Detection and genetic characterization of porcine circovirus 3 from aborted fetuses and pigs with respiratory disease in Korea

A novel porcine circovirus 3 (PCV3) was first detected in pigs showing porcine dermatitis and nephropathy syndrome, reproductive failure, and multisystemic inflammation in the USA. Herein, we report on PCV3 as a potential etiological agent of clinical signs, reproductive failure and respiratory distress on Korean pig farms, based on in situ hybridization, pathological, and molecular findings. Confirmation of the presence of PCV3 may increase co-infection with other causative agents of disease in Korean pig herds, indicating the need for further systemic investigation of pathogenicity and of multiple infections with PCV2 genotypes and bacteria, and the development of an effective PCV3 vaccine.

Uracil-DNA glycosylase-treated reverse transcription loop-mediated isothermal amplification for rapid detection of avian influenza virus preventing carry-over contamination

Here, we describe a uracil-DNA glycosylase (UNG)-treated reverse transcription loop-mediated isothermal amplification (uRT-LAMP) for the visual detection of all subtypes of avian influenza A virus (AIV). The uRT-LAMP assay can prevent unwanted amplification by carryover contamination of the previously amplified DNA, although the detection limit of the uRT-LAMP assay is 10-fold lower than that of the RT-LAMP without a UNG treatment. To the best of our knowledge, this is the first successful application of deoxyuridine triphosphate/UNG strategy in RT-LAMP for AIV detection, and the assay can be applied for the rapid, and reliable diagnosis of AIVs, even in contaminated samples.

Isolation and characterization of fowl adenovirus serotype 4 from chickens with hydropericardium syndrome in Korea / 대한수의학회지

Four strains of fowl adenovirus (FAdV) were isolated from 4 flocks of broiler or layer chickens affected by hydropericardium syndrome in Korea. These FAdVs were classified as serotype 4 by restriction fragment length polymorphism patterns of hexon genes and whole genomes. The virus exhibited cytopathic effects consisting of rounding, ballooning and clustering in primary chicken embryo liver cell cultures. In transmission electron microscopy, virus particles in hexagonal shape aggregated exclusively in the nuclei of hepatocytes of the chickens as the typical appearances in adenovirus infections. Buoyant density of the virus in cesium chloride (CsCl) was 1.34 g/mL. The virus was stable to chloroform, ether, 50~70% ethanol, acidic condition at pH 3, 0.25% trypsin (1 : 250), heat at 50degrees C for 30 min, but labile to 100% ethanol, heat at 52~60degrees C for 30 min, 1 M MgCl2 at 50degrees C for 1 h, 1 : 2,000 formalin (37%). All of the physicochemical properties pertained to the characteristics of adenoviruses. Eight viral polypeptides were determined in CsCl-purified virus by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Phage Typing of Staphylococcus intermedius Isolated from Canine Clinical Specimens

Bacteriophages were induced from staphylococcus intermedius isolates from dogs and used for a phage typing. Mitomycin C induction was performed on 60 strains of S. intermedius and all phages were reacted with the strains. Twenty-eight strains (46.7%) were found to be lysogenic. Based on host ranges, eight phages were selected. By using the eight phages, 129 strains isolated from canine clinical specimens were subjected to the phage typing at the routine test dilution (RTD) and 100xRTD. Typability of the phage set was 78.3%, yielding 40 phage patterns. The phage set was considered useful for differentiating S. intermedius strains isolated from dogs. None of 50 strains of S. aureus, 2 (3.6%) of 56 S. simulance strains, 13 (24.5%) of 53 S. chromogenes strains and 46 (28.1%) of 164 S. hyicus strains were typable by the phages at 100xRTD.