This study was performed to estimate the seroprevalence of PRRSV in breeding farms in Jeju 2008 using a commercial enzyme-linked immunosorbent assay (ELISA) kit. The tested sera were randomly collected from a total of 1,947 sera from 9 breeding farms unvaccinated in Jeju. As a result, all breeding farms were seropositive for PRRSV. Seven hundred-eighty six of 1,947 sera (40.4%) were positive for PRRSV. Seropositve rate of PRRSV infection in 9 farms showed various levels: 1%, 8.9%, 9.1%, 43%, 46.9%, 48.2%, 51.6%, 60.9%, 85.5%, respectively. The results confirmed that PRRSV infection has been prevailing in breeding farms in Jeju. Also, these results must be taken into a consideration in strategy establishment for the control and eradication of PRRS.

The lung and lymph node samples were collected from 786 pig farms associated with wasting and respiratory syndrome during 2005～2009. All samples were tested for the detection of porcine reproductive and respiratory syndrome virus (PRRSV) and the differentiation of its genotype using reverse transcriptase-polymerase chain reaction (RT-PCR). 643 farms (81.8%) of the pig farms examined were positive for PRRSV, of which 57.2% accounted for PRRSV type 1 and 70.2% accounted for PRRSV type 2. Furthermore, 37.5% of the farms positive for PRRSV, showed the coexistence of two genotypes. The results indicate that the PRRSV infections of single genotype or two genotypes are very common in Korean pig farms.

Porcine reproductive and respiratory syndrome (PRRS) virus causes not only breeding disorder such as abortion, stillbirth and premature birth to pregnant sows but economic damage like high estrous return and low delivery rate. The presented study was conducted to confirm seroprevalence of PRRS in Jeju herds. PRRS positive rate was examined with pig serum from hog farms located in Jeju. Serum samples were extracted from the 11 of sow farms and 10 of hog farms, The groups were divided into 20, 40, 60, 80, 100 and older than 120 days of age and pregnant sows in hog farms. Anti-PRRSV antibody titers in sera were analyzed by ELISA. All the breeding farms and hog farms (10/10) showed PRRS positive except one breeding farm (1/11). Serological patterns determined by ELISA did not show any difference regardless of whether pigs were vaccinated or not. Nevertheless, the farms unvaccinated pigs displayed low productivity in terms of piglet loss rate and prolonged period of shipment. Therefore, vaccination against PRRSV appears to be a crucial factor in sanitary management of hog farms. Taken together, since PRRSV was spread widely in Jeju already, stabilization of sows by PRRS vaccination after adapting PRRSV free sow by all-in-all-out method in farms is recommended for the control strategy for PRRS.

Influenza virus infection is a zoonosis that results in high mortality in animals and humans. Several recent avian influenza outbreaks have posed a significant public health threat to humans because there have been many cases of direct interspecies transmission from birds to humans. Influenza virus infection causes acute respiratory failure, which is the main cause of death, while chronic influenza virus infection in the central nervous system results in neural dysfunction. Of particular interest, according to one report, a group of patients who recovered from influenza virus infection during pandemics showed neuropsychiatric disorders, including depression, schizophrenia, and Parkinsonism. Thus, study of the etiology of neuropsychiatric disorders caused by influenza virus infection is needed. In order to conduct necessary experiments, it is essential to reproduce neurological phenomena that are manifested by human patients who have recovered from influenza virus infection using laboratory animals. In this review, we will discuss some of the facts that should be considered when establishing an animal model for study of central nervous system responses to influenza virus infection using mice.

Rice black-streaked dwarf virus (RBSDV), a member of the genus Fijivirus within the family Reoviridae, is the causative agent of maize rough dwarf and rice black-streaked dwarf diseases, both of which can lead to severe yield losses in east Asia. Although molecular approaches such as RT-PCR have potential for detection and diagnosis of this virus infections, their impact on high throughput certification is still limited. Therefore, the development of an antibody-based assay for rapid and effective diagnosis of RBSDV is preferable. In this study, we collected RBSDV from rice with rough dwarf disease and its complete nucleotide sequences of 10 genomic segments encoding 12 non-overlapping ORFs were determined. Among 12 ORFs, ORF1, 2 and 12 showed high level of similarities with the RdRp, major core protein and major outer shell protein, respectively. These ORFs were expressed as polyhedrin fusion protein or full-length soluble protein using baculovirus expression system for the preparation of specific antibody against RBSDV, which could be useful for the detection and diagnosis of this virus.

Classical swine fever virus (CSFV) envelope glycoprotein E2 is the main target for inducing neutralizing antibodies and protective immunity in swine. Here, we report a novel strategy forthe large-scale production of a CSFV E2 subunit vaccine that demonstrates a high immunogenic capability in the larvae of a baculovirus-infected silkworm, Bombyx mori. We constructed a recombinant B. mori nucleopolyhedrovirus (BmNPV) that expressed recombinant polyhedra together with the N-terminal 179 amino acids of CSFV E2 (CSFV E2ΔC). BmNPV-E2ΔC-infected silkworm larvae expressed an approximately 44-kDa fusion protein that was detected using both anti-polyhedrin and anti-CSFV E2 antibodies. Electron and confocal microscopy both demonstrated that the recombinant polyhedra were morphologically normal and contained CSFV E2ΔC. The CSFV E2ΔC antigen produced in BmNPV-E2ΔC-infected silkworm larvae reached 0.68 mg per ml of hemolymph and 0.53 mg per larva at 6 days post-infection. Mice that were immunized with the granule form of recombinant polyhedra or the soluble form of the fusion protein elicited CSFV E2 antibodies, which indicated that the recombinant polyhedra carrying CSFV E2ΔC were immunogenic. The virus neutralization test showed that the serum from mice that were treated with recombinant polyhedra or the soluble form of the fusion protein contained significant levels of virus neutralization activity. These results demonstrate that the present strategy can be used for the large-scale production of CSFV E2 antigen and that the recombinant polyhedra containing CSFV E2ΔC as a granule antigen can be used as a potential subunit vaccine against CSFV.

Recently, several significant plant virus diseases have devastated various crops in agricultural fields of Korea, These virus disease are mostly transmitted and spread by vector insects, such as rice stripe virus (RSV) transmitted by planthopper Laodelphax striatellus, tomato spotted wilted virus (TSWV) by thrips Frankliniella occidentalis and tomato yellow leaf curl virus (TYLCV) by whitefly Bemisia tabaci. Insects as vectors are significantly important for the control of plant disease as well as insect themselves. Here, on the view of insects, interactive mechanisms of vector insect and plant pathogens were discussed on the system of TYLCV and B. tabaci. When insects acquisited virus they would be beneficial, neutral or detrimental. Generally, plant virus are ingested into the mouse and move from the gut to hemolymph and back to salivary gland. During this movement there would be numerous molecular interactions at a vector-virus specific mode. In addition, virus acquisition change vector's physiological and developmental states including longevity, fecundity and dispersal behavior. However, these interactive mechanisms of vector insects with plant virus are largely under investigated. B. tabaci is genetically diverse and transmit many begomoviruses including TYLCV. I demonstrated effects of TYLCV acquisition on fecundity, thermal response, endosymbiont profile and gene expression of B. tabaci.

In many cases over the years, we failed to forecast accurately outbreak of Rice stripe virus (RSV) disease using population density of overwintering small brown planthopper (SBPH), Laodelphax striatellus. What is the source of error in this viral disease assessment? For answering the question, spatial distribution of RSV in paddy fields was investigated in relation to the yield of rice grain, and the population density of overwintering SBPH in ridge of paddy fields. Total 14 paddy fields in 5 regions were surveyed in June, 2008. Disease assessment was carried out with each of 30 rice plants in the one of the borders, 5th, 10th line from ridge, and 90 rice plants in diagonal line for conventional method. The ears of rices from 18 plants in the same surveyed line were collected in the late of August for the weights of 100 rice grains. The infection rate of RSV was decreased by the distance from ridge; on the contrary, the increase tendency was shown in the yield of rice grains in the middle of paddy field. It is suggested that the border effect of viral distribution between ridge and paddy field is caused by the spatial distribution of the vector insect. Thus, in this case, the narrow border effect could represent that the SBPH migrated short distance from the ridge to paddy field. The conventional method, observing the disease in middle area of diagonal line, showed no correlation to the population density of overwintering vector generation in ridge. It might cause underestimation of the regional disease rate. The counting of RSV-diseased plant in border line only overestimated it also. However, the RSV infection rate in the near border had highly positive linear relationship (R2=0.91) to the regional average values by regression analysis. Therefore, the near border sampling method can improve the RSV disease risk assessment.

The effects of the genetically modified virus-resistant pepper (line: H15) and the Non-GM pepper (line: P2377) on the insect community in the pepper cultivation area were evaluated. Sampling was conducted using yellow sticky traps and pheromone funnel traps in Anseong and Deokso fields. Total number of insects caught on sticky trap were 3924 individuals at GM pepper and 3670 individuals at Non-GM pepper in Anseong and 2362 individuals at GM and 2528 individuals at Non-GM in Deokso, respectively. The total number of the insect individuals caught by sticky trap was not shown significant differences between GM and Non-GM pepper at Anseong and Deokso fields, respectively. The number of aphids per sticky trap ranged from 11.60±2.02 to 1.92±0.96 at Non-GM and from 11.56±2.15 to 0.33±0.23 at GM in Anseong, and from 2.78±1.22 to 0.11±0.08 and from 2.73±0.84 to 0.11±0.08 at Non-GM and GM pepper in Deokso, respectively. There were no significant differences in seasonal occurrences of aphids caught on sticky traps in GM and Non-GM pepper at both fields, and significant differences in aphids population density between Non-GM and GM were not observed.

경산 묘목단지는 대단위 과수종묘를 생산하고 있어 경쟁력 강화를 위하여 무독묘 보증 생산이 요구되고 있다. 특히 생산규모가 큰 사과종묘에 대한 빠르고 정확한 바이러스 진단이 시급하다. 본 연구에서는 사과바이러스 진단을 위하여 다량의 시료를 동시 분쇄할 수 있는 bead beater를 이용하였으며 분쇄 bead는 저가의 산업용 glass bead (0.4 mm 직경)를 일회용으로 채택하였다. RNA추출을 위하여서는 guanidine thiocyanate 용액이 Trizol 용액보다 효과적인 것으로 나타났으며 silica membrane tube의 이용으로 RNA추출 간편성을 높일 수 있었다. 사과바이러스는 RT-PCR에 의하여 검증하였다.

Pseudorabies virus (PRV), a member of the Alphaherpesviridae, is the causative agent of Aujeszky’s disease in pigs. Glycoprotein B (gB) of PRV, a major constituent of the viral envelope, consists of 916 amino acids. We continuously combined three gB epitopes, E1 (aa 62-129), E2 (aa 217-282), and E3 (aa 543-737). The DNA fragment containing the PRV gB epitopes was fused with polyhedrin gene in order to generate recombinant baculovirus that expresses the recombinant polyhedra with PRV gB epitopes under the control of the Bombyx mori nucleopolyhedrovirus polyhedrin promoter. Recombinant baculoviruses were injected into fifth-instar B. mori larvae. SDS-PAGE and Western blot analyses revealed that recombinant polyhedra constitute polyhedrin and PRV gB epitopes, and that the recombinant PRV gB epitopes showed cross-reactivity against antiserum of PRV gB produced from pig. To examine the immunogenicity of recombinant PRV gB epitopes, we injected into mice as model animals. ELISA results indicated that antibody production is increased in a similar manner in the injection of recombinant polyhedra with PRV gB epitopes, either injected recombinant polyhedra as a granule form antigen without adjuvant or injected recombinant polyhedrin as a soluble form antigen with adjuvant. Taken together, these data show that PRV gB epitopes were produced as a granule form antigen by fusing recombinant polyhedra in baculovirus-infected silkworm larvae and displayed the immunogenicity in mice, indicating the efficacy of the granule form antigen as a PRV gB vaccine.

Deformed wing virus (DWV) of honeybees (Apis mellifera) is closely associated with characteristic wing deformities, abdominal bloating, paralysis, and rapid mortality of emerging adult bees. Here, we report for the first time the occurrence of DWV-infected bumble bees (Bombus terrestris). For the present study, the detection of DWV virus from the adult bumble bee, death adult bumble bee, mail bumble bee, pupa and larva to the infection cycle was investigated in the same colony. Using specific RT-PCR protocols for the detection of DWV followed by sequencing of the PCR products we could demonstrate that the bumble bees were indeed infected with DWV. The virus was detected from diseased insects, and its partial DWV gene was cloned and sequenced. The partial DWV gene encoding the polyprotein is 711-nt of 235 amino acid residues. The deduced nucleotide sequence of the polyprotein partial gene of DWV showed 96.9%, 96.2%, 96.8%, and 96.5% homology to other structure polyprotein partial gene of DWV, respectively. Phylogenetic analysis further conformed that the deduced nucleotide sequence of the polyprotein partial gene of DWV divided to the outside tree. We describe the first time that presence of Deformed wing virus(DWV) from bumble bee(Bombus terrestris) in korea using RT-PCR.