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1.
Eur J Protistol ; 78: 125767, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33639326

RESUMO

The peritrich genus Epistylis is speciose, however many species lack complete morphological description based on modern criteria and/or molecular data. In the present study, one new species, i.e., E. foissneri n. sp., and two morphologically similar species, i.e., E. hentscheli Kahl, 1935 and E. vaginula Stokes, 1884, collected from freshwater habitats in China, were studied. Epistylis foissneri n. sp. is characterized by its extremely slender zooids encased in a gelatinous sheath, symmetrically dichotomously branched stalk, trochal band located at mid-body, contractile vacuole located on dorsal wall of infundibulum, infundibular polykinety 3 (P3) composed of three equal-length rows that terminate above infundibular polykinety 1 (P1), 105-110 silverlines between the peristome and the trochal band, and about 110 silverlines between the trochal band and the scopula. Epistylis hentscheli is characterized by its asymmetric pyriform zooids (average length ca. 160 µm in vivo), dichotomously branched stalk with transverse striations on the surface of the upper portion, P3 three-rowed and terminating slightly above P1, 60-75 silverlines between the peristome and the trochal band, and 55-90 silverlines between the trochal band and the scopula. Epistylis vaginula is characterized by its elongated body shape (about 100 µm in length in vivo), dichotomously branched and smooth stalk, P3 three-rowed and terminating above P1, 80-100 silverlines between the peristome and the trochal band, and 45-80 silverlines between the trochal band and the scopula. The small subunit ribosomal DNA gene (SSU rDNA) of these three species was sequenced and supported the validity of each. Phylogenetic analyses based on SSU rDNA sequence data revealed that all three morphospecies group with other congeners within the major clade of Epistylis.


Assuntos
Água Doce , Oligoimenóforos/classificação , Filogenia , China , DNA de Protozoário/genética , Água Doce/parasitologia , Oligoimenóforos/citologia , Oligoimenóforos/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
2.
Parasitol Res ; 120(3): 949-962, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33426572

RESUMO

Foodborne zoonotic trematode (FZT) infections are common neglected tropical diseases in Southeast Asia. Their complicated life cycles involve freshwater snails as intermediate hosts. A cross-sectional study was conducted in Yen Bai and Thanh Hoa provinces in North and Central Vietnam, to investigate the diversity of cercariae of potential FZT and to construct the phylogenetic relationship of trematode cercariae based on the Internal Transcribed Spacer 2 (ITS2) region. Among 17 snail species collected from various habitats, 13 were infected by 10 cercarial groups among which parapleurolophocercous, pleurolophocercous, and echinostome cercariae were of zoonotic importance. The monophyletic tree separated cercarial sequences into different groups following the description of the cercariae families in which Haplorchidae, Opisthorchiidae, Echinochasmidae, and Echinostomatidae are important families of FZT. The overall prevalence was different among snail species and habitats and showed a seasonal trend. Parapleurolophocercous and echinostome cercariae emerged as the most common cercariae in snails in Yen Bai, while monostome, echinostome, and megalura cercariae were most common in Thanh Hoa. Using a molecular approach, we identified Parafossarulus striatulus as the first intermediate snail host of Clonorchis sinensis in Thac Ba Lake. Melanoides tuberculata and Bithynia fuchsiana were we identified preferred intermediate snail hosts of a diverse range of trematode species including intestinal flukes (i.e., Haplorchis pumilio and Echinochasmus japonicus) in Yen Bai and Thanh Hoa, respectively.


Assuntos
Doenças Transmitidas por Alimentos/parasitologia , Caramujos/parasitologia , Trematódeos/isolamento & purificação , Infecções por Trematódeos/parasitologia , Zoonoses/parasitologia , Animais , Cercárias/classificação , Cercárias/genética , Cercárias/crescimento & desenvolvimento , Cercárias/isolamento & purificação , Estudos Transversais , Doenças Transmitidas por Alimentos/epidemiologia , Água Doce/parasitologia , Filogenia , Prevalência , Caramujos/classificação , Trematódeos/classificação , Trematódeos/genética , Trematódeos/crescimento & desenvolvimento , Infecções por Trematódeos/epidemiologia , Vietnã/epidemiologia , Zoonoses/epidemiologia , Zoonoses/transmissão
3.
Parasitol Res ; 120(3): 831-848, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33409628

RESUMO

The genus Gyrodactylus von Nordmann, 1832 represents one of the most diverse and widespread taxa within Monogenea, with approximately 500 species described worldwide. Thirty-three species of Gyrodactylus have been recorded in Mexico, and in the last two decades, at least 26 new species have been described mainly from freshwater fish families such as poeciliids, goodeids, profundulids, characids, and cichlids. In this study, we describe two new species of Gyrodactylus infecting freshwater cyprinids based on morphological and molecular characteristics. Gyrodactylus ticuchi n. sp. and Gyrodactylus tobala n. sp. were recovered from Notropis moralesi de Buen and N. imeldae Cortés, respectively, captured in five localities from the State of Oaxaca, Mexico. The new species differ slightly from their congeners in the morphology of the haptoral hard parts and the male copulatory organ. Sequences of the Internal Transcribed Spacers rDNA (ITS1-5.8S-ITS2), cytochrome oxidase subunit I (cox1), and the D2 + D3 domains of the large subunit (28S rDNA) were obtained from multiple specimens and analyzed using Maximum Likelihood (ML) and Bayesian Inference (BI). Phylogenetic hypotheses using ITS rDNA, cox1, and 28S rDNA genes recovered two new species of Gyrodactylus from N. moralesi and N. imeldae; we briefly discuss their phylogenetic relationship with other congeners. These gyrodactylids represent the first species described in species of Notropis from southern Mexico, the cyprinids exhibiting the southernmost distribution in the New World.


Assuntos
Doenças dos Peixes/parasitologia , Trematódeos/fisiologia , Infecções por Trematódeos/veterinária , Animais , Teorema de Bayes , Characidae/parasitologia , Ciclídeos/parasitologia , Cyprinidae/parasitologia , DNA Ribossômico/genética , Feminino , Água Doce/parasitologia , Masculino , México , Filogenia , Especificidade da Espécie , Trematódeos/classificação , Trematódeos/genética , Trematódeos/isolamento & purificação , Infecções por Trematódeos/parasitologia
4.
J Parasitol ; 107(1): 1-15, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33429430

RESUMO

The lecanicephalidean cestodes parasitizing the spiral intestine of the endangered giant freshwater whipray, Urogymnus polylepis (Bleeker), are investigated for the first time. Eight host specimens were collected between 2002 and 2008 at 2 collecting sites off the eastern coast of Borneo: 6 from the Kinabatangan River (Malaysia) and 2 from a fish market in Tarakan (Indonesia). Two of these individuals were found to be infected with a total of 3 new species of TetragonocephalumShipley and Hornell, 1905. Tetragonocephalum georgei n. sp. and Tetragonocephalum opimum n. sp. were recovered from a host specimen from the Kinabatangan River, and Tetragonocephalum levicorpum n. sp. was found parasitizing a host specimen purchased at a fish market in Tarakan. Specimens of each of the new species were prepared for light microscopy; specimens of 2 of the new species were prepared for scanning electron microscopy, and histological sections were prepared for 1 of the new species. The 3 new species are distinct from the 9 valid species of Tetragonocephalum and the 1 species inquirendum based on, for example, total length, number of proglottids and testes, and size of the scolex and acetabula. Tetragonocephalum georgei n. sp. and T. levicorpum n. sp. are unusual among their congeners in that they are euapolytic (i.e., gravid proglottids were not observed) rather than apolytic. They differ from one another in scolex and acetabula size. Tetragonocephalum opimum n. sp. is unusual among its congeners in its possession of vitelline follicles arranged in 2, rather than 3, regions in the proglottid. These new species increase the total number of valid species of Tetragonocephalum to 12 and the total number of known cestodes from U. polylepis to 13 species across 6 genera in 4 orders. This is the first account of lecanicephalideans reported from freshwater. The taxonomic status of each of the 32 nominal taxa historically associated with Tetragonocephalum is re-assessed. Type host identities of all valid species are revised and discussed in light of recent taxonomic efforts in the Dasyatidae Jordan and Gilbert.


Assuntos
Cestoides/isolamento & purificação , Infecções por Cestoides/veterinária , Doenças dos Peixes/parasitologia , Água Doce/parasitologia , Rajidae/parasitologia , Animais , Bornéu/epidemiologia , Cestoides/classificação , Cestoides/ultraestrutura , Infecções por Cestoides/epidemiologia , Infecções por Cestoides/parasitologia , Feminino , Doenças dos Peixes/epidemiologia , Indonésia/epidemiologia , Intestinos/parasitologia , Malásia/epidemiologia , Masculino , Microscopia Eletrônica de Varredura , Rios/parasitologia
5.
Korean J Parasitol ; 58(5): 499-511, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33202502

RESUMO

Echinostome metacercariae were investigated in freshwater snails from 26 districts in 7 provinces of upper northern Thailand. The species identification was carried out based on the morphologies of the metacercariae and adult flukes harvested from experimental hamsters, and on nucleotide sequences of internal transcribed spacer 2 (ITS2) and nicotinamide adenine dinucleotide dehydrogenase subunit 1 (nad1) genes. Twenty-four out of 26 districts were found to be infected with echinostome metacercariae in freshwater snails with the prevalence of 40.4%. The metacercariae were found in all 6 species of snails, including Filopaludina martensi martensi (21.9%), Filopaludina doliaris (50.8%), F. sumatrensis polygramma (61.3%), Bithynia siamensis siamensis (14.5%), Bithynia pulchella (38.0%), and Anenthome helena (4.9%). The echinostome metacercariae found in these snails were identified as Echinostoma revolutum (37-collar-spined) and Echinostoma macrorchis (45-collar-spined) morphologically and molecularly. The 2-week-old adult flukes of E. revolutum revealed unique features of the cirrus sac extending to middle of the ventral sucker and smooth testes. E. macrorchis adults revealed the cirrus sac close to the right lateral margin of the ventral sucker and 2 large and elliptical testes with slight indentations and pointed posterior end of the posterior testis. The ITS2 and nad1 sequences confirmed the species identification of E. revolutum, and the sequences of E. macrorchis have been deposited for the first time in Gen-Bank. The presence of the life cycle of E. macrorchis is a new record in Thailand and the snail F. doliaris as their second intermediate host seems to be new among the literature.


Assuntos
Cricetinae/parasitologia , Echinostoma/anatomia & histologia , Echinostoma/isolamento & purificação , Água Doce/parasitologia , Metacercárias/anatomia & histologia , Metacercárias/isolamento & purificação , Doenças Parasitárias em Animais/parasitologia , Caramujos/parasitologia , Animais , Sequência de Bases , Echinostoma/genética , Genes de Helmintos/genética , Metacercárias/genética , Prevalência , Tailândia/epidemiologia
6.
Appl Environ Microbiol ; 86(23)2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-32978132

RESUMO

This study investigated the use of biofilms to monitor Cryptosporidium in water. Benthic rock and submersible slide biofilms were sampled upstream and downstream of point sources in a suburban watershed in southeastern Pennsylvania. More oocysts were detected in biofilms scraped from rocks downstream than upstream of a wastewater treatment plant (WWTP) (19 versus 5, respectively; n = 1). Although not statistically significant, Cryptosporidium oocysts were detected more frequently, and in greater numbers, in biofilms grown on slides downstream than upstream of this same WWTP (83.3% positive samples [n = 12] versus 45.5% positive samples [n = 11], respectively; P = 0.0567). Similarly, Cryptosporidium oocysts were detected more frequently, and in greater numbers, in rock biofilms collected downstream than upstream of a stormwater outfall impacted by defective sewer laterals (50% positive samples downstream and 17% positive samples upstream; n = 6; P = 0.2207). While oocyst detection data obtained by slide biofilms versus filters did not necessarily agree on a given day, there was no seasonal difference in the frequency of oocyst detection (P > 0.05) or numbers of oocysts detected (P > 0.05) whether the water was monitored by filtration or slide biofilm sampling. Within any given season, there was no difference in the frequency of oocyst detection (P > 0.05) or the numbers of oocysts detected (P > 0.05) whether the water was monitored by filtration or slide biofilm sampling. These data show that oocyst detection in biofilms is comparable to oocyst detection in filtered water samples. Biofilm sampling offers significant cost savings compared to the filtration-based EPA Method 1623.1 and could be used to identify watershed locations at potential risk for increased oocyst loads.IMPORTANCE Monitoring Cryptosporidium occurrence in watersheds that provide drinking water is necessary to determine where limited resources should most effectively be directed to protect consumers from waterborne exposure to pathogenic oocysts. Biofilms are a useful tool to monitor complex watersheds and identify point sources of Cryptosporidium oocyst contamination that need to be managed to protect public health. Compared to EPA Method 1623.1, the cost benefit of using biofilms to monitor for Cryptosporidium contamination will enable utilities to sample water supplies more frequently, and at more locations, than is currently possible given limited operating budgets. Biofilm sampling could be used to identify high-risk regions within a large, complex watershed and the associated water treatment plants at potential risk for increased oocyst loads in the water supply; this information could then be used to select the locations within the watershed where the more expensive EPA Method 1623.1 is warranted.


Assuntos
Biofilmes , Cryptosporidium/isolamento & purificação , Água Doce/parasitologia , Cryptosporidium/fisiologia , Água Potável/parasitologia , Oocistos/isolamento & purificação , Pennsylvania , Abastecimento de Água
7.
Parasitol Res ; 119(10): 3359-3368, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32893331

RESUMO

Acanthocephalans are multi-host endoparasites, many of which use freshwater amphipods as intermediate hosts for their larval stages (e.g., cystacanths) while adults live in the intestines of vertebrates, including waterfowl. In central Alberta, Canada, several co-occurring species of the acanthocephalan genus Polymorphus use the amphipod Gammarus lacustris Sars, 1863 as an intermediate host. We applied DNA barcoding and morphometric analysis to differentiate cystacanth larvae from G. lacustris sampled from 17 Albertan water bodies. We slide-mounted specimens and measured morphological traits relating to proboscis hooks. We sequenced the standard DNA barcoding region of the mitochondrial cytochrome c oxidase subunit I gene (COI). Morphometric analysis suggested that the acanthocephalans we collected belonged to four morphologically different groups that keyed to Polymorphus contortus (Bremser, 1821) Travassos, 1926; P. marilis Van Cleave, 1939; P. paradoxus Connel et Corner, 1957; and P. strumosoides (Lundström, 1942) Amin, 2013. Our Bayesian tree based on COI sequences generally corroborated the morphological results and supported that the specimens assigned to P. cf. contortus and P. cf. strumosoides belong to two distinct species. In contrast, the Bayesian tree showed that specimens of P. cf. marilis were nested as a cluster within the P. cf. paradoxus clade. Similarly, small pairwise genetic distance (< 2%) between specimens identified as P. cf. contortus and P. cf. strumosoides suggests that they are conspecific. Future studies should use morphology and sequence data from adult acanthocephalans to assess the taxonomic identity of the cystacanth-based Polymorphus taxa. Our study is the first to provide genetic information for the four Polymorphus taxa and emphasizes the importance of applying multiple approaches to differentiate parasite species.


Assuntos
Acantocéfalos/classificação , Acantocéfalos/anatomia & histologia , Acantocéfalos/genética , Alberta , Anfípodes/parasitologia , Animais , Código de Barras de DNA Taxonômico , Água Doce/parasitologia , Genes de Helmintos/genética , Genes Mitocondriais/genética , Larva/anatomia & histologia , Larva/classificação , Larva/genética , Especificidade da Espécie
8.
Parasitol Res ; 119(11): 3755-3761, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32918603

RESUMO

Free-living amoeba (FLA) research in the Philippines is still in its infancy but has, by far, demonstrated the presence of potentially pathogenic species. Acanthamoeba may cause sight-threatening and central nervous system infections to humans, yet its epidemiologic distribution from local environmental sources is yet to be defined. The present study aimed to provide a baseline epidemiologic distribution of Acanthamoeba spp. in freshwater systems in the Philippines and establish potential pathogenicity of isolates through thermo-tolerance assay. A total of 63 water samples were collected from 13 freshwater systems all over the Philippine archipelago. The low-volume (50 ml) water samples were processed and cultured on non-nutrient agar lawned with Escherichia coli and observed for amoebic growth using light microscopy. Amoebic culture demonstrated 14.28% (9/63) positivity while further molecular testing of culture-positive plates using Acanthamoeba-specific primers demonstrated 100% (9/9) confirmation of Acanthamoeba species. Genotyping of Acanthamoeba isolates revealed T1, T3, T4, T5, T7, T11, and T15 genotypes. Thermo-tolerance assay demonstrated that T5 and T7 genotypes were potentially pathogenic strains. The evidence of environmental distribution of Acanthamoeba spp. in the freshwater systems in the Philippines and thermo-tolerance profile of isolates are significant aspects of amoeba study in public health and calls for initiatives in the dissemination of relevant information and the expansion of knowledge, awareness, and policies on pathogenic waterborne amoeba to mitigate, prevent, detect, and report cases of human infections.


Assuntos
Acanthamoeba/isolamento & purificação , Acanthamoeba/fisiologia , Água Doce/parasitologia , Acanthamoeba/genética , Acanthamoeba/crescimento & desenvolvimento , DNA de Protozoário/genética , Monitoramento Ambiental , Genótipo , Humanos , Filipinas , Termotolerância
9.
Appl Environ Microbiol ; 86(23)2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-32948525

RESUMO

Cyclospora cayetanensis is a protozoan parasite that causes foodborne and waterborne diarrheal illness outbreaks worldwide. Most of these outbreaks are associated with the consumption of fresh produce. Sensitive and specific methods to detect C. cayetanensis in agricultural water are needed to identify the parasite in agricultural water used to irrigate crops that have been implicated in outbreaks. In this study, a method to detect C. cayetanensis in water by combining dead-end ultrafiltration (DEUF) with sensitive and specific molecular detection was developed and evaluated. Triplicates of 10-liter agricultural water samples were seeded with 200, 100, 25, 12, and 6 C. cayetanensis oocysts. Surface water samples were also collected in the Mid-Atlantic region. All water samples were processed by DEUF and backflushed from the ultrafilters. DNA was extracted from concentrated samples and analyzed by quantitative PCR (qPCR) targeting the C. cayetanensis 18S rRNA gene. All water samples seeded with 12, 25, 100, and 200 oocysts were positive, and all unseeded samples were negative. Samples seeded with 6 oocysts had a detection rate of 66.6% (8/12). The method was also able to detect C. cayetanensis isolates in surface water samples from different locations of the Chesapeake and Ohio Canal (C&O Canal) in Maryland. This approach could consistently detect C. cayetanensis DNA in 10-liter agricultural water samples contaminated with low levels of oocysts, equivalent to the levels that may be found in naturally incurred environmental water sources. Our data demonstrate the robustness of the method as a useful tool to detect C. cayetanensis from environmental sources.IMPORTANCE Cyclospora cayetanensis is a protozoan parasite that causes foodborne and waterborne outbreaks of diarrheal illness worldwide. These foodborne outbreaks associated with the consumption of fresh produce and agricultural water could play a role in the contamination process. In this study, a method to detect C. cayetanensis in agricultural water by combining a robust filtration system with sensitive and specific molecular detection was developed and validated by the FDA. The results showed that this approach could consistently detect low levels of C. cayetanensis contamination in 10 liters of agricultural water, corresponding to the levels that may be found in naturally occurring environmental water sources. The method was also able to detect C. cayetanensis in surface water samples from a specific location in the Mid-Atlantic region. Our data demonstrate the robustness of the method to detect C. cayetanensis in agricultural water samples, which could be very useful to identify environmental sources of contamination.


Assuntos
Agricultura , Cyclospora/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Ultrafiltração/métodos , Águas Residuárias/parasitologia , Água Doce/parasitologia , Maryland , Oocistos
10.
PLoS Negl Trop Dis ; 14(9): e0008647, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32877398

RESUMO

The transmission of trachoma, caused by repeat infections with Chlamydia trachomatis, and many enteropathogens are linked to water quantity. We hypothesized that children living further from a water source would have higher exposure to C. trachomatis and enteric pathogens as determined by antibody responses. We used a multiplex bead assay to measure IgG antibody responses to C. trachomatis, Giardia intestinalis, Cryptosporidium parvum, Entamoeba histolytica, Salmonella enterica, Campylobacter jejuni, enterotoxigenic Escherichia coli (ETEC) and Vibrio cholerae in eluted dried blood spots collected from 2267 children ages 0-9 years in 40 communities in rural Ethiopia in 2016. Linear distance from the child's house to the nearest water source was calculated. We derived seroprevalence cutoffs using external negative control populations, if available, or by fitting finite mixture models. We used targeted maximum likelihood estimation to estimate differences in seroprevalence according to distance to the nearest water source. Seroprevalence among 1-9-year-olds was 43% for C. trachomatis, 28% for S. enterica, 70% for E. histolytica, 54% for G. intestinalis, 96% for C. jejuni, 76% for ETEC and 94% for C. parvum. Seroprevalence increased with age for all pathogens. Median distance to the nearest water source was 473 meters (IQR 268, 719). Children living furthest from a water source had a 12% (95% CI: 2.6, 21.6) higher seroprevalence of S. enterica and a 12.7% (95% CI: 2.9, 22.6) higher seroprevalence of G. intestinalis compared to children living nearest. Seroprevalence for C. trachomatis and enteropathogens was high, with marked increases for most enteropathogens in the first two years of life. Children living further from a water source had higher seroprevalence of S. enterica and G. intestinalis indicating that improving access to water in the Ethiopia's Amhara region may reduce exposure to these enteropathogens in young children.


Assuntos
Anticorpos Antibacterianos/sangue , Anticorpos Antiprotozoários/sangue , Infecções por Chlamydia/microbiologia , Chlamydia trachomatis/imunologia , Criptosporidiose/sangue , Cryptosporidium/imunologia , Entamebíase/sangue , Giardíase/sangue , Criança , Pré-Escolar , Infecções por Chlamydia/sangue , Infecções por Chlamydia/epidemiologia , Chlamydia trachomatis/genética , Estudos Transversais , Criptosporidiose/epidemiologia , Criptosporidiose/parasitologia , Cryptosporidium/genética , Entamoeba histolytica/genética , Entamoeba histolytica/imunologia , Entamebíase/epidemiologia , Entamebíase/parasitologia , Etiópia/epidemiologia , Feminino , Água Doce/parasitologia , Giardia lamblia/genética , Giardia lamblia/imunologia , Giardíase/epidemiologia , Giardíase/parasitologia , Humanos , Masculino , Estudos Soroepidemiológicos
11.
Parasitol Res ; 119(10): 3415-3431, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32783072

RESUMO

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.


Assuntos
Agentes de Controle Biológico , Opistorquíase/prevenção & controle , Opistorquíase/transmissão , Opisthorchis/fisiologia , Caramujos/fisiologia , Animais , Água Doce/parasitologia , Humanos , Opistorquíase/epidemiologia , Caramujos/classificação , Caramujos/parasitologia , Solo/química , Solo/parasitologia , Tailândia/epidemiologia
12.
Parasitol Res ; 119(10): 3459-3467, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32677002

RESUMO

Emys orbicularis (Linnaeus, 1758) was considered as a specific host of Placobdella costata (Fr. Mûller, 1846). However, since the parasite was recorded from outside the distribution area of its host, some authors suggested a possible relationship with other hosts. Although two accidental associations were found with another turtle, Mauremys leprosa (Schweigger, 1812), the obtained data remain insufficient to better understand this discovered host-parasite ecological system. In this context, the present study was carried out to evaluate the relationship between the Mediterranean pond turtle, M. leprosa, and the freshwater rhynchobdellid leech, P. costata (Hirudinida: Glossiphoniidae), in aquatic ecosystems of Morocco. During the period from April to June 2018, we found leeches attached to turtles in five out of 30 populations sampled with a prevalence of infection significantly higher in adult than that in juvenile turtles. Moreover, the males are the most infested with 51% of the total, followed by females (33.3%) and juveniles (15.7%). The obtained results indicated that 51 turtles were infested by 139 leeches with a mean intensity of infestation of 4.17 ± 0.47 leeches/turtle (up to 10 leeches/turtle). It was higher in males than that in females in almost all sites. The posterior limbs are the most preferred attachment site, and the body condition of turtles was not affected by the intensity of infestation but it is rather a function of altitude. Our findings proved that M. leprosa-P. costata association is more than accidental and that M. leprosa is rather the main host of P. costata in aquatic ecosystems of Morocco.


Assuntos
Ectoparasitoses/veterinária , Sanguessugas/fisiologia , Tartarugas/parasitologia , Animais , Ectoparasitoses/epidemiologia , Ectoparasitoses/parasitologia , Feminino , Água Doce/parasitologia , Interações Hospedeiro-Parasita , Masculino , Marrocos/epidemiologia , Prevalência
13.
Parasitol Res ; 119(10): 3315-3326, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32699938

RESUMO

Haemogregarina species are apicomplexan blood parasites infecting vertebrates such as fish, lizards, and turtles. Due to the high morphological similarity of the erythrocytic stages infecting host species, it has always been a challenge to identify the true diversity of these parasites. Therefore, taxonomic studies are presently based on the combination of morphological and molecular data. In Tunisia, two species of Haemogregarina have been reported within the freshwater turtle Mauremys leprosa (Geoemydidae) for more than 40 years. Since M. leprosa occurs in the same aquatic environments as Emys orbicularis (Emydidae) in Tunisia, our objectives were to assess parasite diversity and specificity on the basis of both morphological and molecular approaches. The turtles were surveyed and sampled across six aquatic areas of Tunisia. Among the 39 specimens of M. leprosa and seven of E. orbicularis that were trapped and investigated, the presence of haemogregarines was detected in the blood of turtles only at sites where leeches were observed. Three 18S variants were identified, which corresponded to three distinct Haemogregarina species, among which one was identified as Haemogregarina stepanowi. The two other species that were detected are likely new to science. Because we show the occurrence of more than one blood parasite species within a single host specimen, our study provides the first report of coinfection with molecularly distinct Haemogregarina spp.


Assuntos
Coccidiose/veterinária , Coinfecção/veterinária , Eucoccidiida/genética , Água Doce/parasitologia , Tartarugas/parasitologia , Animais , Coccidiose/parasitologia , Coinfecção/parasitologia , Eucoccidiida/classificação , Eucoccidiida/isolamento & purificação , Variação Genética , Sanguessugas/parasitologia , RNA Ribossômico 18S/genética , Tunísia/epidemiologia , Tartarugas/classificação
14.
Bull Environ Contam Toxicol ; 105(5): 770-776, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32504161

RESUMO

This paper investigates the concentrations of PCBs in the water and sediment media and its bio-concentration in the fish host-parasite bentho-pelagic food chain in Epe lagoon. Samples of water, sediment, plankton, mollusks, fish and intestinal helminth parasites were collected from three stations (Oriba, Imode and Ikosi) in Epe Lagoon. Concentration of total PCBs in the surface water and sediment across the stations ranges from 3.20 to 6.00 ppb and 405.50-860.70 ppb respectively. Imode had the highest concentrations. The plankton bio-concentrates most PCBs in Ikosi (286.70 ppb) followed by Imode concentration (165.40 ppb), then Oribo (92.60 ppb) with total bio-concentration of 544.60 ppb. Surface water temperature negatively and strongly correlates with PCBs in the plankton. The planktons bio-concentrates total PCBs 44 times than that in the surface water. Chrysichthys nigrodigitatus bio-concentrates total PCBs 48 times than that in the surface water. Bioaccumulation of PCBs in human food chain could pose health risk.


Assuntos
Bioacumulação , Peixes-Gato/metabolismo , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Helmintos/metabolismo , Bifenilos Policlorados/análise , Poluentes Químicos da Água/análise , Animais , Peixes-Gato/parasitologia , Cadeia Alimentar , Água Doce/química , Água Doce/parasitologia , Sedimentos Geológicos/parasitologia , Humanos , Nigéria , Plâncton/metabolismo , Bifenilos Policlorados/metabolismo , Poluentes Químicos da Água/metabolismo
15.
PLoS Negl Trop Dis ; 14(6): e0008310, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32511225

RESUMO

Schistosomes infect more than 200 million people worldwide, and globally, over 700 million people are at risk of infection. The snail Biomphalaria straminea, as one of the intermediate hosts of Schistosoma mansoni, consecutively invaded Hong Kong in 1973, raising great concern in China. In this study, a malacological survey was conducted over a period of four years, and investigations were performed on the mechanism of susceptibility of B. straminea to S. mansoni. B. straminea was investigated in China from 2014 to 2018. Out of 185 investigated sites, 61 were positive for stages of black B. straminea (BBS), which shows pigmented spots. Twenty of the 61 sites were positive for red B. straminea (RBS), which is partially albino and red colored. Phylogenetic analyses based on cox1 and 18S rRNA sequences demonstrated that both phenotypes were clustered with Brazilian strains. No S. mansoni infections were detected in field-collected snail. However, in laboratory experiments, 4.17% of RBS were susceptible to a Puerto Rican strain of S. mansoni, while BBS was not susceptible. The highest susceptibility rate (70.83%) was observed in the F2 generation of RBS in lab. The density of RBS has increased from south to north and from west to east in Guangdong since 2014. Five tyrosinase tyrosine metabolism genes were upregulated in BBS. Transcriptome comparisons of RBS and BBS showed that ficolin, C1q, MASP-like, and membrane attack complex (MAC)/perforin models of the complement system were significantly upregulated in BBS. Our study demonstrated that B. straminea is widely distributed in Hong Kong and Guangdong Province, which is expanding northwards very rapidly as a consequence of its adaptation to local environments. Our results suggest that B. straminea from South China is susceptible to S. mansoni, implying the high potential for S. mansoni transmission and increased S. mansoni infection risk in China.


Assuntos
Biomphalaria/parasitologia , Água Doce/parasitologia , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/transmissão , Animais , China/epidemiologia , Vetores de Doenças , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Filogenia , Esquistossomose mansoni/epidemiologia
16.
Parasitol Res ; 119(8): 2495-2503, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32556501

RESUMO

In the present work, we reported for the first time the microbiome from Phyllocaulis soleiformis and Biomphalaria glabrata assessed using high-throughput DNA sequencing pre- and post-infection with the helminth parasite Angiostrongylus cantonensis. B. glabrata and P. soleiformis were experimentally infected with A. cantonensis. Fecal DNAs from control and infected groups were extracted and subjected to 16S rRNA high-throughput sequencing survey. No significant differences were found in the alpha diversity indexes in Phyllocaulis and Biomphalaria experiments independently. PCoA analysis using the unweighted UniFrac measures showed that both microbiotas behaved differently depending on the host. In Biomphalaria microbiota, control and infected groups were significantly different (p = 0.0219), while Phyllocaulis samples were not (p = 0.5190). The microbiome of P. soleiformis infected with A. cantonensis showed a significant decrease of Sphingobacterium and a substantial increase of Cellvibrio when compared to a control group. The microbiome of B. glabrata infected with A. cantonensis showed a significant decline in the abundance of Flavobacterium, Fluviicola, Nitrospira, Vogesella and an OTU belonging to the family Comamonadaceae, and a significant increase of Uliginosibacterium and an OTU belonging to the family Weeksellaceae when compared to a control group. Overall, the microbiome data reported here provided valuable information with regard to the diversity of bacterial communities that comprise the gut microbiome of gastropods. Furthermore, we report here the effect of the infection of the helminth A. cantonensis in the ratio and distribution of the fecal microbiome of the snails. Further studies are highly valuable in order to better understand those interactions by comparing different microbiome profiles and mollusk models. By now, we anticipate that ecological studies will take significant advantage of these advances, particularly concerning improving our understanding of helminth-microbiome-host interactions.


Assuntos
Angiostrongylus cantonensis/isolamento & purificação , Bactérias/isolamento & purificação , Biomphalaria/microbiologia , Biomphalaria/parasitologia , Microbiota , Angiostrongylus cantonensis/genética , Angiostrongylus cantonensis/fisiologia , Animais , Bactérias/classificação , Bactérias/genética , Água Doce/parasitologia , Interações Hospedeiro-Parasita , RNA Ribossômico 16S
17.
Am J Trop Med Hyg ; 103(1_Suppl): 66-79, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32400353

RESUMO

The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was created in 2008 to answer questions of importance to program managers working to reduce the burden of schistosomiasis in Africa. In the past, intermediate host snail monitoring and control was an important part of integrated schistosomiasis control. However, in Africa, efforts to control snails have declined dramatically over the last 30 years. A resurgence of interest in the control of snails has been prompted by the realization, backed by a World Health Assembly resolution (WHA65.21), that mass drug administration alone may be insufficient to achieve schistosomiasis elimination. SCORE has supported work on snail identification and mapping and investigated how xenomonitoring techniques can aid in the identification of infected snails and thereby identify potential transmission areas. Focal mollusciciding with niclosamide was undertaken in Zanzibar and Côte d'Ivoire as a part of elimination studies. Two studies involving biological control of snails were conducted: one explored the association of freshwater riverine prawns and snail hosts in Côte d'Ivoire and the other assessed the current distribution of Procambarus clarkii, the invasive Louisiana red swamp crayfish, in Kenya and its association with snail hosts and schistosomiasis transmission. SCORE also supported modeling studies on the importance of snail control in achieving elimination and a meta-analysis of the impact of molluscicide-based snail control programs on human schistosomiasis prevalence and incidence. SCORE's snail control studies contributed to increased investment in building capacity, and specimens collected during SCORE research deposited in the Schistosomiasis Collections at the Natural History Museum (SCAN) will provide a valuable resource for the years to come.


Assuntos
Reservatórios de Doenças/parasitologia , Moluscocidas/farmacologia , Esquistossomose/transmissão , Caramujos/parasitologia , Animais , Astacoidea , Agentes de Controle Biológico , Monitoramento Biológico , Costa do Marfim/epidemiologia , Decápodes , Água Doce/parasitologia , Humanos , Incidência , Quênia/epidemiologia , Modelos Teóricos , Niclosamida/farmacocinética , Prevalência , Avaliação de Programas e Projetos de Saúde , Schistosoma/isolamento & purificação , Schistosoma/parasitologia , Esquistossomose/parasitologia , Caramujos/efeitos dos fármacos , Tanzânia/epidemiologia
18.
J Water Health ; 18(2): 118-126, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32300086

RESUMO

Water reservoirs are important manmade structures providing water security to deliver clean and safe water for drinking and other purposes to the community. Eighty water samples were collected from Magat and Ipo water reservoirs using purposive sampling between November 2018 and January 2019. Water samples were collected in sterile containers for testing. The samples were cultured in non-nutrient agar and lawned with Escherichia coli and incubated at 33 °C. Twelve out of the 80 (15%) water samples were positive for amoebic growth. Light and scanning electron microscopy (SEM) revealed double-walled cystic stages and were initially identified as Acanthamoeba spp. based on morphological characteristic in reference to Page's established criteria. Their extracted DNAs were used in polymerase chain reaction using JDP1 and JDP2 primers and confirmed the presence of Acanthamoeba DNA in agarose gel electrophoresis. Aligned sequences from PCR products were deposited in GenBank under accession numbers MK886460, MK909919, MK905437, MK910997, MK911021 and MK886514. The presence of potentially pathogenic Acanthamoeba spp. in water reservoirs is considered a potential risk for public health, requiring appropriate processing of water in treatment plants.


Assuntos
Acanthamoeba/isolamento & purificação , Água Doce/parasitologia , Abastecimento de Água , Filipinas , Reação em Cadeia da Polimerase
19.
Parasitol Res ; 119(5): 1523-1545, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32152714

RESUMO

Planarians represent an insufficiently explored group of aquatic invertebrates that might serve as hosts of histophagous ciliates belonging to the hymenostome genus Tetrahymena. During our extensive research on freshwater planarians, parasitic tetrahymenas were detected in two of the eight planarian species investigated, namely, in Dugesia gonocephala and Girardia tigrina. Using the 16S and 18S rRNA genes as well as the barcoding cytochrome oxidase subunit I, one ciliate species was identified as T. scolopax and three species were recognized as new forms: T. acanthophora, T. dugesiae, and T. nigricans. Thus, 25% of the examined planarian taxa are positive for Tetrahymena species and three of them represent new taxa, indicating a large undescribed ciliate diversity in freshwater planarians. According to phylogenetic analyses, histophagous tetrahymenas show a low phylogenetic host specificity. Although T. acanthophora, T. dugesiae, and T. scolopax clustered together within the "borealis" clade, the former species has been detected exclusively in G. tigrina, while the two latter species only in D. gonocephala. Tetrahymena nigricans, which has been isolated only from G. tigrina, was classified within the "paravorax" clade along with T. glochidiophila which feeds on glochidia. The present phylogenetic reconstruction of ancestral life strategies suggested that the last common ancestor of the family Tetrahymenidae was free-living, unlike the progenitor of the subclass Hymenostomatia which was very likely parasitic. Consequently, there were at least seven independent shifts back to parasitism/histophagy within Tetrahymena: one each in the "paravorax" and "australis" clades and at least five transfers back to parasitism in the "borealis" clade.


Assuntos
Filogenia , Planárias/parasitologia , Tetrahymena/classificação , Animais , Biodiversidade , Água Doce/parasitologia , Especificidade de Hospedeiro , Hymenostomatida/classificação , Hymenostomatida/genética , Hymenostomatida/fisiologia , Planárias/classificação , Proteínas de Protozoários/genética , RNA Ribossômico/genética , Tetrahymena/genética , Tetrahymena/fisiologia
20.
PLoS Negl Trop Dis ; 14(3): e0008129, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32203507

RESUMO

BACKGROUND: Schistosomiasis is a neglected tropical parasitic disease associated with severe pathology, mortality and economic loss worldwide. Programs for disease control may benefit from specific and sensitive diagnostic methods to detect Schistosoma trematodes in aquatic environments. Here we report the development of novel environmental DNA (eDNA) qPCR assays for the presence of the human-infecting species Schistosoma mansoni, S. haematobium and S. japonicum. METHODOLOGY/PRINCIPAL FINDINGS: We first tested the specificity of the assays across the three species using genomic DNA preparations which showed successful amplification of target sequences with no cross amplification between the three focal species. In addition, we evaluated the specificity of the assays using synthetic DNA of multiple Schistosoma species, and demonstrated a high overall specificity; however, S. japonicum and S. haematobium assays showed cross-species amplification with very closely-related species. We next tested the effectiveness of the S. mansoni assay using eDNA samples from aquaria containing infected host gastropods, with the target species revealed as present in all infected aquaria. Finally, we evaluated the effectiveness of the S. mansoni and S. haematobium assays using eDNA samples from eight discrete natural freshwater sites in Tanzania, and demonstrated strong correspondence between infection status established using eDNA and conventional assays of parasite prevalence in host snails. CONCLUSIONS/SIGNIFICANCE: Collectively, our results suggest that eDNA monitoring is able to detect schistosomes in freshwater bodies, but refinement of the field sampling, storage and assay methods are likely to optimise its performance. We anticipate that environmental DNA-based approaches will help to inform epidemiological studies and contribute to efforts to control and eliminate schistosomiasis in endemic areas.


Assuntos
DNA Ambiental/isolamento & purificação , Água Doce/parasitologia , Schistosoma/classificação , Schistosoma/genética , Schistosoma/isolamento & purificação , Animais , DNA de Helmintos/isolamento & purificação , Monitoramento Ambiental , Genes de Helmintos/genética , Técnicas de Amplificação de Ácido Nucleico/veterinária , Filogenia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Schistosoma haematobium/genética , Schistosoma haematobium/isolamento & purificação , Schistosoma japonicum/genética , Schistosoma japonicum/isolamento & purificação , Schistosoma mansoni/genética , Schistosoma mansoni/isolamento & purificação , Esquistossomose/epidemiologia , Esquistossomose/parasitologia , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/parasitologia , Caramujos/parasitologia , Especificidade da Espécie , Tanzânia
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