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O gastropode Biomphalaria glabrata presente em grande parte do territorio nacional, atua como principal hospedeiro intermediario do trematodeo, Schistosoma mansoni , causador da esquistossomose no Brasil. O nematoide entomopatogenico (NEP) Heterorhabditis associado com a bacteria, Photorhabdus luminescens, e usado mundialmente no controle biologico de diversos organismos. Porem, nada se conhece sobre a susceptibilidade de B. glabrata a NEPs. Nesse estudo, alem de demonstrar a susceptibilidade do molusco ao nematoide, tambem avaliamos as alteracoes induzidas por Heterorhabditis bacteriophora em seu metabolismo glicemico. Pra tanto, seis grupos foram formados: tres grupos controle, constituido por organismos nao expostos ao nematoide, e tres grupos infectados, que foram expostos as formas infectantes do NEP. O experimento foi realizado em duplicata, utilizando um total de 240 molucos. Significativas alteracoes no metabolismo de carboidratos de B. glabrata foram observadas apos 3 semanas de infeccao. Os resultados indicam diminuicao dos niveis de glicose hemolinfatica, bem como nos conteudos de glicogenio estocados na glândula digestiva e glândula de albumen do caramujo. Em paralelo, os grupos infectados tambem apresentaram aumento na atividade da enzima lactato desidrogenase (LDH), indicando que a infeccao induz a ativacao de vias fermentativas do molusco. Apesar da ausencia de letalidade dos grupos expostos, a infeccao gerou comprometimento no metabolismo glicidico de B. glabrata , sobretudo, nas reservas de galactogenio, sugerindo potencial aplicabilidade em programas de controle biologico do gastropode.

The trematode Schistosoma mansoni is a heteroxenous parasite, meaning that during its life cycle needs the participation of obligatory intermediate and definitive hosts. The larval development occurs in aquatic molluscs belonging to the Biomphalaria genus, leading to the formation of cercariae, which emerge to infect the final vertebrate host. For this reason, studies for control of the diseases caused by digenetic trematodes often focus on combating the snail hosts. Thus, the objective of this study was to evaluate the susceptibility of Biomphalaria tenagophila embryos to the fungus Pochonia chlamydosporia (isolate Pc-10) under laboratory conditions. Two experimental groups were formed: the control group, consisting of egg masses not exposed to the fungus; and the treated group, in which the snail egg masses were exposed to mycelium of the fungal isolate (Pc-10). At the end of 15 days, the egg masses were evaluated under a stereomicroscope to analyze the hatching of B. tenagophila embryos in both experimental groups. The entire experiment was conducted in duplicate, with five replicates for each repetition (five egg masses/replicate), utilizing a total of 100 egg masses, with 20 to 30 eggs/egg mass. After 15 days of interaction, the exposure to the fungal hyphae bodies significantly impaired the viability of the B. tenagophila eggs, inhibiting the embryogenesis process by 83.7% in relation to the control group. Transmission and scanning electron microscopic images revealed relevant structural alterations in the egg masses exposed to the hyphae action of the fungus, interfering in the development and hatching of the young snails under analysis. These results indicate the susceptibility of B. tenagophila embryos to the fungus P. chlamydosporia (isolate Pc-10) and suggests the potential of Pc-10 to be used in the control of parasitic agents, such as S. mansoni, but in vivo experiments become necessary.

Angiostrongylus cantonensis is a metastrongylid nematode that has a heteroxenous cycle, where snails act as intermediate hosts and the rodents Rattus rattus and Rattus novergicus are the definitive hosts. However, humans may act as accidental hosts presenting an atypical form of parasitism. This fact has motivated research to better understand systems of relationships involving A. cantonensis, targeting the control of species of gastropods that act as intermediary hosts. For this, six groups were formed: three control groups (uninfected) and three infected groups, exposed to approximately 1200 L1 larvae of A. cantonensis. At the end of each week (1, 2, and 3 weeks), snails were dissected without anesthesia and the gonad–digestive gland (DGG) complex was separated for determination of oxygen consumption through high-resolution titration-injection respirometer (Oroboros, Oxygraph; Innsbruck, Austria). The results indicate suppression of mitochondrial oxidative metabolism of the host and compromised in different mitochondrial respiratory states. This effect, mainly observed in the group exposed to 1 week of infection, showed a decrease of approximately 38% (2.78 ± 0.37 pmol O2/mg of tissue; P

Heterorhabditis bacteriophora is an entomopathogenic nematode (EPN) that is mutually associated with Photorhabdus luminescens, utilized globally for biological control of numerous organisms. Freshwater snails of the species Biomphalaria glabrata have been incriminated as the main intermediate hosts of Schistosoma mansoni in Brazil, but virtually nothing is known about the susceptibility of these gastropod to EPNs. Information in this respect is relevant for control of these intermediate hosts, and thus of the helminthiases they transmit. This paper for the first time reports the susceptibility of B. glabrata to infective juveniles of H. bacteriophora (isolate HP88) under laboratory conditions. For that purpose, six groups were formed: three Control groups (not exposed) and three Treated groups, in which the snails were exposed to 300 juveniles infecting the nematode over three weeks. The entire experiment was conducted in triplicate, using a total of 270 snails. Significant physiological alterations in B. glabrata were observed in response to the infection by H. bacteriophora HP88, characterized by decreased levels of hemolymphatic glucose as well as reduced contents of glycogen stored in the host's digestive gland. In parallel, the hemolymphatic activity of lactate dehydrogenase increased in the infected snails, indicating that the infection induces breakdown of carbohydrate homeostasis in B. glabrata. Additionally, all the reproductive parameters analyzed were reduced as a consequence of the infection. The results indicate the occurrence of the phenomenon of parasitic castration in the B. glabrata/H. bacteriophora HP88 interface, probably due to the depletion of galactogen in the parasitized organism. Although the infection did not cause lethality in the population of infected snails, H. bacteriophora HP88 compromised the reproductive performance of B. glabrata, suggesting its applicability in programs for biological control of this planorbid.

Made available in DSpace on 2021-06-25T12:29:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-12-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) BBSRC MRC DTG Fellowship Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Background/Aims: Furosemide is a loop diuretic widely used in clinical practice for the treatment of oedema and hypertension. The aim of this study was to determine physiological and molecular changes in the hypothalamic-neurohypophysial system as a consequence of furosemide-induced sodium depletion. Methods: Male rats were sodium depleted by acute furosemide injection (10 and 30 mg/kg) followed by access to low sodium diet and distilled water for 24 h. The renal and behavioural consequences were evaluated, while blood and brains were collected to evaluate the neuroendocrine and gene expression responses. Results: Furosemide treatment acutely increases urinary sodium and water excretion. After 24 h, water and food intake were reduced, while plasma angiotensin II and corticosterone were increased. After hypertonic saline presentation, sodium-depleted rats showed higher preference for salt. Interrogation using RNA sequencing revealed the expression of 94 genes significantly altered in the hypothalamic paraventricular nucleus (PVN) of sodium-depleted rats (31 upregulated and 63 downregulated). Out of 9 genes chosen, 5 were validated by quantitative PCR in the PVN (upregulated: Ephx2, Ndnf and Vwf; downregulated: Caprin2 and Opn3). The same genes were also assessed in the supraoptic nucleus (SON, upregulated: Tnnt1, Mis18a, Nr1d1 and Dbp; downregulated: Caprin2 and Opn3). As a result of these plastic transcriptome changes, vasopressin expression was decreased in PVN and SON, whilst vasopressin and oxytocin levels were reduced in plasma. Conclusions: We thus have identified novel genes that might regulate vasopressin gene expression in the hypothalamus controlling the magnocellular neurons secretory response to body sodium depletion and consequently hypotonic stress. Univ Fed Rural Rio de Janeiro, Dept Physiol Sci, Seropedica, Brazil Univ Bristol Sch Med, Mol Neuroendocrinol Res Grp, Translat Hlth Sci, Bristol, Avon, England Sao Paulo State Univ, Sch Dent, Dept Physiol & Pathol, UNESP, Araraquara, SP, Brazil Queens Univ, Translat Inst Med, Dept Med, Queens Cardiopulm Unit, Kingston, ON, Canada Univ Sao Paulo, Ribeirao Preto Med Sch, Dept Physiol, Ribeirao Preto, Brazil Univ Fed Sao Paulo, Dept Biophys, Lab Neuroendocrinol, Escola Paulista Med, Rua Botucatu 862,Edificio Ciencias Biomed,7 Andar, BR-04023062 Sao Paulo, SP, Brazil Sao Paulo State Univ, Sch Dent, Dept Physiol & Pathol, UNESP, Araraquara, SP, Brazil FAPESP: 2011/507701 FAPESP: 2013/23057-8 FAPESP: 2019/08621-0 FAPESP: 2013/09799-1 FAPESP: 2014/15218-4 FAPERJ: E26/110.045/2014 FAPERJ: E26/202.981/2015 BBSRC: BB/J005452/1 BBSRC: BB/J015415/1 CAPES: 001 CNPq: 400503/2014-0 : MR/N022807/1

Resumo Como ações de saneamento são escassas ou inexistentes no meio rural, o monitoramento das fontes de água permite o diagnóstico dos riscos e da precariedade das situações de saneamento. Neste estudo foi monitorado sazonalmente a qualidade da água dos poços da comunidade rural “Cinturão Verde” por meio de análises físico-químicas, colimétricas, e parasitológicas para identificação de fontes de contaminação devido à ausência de meios adequados de saneamento. Foram analisadas amostras coletadas em quatro períodos sazonais e detectados coliformes acima dos padrões de potabilidade do Ministério da Saúde nos poços tubulares em três dos quatro períodos sazonais. Foi detectada também a presença de parasita no período seco. Os parâmetros físico-químicos também estavam fora dos padrões da legislação em algumas estações, e foi constatado que esses riscos eram devido à inexistência de serviços de saneamento como: abastecimento com poços sem tratamento, precariedade de esgotamento e proximidade dos mananciais à criação de animais. Conclui-se que o monitoramento permitiu detectar períodos de riscos no uso de águas dos poços, avaliar diferenças regionais, e a necessidade de medidas de desinfecção da água antes de ser utilizada. Estas medidas de saneamento rural podem garantir a proteção dos mananciais de águas subterrâneas. Abstract As sanitation is scarce or nonexistent in a rural environment, the monitoring of water sources allows for the diagnosis of risks and precarious sanitation situations. This study seasonally monitored the water quality of wells in the rural community of Cinturão Verde by means of physical and chemical analysis and colimetric and parasitological assays, and identified sources of contamination due to the lack of adequate sanitation. Samples collected in four seasonal periods detected levels of coliform in wells above the potability standards of the Health Ministry in three of the periods, and detected the presence of parasites in the dry season. Physical and chemical parameters also exceeded legal standards in some periods, and it was found that these risks were due to lack of proper sanitation practices, such as water supplied by untreated wells, improper drainage and the proximity of water sources to livestock. Water monitoring enabled the detection of risk periods when using well waters, the evaluation of regional differences, and the showed the need for water disinfection before use. These rural sanitation measures can help to ensure the protection of groundwater sources.

Intestinal helminths are among the pathogens most often found in humans and can result in serious pathological, such as visceral larva migrans syndrome. Domestic animals serve as the natural hosts, but under certain conditions humans can acquire infection, developing an atypical cycle. Thus, the contamination for animal droppings in public spaces, such as beaches, poses risk factor in the transmission, increasing the incidence of these zoonoses. In this context, informations about environmental health is necessary because the monitoring would be the first step for treating unhealthy environments. Therefore, the study monitored the sand of beaches of two islands within Guanabara Bay, Rio de Janeiro state, was carried out by traditional methods (Lutz and Baermann) and the ELISA immunological test, in order to determine the level and the influence of seasonality on this contamination. Among the genera detected, Ascaris sp. and Ancylostoma sp. occurred with greatest frequency, functioning as important biological markers of environmental contamination. The highest frequency of parasite structures occurred in the summer, meaning a greater risk of disease transmission. The results evidence the high level of environmental contamination and the seasonal variations of this contamination. Additionally, the data obtained from ELISA confirm the sensitivity of this technique to detect cysts and oocysts of protozoa in the sand samples analyzed.

The effect of experimental infection by different parasitic loads of Angiostrongylus cantonensis (Nematode, Metastrongylidae) on the activities of the aminotransferases and concentration of total proteins, uric acid and urea in the hemolymph of Achatina fulica (Mollusca, Gastropoda) were investigated. There was a significant decrease in the concentration of total proteins in the exposed snails to 5000 or more larvae. This change was accompanied by an increase in the concentrations of urea and uric acid in the hemolymph, suggesting a higher rate of deamination of the amino acids. Besides this, variations in the activities of the aminotransferases were also observed, with the highest values recorded in the groups exposed to greater parasite load. These results suggest an increase in the use of total proteins, since there was increased formation of nitrogenous catabolites, in conformity with an increase in the aminotransferase activities. Infection was verified by the fact that L3 larvae recovered from the snails was proportion to the exposure dose of L1 larvae. Histopathological results also indicated presence of an inflammatory cell infiltrate, favoring an increase of both transaminases.

This study showed for the first time changes in the reproductive biology of Biomphalaria glabrata experimentally infected with Angiostrongylus cantonensis. The values of all the parameters analyzed (total number of eggs, number of egg masses, number of eggs/mass, number of eggs/snail, percentage of viable eggs and galactogen content in albumen gland) changed with progressive infection. The results indicate the occurrence of partial parasitic castration of B. glabrata by A. cantonensis larvae, probably in response to the depletion of energy reserves, with no injuries to the gonadal tissues.