The outcome of acute schistosomiasis infection in adult mice with postnatal exposure to maternal malnutrition

Maternal malnutrition during the lactation period in early development may have long-term programming effects on adult offspring. We evaluated the combined effects of parasitological behaviour and histopathological features and malnutrition during lactation. Lactating mice and their pups were divided into a control group (fed a normal diet of 23 percent protein), a protein-restricted group (PR) (fed a diet containing 8 percent protein) and a caloric-restricted group (CR) (fed according to the PR group intake). At the age of 60 days, the offspring were infected with Schistosoma mansoni cercariae and killed at nine weeks post-infection. Food intake, body and liver masses, leptinaemia, corticosteronaemia, collagen morphometry and neogenesis and the cellular composition of liver granulomas were studied. PR offspring showed reduced weight gain and hypophagia, whereas CR offspring became overweight and developed hyperphagia. The pre-patent period was longer (45 days) in both programmed offspring as compared to controls (40 days). The PR-infected group had higher faecal and intestinal egg output and increased liver damage. The CR-infected group showed a lower number of liver granulomas, increased collagen neogenesis and a higher frequency of binucleate hepatocytes, suggesting a better modulation of the inflammatory response and increased liver regeneration. Taken together, our findings suggest that neonatal malnutrition of offspring during lactation affects the outcome of schistosomiasis 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.

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.

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

An autochthonous case of Echinococcus vogeli Rausch & Bernstein, 1972 polycystic echinococcosis in the State of Rondônia, Brazil

The present case report refers to a patient from the State of Rondônia, North region of Brazil, attended with clinical suspicion of hepatic echinococcosis. Examination by imaging (ultrasonography and computerized tomography) revealed a conglomerate of cystic lesions, with mobile contents within the cyst. The serology (immunoblot) for Echinococcus sp. was positive (21 and 31 kDa bands). This case is the first reported in Rondônia, suggesting the need to investigate the polycystic echinococcosis in individuals with hepatic cysts from areas of tropical forest and hunting habits where wild life was present as wild dogs, cats and rodents, particularly Agouti paca (paca) and Dasyprocta aguti (agouti)

Differences in Brazilian strains of Schistosoma mansoni evaluated by means of morphometric analysis of cercariae of both sexes

Morphometrics of Brazilian strains (BH, SJ and CMO) of Schistosoma mansoni cercariae were obtained with a computerized image analyzer (IMAGE PRO PLUS, MEDIA CYBERNETICS), considering the following characters: body area, tail, furcae, oral and ventral suckers and distance between them. For statistical analysis, the variance test (one-way Anova) was applied and significant differences of p< 0.05 were considered. All morphometric values in the BH strain were significantly higher (p< 0.05) than in the others. Lower values were obtained in females of SJ strain for all characters, excepting the body area. Only this character showed to be significantly different in males and females of the three strains. Specimens of both sexes in the BH and SJ strains showed significant differences regarding all characters. It was observed that this morphometric analysis permits the characterization of strains and also the sex identification in S. mansoni cercariae. Due to its feasibility, this method can be applied as a tool in laboratories devoid of more complex equipment

Schistosoma mansoni Sambon 1907: morphometric differences between adult worms from sympatric rodent and human isolates

A computer software for image (IMAGE PRO PLUS, MEDIA CYBERNETICS) was utilized in male and females adult worms aiming the morphological characterization of Schistosoma mansoni samples isolated from a sylvatic rodent, Nectomys squamipes and humans in Sumidouro, Rio de Janeiro, Brazil and recovered from Mus musculus C3H/He. The following characters for male's testicular lobes were analyzed: number, area, density, larger and shorter diameter, longer and shorter axis and perimeter and extension; for females: area, longer and shorter axis, larger and smaller diameter and perimeter of the eggs and spine; oral and ventral suckers area and distance between them in both sex were determined. By the analysis of variance (one way ANOVA) significant differences (p<0.05) were observed in all studied characters, except for the density of testicular lobes. Significant differences (p<0.05) were detected for all characters in the female worms. Data ratify that sympatric isolates present phenotypic differences and the adult female characters are useful for the proper identification of S. mansoni isolates.

Schistosoma mansoni Sambon, 1907: comparative morphological studies of some brazilian strains

A morfologia de vermes adultos machos de tres cepas de Schistosoma mansoni, mantidas por variacoes em camundongos albinos, foi comparada com uma cepa isolada do hospedeiro natural Nectomys squamipes (Rodentia:Maridae) e mantida, em laboratorio, neste mesmo roedor silvestre. Como caracteres taxonomicos foram analisados o comprimento total, o numero de testiculos, a distancia entre as ventosas e a distancia ocupada pelos testiculos nos especimes. Os vermes recuperados de N. squamipes apresentaram diferencas significativas (p<0,01) em relacao as outras cepas para quaisquer caracteres morfologicos estudados. A cepas mantidas em camundongos apresentaram diferenca estatistica em varios caracteres (p<0,01). Alguns vermes adultos alem da disposicao normal dos testiculos apresentaram tambem uma localizacao atipica destas glandulas sexuais.