Morphological and molecular studies of the taxa of the Biomphalaria tenagophila complex were conducted on specimens from Argentina, Brazil, Paraguay, Peru, Uruguay and Venezuela. The morphological analysis included aspects of the shell, mantle, excretory organs and reproductive system. DNA barcode, ABGD and mPTP were used to group specimens into Operational Taxonomic Units (OTUs) and in attempt to solve species boundary delimitation problems within the Biomphalaria tenagophila complex. Population analyzes were also performed based on the cytochrome C oxidase I (COI) and 16S genes. The seminal vesicle, extension of the oviduct in relation to the distal ovispermioduct, vaginal pouch, aspect of the penial complex, aspect of the prepuce diaphragm, diaphragm papilla, extension of the penial sheath in relation to the prepuce and prepuce dimensions are essential for the determination of the taxa of the Biomphalaria tenagophila complex. An updated molecular phylogeny for Biomphalaria based on COI, 16S and ITS2 genes is presented and recover Biomphalaria tenagophila complex as monophyletic. The morphological, population and phylogenetic data observed in an integrated way define taxonomic questions, such as the proposition of a new status for B. guaibensis, which integrates into the Biomphalaria tenagophila complex.http://www.zoobank.org/urn:lsid:zoobank.org:pub:478145E5-D4A5-4128-AA80-DB6A69164E1E
Histological studies were carried out with 49 specimens; 18 Biomphalaria tenagophila guaibensis, 19 B. t. tenagophila and 12 B. occidentalis, collected in 10 municipalities in the states of São Paulo and Rio Grande do Sul, Brazil. The study considered histological aspects of the vagina, vaginal pouch and penial complex. In this study, we describe, for the first time, the histological features of the vagina, vaginal pouch and penial complex of B. t. tenagophila, B. t. guaibensis and B. occidentalis. The lining epithelial tissue and muscular tissue of the vagina, vaginal pouch and penial complex show a similar pattern in B. t. tenagophila, B. t. guaibensis and B. occidentalis, except for the intermediate muscular layer of the prepuce, which distinguishes B. t. guaibensis from the other two taxa. Histological studies on the penial complex and vagina region of other Biomphalaria species are necessary to confirm the taxonomic value of these two regions, in order to contribute to the group’s systematics.
The present study identified locations with the presence of Biomphalaria and the areas at risk for Schistosoma mansoni, the etiological agent of schistosomiasis, in the Metropolitan Region of São Paulo (MRSP), located in the Alto Tietê Basin (ATB), São Paulo, Brazil. The study area comprises floodplains of the Tietê River from its source, in Salesópolis, to Rasgão Dam, in Pirapora do Bom Jesus, covering 39 municipalities. Data from the planorbidic chart of the malacology laboratory of the Endemic Control Superintendence for 2008-2016 were used, as well as data from the notification forms of cases of human schistosomiasis in 2006-2015 made available by the Epidemiological Surveillance Groups of Mogi das Cruzes and Osasco, and by the Health and Surveillance Coordination of São Paulo. These data were used to generate maps of the distribution of Biomphalaria, of the scanning analysis, of the Gi statistics of the autochthonous and imported schistosomiasis cases, and of the flow of cases imported from other Brazilian states and municipalities in the state of São Paulo to the study area. A total of 21,618 specimens of the genus Biomphalaria were captured and six species were identified. Biomphalaria tenagophila was the predominant species in the region and of greatest epidemiological importance as it is the main responsible for the transmission of the disease in the state of São Paulo. A total of 3,623 cases of schistosomiasis were reported in the study area, and São Paulo and Guarulhos were the municipalities with the highest number of autochthonous and imported cases during the study period. The imported cases originated from 21 Brazilian states plus the Federal District and from 51 municipalities in São Paulo state located outside the study area. Autochthonous clusters with high risk for the occurrence of schistosomiasis were identified in the municipalities of São Paulo, Guarulhos, Santa Isabel/Mogi das Cruzes/Arujá, and Cotia/Itapevi. Clusters of imported cases were also identified in Itaquaquecetuba, at the border of Cotia/Itapevi and Suzano/São Paulo/Mogi das Cruzes. The presence of B. tenagophila in the ATB and in the clusters of autochthonous cases herein identified, although not carrying schistosome larvae, represents a risk for the transmission of infectious agents. The human population in the MRSP mainly occupies the lowlands of the Tietê River, which are locations with poor coverage of basic sanitation. Therefore, measures for the control and surveillance of schistosomiasis such as educational actions, improvements in basic sanitation, and the malacological and epidemiological monitoring of these areas are extremely important.
Abstract: Morphological and molecular identifications were carried out for Biomphalaria occidentalis, Biomphalaria oligoza, Biomphalaria peregrina, Biomphalaria schrammi, Biomphalaria straminea and Biomphalaria tenagophila collected from 55 sites located along the upper basin of Tietê River in the Southeast Region of Brazil. Morphological analysis considered aspects of the shell, mantle, excretory organs and reproductive system. Molecular data included 122 sequences of Cytochrome C Oxidase I gene (COI). Our results showed that some shell characters, as well as other characters related to the mantle and the reproductive system, are fundamental for the identification of the six Biomphalaria species included in this study. The use of DNA barcoding together with morphological taxonomy generated more reliable results, proving to be a very useful approach, even for malacological surveillance services.
The radular apparatus of Biomphalaria occidentalis Paraense, 1981, Biomphalaria oligoza Paraense, 1971, Biomphalaria peregrina (d'Orbigny, 1835), Biomphalaria schrammi (Crosse, 1864) and Biomphalaria tenagophila (d'Orbigny, 1835) from the Metropolitan Region of Sao Paulo, Brazil were analyzed from Scanning Electron Microscope (SEM) micrographs. The data support the usage of characters of central, lateral and intermediate teeth in the species identification of Biomphalaria. The use of SEM provided additional quantitative and structural details to radula descriptions, which are extremely important for elucidating the taxonomy of Biomphalaria species.
DNA barcoding and morphological characters were used to identify adult snails belonging to the genus Biomphalaria from 17 municipalities in the state of São Paulo, Brazil. The DNA barcode analysis also included twenty-nine sequences retrieved from GenBank. The final data set of 104 sequences of the mitochondrial cytochrome oxidase I (COI) gene was analyzed for K2P intraspecific and interspecific divergences, through tree-reconstruction methods (Neighbor-Joining, Maximum Likelihood and Bayesian inference), and by applying different models (ABGD, bPTP, GMYC) to partition the sequences according to the pattern of genetic variation. Twenty-seven morphological parameters of internal organs were used to identify specimens. The molecular taxonomy of Biomphalaria agreed with the morphological identification of specimens from the same collection locality. DNA barcoding may therefore be a useful supporting tool for identifying Biomphalaria snails in areas at risk for schistosomiasis.
A protocol combining acute toxicity, developmental toxicity and mutagenicity analysis in freshwater snail Biomphalaria glabrata for application in ecotoxicological studies is described. For acute toxicity testing, LC50 and EC50 values were determined; dominant lethal mutations induction was the endpoint for mutagenicity analysis. Reference toxicant potassium dichromate (K2Cr2O7) was used to characterize B. glabrata sensitivity for toxicity and cyclophosphamide to mutagenicity testing purposes. Compared to other relevant freshwater species, B. glabrata showed high sensitivity: the lowest EC50 value was obtained with embryos at veliger stage (5.76mg/L). To assess the model applicability for environmental studies, influent and effluent water samples from a wastewater treatment plant were evaluated. Gastropod sensitivity was assessed in comparison to the standardized bioassay with Daphnia similis exposed to the same water samples. Sampling sites identified as toxic to daphnids were also detected by snails, showing a qualitatively similar sensitivity suggesting that B. glabrata is a suitable test species for freshwater monitoring. Holding procedures and protocols implemented for toxicity and developmental bioassays showed to be in compliance with international standards for intra-laboratory precision. Thereby, we are proposing this system for application in ecotoxicological studies.
El trabajo identifica larvas de trematodos encontradas parasitando moluscos dulceacuicolas en municipios de la Region Metropolitana de Sao Paulo, Estado de Sao Paulo, Brasil. La investigacion malacologica se realizo en el periodo de noviembre de 2008 a octubre de 2011. Los moluscos fueron identificados y sometidos a examen parasitario. Se identificaron moluscos de las familias Ampullariidae, Ancylidae, Lymnaeidae, Physidae, Planorbidae y Thiaridae. Se observaron 21 formas larvales de trematodos parasitando a los moluscos. De estas, siete no fueron encontradas en la literatura consultada: cercaria I, echinocercaria I, echinocercaria IV, strigeocercaria I, strigeocercaria II, strigeocercaria III y strigeocercaria IV. La presencia de moluscos dulceacuicolas, huespedes intermediarios de trematodos, puede representar riesgo de transmision de agentes infectantes causadores de enfermedades de interes medico y veterinario en municipios de la Region Metropolitana de Sao Paulo, siendo el monitoreo de estas areas extremamente importante
BACKGROUND: Schistosomiasis is one of the most significant diseases in tropical countries and affects almost 200 million people worldwide. The application of molluscicides to eliminate the parasite's intermediate host, Biomphalaria glabrata, from infected water supplies is one strategy currently being used to control the disease. Previous studies have shown a potent molluscicidal activity of crude extracts from Piper species, with extracts from Piper tuberculatum being among the most active. METHODS AND FINDINGS: The molluscicidal activity of P. tuberculatum was monitored on methanolic extracts from different organs (roots, leaves, fruit and stems). The compounds responsible for the molluscicidal activity were identified using (1)H NMR and ESIMS data and multivariate analyses, including principal component analysis and partial least squares. These results indicated that the high molluscicidal activity displayed by root extracts (LC50 20.28 µg/ml) was due to the presence of piplartine, a well-known biologically-active amide. Piplartine was isolated from P. tuberculatum root extracts, and the molluscicidal activity of this compound on adults and embryos of B. glabrata was determined. The compound displayed potent activity against all developmental stages of B. glabrata. Next, the environmental toxicity of piplartine was evaluated using the microcrustacean Daphnia similis (LC50 7.32 µg/ml) and the fish Danio rerio (1.69 µg/ml). The toxicity to these organisms was less compared with the toxicity of niclosamide, a commercial molluscicide. CONCLUSIONS: The development of a new, natural molluscicide is highly desirable, particularly because the commercially available molluscicide niclosamide is highly toxic to some organisms in the environment (LC50 0.25 µg/ml to D. similis and 0.12 µg/ml to D. rerio). Thus, piplartine is a potential candidate for a natural molluscicide that has been extracted from a tropical plant species and showed less toxic to environment.
We registered the malacological and helminthological fauna in water collections in the county of Santo Andre, espe cially the Billings Reservoir, auxiliary in the identification of outbreaks of parasitic diseases in the county, special of schistosomiasis. The snails were collected in water collections like artificial pool, lake, stream and reservoir in the period from April to May 2009. The freshwater mollusks were identified and submitted to a parasitological exam to verify the presence of trematodes larvae. Eight species and one genus of mollusks were found: Biomphalaria tenagophila, Drepanotrema depressissimum, Lymnaea columella, Lymnaea viatrix, Melanoides tuberculatus, Omalonyx matheroni, Physa acuta, Physa marmorata e Pomacea sp. The geographic distribution of L. viatrix is expanded in the state of Sao Paulo, which until now was only known in the states of Minas Gerais, Rio de Janeiro and Rio Grande do Sul. Specimens of B. tenagophila were also found infected by larvae of trematodes, identified as Cercaria caratinguensis, Cercaria granulifera and echinocercaria I and of L. columella infected by Ornatae cercaria. The presence of B. tenagophila, L. columella, L. viatrix and M. tuberculatus in water collections in the county of Santo Andre should be viewed with some caution, because they are intermediate hosts of trematode that affect animal.and human population. Santo Andre is considered a potential risk for parasitic diseases for presenting records of intermediate helminthes host mollusks.
B. tenagophila is the nominal member of a species complex of freshwater snails distributed widespread in the neotropical region (Figure 2).B. tenagophila is the main host of S. mansoni in the southeastern Brazil.(Paraense & Corrêa,1978).As currently defined,the B. tenagophila complex includes a sub-species B. tenagophila guaibensis (Paraense,1984) and a species B. occidentalis (Paraense,1981).
The currently known distribution range of Achatina fulica Bowdich, 1822, in the state of São Paulo, Brazil, is presented. The record of A. fulica naturally infested with Aelurostrongylus abstrusus larvae (Railliet, 1898) (Nematoda: Metastrongylidae) can be found in the city of Guaratinguetá. It was found A. fulica with Metastrongylidae larvae without known medical and veterinary importance in the cities of Carapicuíba, Embu-Guaçu, Itapevi, São Caetano do Sul, São Paulo and Taboão da Serra.
Schistosomiasis is a tropical disease caused by Schistosoma and occurs in 54 countries, mainly in South America, the Caribbean region, Africa and the eastern Mediterranean. Currently, 5 to 6 million Brazilian people are infected and 30,000 are under infection risk. Typical of poor regions, this disease is associated with the lack of basic sanitation and very frequently to the use of contaminated water in agriculture, housework and leisure. One of the most efficient methods of controlling the disease is application of molluscicides to eliminate or to reduce the population of the intermediate host snail Biomphalaria glabrata. Studies on molluscicidal activity of plant extracts have been stimulated by issues such as environmental preservation, high cost and recurrent resistance of snails to synthetic molluscicides. The aim of this study was to determine the molluscicide action of extracts from Piperaceae species on adult and embryonic stages of B. glabrata. Fifteen extracts from 13 Piperaceae species were obtained from stems, leaves and roots. Toxicity of extracts was evaluated against snails at two different concentrations (500 and 100 ppm) and those causing 100% mortality at 100 ppm concentration were selected to obtain the LC90 (lethal concentration of 90% mortality). Piper aduncum, P. crassinervium, P. cuyabanum, P. diospyrifolium and P. hostmannianum gave 100% mortality of adult snails at concentrations ranging from 10 to 60 ppm. These extracts were also assayed on embryonic stages of B. glabrata and those from P. cuyabanum and P. hostmannianum showed 100% ovicidal action at 20 ppm.
To observe the effects of the parasitic infection on the biology of B. tenagophila, field and laboratory populations of this mollusk from Itariri, in Vale do Ribeira, Brazil, were experimentally infected. Each mollusk received 10 miracidia of Schistosoma mansoni (SJ lineage) and was observed throughout the parasite's development. The biological variables were compared according to the criteria "group" and "infectious phase". The main damage caused by the parasitic infection manifested itself in reproduction, longevity and lesions on the shell of the mollusks in the patent phase. An infection rate of 58.8% was observed. Microanatomical study of the mollusk's digestive gland and ovotestis revealed the presence of evolving larval forms and cercariae. It was concluded that the effects of the parasitic infection on both populations were moderate, despite the low survival rate of the infected mollusks, the damage did not prevent either reproduction or the elimination of cercariae, which continued for a long time.
A new species is proposed based on material collected in the states of Minas Gerais, Sao Paulo, Santa Catarina, and Rio Grande do Sul, Brazil. The morphology, radula, and jaw are described and illustrated. The new species is compared to Belocaulus angustipes, the only species of the genus Currently considered valid. The main differences are found in the penis. The new species has small projections, similar to tubercles, on the anterior region of the glans, which can be scattered or arranged in two, three or more longitudinal rows. The terminal extremity of the glans has digitiform margin. The penis base is short and poorly defined. The accessory gland is completely immersed in the tegument. The description of the new species extends the distribution range of Belocaulus for the states of Minas Gerais and Sao Paulo, Brazil.
A total of 909 Biomphalaria tenagophila were collected from two areas in Guarulhos (Metropolitan area of São Paulo, São Paulo State, Brazil) to assess larval trematode infections. In all collection sites, only this species was found and 183 (20.13%) harbored trematode infections. In these collections, four morphologically distinguishable types of cercariae were identified by confocal microscopy. Xiphidiocercaria (Cercaria lutzi) was the most common type of cercaria recovered, contributing 76.5% of all infections. Schistosoma mansoni cercariae were recovered and comprised the total of 13.11%. Strigea cercaria (Cercaria caratinguensis) and Brevifurcate pharyngeate Clinostomatoide cercaria (Cercaria ocellifera) contributed 8.33% and 2.22% of all infections, respectively. Double infections (S. mansoni and C. lutzi) were found in twelve snails, contributing 6.55% of all infections. In all sites studied, small vertebrates were found in snail habitats and it was observed human contact with the water. The presence of trematode infected snails in large cities has public health implications. It further provides a starting point for some comprehensive studies on snail-related aspects of transmission and biology of trematode of medical and veterinary importance.