The Onchocercidae family is composed of more than 30 valid nematode species with notable zoonotic potential. Current limitations in molecular characterization methods and species identification are the main obstacles to a better understanding of the biology of Onchocercidae species, particularly in wildlife. This study describes for the first time the complete mitochondrial (mt) genome sequence of Neofoleyellides sp. isolated from a wild bird (Pyrrhocorax pyrrhocorax) and belonging to the Neofoleyellides genus (Nematoda: Onchocercidae). The mt genome of Neofoleyellides sp. (GenBank accession number: ON641583) was a typical circular DNA molecule of 13,628 bp in size with an AT content of 76.69%. The complete mt genome comprised 36 functional subunits, including 12 protein-coding genes (PCGs), 2 ribosomal RNA genes, and 22 transfer RNA genes. The most common start codon was ATT/ATG except for nad2 with TTG, and TAA was the termination codon for all protein-coding genes (PCGs). Phylogenetic analysis of the concatenated and aligned amino acid sequences of the 12 PCGs showed that the trees generated using different methods (Bayesian inference and maximum likelihood) with different partition schemes shared similar topologies. The isolated Neofoleyellides sp. was placed in the Onchocercidae family and formed a sister branch with the genera Onchocerca and Dirofilaria. The entire mt genome of Neofoleyellides sp. presented in this study could provide useful data for studying the population genetics and phylogenetic relationships of Onchocercidae species.

Fasciolosis is a significant zoonotic and common parasitic disease for animals and humans, creating public health concerns worldwide. This study retrieved articles related to the occurrence of Fasciola hepatica and Fasciola gigantica in sheep and goats in China by searching five databases: PubMed, ScienceDirect, the Chinese National Knowledge Infrastructure (CNKI), Wanfang Data, and the VIP Chinese Journal Database. A total of 60 valid articles were captured. The pooled prevalence of ovine and caprine fasciolosis was 26.00%. It was also found to be higher in the subgroups of Northwest China and Shaanxi Province, as well as in areas with a high altitude, rainfall of ≥800 mm, and temperature ranging between 10 °C and 20 °C. Analysis of the type of season and sampling years showed significant (p < 0.05) difference. In other subgroups, sheep (34.74%), hosts aged over 2 years (32.26%), females (48.33%) and free-range animals (26.83%) showed a higher disease prevalence. These results indicated that ovine and caprine fasciolosis was widely distributed, especially in Northwest China. The sampling years and the type of season are risk factors for the prevalence of ovine and caprine fasciolosis. Therefore, strategies for ovine and caprine fasciolosis control should be developed based on these epidemic risk factors, which will reduce the prevalence of fasciolosis in China.

Ticks carry and transmit a variety of pathogens, which are very harmful to humans and animals. To characterize the microbial interactions in ticks, we analysed the microbiota of the hard ticks, Dermacentor silvarum, Ixodes persulcatus, and Haemaphysalis concinna, using 16S rRNA, showing that microbial interactions are underappreciated in terms of shaping arthropod microbiomes. The results show that the bacterial richness and microbiota structures of these three tick species had significant differences. Interestingly, the bacterial richness (Chao1 index) of all ticks decreased significantly after they became engorged. All the operational taxonomic units (OTUs) were assigned to 26 phyla, 67 classes, 159 orders, 279 families, and 627 genera. Microbial interactions in D. silvarum demonstrated more connections than in I. persulcatus and H. concinna. Bacteria with a high abundance were not important families in microbial interactions. Positive interactions of Bacteroidaceae and F_Solibacteraceae Subgroup 3 with other bacterial families were detected in all nine groups of ticks. This study provides an overview of the microbiota structure and interactions of three tick species and improves our understanding of the role of the microbiota in tick physiology and vector capacity, thus being conducive to providing basic data for the prevention of ticks and tick-borne diseases.

Astacins, a family of zinc metalloproteinases, are involved in invasion and tissue migration processes in a variety of parasites. An astacin-like proteinases have been detected in the excretory-secretory products (ESPs) of Trichinella spiralis (T. spiralis), zinc metalloproteinase Nas-14 (TsNas14), but its function in T. spiralis remains unclear. The primary objective of this research was to delineate the molecular characterization of TsNas14 and explore its potential to compromise the integrity of the intestinal barrier. Results showed that TsNas14 contains an Astacin domain and two ShK domains. It is highly conserved and has a consistent transcriptional expression pattern in the Trichinella genus. Quantitative results showed that the TsNas14 is transcribed and expressed during the whole life cycle, but that the expression level was highest in the adult worm (AW) stage. In the 3d AW stage, TsNas14 is mainly distributed on the stichosome, ovary, cuticle, and hypodermis, while in the 6d AW stage, it is only present on the cuticle. Gelatin zymography showed that the oligomerized rTsNas14 had the enzyme activity to degrade gelatin, and could be effectively inhibited by 1,10-Phenanthroline, indicating that it had the natural activity of metalloproteinases. In vitro experiments showed that rTsNas14 can down-regulate the expression of occludin and claudin-1 proteins of human colorectal adenocarcinoma (Caco-2) cells and improve the permeability of an intestinal barrier model. In addition, the direct incubation of rTsNas14 with claduin-1 showed that rTsNas14 could significantly degrade claudin-1. In vivo studies have demonstrated that inhibition of TsNas14 expression significantly impairs the infectivity of T. spiralis in mice, resulting in a decreased AW and muscle larvae burden. These findings suggest that TsNas14 plays a crucial role in T. spiralis intestinal invasion and may serve as a novel potential target for Trichinella vaccines or therapeutic interventions.