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Journal of Helminthology
Cambridge University Press
Journal of Helminthology

Cambridge University Press

0022-149X

Journal of Helminthology/Journal Journal of HelminthologySCIISTP
正式出版
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    Traditional Kenyan herbal medicine: exploring natural products’ therapeutics against schistosomiasis

    Ndegwa Fidensio K.Kondam ChaitanyaAboagye Samuel Y.Esan Taiwo E....
    7页
    查看更多>>摘要:Abstract Praziquantel (PZQ) remains the only drug of choice for the treatment of schistosomiasis, caused by parasitic flatworms. The widespread use of PZQ in schistosomiasis endemic areas for about four decades raises concerns about the emergence of resistance of Schistosoma spp. to PZQ under drug selection pressure. This reinforces the urgency in finding alternative therapeutic options that could replace or complement PZQ. We explored the potential of medicinal plants commonly used by indigenes in Kenya for the treatment of various ailments including malaria, pneumonia, and diarrhoea for their antischistosomal properties. Employing the Soxhlet extraction method with different solvents, seven medicinal plants Artemisia annua, Ajuga remota, Bredilia micranta, Cordia africana, Physalis peruviana, Prunus africana and Senna didymobotrya were extracted. Qualitative phytochemical screening was performed to determine the presence of various phytochemicals in the plant extracts. Extracts were tested against Schistosoma mansoni newly transformed schistosomula (NTS) and adult worms and the schistosomicidal activity was determined by using the adenosine triphosphate quantitation assay. Phytochemical analysis of the extracts showed different classes of compounds such as alkaloids, tannins, terpenes, etc., in plant extracts active against S. mansoni worms. Seven extracts out of 22 resulted in <20% viability against NTS in 24 h at 100 μg/ml. Five of the extracts with inhibitory activity against NTS showed >69.7% and ≥72.4% reduction in viability against adult worms after exposure for 24 and 48 h, respectively. This study provides encouraging preliminary evidence that extracts of Kenyan medicinal plants deserve further study as potential alternative therapeutics that may form the basis for the development of the new treatments for schistosomiasis.

    First isolation and scanning electron microscopy of haptoral sclerites of Macrogyrodactylus (Monogenea)

    Maduenyane MphoDos Santos Quinton MarcoAvenant-Oldewage Annemariè
    9页
    查看更多>>摘要:Abstract Macrogyrodactylus congolensis (Prudhoe, 1957) is one of six species of Macrogyrodactylus, all of which are endemic to Africa. This monogenean is a host-specific ectoparasite of the African sharptooth catfish, Clarias gariepinus (Burchell, 1822). It attaches to the host with a posterior haptor armed with sclerites. The specific morphology of sclerites is taxonomically significant and usually studied using light microscopy. The aim of the present study was to confirm the identification of macrogyrodactylid parasites using classic morphology (light microscopy of glycerine ammonium picrate mounted specimens) and molecular techniques (18S rDNA, ITS rDNA and cytochrome oxidase subunit 1 (COI) mtDNA). Additionally, the sclerites were accurately described with a technique not previously used for the genus, whereby haptoral sclerites were isolated by removing the encapsulating soft tissue with a digestion buffer and studied with scanning electron microscopy (SEM). Morphology and morphometry of studied specimens corresponded to available data for M. congolensis, confirming the identity of the parasite. All previous descriptions were summarized in a table and discrepancies discussed. Molecular analysis also confirmed the specimens to be M. congolensis, but ITS rDNA and COI mtDNA was more reliable than 18S rDNA in this regard. The isolation of haptoral sclerites and their study using SEM was successful, resolving the morphology of all sclerites. This study provided the first reconstruction of the haptor of a Macrogyrodactylus species following SEM analysis, as well as the first mtDNA for M. congolensis. Further study of isolated haptoral sclerites of other macrogyrodactylids is required to determine the full benefits of studying their isolated sclerites.

    Ex vivo development of Phasmarhabditis spp. associated with terrestrial molluscs

    Pieterse A.Haukeland S.P??a V.Ross J.L....
    7页
    查看更多>>摘要:Abstract The success of Phasmarhabditis hermaphrodita (Schneider) Andrássy (Rhabditida: Rhabditidae) as a biological control agent of molluscs has led to a worldwide interest in phasmarhabditids. However, scant information is available on the lifecycle development of species within the genus. In the current study, the development of P. hermaphrodita, Phasmarhabditis papillosa, Phasmarhabditis bohemica and Phasmarhabditis kenyaensis were studied using ex vivo cultures, in order to improve our understanding of their biology. Infective juveniles (IJs) of each species were added to 1 g of defrosted homogenized slug cadavers of Deroceras invadens and the development monitored after inoculated IJ recovery, over a period of eight–ten days. The results demonstrated that P. bohemica had the shortest development cycle and that it was able to produce first-generation IJs after eight days, while P. hermaphrodita, P. papillosa and P. kenyaensis took ten days to form a new cohort of IJs. However, from the perspective of mass rearing, P. hermaphrodita has an advantage over the other species in that it is capable of forming self-fertilizing hermaphrodites, whereas both males and females are required for the reproduction of P. papillosa, P. bohemica and P. kenyaensis. The results of the study contribute to the knowledge of the biology of the genus and will help to establish the in vitro liquid cultures of different species of the genus.

    Three new species of Duplicibothrium (Cestoda: ‘Tetraphyllidea’) from cownose rays in Senegal with a phylogenetic analysis of the genus

    Stephan DouglasCaira Janine N.
    14页
    查看更多>>摘要:Abstract Three new species of ‘tetraphyllideans’ in the family Serendipeidae are described from cownose rays off Senegal. Duplicibothrium jeannettae n. sp. and Duplicibothrium collosum n. sp. parasitize both Rhinoptera marginata and Rhinoptera peli. Duplicibothrium jillae n. sp. parasitizes R. marginata. Duplicibothrium jeannettae n. sp. and D. jillae n. sp. differ from one another and their described congeners in size, number of proglottids, and locular configuration. The generic assignment of D. collosum n. sp. was initially unclear because its scolex more closely resembles that of Serendip than Duplicibothrium. To help inform generic placement, sequence data were generated for the 28S rDNA gene (D1–D3 region) for the three new species as well as for Duplicibothrium minutum and Duplicibothrium n. sp. 2 from Rhinoptera bonasus off North Carolina, Duplicibothrium n. sp. 3 from Rhinoptera brasiliensis off Belize, Duplicibothrium n. sp. 4 and Duplicibothrium n. sp. 5 from Rhinoptera jayakari off Mozambique, and Duplicibothrium n. sp. 6 from Rhinoptera neglecta off Australia. Comparable data were obtained from GenBank for adults and larvae of Duplicibothrium collected from the Gulf of Mexico. The tree resulting from a maximum likelihood analysis (MLA) placed D. collosum n. sp. robustly within Duplicibothrium; the generic diagnosis is emended accordingly. This raises a question regarding the independence, and thus also validity, of the three genera of the Serendipeidae – a question that must await a molecular analysis that includes Serendip and Glyphobothrium. These results extend the hosts of Duplicibothrium to include R. brasiliensis, R. jayakari, R. marginata, R. neglecta and R. peli, and the distribution to include the western Pacific Ocean, eastern Atlantic Ocean, and western Indian Ocean (Zoobank Registration: 97BB5020-BFFF-4FEA-AE07-B4711D1110FC).

    Hybridization between Anguillicola crassus and A. novaezelandiae, and viability of the F1 generation

    Honka K.I.Grabner D.Sures B.
    6页
    查看更多>>摘要:Abstract For decades, it has remained unclear how the Asian swim bladder nematode Anguillicola crassus was able to supplant the previously stable population of its relative from New Zealand Anguillicola novaezelandiae in the Lake Bracciano, Italy. Previously, researchers have hypothesized that A. crassus possesses an ecological advantage due to a more efficient life cycle in combination with a pattern of unidirectional hybridization between A. novaezelandiae females and A. crassus males. The present study focuses on the viability of hybrid offspring and their allelic pattern, particularly in developed adult stages of the hybrid F1 generation. While the percentages of hybrid individuals from A. novaezelandiae mothers and A. crassus fathers increased from egg to adult stages, it was more distinct in egg stages of A. crassus females and A. novaezelandiae males, but did not occur in adult F1 individuals at all. Therefore, we corroborate the hypothesis of unidirectional hybridization by differentiating between egg and adult stages, and suggest this as another explanatory factor for the extinction of A. novaezelandiae in Lake Bracciano in Italy and the predominance of A. crassus.

    Nematicidal activity of leaf extract of Moringa oleifera Lam. against Haemonchus contortus and Nacobbus aberrans

    Páez-León S.Y.Carrillo-Morales M.Gómez-Rodríguez O.López-Guillén G....
    7页
    查看更多>>摘要:Abstract In the present study, the nematicidal activity of a Moringa oleifera ethyl acetate leaf extract against the eggs and larvae of Haemonchus contortus and Nacobbus aberrans, nematodes of agricultural importance, was evaluated. The experimental design for the evaluation of the effects against both nematodes consisted of eight treatments (n = 4). Distilled water, Tween (4%) and a commercial anthelmintic agent (ivermectin, 5 mg/mL) were used as controls, and for treatments 4–8, the concentrations of the extract were 20, 10, 5, 2.5 and 1.25 mg/mL, respectively. Readings were taken at 12 h and 24 h for N. aberrans and 48 h and 72 h for H. contortus post-treatment under an optical microscope (10× and 40×). The data obtained were analysed by analysis of variance through a completely randomized factorial design using the SAS V9 program. The results show that, for H. contortus egg hatching, 85.88% inhibition was obtained at a concentration of 20 mg/mL at 48 h, while for third-stage larva (L3) mortality, the highest percentage was 68.19% at 1.25 mg/mL at 72 h. In the case of N. aberrans, the greatest inhibition of egg hatching was 90.69% at 5 mg/mL at 12 h post-treatment, and for larval mortality, it was 100% at 10 mg/mL at 24 h post-treatment. The main major compounds identified by qualitative analysis and by gas chromatography coupled to mass spectrometry were 9,12,15-octadecatrienoic acid, (Z,Z,Z)-, n-hexadecanoic acid and 2,4-di-tert-butylphenol, and the minor compounds included phytol, γ-sitosterol and α-tocopheryl acetate. It was demonstrated that the ethyl acetate leaf extract of M. oleifera Lam. shows great potential for combating agricultural nematodes.

    New trematode species Lecithostaphylus halongi n. sp. (Zoogonidae, Microphalloidea) and Gymnotergestia strongyluri n. sp. (Fellodistomidae, Gymnophalloidea) from beloniform fishes in Vietnam

    Atopkin D.M.Besprozvannykh V.V.Ha N.D.Nguyen H.V....
    9页
    查看更多>>摘要:Abstract In this study we described two new trematode species, Lecithostaphylus halongi n. sp. (Zoogonidae, Lecithostaphylinae) and Gymnotergestia strongyluri n. sp. (Fellodistomidae, Tergestiinae), on the basis of morphological and molecular data. Adult worms of these two species were collected from, respectively, Hemiramphus spp. (Hemiramphidae) and Strongylura strongylura (Belonidae) caught in the coastal waters of Vietnam. Adult worms of L. halongi n. sp. are morphologically close to Lecithostaphylus gibsoni Cribb, Bray & Barker, 1992 ex Abudefduf whitleyi from Heron Island and Lecithostaphylus depauperati Yamaguti, 1970 ex Hemiramphus depauperatus from Hawaii, but differ from these species in having a larger cirrus sac and a different arrangement of vitelline fields. They also differ from Lecithostaphylus brayi Caba?as-Granillo, Solórzano-García, Mendoza-Garfias & Pérez-Ponce de León, 2020 in the 28S ribosomal DNA (rDNA) sequence data at the interspecific level. Adult worms of G. strongyluri n. sp. ex S. strongylura are morphologically similar to Gymnotergestia chaetodipteri, the only previously known species of this genus, described from Chaetodipterus faber in Jamaica. The new species differs from G. chaetodipteri in body shape, testicular arrangement and the size of the pharynx and eggs. The 28S rDNA-based phylogenetic analysis indicates that G. strongyluri n. sp. is closely related to Tergestia spp., rendering Tergestia paraphyletic. Genetic divergence values between G. strongyluri n. sp. and Tergestia spp. are similar to those among species in the genera Tergestia, Steringophorus and Proctoeces. Our molecular results indicate that G. strongyluri n. sp. and Tergestia spp. may belong the same genus, but additional molecular data are needed for the final conclusion.

    Predation of the fungus Duddingtonia flagrans on infective larvae of gastrointestinal nematodes from heifers in a silvopastoral system under shaded and sunny conditions

    Buss Baiak Barbara Halinede Sousa Karolini TenffenDeniz MatheusGasparina Jennifer Mayara...
    9页
    查看更多>>摘要:Abstract The objective of this study was to evaluate the predatory activity of the nematophagous fungus Duddingtonia flagrans on infective larvae of gastrointestinal nematodes from dairy heifers in different conditions (shaded and sunny) of a silvopastoral system (SPS) on an agroecological farm. Ten Jersey heifers were divided into two groups: treated (received pellets containing fungus); and control (received pellets without fungus). Twelve hours after fungus administration, faeces samples were collected for in vitro efficacy tests. The animals then remained for 8 h in the experimental pasture area. At the end of this period, 20 faecal pads (10 treated and 10 control) were selected. Pasture, faecal pad and soil collections occurred at intervals of seven days (d), totalling four assessments over 28 d. To evaluate the influence of the conditions shaded and sunny, we registered the condition of the location of each faecal pad per hour. After 12 h of gastrointestinal transit in dairy heifers, a reduction of 65% was obtained through the in vitro test. The treated group presented a lower number of infective larvae (L3) in the faecal pad and upper pasture. Differences in numbers of L3 were observed between the conditions (sunny and shaded) in the faecal pad of the control group; while in the treated group there were no differences between the conditions. The predatory activity of the fungus was efficient over time in the shaded and sunny conditions of an SPS, decreasing the parasite contamination during the pasture recovery time in a subtropical climate.

    Temporal effects and changes in the parasitic community of Prochilodus lineatus (Valenciennes, 1837) (Characiformes: Prochilodontidae) in a floodplain

    Lehun Atsler LuanaCavalcanti Lidiany DoretoLizama Maria de los Angeles PerezSantos Silva Jo?o Otávio...
    8页
    查看更多>>摘要:Abstract The construction of dams causes several impacts on aquatic environments, altering the flow of rivers, environmental variables, and all biota present, including parasites. Little is known about how the parasitic community can be influenced in the long term by environmental changes. In this study, it was expected that the impacts caused by environmental disturbances will be directly reflected by the composition of the parasite populations. We evaluated the change in the structure of the Prochilodus lineatus endoparasite community between two periods sampled 15 years apart in the upper Paraná River floodplain. There was a significant difference in the weight–length relationship of P. lineatus between these periods and a total of 15 species of parasites were found: 11 species in Period 1 and nine species in Period 2 and five species occurred in both periods. The species richness and diversity were higher in Period 1, and we observed that the correlation of descriptors (richness, diversity and evenness) increased with fish length in this period. In both periods, digeneans numerically dominated the parasitic community, and we verified changes in the composition of parasites between periods. Both the host and the parasites were possibly affected by the environmental impacts resulting from the construction of dams over time, and it is noteworthy that complex life cycle parasites such as Digenea and Acanthocephala require intermediate hosts to complete their life cycle, and the population responds to fluctuations in the face of modified environments.

    Geography and ecology of invasive Pseudosuccinea columella (Gastropoda: Lymnaeidae) and implications in the transmission of Fasciola species (Digenea: Fasciolidae) – a review

    Ngcamphalala P.I.Malatji M.P.Mukaratirwa S.
    18页
    查看更多>>摘要:Abstract Pseudosuccinea columella is considered invasive and has become an important intermediate host of both Fasciola species in many regions of the world. This systematic review assessed the geographical distribution of P. columella, and its implications in the transmission of Fasciola hepatica and Fasciola gigantica, globally. A literature search was conducted on Google Scholar, JSTOR and PubMed databases using Boolean operators in combination with predetermined search terms for thematic analysis. Results show that P. columella has been documented in 22 countries from Europe (3), Africa (8), Oceania (2), North America (3) and South America (6). Furthermore, this snail species has shown to adapt to and inhabit a vast array of freshwater bodies including thermal lakes and ditches with acidic soils. Studies showed that P. columella transmits F. hepatica, with natural and experimental infections documented in sub-Saharan Africa, Europe, South America and North America. Experimental infection studies in Cuba showed the presence of P. columella populations resistant to F. hepatica infection. Furthermore, some populations of this invasive snail collected from F. hepatica endemic locations in Brazil, Venezuela, Australia, South Africa, Colombia and Argentina were found without Fasciola infection. As a result, the role played by this snail in the transmission of Fasciola spp. in these endemic areas is still uncertain. Therefore, further studies to detect natural infections are needed in regions/countries where the snail is deemed invasive to better understand the veterinary and public health importance of this snail species in Fasciola-endemic areas and determine the global dispersion of resistant populations of P. columella.