Entering the spatial age of parasite genomics.

Reconciling organism-scale biology at cellular-scale resolution has been a monumental challenge. Recently, Gramberg et al. uncovered the spatial organisation of gene expression in the common liver fluke, Fasciola hepatica.

Deep-amplicon sequencing of the complete beta-tubulin gene in Trichuris trichiura before and after albendazole treatment.

Concerns about the emergence of benzimidazole resistance in soil-transmitted helminths (STH) infections, particularly against Trichuris trichiura, have arisen. Previous studies of veterinary nematodes have linked benzimidazole resistance to single-nucleotide polymorphisms (SNPs) at three specific codons in the beta-tubulin gene, but similar associations in STH have not been consistently observed. In this work, we screened the complete beta-tubulin gene previously linked to benzimidazole resistance in T.

Extensive transmission and variation in a functional receptor for praziquantel resistance in endemic .

Mass-drug administration (MDA) of human populations using praziquantel monotherapy has become the primary strategy for controlling and potentially eliminating the major neglected tropical disease schistosomiasis. To understand how long-term MDA impacts schistosome populations, we analysed whole-genome sequence data of 570 samples (and the closely related outgroup species, from eight countries incorporating both publicly-available sequence data and new parasite material. This revealed broad-scale genetic structure across countries but with extensive transmission over hundreds of kilometres.

Functional validation of novel levamisole resistance marker S168T in Haemonchus contortus.

Recently, a S168T variant in the acetylcholine receptor subunit ACR-8 was associated with levamisole resistance in the parasitic helminth Haemonchus contortus. Here, we used the Xenopus laevis oocyte expression system and two-electrode voltage-clamp electrophysiology to measure the functional impact of this S168T variant on the H. contortus levamisole-sensitive acetylcholine receptor, L-AChR-1.

Real-time single-base specific detection of the Haemonchus contortus S168T variant associated with levamisole resistance using loop-primer endonuclease cleavage loop-mediated isothermal amplification.

Haemonchus contortus is a parasitic haematophagous nematode that primarily affects small ruminants and causes significant economic loss to the global livestock industry. Treatment of haemonchosis typically relies on broad-spectrum anthelmintics, resistance to which is an important cause of treatment failure. Resistance to levamisole remains less widespread than to other major anthelmintic classes, prompting the need for more effective and accurate surveillance to maintain its efficacy.

The stage- and sex-specific transcriptome of the human parasite Schistosoma mansoni.

The flatworm Schistosoma mansoni is an important but neglected pathogen that causes the disease schistosomiasis in millions of people worldwide. The parasite has a complex life cycle, undergoing sexual reproduction in a mammalian host and asexual replication in a snail host. Understanding the molecular mechanisms that the parasite uses to transition between hosts and develop into dimorphic reproductively competent adults may reveal new strategies for control.

Genome structure and population genomics of the canine heartworm Dirofilaria immitis.

The heartworm, Dirofilaria immitis, is a filarial parasitic nematode responsible for significant morbidity and mortality in wild and domesticated canids. Resistance to macrocyclic lactone drug prevention represents a significant threat to parasite control and has prompted investigations to understand the genetic determinants of resistance. This study aimed to improve the genomic resources of D.

Trophic ecology of Octopus vulgaris paralarvae along the Iberian Canary current eastern boundary upwelling system.

Our knowledge of the diet of wild octopus paralarvae, Octopus vulgaris, is restricted to the first 2 weeks of its planktonic phase when they are selective hunters found near the coastline. These small paralarvae, bearing only three suckers per arm, are transported by oceanic currents from the coast towards offshore waters, where they complete the planktonic phase over 2 months. Here, we have investigated the trophic ecology of O.

Evaluation of genome skimming to detect and characterise human and livestock helminths.

The identification of gastrointestinal helminth infections of humans and livestock almost exclusively relies on the detection of eggs or larvae in faeces, followed by manual counting and morphological characterisation to differentiate species using microscopy-based techniques. However, molecular approaches based on the detection and quantification of parasite DNA are becoming more prevalent, increasing the sensitivity, specificity and throughput of diagnostic assays. High-throughput sequencing, from single PCR targets through to the analysis of whole genomes, offers significant promise towards providing information-rich data that may add value beyond traditional and conventional molecular approaches; however, thus far, its utility has not been fully explored to detect helminths in faecal samples.

An adaptive phase II/III safety and efficacy randomized controlled trial of single day or three-day fixed-dose albendazole-ivermectin co-formulation versus albendazole for the treatment of and other STH infections. ALIVE trial protocol.

Soil-transmitted helminths (STH) are targeted for control through mass drug-administration campaigns to prevent morbidity affecting at-risk groups in endemic regions. Although broadly successful, the use of albendazole and mebendazole achieved variable progress, with deficiencies against and a predictable low efficacy against . Novel drug combinations offer a potential solution, providing they can be delivered safely and maintain efficacy against all STH species.

Faecal egg counts and nemabiome metabarcoding highlight the genomic complexity of equine cyathostomin communities and provide insight into their dynamics in a Scottish native pony herd.

Understanding the composition of gastrointestinal nematode communities may help to mitigate or exploit parasite adaptations within their host. We have used nemabiome deep amplicon sequencing of internal transcribed spacer-2 (ITS-2) ribosomal DNA to describe the temporal and host species composition of gastrointestinal nematode communities following sampling of six Scottish ponies across 57 months. In the absence of parasite control, each horse showed seasonal trends of increases and decreases in faecal egg counts, consistent with the epidemiology of equine strongylid parasites, however, the composition of parasites within individuals changed over time.

Ivermectin and albendazole coadministration: opportunities for strongyloidiasis control.

In 2020, WHO recognised the importance of strongyloidiasis alongside soil-transmitted helminths (STH) in their 2021-30 roadmap, which aspires to target Strongyloides stercoralis with preventive chemotherapy by use of ivermectin. Combination treatment with both albendazole, the primary drug used to treat STH, and ivermectin, would improve the efficiency of mass drug administration targeting both STH and S stercoralis. In this Personal View, we discuss the challenges and opportunities towards the development of an efficient control programme for strongyloidiasis, particularly if it is to run concurrently with STH control.

Improving helminth genome resources in the post-genomic era.

Rapid advancement in high-throughput sequencing and analytical approaches has seen a steady increase in the generation of genomic resources for helminth parasites. Now, helminth genomes and their annotations are a cornerstone of numerous efforts to compare genetic and transcriptomic variation, from single cells to populations of globally distributed parasites, to genome modifications to understand gene function. Our understanding of helminths is increasingly reliant on these genomic resources, which are primarily static once published and vary widely in quality and completeness between species.

Worms and bugs of the gut: the search for diagnostic signatures using barcoding, and metagenomics-metabolomics.

Gastrointestinal (GI) helminth infections cause significant morbidity in both humans and animals worldwide. Specific and sensitive diagnosis is central to the surveillance of such infections and to determine the effectiveness of treatment strategies used to control them. In this article, we: (i) assess the strengths and limitations of existing methods applied to the diagnosis of GI helminth infections of humans and livestock; (ii) examine high-throughput sequencing approaches, such as targeted molecular barcoding and shotgun sequencing, as tools to define the taxonomic composition of helminth infections; and (iii) discuss the current understanding of the interactions between helminths and microbiota in the host gut.

A genetic TRP down the channel to praziquantel resistance.

The anthelmintic praziquantel (PZQ) is an essential tool in controlling schistosomiasis, so reports of reduced PZQ efficacy are of great public health concern. Le Clec'h et al. recently identified a gene responsible for PZQ resistance in experimentally selected resistant Schistosoma mansoni.

Genome-wide analysis of the response to ivermectin treatment by a Swedish field population of Haemonchus contortus.

Haemonchus contortus is a pathogenic gastrointestinal nematode of small ruminants and, in part due to its capacity to develop resistance to drugs, contributes to significant losses in the animal production sector worldwide. Despite decades of research, comparatively little is known about the specific mechanism(s) driving resistance to drugs such as ivermectin in this species. Here we describe a genome-wide approach to detect evidence of selection by ivermectin treatment in a field population of H.

The genome sequence of the Australian filarial nematode, .

We present a genome assembly and annotation of an individual female , a parasitic filarial nematode that is transmitted by hard ticks (Ixodidae) to infect a broad range of native Australian murid and marsupial hosts. The genome sequence is 76.9 Mbp in length, and although in draft form (N50 = 99 kbp, N50[n] = 232), is largely complete based on universally conserved orthologs (BUSCOs; genome = 94.