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Bonfim TCDS, Martins FG, Tunholi-Alves VM, Dos Santos MAJ, Castro RN, Brandolini SVPB, Pinheiro J. Carbohydrate metabolism evaluation of terrestrial snail Subulina octona (Gastropoda, Subulinidae) experimentally infected by the Paratanaisia bragai digenetic trematode (Digenea, Eucotylidae). Parasitol Int 2024; 98:102805. [PMID: 37696330 DOI: 10.1016/j.parint.2023.102805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 08/24/2023] [Accepted: 09/03/2023] [Indexed: 09/13/2023]
Abstract
Among the effects of the larval development of digenetic trematodes on their intermediate hosts, changes in the carbohydrate metabolism in the snails stand out. The aim of this study was to analyze, every 10 days after infection (d.p.i.), the effects of Paratanaisia bragai infection on the glycogen content in the digestive gland and cephalopedal mass in Subulina octona snail, and also verify the glucose concentration and the enzyme D- and L-lactate dehydrogenase activity (EC1.1.1.27 and EC1.1.1.28) (LDH) and the concentration of some metabolites(oxalic, succinic, pyruvic and lactic acid) presents in the hemolymph. Histochemical analisys were also performed. We verified a total increase of 54.81% in glucose concentration in infected snails and an oscillating pattern in the glycogen content in the cephalopedal mass and in the digestive gland. LDH activity shows an increase of 10 d.p.i. (+ 74.32%) and 40 d.p.i. (+ 47.81%) and decrease at 20 d.p.i. and 30 d.p.i. The concentrations of oxalic, succinic and pyruvic acids showed significant and progressive reductions; however, lactic acid had a significant increase. Histological and histochemical analysis showed a tissue disorganization in the cephalopedal mass of infected snails and morphological changes in the digestive gland. These results confirm that infection causes metabolic pathway changes in the snails due to activation of an alternative anaerobic pathway for producing energy, indicated by the increased lactic acid content and LDH activity.
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Affiliation(s)
- Tatiane Cristina Dos Santos Bonfim
- Curso de Pós-Graduação em Ciências Veterinárias, Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, UFRRJ, BR-465-km 7, CEP 23.890-000 Seropédica, RJ, Brazil; Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas e da Saúde, Universidade Federal Rural do Rio de Janeiro, UFRRJ, BR465, km 7, CEP 23.890-000 Seropédica, RJ, Brazil
| | - Florence Gonçalves Martins
- Curso de Pós-Graduação em Ciências Veterinárias, Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, UFRRJ, BR-465-km 7, CEP 23.890-000 Seropédica, RJ, Brazil; Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas e da Saúde, Universidade Federal Rural do Rio de Janeiro, UFRRJ, BR465, km 7, CEP 23.890-000 Seropédica, RJ, Brazil
| | - Vinicius Menezes Tunholi-Alves
- Curso de Pós-Graduação em Ciências Veterinárias, Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, UFRRJ, BR-465-km 7, CEP 23.890-000 Seropédica, RJ, Brazil; Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), process number E-26/202.866/2016, Av. Erasmo Braga, 118 - Centro, CEP 20.020-000, Rio de Janeiro, RJ, Brazil
| | - Marcos Antônio José Dos Santos
- Departamento de Biologia Animal, Instituto de Ciências Biológicas e da Saúde, Universidade Federal Rural do Rio de Janeiro, UFRRJ, BR465, km 7, CEP 23.890-000 Seropédica, RJ, Brazil
| | - Rosane Nora Castro
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro, UFRRJ, BR465, km 7, CEP 23.890-000 Seropédica, RJ, Brazil
| | - Solange Viana Paschoal Blanco Brandolini
- Departamento de Biologia Animal, Instituto de Ciências Biológicas e da Saúde, Universidade Federal Rural do Rio de Janeiro, UFRRJ, BR465, km 7, CEP 23.890-000 Seropédica, RJ, Brazil
| | - Jairo Pinheiro
- Curso de Pós-Graduação em Ciências Veterinárias, Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, UFRRJ, BR-465-km 7, CEP 23.890-000 Seropédica, RJ, Brazil; Departamento de Ciências Fisiológicas, Instituto de Ciências Biológicas e da Saúde, Universidade Federal Rural do Rio de Janeiro, UFRRJ, BR465, km 7, CEP 23.890-000 Seropédica, RJ, Brazil.
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Wang YC, Liew TZ, Namsanor J, Sithithaworn P. Assessing the role of Filopaludina martensi martensi as a biocontrol agent of Bithynia siamensis goniomphalos, the first intermediate host of Opisthorchis viverrini. Parasitol Res 2020; 119:3415-3431. [PMID: 32783072 DOI: 10.1007/s00436-020-06837-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/28/2020] [Indexed: 01/23/2023]
Abstract
The freshwater snail Bithynia siamensis goniomphalos serves as the first intermediate host of liver fluke Opisthorchis viverrini, a foodborne parasite, of which human infection has persisted in Southeast Asia for decades. The snail Filopaludina martensi martensi has been proposed as a biological control agent against B.s. goniomphalos, but knowledge on the snail ecology and population dynamics between the two species remains rudimentary. This study investigated selected abiotic and biotic factors influencing the distribution and abundance of B.s. goniomphalos and F.m. martensi. Water quality, soils, and snails were collected from 34 localities in Northeast Thailand. Soil properties and snail soft tissue elemental concentrations were analyzed. Experiments were performed to examine interspecific competition. Statistical analysis was conducted to explore the associations between water and soil properties and soft tissue elemental concentrations. The results showed that B.s. goniomphalos had the highest mean dominance in streams and red-yellow podzolic soils, while F.m. martensi snails preferred ponds and latosol soils. Negative correlation in species abundances was found between the two species. Interspecific competition was detected, with B.s. goniomphalos growth rates hampered by the presence of F.m. martensi. Despite the possibility of using F.m. martensi to control B.s. goniomphalos, B.s. goniomphalos exhibited a greater adaptability to different water and soil properties, suggesting that the species could colonize a wide range of environmental conditions. This study provides further insights into the ecology of the two snail species, underscoring the importance of considering abiotic factors when assessing the possible biological control agent to control O. viverrini transmission.
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Affiliation(s)
- Yi-Chen Wang
- Department of Geography, National University of Singapore, 1 Arts Link, Singapore, 117570, Singapore.
| | - Timothy Zherui Liew
- Department of Geography, National University of Singapore, 1 Arts Link, Singapore, 117570, Singapore
| | - Jutamas Namsanor
- Department of Geography, National University of Singapore, 1 Arts Link, Singapore, 117570, Singapore. .,Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand. .,Cholangiocarcinoma Research Institute, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.
| | - Paiboon Sithithaworn
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand.,Cholangiocarcinoma Research Institute, Faculty of Medicine, Khon Kaen University, Khon Kaen, 40002, Thailand
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Alba A, Tetreau G, Chaparro C, Sánchez J, Vázquez AA, Gourbal B. Natural resistance to Fasciola hepatica (Trematoda) in Pseudosuccinea columella snails: A review from literature and insights from comparative "omic" analyses. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2019; 101:103463. [PMID: 31381929 DOI: 10.1016/j.dci.2019.103463] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 07/25/2019] [Accepted: 08/01/2019] [Indexed: 06/10/2023]
Abstract
The snail Pseudosuccinea columella is one of the main vectors of the medically-important trematode Fasciola hepatica. In Cuba, the existence of natural P. columella populations that are either susceptible or resistant to F. hepatica infection offers a unique snail-parasite for study of parasite-host compatibility and immune function in gastropods. Here, we review all previous literature on this system and present new "omic" data that provide a molecular baseline of both P. columella phenotypes from naïve snails. Comparison of whole snail transcriptomes (RNAseq) and the proteomes of the albumen gland (2D-electrophoresis, MS) revealed that resistant and susceptible strains differed mainly in an enrichment of particular biological processes/functions and a greater abundance of proteins/transcripts associated with immune defense/stress response in resistant snails. These results indicate a differential allocation of molecular resources to self-maintenance and survival in resistant P. columella that may cause enhanced responsiveness to stressors (i.e. F. hepatica infection or tolerance to variations in environmental pH/total water hardness), possibly as trade-off against reproduction and the ecological cost of resistance previously suggested in resistant populations of P. columella.
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Affiliation(s)
- Annia Alba
- Centro de Investigaciones, Diagnóstico y Referencia, Instituto de Medicina Tropical "Pedro Kourí", La Habana, Cuba; University of Perpignan Via Domitia, Interactions Hosts Pathogens Environments UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860, Perpignan, France.
| | - Guillaume Tetreau
- University of Perpignan Via Domitia, Interactions Hosts Pathogens Environments UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860, Perpignan, France
| | - Cristian Chaparro
- University of Perpignan Via Domitia, Interactions Hosts Pathogens Environments UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860, Perpignan, France
| | - Jorge Sánchez
- Centro de Investigaciones, Diagnóstico y Referencia, Instituto de Medicina Tropical "Pedro Kourí", La Habana, Cuba
| | - Antonio A Vázquez
- Centro de Investigaciones, Diagnóstico y Referencia, Instituto de Medicina Tropical "Pedro Kourí", La Habana, Cuba; MIVEGEC, IRD, CNRS, Université de Montpellier, Montpellier, France
| | - Benjamin Gourbal
- University of Perpignan Via Domitia, Interactions Hosts Pathogens Environments UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860, Perpignan, France.
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Tunholi VM, Tunholi-Alves VM, Monteiro CO, Silva LCD, Dolinski CDM, Castro RN, Bittencourt VREP, Silva JPD, Freire Martins IV. Biological, biochemical and histological features of Bradybaena similaris (Gastropoda: Pulmonata) infected by Heterorabditis indica (Rhabditida: Heterorhabditidae) strain LPP1. Exp Parasitol 2017; 179:28-35. [PMID: 28655584 DOI: 10.1016/j.exppara.2017.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 05/25/2017] [Accepted: 06/23/2017] [Indexed: 10/19/2022]
Abstract
This study investigated the possible biological, biochemical and histological changes in Bradybaena similaris(Gastropoda: Pulmonata) infected by Heterorhabditis indica (Rhabditida: Heterorhabditidae), strain LPP1. Two groups of 16 snails were formed: the control group (unexposed) and the treated group, which was exposed for three weeks to infective juveniles (J3) of H. indica LPP1. The experiment was conducted in duplicate, using a total of 64 snails. After the exposure period, the snails were dissected to collect the hemolymph and tissues, for evaluation of the physiological changes caused by the infection. The number of eggs laid/snail and the viability of these eggs were also assessed as indicators of the reproductive activity of B. similaris. Intense glycogenolysis was accompanied by a significant reduction (p < 0.05) in the glucose content of the hemolymph of the exposed snails, indicating that infection by H. indica induces breakdown of the host's glycemic homeostasis. Significant variations (p < 0.05) in the lactate dehydrogenase activity occurred together with changes in the concentration of pyruvic and lactic acid in the hemolymph of the infected B. similaris snails, corroborating the transition from aerobic to anaerobic metabolism in the hosts. These metabolic alterations reflect the parasitic castration process in this interface. The results suggest that the use of H. indica LPP1 is a potential alternative for biological control of B. similaris.
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Affiliation(s)
- Victor Menezes Tunholi
- Departamento de Medicina Veterinária, Centro de Ciências Agrárias, Universidade Federal do Espírito Santo - UFES, Alegre, ES, Brazil.
| | - Vinícius Menezes Tunholi-Alves
- Departamento de Ciências Fisiológicas, Instituto de Biologia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brazil; Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brazil.
| | - Caio Oliveira Monteiro
- Programa de Pós-graduanção em Ciência Animal da Universidade Federal de Goiás - Avenida Esperança, s/n, Campus Samambaia, Goiânia GO, 74.690-900, Brazil
| | - Lidiane Cristina da Silva
- Programa de Pós-graduação em Ciências Biológicas, Comportamento e Biologia Animal da Universidade Federal de Juiz de Fora, Rua José Lourenço Kelmer, s/n - Campus Universitário, Bairro São Pedro, Juiz de Fora MG, 36036-900, Brazil
| | - Cláudia de Melo Dolinski
- Universidade Estadual do Norte Fluminense Darcy Ribeiro, Centro de Ciências e Tecnologias Agropecuárias, Campos dos Goytacazes, RJ, Brazil
| | - Rosane Nora Castro
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal Rural do Rio de Janeiro, BR 465, Km 7, 23890-000, Seropédica RJ, Brazil
| | | | - Jairo Pinheiro da Silva
- Departamento de Ciências Fisiológicas, Instituto de Biologia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brazil; Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, Brazil
| | - Isabella Vilhena Freire Martins
- Departamento de Medicina Veterinária, Centro de Ciências Agrárias, Universidade Federal do Espírito Santo - UFES, Alegre, ES, Brazil
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Lima MG, Tunholi-Alves VM, Gaudêncio FN, Martins FG, Castro RN, Thiengo SC, Garcia JS, Maldonado A, Pinheiro J. The influence of Angiostrongylus cantonensis (Nematoda, Metastrongylidae) infection on the aerobic metabolism of Biomphalaria straminea and Biomphalaria tenagophila (Mollusca, Gastropoda). Exp Parasitol 2016; 171:1-9. [DOI: 10.1016/j.exppara.2016.10.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 08/23/2016] [Accepted: 10/09/2016] [Indexed: 10/20/2022]
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Silva LD, Amaral VCS, Vinaud MC, Castro AM, Rezende HHA, Santos DB, Mello-Silva CC, Bezerra JCB. Changes in energetic metabolism of Biomphalaria glabrata (Mollusca, Planorbidae) in response to exogenous calcium. BRAZ J BIOL 2016; 77:304-311. [DOI: 10.1590/1519-6984.13315] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 12/21/2015] [Indexed: 11/22/2022] Open
Abstract
Abstract Calcium is considered an essential element for the metabolism of aquatic snail Biomphalaria glabrata (Say, 1818), intermediate host of Schistosoma mansoni Sambon, 1907 in Brazil, and represents a limiting factor to its distribution and adaptation to the environment. This study investigated the effect of different concentrations of exogenous CaCO3 on the energetic metabolism of B. glabrata for better understanding the physiological interference of chemical elements dissolved in the environment with the physiology of this species. Sixty-day-old snails were distributed into six groups, five exposed to different concentrations of CaCO3 (20, 40, 60, 80 and 100 mg/L) and a control group. The exposure to CaCO3 was assessed over time, with analysis of 15 snails of each group in the following intervals: 1, 14, 21 or 30 days for hemolymph extraction. Concentrations of calcium and glucose in the hemolymph were determined by commercial kits, and organic acids were extracted using an ion exchange column and analyzed by high-performance liquid chromatography. Concentration of calcium in the hemolymph showed no significant difference (p>0.05) from the control group and between the concentrations tested. Concentration of glucose decreased (p<0.05) in the treatments of exposure to 20 and 40 mg/L and increased when exposed to 80 and 100 mg/L CaCO3 compared to control and to other concentrations tested over 30 days. The organic acids pyruvate, oxaloacetate, citrate, succinate, fumarate, beta-hydroxybutyrate and lactate presented increased concentrations, while propionate and acetoacetate, decreased concentrations, when exposed to CaCO3 compared to control. Considering the influence of different periods of exposure to CaCO3, on the 14th day, there were stronger alterations in the metabolism of B. glabrata. In conclusion, exposure to CaCO3 reduced the concentration of glucose, which is metabolized into pyruvate, the final product of glycolysis, and also influenced the energetic metabolism pathways, indicating an aerobic or partially anaerobic functioning.
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Affiliation(s)
- L. D. Silva
- Universidade Estadual de Goiás, Brazil; Universidade Estadual de Goiás, Brazil
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dos Santos EGN, Costa VDS, Santos CP. Does the trematode Centrocestus formosanus affect the locomotory activity of the mollusc Melanoides tuberculatus? Parasit Vectors 2013; 6:92. [PMID: 23574763 PMCID: PMC3635958 DOI: 10.1186/1756-3305-6-92] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 03/25/2013] [Indexed: 11/24/2022] Open
Abstract
Background Melanoides tuberculatus (Müller, 1774) (Thiaridae), an introduced gastropod mollusc with a wide geographical distribution in the Neotropics, is the intermediate host of the trematode Centrocestus formosanus (Nishigori, 1924) (Heterophyidae). This parasite is considered to be pathogenic to humans. The aim of the present work was to evaluate the locomotory activity of uninfected M. tuberculatus compared with those naturally infected with C. formosanus. Findings The locomotory activity of each mollusc was recorded using an image analysis biomonitoring system, Videomex-V ®, to evaluate and quantify the parameters of ‘Stereotypic’ and ‘Resting time’. The Generalized Estimating Equation analysis of locomotory activity of M. tuberculatus infected with C. formosanus revealed significant differences compared with uninfected molluscs for the parameters ‘Stereotypic time’ and ‘Resting time’ with a reduction of movement. The variations in the values of the monitoring intervals recorded showed a significant difference for the infected molluscs in the case of Stereotypic time, with an irregular locomotory activity pattern, as compared to that of uninfected molluscs. The analysis of the standard length of all molluscs did not exhibit any correlation with locomotory activity, showing that C. formosanus is able to alter the locomotory activity of its snail host regardless of the standard length. Conclusions The trematode C. formosanus affects the locomotory activity of the mollusc M. tuberculatus by reducing its movement and causing it to exhibit an irregular pattern of activity, both of which are independent of the snail's standard length.
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Affiliation(s)
- Everton Gustavo Nunes dos Santos
- Laboratório de Avaliação e Promoção da Saúde Ambiental, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Av, Brasil, 4,365, Manguinhos, Rio de Janeiro 21040-360, Brazil
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Tunholi VM, Tunholi-Alves VM, Lustrino D, Castro RN, Sant'Ana LD, Garcia JS, Maldonado A, dos Santos MAJ, de Lurdes de Azevedo Rodrigues M, Pinheiro J. Aerobic to anaerobic transition in Biomphalaria glabrata (Say, 1818) infected with different miracidial doses of Echinostoma paraensei (Lie and Basch, 1967) by high-performance liquid chromatography. Exp Parasitol 2013; 133:403-10. [PMID: 23376444 DOI: 10.1016/j.exppara.2013.01.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 12/24/2012] [Accepted: 01/10/2013] [Indexed: 10/27/2022]
Abstract
The glucose content in the hemolymph and glycogen content in the digestive gland-gonad complex (DGG) and cephalopedal mass of Biomphalaria glabrata exposed to different parasite doses (5 and 50 miracidia) of Echinostoma paraensei as well as the activity of lactate dehydrogenase were evaluated. HPLC (high-performance liquid chromatography) analyses were also performed to determine the concentrations of four organic acids (oxalic, succinic, pyruvic and lactic) present in the hemolymph of infected and uninfected snails, to better understand the effect of infection on the host's energetic/oxidative metabolism. The snails were dissected 1-4 weeks after infection to collect the hemolymph and separate the tissues. There was alteration in the glycemia of the snails at both parasite doses, with a significant increase of glycemia from of the third week after infection in comparison to the control group. Changes were also observed in the lactate dehydrogenase activity, with increased activity as the infection progressed. In parallel, there was a decrease in the glycogen content in the storage tissues, with a markedly greater reduction in the digestive gland-gonad complex (larval development site) in comparison with the cephalopedal mass. Additionally, the infection by both miracidial doses resulted in an increase of oxalic and lactic acid levels, as well as in a decline of piruvic and succinic acid levels in B. glabrata, thus explaining the reduction of the oxidative decarboxylation rate in the tricarboxylic acid cycle and acceleration of the anaerobic degradation of carbohydrates in the snails, through lactic fermentation, which is essential to ensure energy supply and success of the infection.
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Affiliation(s)
- Victor Menezes Tunholi
- Curso de Pós-Graduação em Ciências Veterinárias, Departamento de Parasitologia Animal, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Km7, BR 465, Antiga estrada Rio-São Paulo, 23890-000 Seropédica, RJ, Brazil.
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Changes in the calcium metabolism of Biomphalaria glabrata experimentally infected with Angiostrongylus cantonensis. J Helminthol 2013; 88:160-5. [PMID: 23290340 DOI: 10.1017/s0022149x12000867] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Levels of calcium in the haemolymph and reserves in the shell of Biomphalaria glabrata experimentally infected by Angiostrongylus cantonensis were determined for the first time. At the same time, histochemical analyses of the digestive gland of infected and uninfected snails were performed to better understand the possible changes in metabolism of calcium in these organisms. After 1, 2 and 3 weeks of infection, the snails were dissected for collection of haemolymph and separation of tissues. The highest calcium concentrations in the haemolymph were found 2 weeks after infection, with a 39.61% increase in relation to the respective control group. However, there was a significant reduction in the concentration of this ion in the haemolymph of infected snails after 1 week of infection in relation to the uninfected specimens. In parallel, intense hypocalcification was shown in the shell of infected snails 1 and 2 weeks after infection, differing significantly in relation to the respective control groups. Morphological changes in the digestive gland of infected snails were also observed, confirming the role of this ion as an important element in the parasite encapsulation process.
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