed high-fat chow showed myocarditis characterized by a higher number of inflammatory foci, several areas displaying coagulation of cardiac fibres, a greater loss of cardiomyocytes and fibroblast proliferation than in the standard chow control. Comparing infected mice from acute and chronic infections, a higher cardiomyocyte hyperplasia (P < 0·0001) and higher amounts of collagen (P < 0·05) were observed than in standard chow control. In addition, all animals fed high-fat chow showed lower numerical density and total number of cardiomyocytes (P < 0·05), thicker vessel walls and narrowed luminal intramyocardial vessels (P > 0·05) than in the standard chow control. Altogether the data supported the view that a double burden has a synergistic deleterious effect on the myocardial tissue.
Assuntos
Dieta Hiperlipídica , Gorduras na Dieta/metabolismo , Miocárdio/patologia , Esquistossomose mansoni/patologia , Doença Aguda , Animais , Vasos Sanguíneos/patologia , Doença Crônica , Feminino , Camundongos , Miócitos Cardíacos/patologiaRESUMO
Infected hosts progressively decrease egg output during the chronic phase of Schistosoma mansoni infection. Ageing may be a factor that results in a progressive decrease in the ability to reproduce. This study was performed to gain insight into the effects of ageing on adult schistosomes, using confocal laser scanning microscopy. Adult worms were recovered from experimentally infected Nectomys squamipes (water rat). Viable eggs were voided in the faeces for 65 weeks and, thereafter, only unviable eggs were eliminated. The rat died after 70 weeks in captivity. Recovered worms (six males and one female) were prepared for confocal microscopy and images were obtained with an LSM 510-ZETA laser confocal microscope. The overall morphology of the adult worms (suckers and tegument) and reproductive organs were the focus of this work. The suckers, ovary, vitellaria and oocytes appeared to be apparently normal. The ootype was formed by flattened cells and unclear nuclei, suggesting that the mechanism for eggshell production by the ootype during organogenesis might have been impaired. Testicular lobes showed empty areas around the germinative cells. Male adult worms showed flaccid musculature of the dorsal surface. Taken together, the present results provided several indications of infertility in older male and female schistosomes.
Assuntos
Ratos/parasitologia , Doenças dos Roedores/parasitologia , Schistosoma mansoni/anatomia & histologia , Schistosoma mansoni/fisiologia , Esquistossomose mansoni/veterinária , Animais , Feminino , Masculino , Microscopia Confocal , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/parasitologiaRESUMO
A study was undertaken to investigate the effect of administering praziquantel (PZQ), focusing on the liver stereological findings of malnourished mice infected with Schistosoma mansoni. Thirty female Swiss Webster mice (age: 21 days; weight: 8-14 g) were fed either a low-protein diet (8%) or standard chow (22% protein) for 15 days. Five mice in each group were infected with 50 cercariae each of the BH strain (Brazil). PZQ therapy (80 mg/kg body weight, per day) was started on the 50th day of infection and consisted of daily administration for 5 days. Volume density (hepatocytes, sinusoids and hepatic fibrosis) was determined by stereology using a light microscope. Body weight gain and total serum albumin levels were always lower in undernourished mice. Our stereological study demonstrated that treatment increased both volume density of hepatocytes in mice fed standard chow (47.56%, treated group and 12.06%, control) and low-protein chow (30.98%, treated group and 21.44%, control), and hepatic sinusoids [standard chow (12.52%, treated group and 9.06%, control), low-protein chow (14.42%, treated group and 8.46%, control)], while hepatic fibrosis was reduced [standard chow (39.92%, treated group and 78.88%, control) and low-protein chow (54.60%, treated group and 70.10%, control)]. On the other hand, mice fed low-protein chow decreased density volume of hepatocytes and hepatic fibrosis. In conclusion, our findings indicate that treatment with PZQ ameliorates hepatic schistosomiasis pathology even in mice fed a low-protein diet.
Assuntos
Anti-Helmínticos/uso terapêutico , Dieta com Restrição de Proteínas , Fígado/patologia , Praziquantel/uso terapêutico , Esquistossomose mansoni/tratamento farmacológico , Animais , Feminino , Hepatócitos/patologia , Fígado/parasitologia , Cirrose Hepática/patologia , Camundongos , Esquistossomose mansoni/patologia , Albumina Sérica/análise , Aumento de PesoRESUMO
A study was undertaken to investigate the effect of administering praziquantel (PZQ), focusing on the liver stereological findings of malnourished mice infected with Schistosoma mansoni. Thirty female Swiss Webster mice (age: 21 days; weight: 8-14 g) were fed either a low-protein diet (8 percent) or standard chow (22 percent protein) for 15 days. Five mice in each group were infected with 50 cercariae each of the BH strain (Brazil). PZQ therapy (80 mg/kg body weight, per day) was started on the 50th day of infection and consisted of daily administration for 5 days. Volume density (hepatocytes, sinusoids and hepatic fibrosis) was determined by stereology using a light microscope. Body weight gain and total serum albumin levels were always lower in undernourished mice. Our stereological study demonstrated that treatment increased both volume density of hepatocytes in mice fed standard chow (47.56 percent, treated group and 12.06 percent, control) and low-protein chow (30.98 percent, treated group and 21.44 percent, control), and hepatic sinusoids [standard chow (12.52 percent, treated group and 9.06 percent, control), low-protein chow (14.42 percent, treated group and 8.46 percent, control)], while hepatic fibrosis was reduced [standard chow (39.92 percent, treated group and 78.88 percent, control) and low-protein chow (54.60 percent, treated group and 70.10 percent, control)]. On the other hand, mice fed low-protein chow decreased density volume of hepatocytes and hepatic fibrosis. In conclusion, our findings indicate that treatment with PZQ ameliorates hepatic schistosomiasis pathology even in mice fed a low-protein diet.
Assuntos
Animais , Feminino , Camundongos , Anti-Helmínticos/uso terapêutico , Dieta com Restrição de Proteínas , Fígado/patologia , Praziquantel/uso terapêutico , Esquistossomose mansoni/tratamento farmacológico , Hepatócitos/patologia , Cirrose Hepática/patologia , Fígado/parasitologia , Esquistossomose mansoni/patologia , Albumina Sérica/análise , Aumento de PesoRESUMO
The kinetic of maturation (schistogram) of Schistosoma mansoni worms grown in laboratory rats was studied by light and confocal laser scanning microscopy. Infected rats with the BH strain were weekly euthanized 3-9weeks pi. Recovered flukes stained with hydrochloric carmine were preserved as whole-mounts and analyzed by confocal and brightfield microscopy. Worms displayed varying degrees of maturation of the reproductive system at weeks 3-6. Male worms showed complete maturation of the reproductive system at week 6, while female worms completed their maturation at week 7. Males presented few tubercles in tegument in all weeks. Despite the presence of a developing embryo within the ootype, no uterine egg was found. The schistogram in rats follows a pattern similar to that observed in mice hosts.
Assuntos
Schistosoma mansoni/crescimento & desenvolvimento , Esquistossomose mansoni/parasitologia , Animais , Modelos Animais de Doenças , Feminino , Interações Hospedeiro-Parasita , Masculino , Microscopia Confocal , Ratos , Ratos Wistar , Schistosoma mansoni/anatomia & histologia , Razão de Masculinidade , Maturidade SexualRESUMO
Previous studies have shown that protein deficiencies can hamper both the course of experimental schistosomiasis and normal development of adult worms. To further investigate this relationship, we compared adult male and female Schistosoma mansoni from malnourished and well-fed mice through morphometric and confocal laser scanning microscopy analysis. Swiss mice were fed protein-deficient diets (8%) and infected subcutaneously with approximately 80 S. mansoni cercariae (BH strain, Brazil). Control mice were fed a standard rodent diet (23% protein). The nutritional status was evaluated by body weight gain and albumin values. Mice were sacrificed 63 days post-infection. Recovered worms were stained with hydrochloric carmine and preserved as whole-mounts for bright-field examination and confocal microscopy. The body weight gain and serum albumin concentrations were significantly lower (P < 0.05) in malnourished mice than in controls. In general, all morphometric values of specimens grown in malnourished mice were lower than those of control mice. Schistosome worms grown in malnourished mice had statistically significant differences (P < 0.05) in the reproductive system and tegument than those grown in mice fed standard diets. In female worms, vitelline glands showed few remaining follicles and ovaries lacked mature oocytes. In male parasites, tubercles were fewer in number on the dorsal surface and testicular lobes presented fewer differentiated germinal cells. In summary, we describe novel data supporting the view that low-protein diets may influence the development of adult worms.
Assuntos
Peso Corporal , Deficiência de Proteína/parasitologia , Schistosoma mansoni/ultraestrutura , Animais , Criança , Modelos Animais de Doenças , Feminino , Interações Hospedeiro-Parasita , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Camundongos , Microscopia Confocal , Schistosoma mansoni/crescimento & desenvolvimento , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/parasitologia , Albumina Sérica/análiseRESUMO
Schistosoma mansoni belongs to the dioecious Schistosomatidae. The occasional observation of males with rudimentary female characteristics is thought to attest the hermaphroditic roots of this parasite. Supernumerary testicular lobes also are recurrently seen in this helminth, but their morphology and origin are elusive. Here, we investigated the morphology of the supernumerary lobes from 15 S. mansoni males and similar structures of 2 females in whole mounts by brightfield and confocal laser scanning microscopy. The follicles in the females were not regarded as testicular lobes, but 1 male had a rudimentary ovary with a residual oviduct posterior to the normal set of testicular lobes and was considered hermaphroditic. In addition, 6 other males contained supernumerary lobes that enclosed fully matured oocytes in variable amounts. In the remaining 8 males, no female characteristics could be seen, and the lobes showed morphologically a more testicular aspect, although this morphology was only confirmed in 1 male where spermatozoids were detected. The process underlying the expression of supernumerary testes or lobes with oocytes is similar and is, at least in part, induced by the host.