Seroprevalence of and risk factors for Neospora caninum infection in yaks (Bos grunniens) in China.

The aim of the present study was to detect the seroprevalence of Neospora caninum infection in yaks in Gansu province, China. Serum samples from 974 white yaks and 610 black yaks were tested by a commercial competitive-inhibition ELISA for the detection of specific anti-N. caninum antibodies.; N. caninum antibodies were detected in 10.4% of yaks with higher prevalence in black (11.5% of 610) than white yak (8.6% of 974). Age, regions and sampling times were considered as risk factors associated with N. caninum infection. These results revealed the seroprevalence of N. caninum in white yaks for the first time in China.

Seroprevalence of Neospora caninum infection in farmed sika deer (Cervus nippon) in China.

Neospora caninum is a worldwide protozoan that can induce neuromuscular disease in dogs and reproductive failure in domestic and wild ruminants. The objective of the present investigation was to determine the seroprevalence of N. caninum infection in farmed sika deer in China as little is known of this host-parasite relationship. A total of 1800 serum samples were collected during 2013 and 2014 from farmed sika deer in the major production areas of Liaoning, Jilin and Heilongjiang provinces.Assay by ELISA for N. caninum antibodies indicated a seroprevalence of 13.6% in 2013 and 15.8% in 2014, varying in different regions from 9.5% to 27.5%. Statistical analysis revealed that prevalence in animals aged >4 years (20.4%) was significantly higher than in the age ranges <2 years (9.6%) and 2-4 years (11.4%) (P<0.01). Moreover, sika deer in herds with a history of miscarriage (41.9%) had a significantly higher seroprevalence than in those without (12.6%) (P<0.01). The present survey confirms that N. caninum does occur in farmed sika deer in China and provides base-line data for the design and evaluation of measures for its control and prevention in this host.

Isolation and identification of a canine coronavirus strain from giant pandas (Ailuropoda melanoleuca).

Two giant pandas (Ailuropoda melanoleuca) died of unknown causes in a Chinese zoo. The clinical disease profile suggested that the pandas may have suffered a viral infection. Therefore, a series of detection including virus isolation, electron microscopy, cytobiological assay, serum neutralization and RT-PCR were used to identify the virus. It was determined that the isolated virus was a canine coronavirus (CCV), on the basis of coronavirus, neutralization by canine anti-CCV serum, and 84.3% to 100% amino acid sequence similarity with CCV. The results suggest that the affected pandas had been infected with CCV.

Structure and function study of paramyxovirus fusion protein heptad repeat peptides.

Paramyxovirus might adopt a molecular mechanism of membrane fusion similar to that of other class I viruses in which the heptad repeat (HR) regions of fusion protein (F) HR1 and HR2 form a six-helix bundle structure inducing membrane fusion. In this study, we examined the structure and function of HR1 and HR2 from the avian paramyxovirus-2 (APMV-2) F protein. The study showed that APMV-2 HR1 and HR2 formed a stable six-helix bundle. Only a soluble APMV-2 HR2 peptide showed potent and specific virus-cell fusion inhibition activity. Cross-inhibiting activity with APMV-1 (Newcastle disease virus, NDV) was not found. A possible mechanism of membrane fusion inhibition by the paramyxovirus HR2 peptide is discussed.