Canine parvovirus (CPV) type 2a (CPV-2a) has recently been identified as the main genotype circulating in the dog population in South Korea. Although CPV vaccines protect domestic dogs from CPV-2 infection, the efficacy of commercial live or inactivated CPV vaccines against CPV-2a has not been reevaluated. In this study, dogs were immunized with one of 7 commercial CPV vaccines (4 modified live and 3 inactivated vaccines) followed by challenge with CPV-2a strain, KV0901 that had been isolated from naturally infected dog in 2009. All dogs vaccinated twice with 4 commercial modified live CPV vaccines were seroconverted (geometric mean HI titer > 190.2) and most of dogs were completely protected against virulent CPV-2a strain infection. The dogs inoculated with 3 commercial inactivated CPV vaccines were also seroconverted and showed a slight loss of appetite and light diarrhea for 4 days after challenge and returned to normal at 5 days post challenge. However, the non-vaccinated dogs revealed the typical clinical signs of CPV infection including haemorrhgic diarrhea. In conclusion, the 4 live CPV vaccines licensed in Korea cross-protected dogs against virulent challenge with CPV-2a and are applicalble to pet dogs for the prevention of CPV infection.

The objective of this study was to investigate the effect of a herd specific vaccine against Staphylococcus aureus (S. aureus) by different inoculation route, IMI (intramammary injection), Koso, and supramammary lymphnode area. Based on strains of S. aureus from a case of acute clinical mastitis in Daekwanryeong farm, two experimental vaccines were made, inactivated vaccine and sonicated one. To determine the antigen concentration of the vaccine, 220 ICR-mice were immunized by the intraperitoneal route with inactivated or sonicated experimental vaccines according to different schedules with 10 ICR mice as a control group. The sonicated vaccine was selected for further experiments in vaccination and the highest antibody titer in ELISA was observed at 3㎎/㎖ of the vaccine. The vaccine was administrated to 22 healthy cows at drying up. The quarter milk samples and bloods were collected before vaccination, right after parturition and 3 months postpartum. There were no significant differences among vaccination routes based on the antibody titers in serum and intramammary bacterial infections during drying up period. The antibody titer in serum of vaccinated cows was higher at parturition than 3 months postpartum but it had no statistical meaning, though decreased clinical signs and morbidity were observed. Results of this study suggest that the concept of the vaccine against S. aureus is to decreasing clinical mastitis rather than preventing the disease.

Although several enteric viral pathogens including the porcine groups A, B and C rotaviruses (PGARV, PGBRV, and PGCRV), sapovirus (PSaV), and torovirus (PToV) are known to cause endemic diarrheas in weaning and post-weaning piglets, their precise prevalence in Korea is not clear. Therefore, we examined 1,222 diarrhea stools obtained from 627 farms during 2004～2009 by RT-PCR and/or nested PCR for evaluating their precise prevalence in Korea. PGARV was the predominant pathogen during 2004～2007 but its prevalence was markedly reduced during 2008～2009. PGBRV infections caused endemic diarrhea during 2004～2007, but was hardly detected during 2008-2009. PGCRV was detected at 27.0%, 14.5%, 42.4%, 28.8%, 7.3%, and 54.2% during each year of 2004～2009, respectively, indicating its high prevalence in Korea throughout the years. PSaV induced with high prevalence (32.4-39.2%) during 2004～2005 but its detection rate was markedly decreased during 2006～2009. PToV caused sporadic infections only during 2006 (1.0%) and 2007 (6.9%). These enteric viruses were detected in diarrhea specimens in piglets usually in combination with each other and/or together with bacterial pathogens including the Escherichia coli, Salmonella spp., Brachispira hyodysenteriae, and Lawsonia intracellularis. Infections with PGARV, PGCRV, PSaV, and PToV were more prevalent in fecal samples collected in cold seasons. These results provide important epidemiological data for the control and establishment of a surveillance system for the prevailing enteric viruses in Korea.