Mink enteritis virus (MEV) causes mink viral enteritis, an acute and highly contagious disease whose symptoms include violent diarrhea, and which is characterized by high morbidity and mortality. Nanoparticle-assisted polymerase chain reaction (nanoPCR) is a recently developed technique for the rapid detection of bacterial and viral DNA. Here we describe a novel nanoPCR assay for the clinical detection and epidemiological characterization of MEV. This assay is based upon primers specific for the conserved region of the MEV NS1 gene, which encodes nonstructural protein 1. Under optimized conditions, the MEV nanoPCR assay had a detection limit of 8.75 × 101 copies recombinant plasmids per reaction, compared with 8.75 × 103 copies for conventional PCR analysis. Moreover, of 246 clinical mink samples collected from five provinces in North-Eastern China, 50.8% were scored MEV positive by our nanoPCR assay, compared with 32.5% for conventional PCR. Furthermore no cross reactivity was observed for the nanoPCR assay with respect to related viruses, including canine distemper virus (CDV) and Aleutian mink disease parvovirus (AMDV). Phylogenetic analysis of four Chinese wild type MEV isolates using the nanoPCR assay indicated that they belonged to a small MEV clade, named “China type”, in the MEV/FPLV cluster, and were closely clustered in the same location. Our results indicate that the MEV China type clade is currently circulating in domestic minks in China. We anticipate that the nanoPCR assay we have described here will be useful for the detection and epidemiological and pathological characterization of MEV.

Serine proteases form one of the most important families of enzymes and perform significant functions in a broad range of biological processes, such as intra- and extracellular protein metabolism, digestion, blood coagulation, regulation of development, and fertilization. A number of serine proteases have been identified in parasitic helminths that have putative roles in parasite development and nutrition, host tissues and cell invasion, anticoagulation, and immune evasion. In this review, we described the serine proteases that have been identified in parasitic helminths, including nematodes (Trichinella spiralis, T. pseudospiralis, Trichuris muris, Anisakis simplex, Ascaris suum, Onchocerca volvulus, O. lienalis, Brugia malayi, Ancylostoma caninum, and Steinernema carpocapsae), cestodes (Spirometra mansoni, Echinococcus granulosus, and Schistocephalus solidus), and trematodes (Fasciola hepatica, F. gigantica, and Schistosoma mansoni). Moreover, the possible biological functions of these serine proteases in the endogenous biological phenomena of these parasites and in the host-parasite interaction were also discussed.

In this study, a total of 37 samples (58.0%) were found through PCR assay to be positive for canine parvovirus (CPV) of 66 suspected faecal samples of dogs collected from various cities throughout China. Eight CPV isolates could be obtained in the CRFK cell line. The sequencing of the VP2 gene of CPV identified the predominant CPV strain as CPV‐2a (Ser297Ala), with two CPV‐2b (Ser297Ala). Sequence comparison revealed homologies of 99.3–99.9%, 99.9% and 99.3–99.7% within the CPV 2a isolates, within the CPV 2b isolates and between the CPV 2a and 2b isolates, respectively. In addition, several non‐synonymous and synonymous mutations were also recorded. The phylogenetic tree revealed that most of the CPV strains from different areas in China were located in the formation of a large branch, which were grouped together along with the KU143‐09 strain from Thailand and followed the same evolution. In this study, we provide an updated molecular characterization of CPV 2 circulation in China.