International journal for parasitology最新文献

Livestock production is vital to the economies and food security of African countries. Rising global demand for livestock-derived products intensifies the challenge of managing ticks and tick-borne diseases. This study aimed to optimize a Bm86-based vaccine for controlling Rhipicephalus microplus. Commercial Bm86-based vaccines show variable efficacy (0-100 %), reflecting incomplete understanding of the antigen and the immune response elicited. To address this, homologous challenge was conducted in Holstein-Friesian calves with Bm86 formulated with Montanide™ ISA 71 VG (referred to as Montanide™) and a novel Alum-based adjuvant alternative in two separate vaccine trials. Antibody responses were determined utilising indirect ELISA. Vaccine efficacy was assessed through controlled R. microplus challenge. Immunoinformatics mapped the antigenic regions of Bm86, followed by ex vivo validation using antisera from vaccinated cattle. Both adjuvant formulations induced high levels of Bm86-specific total IgG antibodies. However, only the Montanide™ formulation induced a protective response of 88.2 %, which correlated with total IgG antibody levels (r = 0.86). In contrast, the Alum-based adjuvant formulation induced low efficacy (2.3 %) with a strong inverse correlation with total IgG antibodies (r = -0.95). Both formulations induced an IgG1-biased (i.e. T-helper 2) antibody response, but the Montanide™ formulation conferred a more balanced IgG1/IgG2 response. The efficacy induced by the Montanide™ formulation strongly correlated with the levels of IgG2 antibodies (r = 0.91), suggesting that a balanced Th1/Th2 response plays a key role in protection. Despite its efficacy, the Montanide™ formulation caused adverse injection site effects, highlighting the need for safer alternatives. Epitope mapping identified similar linear B-cell epitope regions recognised by total IgG antibodies induced by vaccination with both adjuvant formulations. These findings suggest that Bm86 vaccination activates broader immune pathways than previously understood, emphasizing the need for exploration of additional immune markers to improve vaccine performance.

The subfamily Chalcinotrematinae (Haploporidae) comprises an understudied group of digenean parasites infecting freshwater and brackish water fishes across the Americas, Africa, and Asia. Its systematics has rarely been investigated using molecular data, with DNA sequences available for only a few species representing two of the six recognised genera. We collected chalcinotrematine trematodes from freshwater fishes in the Jari River, Amazon Basin, Brazil, and in Misiones, Argentina. Specimens from Brazil were characterised through an integrative approach combining morphological examination with molecular data (partial 28S and ITS2 rDNA sequences), whereas those from Argentina were analysed morphologically. As a result, we describe two new species from Brazil: Chalcinotrema arleneae sp. nov. from Leporinus friderici and Laemolyta proxima, and Unicoelium gerardoi sp. nov. from Hypostomus plecostomus. This study provides the first molecular data for both Chalcinotrema and Unicoelium, expanding the phylogenetic framework of Chalcinotrematinae. Paralecithobotrys brasiliensis is recorded from Argentina in Megaleporinus obtusidens, extending its geographical range. We reassessed the generic limits of Saccocoelioides, the most species-rich genus within the subfamily. Based on combined morphological, molecular, host, and distributional evidence, we propose taxonomic revisions, establishing Neosaccocoelioides gen. nov. for several South American species formerly assigned to Saccocoelioides: N. antonioi comb. nov., N. bacilliformis comb. nov., N. elongatus comb. nov., N. magnus comb. nov., N. miguelmontesi comb. nov. (type species), and N. szidati comb. nov. Additionally, N. platense comb. nov., previously placed in Chalcinotrema, is transferred to the new genus. Saccocoelioides chilkaensis and S. lizae are considered species inquirendae; and S. guaporense is considered incertae sedis. These findings refine chalcinotrematine relationships and highlight the need for expanded molecular datasets to resolve systematic and biogeographical uncertainties.

Deep amplicon sequencing is transforming parasitology by enabling high-throughput profiling of parasite communities and detection of resistance-associated genetic variants. Despite its growing adoption, many researchers face challenges in implementation, and its full potential is often hindered by challenges in experimental design, including marker selection, data analysis and reproducibility. This article presents ten simple rules for applying deep amplicon sequencing in parasitology, developed through expert consensus at a deep amplicon sequencing symposium during the 2025 World Association for the Advancement of Veterinary Parasitology conference. These rules cover essential aspects from formulating research questions and choosing appropriate markers to managing data workflows and contributing to reference databases. We highlight the importance of integrating deep amplicon sequencing with traditional parasitological methods, ensuring transparent reporting and investing in capacity building. Whether you are new to deep amplicon sequencing or seeking to improve your current practices, these guidelines offer practical advice to enhance the robustness, reproducibility, and impact of your research. By adopting these principles, parasitologists can contribute to, and advance, a more reliable and collaborative scientific landscape.