Trematode Infection Publications (33395)
Trematode Infection Publications
viverrini is crucial for disease prevention and containment. Therefore, in this study we sought to develop a novel species-specific real-time PCR assay for detecting O. viverrini using environmental DNA (eDNA). The diagnostic sensitivity of the newly developed real-time PCR assay was similar to that of the traditional PCR assay for 50 fecal samples collected in Lao PDR (21 and 19 samples were positive by real-time PCR and traditional PCR, respectively). The efficacy of eDNA analysis and its applicability in the field were tested using a total of 94 environmental water samples collected from 44 sites in Savannakhet, Lao PDR during May and October 2015 and February 2016. O. viverrini eDNA was detected in five samples by real-time PCR, indicating the presence of the fluke in the area and the risk of infection for individuals consuming fish from these water sources. The application of eDNA analysis would facilitate the identification of O. viverrini endemic hotspots and contribute to the ecological control of opisthorchiasis, and this strategy can be applied to other eukaryotic water pathogens.
Here, the microflora found on the nasal mucosa and sections of the intestinal tract and endoparasites of freshly shot agouti from various areas of Trinidad are described. Staphylococcus epidermidis , S. intermedius , Bacillus spp., Enterobacter spp. and Escherichia coli comprised the majority of bacteria isolated from the nasal mucosa whereas Escherichia coli , Streptococcus viridans, Bacillus spp. and Klebsiella pneumoniae were predominant in all sections of the intestinal tract. The fungi Aspergillus fumigatus , Aspergillus spp., Candida spp., Penicillium spp., and Mucor spp. were only isolated from the nasal cavity but not in any section of the intestinal tract. The parasites Strongyloides spp., Ascaridia spp., a hookworm, a trematode, and Trichuris spp. were detected at variable frequencies in each of the sections of the intestines (small intestine, large intestine, caecum), whereas Eimeria spp. were found in all sections (76.9%, 10 of 13 agoutis). These wild agoutis were presumably healthy at the time of death and represent animals that hunters may encounter. Some of the detected pathogens and parasites have the potential to cause opportunistic infections or infestations, especially in immune-compromised hosts.
Furthermore, exposure of DCs to Fhmuc augmented LPS-induced Toll-like receptor (TLR) 4 expression on the cell surface. Finally, Fhmuc-conditioned DCs induced parasite specific-adaptive immunity with increased levels of IFN-γ secreted by splenocytes from vaccinated animals, and higher parasite-specific IgG antibodies. However, Fhmuc-treated DC conferred modest protection against F. hepatica infection highlighting the potent immuno-regulatory capacity of the parasite. In summary, this work highlights the capacity of a mucin-derived peptide from F. hepatica to enhance LPS-maturation of DCs and induce parasite-specific immune responses with potential implications in vaccination and therapeutic strategies.
Girls reporting macrohematuria were 4.1 times more likely to have measured hematuria than girls not reporting macrohematuria (CI95%: 2.1-7.9); girls who swim were 3.6 times more likely to have measured hematuria than nonswimmers (CI95%: 1.6-7.9). For boys, neither self-reported metric was predictive. Girls with measured hematuria in 2010 were 3.3 times more likely to be positive in 2012 (CI95%: 1.01-10.5), but boys showed no association. Boys with measured hematuria in 2008 were 6.0 times more likely to have measured hematuria in 2009 (CI95%: 1.5-23.9) and those with eggs in urine in 2008 were 4.8 times more likely to have eggs in urine in 2009 (CI95%: 1.2-18.8). For girls, measured hematuria in 2008 predicted a positive test in 2009 (OR = 2.8; CI95%: 1.1-6.8), but egg status did not. Agreement between dipstick results and eggs suggests continued dipstick used is appropriate. Self-reported swimming should be further examined. For effective disease monitoring, we recommend annual dipstick testing.
We initially performed a field survey of trematode infection in first (snail) and second (larval green frog, Rana clamitans) intermediate hosts over 5 years across a landscape of 23 ponds in southeastern Michigan. We then combined this study with a tadpole enclosure experiment in eight ponds. We found echinostomes in all ponds during the survey, although infection levels in both snails and amphibians differed across ponds and years. Echinostome prevalence (proportion of hosts infected) in snails also changed seasonally depending on host species, and abundance (parasites per host) in tadpoles depended on host size and prevalence in snails. The enclosure experiment demonstrated that infection varied at sites within ponds, and tadpole survival was lower in enclosures with higher echinostome abundance. The observed effects enhance our ability to predict when and where host-parasite interactions will occur and the potential fitness consequences of infection, with implications for population and community dynamics, evolution and conservation.
) infections following exposure to the insecticide carbaryl. Northern leopard frogs exposed to 1 mg L-1 of carbaryl had 61% higher parasite loads compared with unexposed individuals, while there was no immediate effect of carbaryl on parasite encystment in American toads. However, when tadpoles were exposed to carbaryl and moved to freshwater for 14 days before the parasite challenge, we recovered 37 and 63% more parasites from carbaryl-exposed northern leopard frogs and American toads, respectively, compared with the control. No effects on clearance were found for either species. Collectively, our results suggest that pesticide exposure can reduce the ability of amphibians to resist parasite infections and that these effects can persist weeks following exposure. It is critical for researchers to incorporate species interactions into toxicity studies to improve our understanding of how contaminants affect ecological communities.
yokogawai, Procerovum varium and Stellantchasmus falcatus. For molecular phylogenetic and systematic studies on trematodes, we need more prospective markers for taxonomic identification and classification. This study provides near-complete ribosomal transcription units (rTU) from Haplorchis pumilio and H. taichui and demonstrates the use of 28S rDNA sequences for identification and phylogenetic analysis.
The near-complete ribosomal transcription units (rTU), consisting of 18S, ITS1, 5.8S, ITS2 and 28S rRNA genes and spacers, from H. pumilio and H. taichui from human hosts in Vietnam, were determined and annotated. Sequence analysis revealed tandem repetitive elements in ITS1 in H. pumilio and in ITS2 in H. taichui. A phylogenetic tree inferred from 28S rDNA sequences of 40 trematode strains/species, including 14 Vietnamese heterophyid individuals, clearly confirmed the status of each of the Vietnamese species: Centrocestus formosanus, Haplorchis pumilio, H. taichui, H. yokogawai, Procerovum varium and Stellantchasmus falcatus. However, the family Heterophyidae was clearly not monophyletic, with some genera apparently allied with other families within the superfamily Opisthorchioidea (i.e. Cryptogonimidae and Opisthorchiidae). These families and their constituent genera require substantial re-evaluation using a combination of morphological and molecular data. Our new molecular data will assist in such studies.
The 28S rDNA sequences are conserved among individuals within a species but varied between genera. Based on analysis of 40 28S rDNA sequences representing 19 species in the superfamily Opisthorchioidea and an outgroup taxon (Alaria alata, family Diplostomidae), six common human pathogenic heterophyids were identified and clearly resolved. The phylogenetic tree inferred from these sequences again confirmed anomalies in molecular placement of some members of the family Heterophyidae and demonstrates the need for reappraisal of the entire superfamily Opisthorchioidea. The new sequences provided here supplement those already available in public databases and add to the array of molecular tools that can be used for the diagnosis of heterophyid species in human and animal infections.
in North America and are endemic on most commercial catfish operations. The great egret Ardea alba L. is an avian predator often found foraging on commercial catfish operations, but to date the trematode fauna of great egrets preying on catfish ponds remains mostly understudied. Thirteen great egrets were captured from commercial catfish ponds in northeast Mississippi, and examined for trematode infections. Two morphologically distinct Clinostomum spp. were observed in the great egrets sampled, one morphologically consistent with Clinostomum marginatum (Rudolphi, 1819) and one morphologically unique species. These morphological descriptions were supplemented with molecular sequence data (c.4,800 bp of ribosomal DNA and c.600 bp of mitochondrial DNA). Gene sequences confirmed the identification of C. marginatum. However, the second species differed significantly from its congeners in both morphology and DNA sequence. Given these distinct morphological and molecular characters we propose this second species as Clinostomum album n. sp.
The results revealed that the total prevalence of infection was 99.2%. Cestode and nematode infections showed the highest prevalence in rainy season, while trematode infections were low and only found in hot season. The species and their prevalence were: Ascaridia galli (50.8%), Heterakis gallinarum (86.7%), Prosthogonimus macrorchis (1.7%), Echinostoma revolutum (0.8%), Raillietina echinobothrida (48.3%), Raillietina tetragona (57.5%), Raillietina cesticillus (12.5%), Raillietina sp. (35.8%), Cotugnia chiangmaii (14.2%) and Cotugnia sp. (32.5%). The prevalence of helminth infections did not differ significantly between male and female chickens. HAT-RAPD analysis, the specific fragment of 400 and 250 bp indicated that Raillietina sp. and Cotugnia sp. found, respectively, differ from other closely related species. This study has confirmed that HAT-RAPD technique can be used to differentiate among related species combined with morphological observations.
We generated predictions for differential effects of litter nutrition and secondary polyphenolic compounds on tadpole (Lithobates sylvatica) exposure and susceptibility to Ribeiroia ondatrae, based on ecological stoichiometry and community-ecology theory. We predicted direct and indirect effects on key traits of the tadpole host (rates of growth, development and survival), the trematode parasite (production of the cercaria infective stages) and the parasite's snail intermediate host (growth and reproduction). To test these predictions, we conducted a large-scale mesocosm experiment using a natural gradient in the concentrations of nutrients (nitrogen) and toxic secondary compounds (polyphenolics) of nine leaf litter species. To differentiate between effects on exposure vs. susceptibility to infection, we included multiple infection experiments including one with constant per capita exposure. We found that increased litter nitrogen increased tadpole survival, and also increased cercaria production by the snail intermediate hosts, causing opposing effects on tadpole per capita exposure to trematode infection. Increased litter polyphenolics slowed tadpole development, leading to increased infection by increasing both their susceptibility to infection and the length of time they were exposed to parasites. Based on these results, recent shifts in forest composition towards more nitrogen-poor litter species should decrease trematode infection in tadpoles via density- and trait-mediated effects on the snail intermediate hosts. However, these shifts also involve increased abundance of litter species with high polyphenolic levels, which should increase trematode infection via trait-mediated effects on tadpoles. Future studies will be needed to determine the relative strength of these opposing effects in natural wetland communities. [Correction added after online publication on 5 January 2017: wording changed to 'which should increase trematode infection via trait-mediated effects on tadpoles'.].