Crytosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi are important diarrheal pathogens with a global distribution that threatens the health of humans and animals. Despite cattle being potential transmission hosts of these protozoans, the associated risks to public health have been neglected. In the present study, a total of 1155 cattle fecal samples were collected from 13 administrative regions of Heilongjiang Province. The prevalence of Cryptosporidium spp., G. duodenalis, and E. bieneusi were 5.5% (64/1155; 95% CI: 4.2–6.9), 3.8% (44/1155; 95% CI: 2.7–4.9), and 6.5% (75/1155; 95% CI: 5.1–7.9), respectively. Among these positive fecal samples, five Cryptosporidium species (C. andersoni, C. bovis, C. ryanae, C. parvum, and C. occultus), two G. duodenalis assemblages (E and A), and eight E. bieneusi genotypes (BEB4, BEB6, BEB8, J, I, CHS7, CHS8, and COS-I) were identified. Phylogenetic analysis showed that all eight genotypes of E. bieneusi identified in the present study belonged to group 2. It is worth noting that some species/genotypes of these intestinal protozoans are zoonotic, suggesting a risk of zoonotic disease transmission in endemic areas. The findings expanded our understanding of the genetic composition and zoonotic potential of Cryptosporidium spp., G. duodenalis, and E. bieneusi in cattle in Heilongjiang Province.

Fasciolosis is a globally prevalent trematode infection of major veterinary and public-health relevance. Juveniles migrate through liver tissue for weeks before patency, so clinically important infection may occur while faecal egg output is undetectable, complicating control and interpretation of apparent treatment failure. Triclabendazole (TCBZ) remains central because it targets both immature and adult flukes, but sustained use has been accompanied by geographically expanding reports of reduced efficacy and confirmed resistance. Most alternative fasciolicides, such as albendazole, closantel, oxyclozanide, rafoxanide, clorsulon and nitroxynil, are largely adulticidal and used alone or in combinations, yet reports of reduced efficacy/resistance are increasing worldwide. This review summarises drugs in current use and reported resistance status, and outlines a practical pathway for detecting and confirming resistance. We then appraise leading mechanistic hypotheses for TCBZ resistance as a central case study, organised around microtubule-associated phenotypes, reduced effective drug exposure, genetic architecture with tissue context, stress response and detoxification capacity, and we highlight mechanistic gaps for other fasciolicides. Finally, we discuss management implications, including monitoring-guided stewardship, stage-appropriate drug selection, rational combinations, integrated parasite management, and identify near-term priorities for harmonised surveillance, improved diagnostics and tool development. This review updates the resistance landscape and supports practical, monitoring-guided control of fasciolosis.

Background: Cambaroides schrenckii is an endangered freshwater crayfish in China, belonging to the genus Cambaroides, that can act as a complementary host for paragonimus. The objective of this study was to examine the complete mitochondrial genome characteristics and their evolutionary relationships within the Astacidea. Methods: The analysis of gene rearrangements and evolutionary relationships was conducted through the sequencing of the mitochondrial genome of C. schrenckii. Results: C. schrenckii mitochondrial genome length was 15,572, comprising thirteen PCGs, two rRNAs, 22 tRNAs, and one d-loop region of C. schrenckii. The mitochondrial genome of C. schrenckii exhibits an A + T content of 69.61% and a G + C content of 30.39%. Among the thirteen PCGs, cytb, nad3, and nad6 have a start codon of ATT, while the other ten PCGs have ATC, ATA, and ATG start codons. All 22 tRNA genes displayed a typical cloverleaf secondary structure. Gene rearrangement analysis showed that seven gene arrangements were identified based on PCGs in the infraorder Astacidea, with type I being the most common. Conclusions: The relationship between the American Cambaridae is closer to Astacidae than the Asian Cambaridae. The present study provides a theoretical basis for further discussions of developmental relationships in the infraorder Astacidea.