Preliminary genetic evidence of two different populations of Opisthorchis viverrini in Lao PDR

Opisthorchis viverrini is a major public health concern in Southeast Asia. Various reports have suggested that this parasite may represent a species complex, with genetic structure in the region perhaps being dictated by geographical factors and different species of intermediate hosts. We used four microsatellite loci to analyze O. viverrini adult worms originating from six species of cyprinid fish in Thailand and Lao PDR. Two distinct O. viverrini populations were observed. In Ban Phai, Thailand, only one subgroup occurred, hosted by two different fish species. Both subgroups occurred in fish from That Luang, Lao PDR, but were represented to very different degrees among the fish hosts there. Our data suggest that, although geographical separation is more important than fish host specificity in influencing genetic structure, it is possible that two species of Opisthorchis, with little interbreeding, are present near Vientiane in Lao PDR

Phylogenetic relationships within the Opisthorchis viverrini species complex with specific analysis of O. viverrini sensu lato from Sakon Nakhon, Thailand by mitochondrial and nuclear DNA sequencing

The liver fluke Opisthorchis viverrini sensu lato causes serious public-health problems in Northeast Thailand and Southeast Asian countries. A hypothesis has been proposed that O. viverrini represents a species complex with varying levels of genetic differentiation in Thailand and Lao PDR. This study aimed to clarify whether O. viverrini populations can be genetically divided into separate taxa. We collected O. viverrini s.l. from eight different locations in Lao PDR and Thailand. The results of nad1, cox1, CF-int6, Pm-int9, ITS2 and 28S rDNA sequence analysis revealed that sub-structuring occurred between the eight populations. We found that O. viverrini s.l. from Sakon Nakhon (SK), Thailand, shows significant genetic differentiation (P < .05) from all other isolates from different localities in Thailand and Lao PDR. This was supported by haplotype and phylogenetic tree analyses in which the SK isolate was separated from all other isolates. This suggests that O. viverrini s.l. from SK is a cryptic species. The data, however, also confirm the association between genetic groups of O. viverrini s.l. and specific wetland systems, and raise important questions regarding the epidemiological significance of these genetic differences

Insights in the global genetics and gut microbiome of black soldier fly, Hermetia illucens: implications for animal feed safety control

Open Access Journal; Published online: 07 July 2020The utilization of the black soldier fly (BSF) Hermetia illucens L. for recycling organic waste into high-quality protein and fat biomass for animal feeds has gained momentum worldwide. However, information on the genetic diversity and environmental implications on safety of the larvae is limited. This study delineates genetic variability and unravels gut microbiome complex of wild-collected and domesticated BSF populations from six continents using mitochondrial COI gene and 16S metagenomics. All sequences generated from the study linked to H. illucens accessions KM967419.1, FJ794355.1, FJ794361.1, FJ794367.1, KC192965.1, and KY817115.1 from GenBank. Phylogenetic analyses of the sequences generated from the study and rooted by GenBank accessions of Hermetia albitarsis Fabricius and Hermetia sexmaculata Macquart separated all samples into three branches, with H. illucens and H. sexmaculata being closely related. Genetic distances between H. illucens samples from the study and GenBank accessions of H. illucens ranged between 0.0091 and 0.0407 while H. sexmaculata and H. albitarsis samples clearly separated from all H. illucens by distances of 0.1745 and 0.1903, respectively. Genetic distance matrix was used to generate a principal coordinate plot that further confirmed the phylogenetic clustering. Haplotype network map demonstrated that Australia, United States 1 (Rhode Island), United States 2 (Colorado), Kenya, and China shared a haplotype, while Uganda shared a haplotype with GenBank accession KC192965 BSF from United States. All other samples analyzed had individual haplotypes. Out of 481,695 reads analyzed from 16S metagenomics, four bacterial families (Enterobactereaceae, Dysgonomonadaceae, Wohlfahrtiimonadaceae, and Enterococcaceae) were most abundant in the BSF samples. Alpha-diversity, as assessed by Shannon index, showed that the Kenyan and Thailand populations had the highest and lowest microbe diversity, respectively; while microbial diversity assessed through Bray Curtis distance showed United States 3 (Maysville) and Netherlands populations to be the most dissimilar. Our findings on genetic diversity revealed slight phylogeographic variation between BSF populations across the globe. The 16S data depicted larval gut bacterial families with economically important genera that might pose health risks to both animals and humans. This study recommends pre-treatment of feedstocks and postharvest measures of the harvested BSF larvae to minimize risk of pathogen contamination along the insect-based feed value chain

Unlocking the Transcriptomes of Two Carcinogenic Parasites, Clonorchis sinensis and Opisthorchis viverrini

The two parasitic trematodes, Clonorchis sinensis and Opisthorchis viverrini, have a major impact on the health of tens of millions of humans throughout Asia. The greatest impact is through the malignant cancer ( = cholangiocarcinoma) that these parasites induce in chronically infected people. Therefore, both C. sinensis and O. viverrini have been classified by the World Health Organization (WHO) as Group 1 carcinogens. Despite their impact, little is known about these parasites and their interplay with the host at the molecular level. Recent advances in genomics and bioinformatics provide unique opportunities to gain improved insights into the biology of parasites as well as their relationships with their hosts at the molecular level. The present study elucidates the transcriptomes of C. sinensis and O. viverrini using a platform based on next-generation (high throughput) sequencing and advanced in silico analyses. From 500,000 sequences, >50,000 sequences were assembled for each species and categorized as biologically relevant based on homology searches, gene ontology and/or pathway mapping. The results of the present study could assist in defining molecules that are essential for the development, reproduction and survival of liver flukes and/or that are linked to the development of cholangiocarcinoma. This study also lays a foundation for future genomic and proteomic research of C. sinensis and O. viverrini and the cancers that they are known to induce, as well as novel intervention strategies

Mitochondrial DNA sequences and microsatellite analyses of Opisthorchis viverrini

The attached files are the data set of mitochondrial DNA sequences deposited in GenBank and microsatellites analysis of Opisthorchis viverrini collected from different localities in Thailand and Laos. These data set was used for publication in the &quot;International Journal for Parasitology&quot; entitle &quot;Impact of geography and time on genetic clusters of Opisthorchis viverrini identified by microsatellite and mitochondrial DNA analysis.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Biological variation within opisthorchis viverrini sensu lato in Thailand and Lao PDR

10.1645/GE-2116.1Journal of Parasitology9561307-1313JOPA

Molecular identification of trematode parasites infecting the freshwater snail Bithynia siamensis goniomphalos in Thailand

Digenetic trematodes are important parasites of humans and animals. They have complex life cycles and typically infect a gastropod as the first intermediate host. Bithynia siamensis goniomphalos, the first intermediate host of the liver fluke, Opisthorchis viverrini, harbours a wide variety of other trematode species. Morphological details of cercariae of 20 trematode taxa from B. s. goniomphalos, collected mainly in Thailand from 2009 to 2014, were provided in an earlier paper. Correct identification to the species or genus level based on morphology of these cercariae is generally not possible. Therefore, we used molecular data to improve identification and to investigate the diversity of the species of trematodes infecting B. s. goniomphalos. We were successful in extracting, amplifying and sequencing portions of the 28S ribosomal RNA (rRNA) gene for 19 of these 20 types of cercaria, and the internal transcribed spacer 2 region for 18 types. BLAST searches in GenBank and phylogenetic trees inferred from the 28S rRNA sequences identified members of at least nine superfamilies and 12 families. Only a few cercariae could be assigned confidently to genus or species on the basis of the sequence data. Matching sequence data from named adult trematodes will be required for definitive identification. There is clearly a great diversity of trematode species utilizing B. s. goniomphalos in Thailand