The present study was carried out to investigate the pathogenicity and pathogenesis of wild rats(Rattus norvegicus), trapped in nature, intranasally infected Aujeszky's disease virus(ADV/NYJ-1-87) by histopathology, immunohistochemistry and in situ hybridization(ISH). Fifteen rats inoculated intranasally were roughened haircoat, anorexia, listlessness, and depression second day after inoculation, and three rats died in 66-72 hours. Eight rats showed severe pruritus at the fact that was accompanied by frequent face-washing movements of the forelegs, and then became violent and spasmodic for and hour or until they died. Four rats slowly recovered after showing mild clinical signs of the disease. Microscopic lesions in infected rats were characterized by meningitis, perivascular round cell infiltration, focal gliosis, and neuronal degeneration and necrosis. And intranuclear inclusion bodies were frequently detected in the cerebral cortex and medulla. Positive reaction to ADV by immunohistochemistry and ISH were detected in the following areas:trigemimal ganglion, brain, tonsil, nasal mucosa, spleen, lung and liver. The result has suggested that ADV intranasally infected in wild rats is followed by replication in epithelial cells of nasal mucosa and tonsil, then invade local lymph nodes by way of the lymphatics. It is also believed that the virus invades bipolar olfactory cells and trigerminal ganglion, and then spread into central nervous system.

Trichuris suis does not excrete eggs during larval stage as well as in particular adult stage. It is impossible to diagnose by use of fecal examination method in those periods. Therefore, serological diagnostic method can be very useful for those stages. In order to produce monoclonal antibody, specific somatic and secretory-excretory (SE) antigens of T. suis were identified and analyzed by SDS-PAGE and Western blot. Monoclonal antibody-producing hybridoma cells were cloned, which were made of popliteal lymph node of BALB/c mice immunized with a 45 kDa somatic antigen of T. suis.

A 474-base pair segment covering the hypervaible region of VP2 gene from six Korean infectious bursal disease virus(K-IBDV) isolates(K1, K2, SH/92, 225, 269, 310) and one attenuated IBDV(DAE) were amplified using RT-PCR, sequenced, and compared with published sequences for IBDV. K-IBDV isolates(K1, K2, SH/92, 225, 269) and foreigh very virulent(vv) IBDV strains had 94.93-100% amino cid sequence similarity. K-IBDV isolate 310 and other K-IBDV isolates had 84.31%-86.07% amino acid sequence similarity. Attenuated strain(DAE), like other attenuated strain, has substitution at positions 279(D to N) and 284(A to T) as well as in the serine-rich heptapeptide region. Five K-IBDV isolates except 310 isolate share unique amino acid residues at positions 222(A), 256(I), 294(I) which are not present in other standard and attenuated strains. At the two hydrophilic region, K-IBDV isolates except 310 isolate had identical amino cids comparing with Belgium vv IVDV 894VB but had four amino acid substitutions comparing with Chinese vv IBDV F9502. The SWSASGS heptapeptide is conserved in all KIBDV isolates. The sequence of K-IBDV isolate 310 was markedly different from other IBDV strains, evolving from a separate lineage than the others. By phylogenetic analysis, Five K-IBDV isolates except 310 isolate were categorized in one group with foreign vv IBDV isolates but K-IBDV isolate 310 was categorized ina separate group which was differentiated form other compared IBDV strains

The present work was conducted to investigate the drug susceptibility of microorganisms isolated form canine external ear canals. Antifungal susceptibility test of M pachydermatis(17 strains) was performed by agar dilution method, using 11 antifungal drugs including amphotericin B(A), nystatin(N), pimaricin(P), griseofulvin(G), gifonazole(B), clotrimazole(C), miconazole(M), econazole(E), ketoconazole(K), tolnaftate(T), 5-fluorocytosine(F). All isolates were highly sensitive to K, M, T(geometric mean MIC;GM MIC_0.16 micro gram/ml). Antibacterial susceptibility test against 119 isolates of bacteria was performed by agar dilution method, using 9 antibacterial drugs including erythromycin(ET), chloramphenicol(CP), gentamycin(G), vancomycin(V), ampicillin(AP), amoxacillin(AX), chlortetracycline(CT), ciprofloxacin(CF), enrofloxacine(EF). All isolates of Staphylococcus spp(101 strains) were highly sensitive to EF, CF, G(GM MIC 0.33~1.47 micro gram/ml). In other gram positive cocci(4 strains), they were highly sensitive to EF, CF, V(GM MIC 1~4.76 micro gram/ml) and CT(GM MIC 1 UFL unit/ml). In gram positive rods(13 strains), they were highly sensitive to EF, CF, G(GM MIC_0.19~1 micro gram/ml). In Pseudomonas aeruginosa(1 strain), it was highly sensitive to AX, EF, ET, CF(GM MIC 0.06~1 micro gram/ml) and CT(GM MIC 1 UFL unit/ml). All isolates weren't sensitive to AP(GM MIC 16~32 micro gram/ml).

The common pathogen Salmonella enteirtidis (S. enteritidis) is the major cause of foodborne disease. Protein identification by peptide mass fingerprinting using the matrix-assisted laser desorption ionization time of fight (MALDI-TOF) mass spectrometry (MS) can analysis unambiguously identity the spots from 2-dimensional electrophoresis (2-DE) gel. In this report, we examined protein components from patterns of S. enteritidis proteins. In addition, antigens that are recognized by sera can be identified by immunoblotting.

The oil emulsion and alhydrogel pilli vaccines were prepared from a strain (O9: K35, K99, F41) of enterotoxigenic Escherichia coli isolated from calves with diarrhea and their immunogenicity was tested in guinea-pigs, pregnant goats and cows. Serum antibody responses to K99 and F41 antigens in guinea-pigs given experimental oil and gel vaccines peaked at 4 and 6 weeks after vaccinations. At that time, the mean hemagglutination inhibition titers to K99 and F41 antigens in guinea pigs given oil vaccine were 1:25 and 1:1,218 and those given gel vaccine were 1:54 and 1:724 respectively

Effects of binary ethylenimine (BEI) treatment on the inactivation of infectivity and hemagglutinin of Newcastle disease virus (NDV) were studied in comparison with those of formalin treatment. Immune responses of chickens vaccinated with BEI- inactivated NDV vaccines were also investigated. Complete loss of infectivity of NDV (BI) was observed at 3, 7, and 24 hrs after the treatment at 37 deg C with BEI concentrations of 0.01M, 0.005M and 0.001M, respectively