Actinobacillus (A.) pleuropneumoniae is the causative agent of pleuropneumonia which is one of the most important respiratory diseases in pigs worldwide. A total of 32 A. pleuropneumoniae isolates from diseased pigs during 2008 to 2010 were serotyped by polymerase chain reaction method. The susceptibility of the isolates to 13 antimicrobial agents were determined by disk diffusion test. In all the 32 isolates examined in this study, serotype 5 (16 isolates: 50%), 1 (7 isolates: 21.9%), 2 (5 isolates: 15.6%) and 12 (1 isolate: 3.1%) were found. Of all tested antimicrobial agents, resistance to oxytetracycline was found in 96.9% of isolates, followed by resistance to amikacin (81.2%), neomycin (68.7%), kanamycin (53.1%), penicillin (50.0%), gentamicin (43.7%), florfenicol (25.0%), ampicillin (18.7%), colistin (9.4%), trimethoprim/sulfamethoxazole, ceftiofur (8.3%), amoxicillin/clavulanic acid (3.1%) and enrofloxacin (0%). Oxytetracycline or florfenicol-resistant isolates were examined for the presence of resistance gene. Among the 31 oxytetracycline-resistant isolates, tetB, tetH and tetO genes were detected in 22 (71%), 8 (26%) and 1 (3%) isolates, respectively. The floR genes were detected in 8 (100%) of the 8 florfenicol-resistant A. pleuropneumoniae isolates.

The maintenance of peripheral immune tolerance and prevention of chronic inflammation and autoimmune disease require CD4+CD25+ T cells (regulatory T cells). The transcription factor Foxp3 is essential for the development of functional, regulatory T cells, which plays a prominent role in self-tolerance. Retroviral vectors can confer high level of gene transfer and transgene expression in a variety of cell types. Here we observed that following retroviral vector-mediated gene transfer of Foxp3, transductional Foxp3 expression was increased in the liver, lung, brain, heart, muscle, spinal cord, kidney and spleen. One day after vector administration, high levels of transgene and gene expression were observed in liver and lung. At 2 days after injection, transductional Foxp3 expression level was increased in brain, heart, muscle and spinal cord, but kidney and spleen exhibited a consistent low level. This finding was inconsistent with the increase in both CD4+CD25+ T cell and CD4+Foxp3+ T cell frequencies observed in peripheral immune cells by fluorescence-activated cell-sorting (FACS) analysis. Retroviral vector-mediated gene transfer of Foxp3 did not lead to increased numbers of CD4+CD25+ T cell and CD4+Foxp3+ T cell. These results demonstrate the level and duration of transductional Foxp3 gene expression in various tissues. A better understanding of Foxp3 regulation can be useful in dissecting the cause of regulatory T cells dysfunction in several autoimmune diseases and raise the possibility of enhancing suppressive functions of regulatory T cells for therapeutic purposes.

A total of 18 Newcastle disease virus (NDV) isolates that were recovered from 1949 through 1997 were characterized and pathotyped. All viruses were highly virulent as determined by intracerebral pathogenicity indices greater-than or equal to 1.81 in day-old. These pathotypes are typical for viscerotropic velogenic NDV (VVNDV) pathotype viruses. Some differences were observed for the chicken red blood cell elution rate and thermostability of the hemagglutinin at 56℃. Three antigenic groups were identified by a hemagglutination-inhibition assay using NDV monoclonal antibodies. And the predominant gross lesions were as follows: discharge from the nasal cavity, tracheal mucus, petechial hemorrhage in the heart fat, kidney urates and hemorrhage with or without necrosis in the gastrointestinal tract. Severe hemorrhagic or necrotic lesions were also noted in the lymphoid organs and were localized primarily in the spleen and cecal tonsil. However, differences in the occurrence and frequency of the gross lesions were observed between the virus strains. Among them, NDV strains that induced neurological symptoms belonged only to genotype Ⅵ. This strain had spread throughout Korea during the late 1980s to the 1990s, which suggests that specific VVNDVs genotypes might result in neurological symptoms.

The worldwide distribution and continuing genetic mutation of avian influenza virus (AIV) has been posed a great threat to human and animal health. A comparison of 3 isolates of AIV H9N2, A/chicken/Korea/KBNP-0028/00 (H9N2) (KBNP-0028), A/chicken/Korea/SNU8011/08 (H9N2) (SNU 8011) and an inactivated oil vaccine strain A/chicken/Korea/01310/01 (H9N2) (01310), was performed. The former 2 AIVs were isolated from field cases before and after the application of an inactivated H9N2 vaccine in 2007, respectively. The antigenic relationship, viral shedding, tissue tropism and genetic analysis were examined. The comparison of virus shedding from the cloaca and the oropharynx revealed that both isolates were more frequently isolated from the upper respiratory tract (90~100%) 1 day post inoculation (DPI) compared with isolation 5 DPI from gastrointestinal tracts (10~60%). Moreover, the isolate KBNP-0028 were recovered from all organs including bone marrow, brain and kidneys, indicating higher ability for broad tissue dissemination than that of SNU 8011. KBNP-0028 replicated earlier than other strains and with a higher titer than SNU 8011. In full-length nucleotide sequences of the NA gene and a partial sequence of the HA gene of SNU 8011, we found that there might be significant changes in tissue tropism, virus replication and genetic mutation in AIV H9N2 isolates.

The purpose of this study was to investigate the prevalence of Brachyspira species and antimicrobial susceptibility of Brachyspira (B.) hyodysenteriae isolates in Korea. A total of fifty-five Brachyspira species were isolated; five (1.0%) beta-hemolytic Brachyspira species and 50 (10.4%) weak hemolytic Brachyspira species from 116 different diarrheic pig samples and 367 apparently normal pig samples. In farm level, beta hemolytic and weak hemolytic Brachyspira species were detected in 7.4% (5/68) and 19.1% (13/68) of tested pig farms, respectively. By phenotypic and genotypic characterization, all beta hemolytic Brachyspira isolates was classified as group Ⅰ (B. hyodysenteriae), whereas weak hemolytic Brachyspira species isolates were group Ⅲ (B. innocens or B. murdochii). B. hyodysenteriae isolates showed high level of minimum inhibition concentrations to macrolide antimicrobials. This study shows that the prevalence of pathogenic B. hyodysenteriae in pigs is low but antimicrobial resistance of the pathogens is high in Korea. This is the first report of the prevalence of Brachyspira group Ⅲ and antimicrobial susceptibility of B. hyodysenteriae in pigs in Korea. Our results could provide basic data for the management and treatment guidelines of Brachyspira infection.

In this study, we produced iron-fortified yeast (Saccharomyces cerevisiae) producing Sus scrofa ferritin heavy-chain to provide iron supplementation in anemic piglets. We determined whether iron-ferritin accumulated in recombinant yeasts could improve iron deficiency in mice. C57BL/6 male mice exposed to Fe-deficient diet for 2 weeks were given a single dose of ferrous ammonium sulfate (FAS), ferritin-producing recombinant yeast (APO), or APO reacted with iron (Fe²+) (FER). The bioavailability of recombinant yeasts was examined by measuring body weight gain, hemoglobin concentration and hematocrit value 1 week later. In addition, ferritin protein levels were evaluated by western blot analysis and iron stores in tissues were measured by inductively coupled plasma spectrometer. We found that anemic mice treated with FER exhibited increased levels of ferritin heavy-chain in spleen and liver. Consistently, this treatment restored the iron concentration in these tissues. In addition, this treatment significantly increased hemoglobin value and the hematocrit ratio. Furthermore, FER treatment significantly enhanced body weight gain. These results suggest that the iron-fortified recombinant yeast strain is bioavailable.

In the present study, we investigated the expression patterns of ErbB family proteins in the pre-pubertal and pubertal mammary glands of dairy cows in association with gland development. For this study, we performed immunohistochemistry for ErbB-1-4 and Ki-67 cell proliferation marker. We found that the pre-pubertal and pubertal mammary glands had typical structures, including ducts and terminal end buds embedded in the stroma, and no development of lobuloalveolar structures. On immunohistochemistry, ErbB-2 and ErbB-3 were strongly expressed in the cytoplasm and nuclei in the epithelial cells of mammary ducts and terminal end buds, and stromal cells, whereas ErbB-1 and ErbB-4 were weakly expressed only in the cytoplasm of gland epithelium and stromal cells, irrespective of the developmental stage. Cell proliferation was inactive in the mammary gland cell compartments in both phases. Thus, expression of the ErbB family in the developing mammary glands was not associated with their functional effects, such as cell proliferation and lobuloalveolar development. In conclusion, ErbB receptors were differentially expressed in the epithelial and stromal cells of virgin mammary glands of dairy cows. Compared with rodent mammary glands, ErbB-3 and ErbB-4 were found to be highly expressed in bovine mammary glands.

This study evaluated the epizootiological characteristics of equine coital exanthema (ECE) in South Korea. A PCR test was used to determine the equine herpesvirus 3 (EHV-3) release period, excretion by suckling foals, morbidity rate, effect on fertility, and onset of breeding partner after treatment. The morbidity rate of ECE based on clinical symptoms was 8.3% (2/24) for stallions and 10.8% (45/416) for mares, and 29 of 45 (64.4%) animals were positive on the PCR test. Ten (22%) broodmares had symptoms before breeding, while 26 (58%) had symptoms after breeding. Nine (20%) mares had uncertain coverage periods and occurrence times. Suckling foals had no clinical findings and EHV-3 was not detected in their nostrils, although it was detected on teasers. No lesions were observed in the clitoral fossa on broodmares, although EHV-3 was detected by PCR. The period of EHV-3 emission was 22~23, 18~19, 6, and 58 days in stallions, broodmares, teasers, and mares with a mixed E. coli-like infection, respectively. ECE had no negative effects on the breeding capability of stallions and no symptoms were observed in broodmares after recovering from ECE.

In this study, a medicinal herbal plant, Meliae fructus, was examined and screened for anti-Helicobacter (H.) pylori activity. Seventy percent ethanol was used for herbal extraction. For anti-H. pylori activity screening, inhibitory zone tests as an in vitro assay and in vivo study using a Mongolian gerbil (Meriones unguiculatus) model were performed. Also, the safety of herbal compounds was evaluated by animal study. As a result of inhibitory zone test, Meliae fructus extract demonstrated strong anti-H. pylori activities. Also, as results of in vivo animal studies, Meliae fructus demonstrated strong therapeutic effects against H. pylori infection according to the criteria of histological examination and rapid urease test. As results of the safety study, after 28 days treatment of the Meliae fructus extract, the animals were not detected any grossly and histological changes. These results demonstrate that it can be successfully cured against H. pylori infection and protected from H. pylori-induced pathology with Meliae fructus. It could be a promising native herbal treatment for patients with gastric complaints including gastric ulcer caused by H. pylori.

Histochemical patterns of lectin binding during development of the rat vomeronasal organ (VNO) were studied to determine whether glycoconjugates are differently expressed after birth. Three types of lectins, Dolichos biflorus agglutinin (DBA), wheat germ agglutinin (WGA), and Ulex europaeus agglutinin I (UEA-I), were studied histochemically in the rat VNO at various stages post-birth: postnatal days 1 and 7, the preweaning period (4 weeks after birth), and at sexual maturity (8 weeks after birth). The free border of the vomeronasal sensory epithelium was positive for both WGA and UEA-I in rats of all ages; whereas, VNO receptor cells and supporting cells were positive only for both WGA and UEA-I from 4 weeks after birth. DBA reactivity was detected in the free border but less so in receptor cells and supporting cells. WGA and UEA-I, but not DBA, showed similar patterns in various ages. In the Jacobson's gland, WGA, UEA-I and DBA were detected in some acini from 4 weeks after birth but not at postnatal days 1 or 7. Collectively, reactivity for three lectins, WGA, UEA-I and DBA, increased in receptor cells and gland acini during postnatal development, possibly contributing to the enhanced chemoreception in rats.