First detection of porcine circovirus type 3 in Japan.

Porcine circovirus associated diseases (PCVAD) have multiple manifestations that have been attributed to porcine circovirus type 2 (PCV2). Recently, a novel porcine circovirus, PCV type 3 (PCV3), was identified in pigs with systemic inflammation of unknown etiology. In this study, we tried to detect the PCV3 genome in tissue samples collected from Japanese pig herds in 2016. The PCV3 genome was detected by PCR in 7 of 73 samples. The homology between each Japanese strain was 99.5% for the full-length sequence and 98.9 to 99.2% for the open reading frame 2. These results suggest that PCV3 has already invaded Japanese pig farms.

Efficacy of genogroup 1 based porcine epidemic diarrhea live vaccine against genogroup 2 field strain in Japan.

BACKGROUND: Porcine epidemic diarrhea (PED) is a lethal infectious disease in suckling piglets with symptoms including watery diarrhea caused by PED virus (PEDV). Since the late 1990's, live vaccines based on genogroup 1 virus have been used in Japan, and a significant amount of the vaccine has been used even after new genogroups invaded in 2013. In this study, we evaluated the effect of a conventional PED live vaccine on a newly prevalent genogroup 2 field strain in experimental and field situations. METHODS: Two pregnant sows were administered twice the live vaccine before farrowing. A pregnant sow was served as a negative control. All newborn piglets were challenged with the genogroup 2 virus, and clinical signs were monitored for 7 days post challenge. PEDV-specific immune responses in serum and milk of the sows were assayed by virus neutralization assay. The efficacy of PED live vaccine in vaccinated or non-vaccinated farms was evaluated by comparing the mortality rate of suckling piglets after the onset of PED. RESULTS: The challenged piglets exhibited watery diarrhea with or without vaccination. However, the clinical score of piglets born from vaccinated sows significantly improved after the 4th day of the challenge. The survival rate of piglets in the vaccinated group at the end of the experimental period was 80%, whereas in the control group was 0%. Neutralizing antibody titers in serum and milk of control sow was negative throughout the experimental period, whereas high titers were observed in the vaccinated sows. The vaccinated farms significantly reduced the mortality rate of suckling piglets after the onset of PED, compared to farms not vaccinated. CONCLUSIONS: The conventional PED live vaccine induced the lactogenic immunity to vaccinated sows and showed partial protection against the genogroup 2 virus both under the experimental and field conditions.

Distraction osteogenesis enhanced by osteoblastlike cells and collagen gel.

Femoral distraction was done in rats to determine whether the injection of osteoblastlike cells with collagen gel into the distracted callus was useful for new bone formation. The cells were obtained from the femoral marrow of Sprague-Dawley rats and cultured for approximately 3 weeks. These rats were divided into four groups. The rats in Group A received injections of physiologic saline, those in Group B received injections of collagen gel, those in Group C received injections of cells, and those in Group D received injections containing a mixture of cells and collagen gel. The distracted areas were harvested and evaluated by histologic analysis, radiography, three-point bending testing, and the weight of femoral ash. Histologic evaluation did not show an immunoreaction between the donor and recipient. Radiographs showed that Group D had the most callus, and the fracture strength in this group as determined by the three-point bending test was higher than in Group A at 2, 4, and 6 weeks after elongation was completed. Group D showed a significant difference in the ash weight of the distracted femurs at 2 weeks. The current study showed that osteoblastlike cells with collagen gel promoted new bone formation in the distracted gap, and shortened the consolidation period.