Hee‐Chun Chung

Laboratory studies quantified the relative survival of F+ coliphages, B. fragilis phages, hepatitis A virus, poliovirus, and rotavirus in seawater and seawater-sediment mixtures. Samples of each matrix were seeded with mixed populations of the viruses and incubated at 5 and 25°C for 60 days. F+ coliphages were inactivated faster than three enteric viruses in seawater at 25°C. In seawater-sediment mixture at 5 and 25°C or at 5°C in seawater, their survival was comparable to those enteric viruses

Porcine circovirus 4 (PCV4), a novel and unclassified member of the genus Circovirus, was first reported in China in 2019. Aiming to provide more evidence about the active circulation of PCV4, this study screened 335 pooled internal organs and detected the virus (i) at a rate of 3.28%, (ii) from both clinically healthy and clinically sick pigs of various age groups, and (iii) in six out of nine provinces of Korea. The complete genomic sequence of the Korean PCV4 strain (E115) was 1,770 nucleotid

This study describes the detection of enteroviruses and hepatitis A virus in 31 naturally contaminated oyster specimens by nucleic acid amplification and oligonucleotide probing. Viruses were extracted by adsorption-elution-precipitation from 50-g oyster samples harvested from an area receiving sewage effluent discharge. Ninety percent of each extract was inoculated into primate kidney cell cultures for virus isolation and infectivity assay. Viruses in the remaining 10% of oyster extract that wa

The S glycoprotein of coronaviruses is important for viral entry and pathogenesis with most variable sequences. Therefore, we analyzed the S gene sequences of SARS-CoV-2 to better understand the antigenicity and immunogenicity of this virus in this study. In phylogenetic analysis, two subtypes (SARS-CoV-2a and -b) were confirmed within SARS-CoV-2 strains. These two subtypes were divided by a novel synonymous mutation of D614G. This may play a crucial role in the evolution of SARS-CoV-2 to evade

Porcine parvovirus (PPV) is one of the main causes of porcine reproductive failure. It is important for swine industries to understand the recent trends in PPV evolution. Previous data show that PPV has two genetic lineages originating in Germany. In this study, two more genetic lineages were defined, one of which was distinctly Asian. Additionally, amino acid substitutions in European strains and Asian strains showed distinct differences in several regions of the <i>VP2</i> gene. The <i>VP1</i>

We provided an updated insight on FPV and CPV-2 genotypes by molecular-based and our findings demonstrate the genetic characterization according to the new genotypes.

This study confirmed the presence of different genotypes of porcine parvoviruses in South Korea. The PPVs circulating in South Korea were phylogenetically classified as PPV1 and PPV7 genotypes. Three Korean PPV1 strains collected in 2018 were predicted to have antigenic alteration in VP2 compared to several reference strains of PPV1.

To the Editor: Porcine epidemic diarrhea (PED) is an acute infectious diarrhea caused by the PED virus (PEDV), which belongs to the order Nidovirales, family Coronaviridae, genus Alphacoronavirus (1). The virus is transmitted mainly through fecal-oral routes and infects all age groups of pigs; the most severe form of disease occurs in suckling piglets (1). PEDV was first reported in South Korea in 1992 (2), with the occurrence of an outbreak, and has since circulated with considerable genetic di

New viruses are continuously emerging and recently there have been many great concerns on severe acute respiratory syndrome coronavirus (SARS-CoV-2). Nanographene oxide (nanoGO) has received much attention and is widely investigated to be utilised in therapy for infectious diseases by viruses. Thus, antiviral activity of nanoGO was evaluated using the porcine epidemic diarrhoea virus (PEDV), bovine coronavirus (BCoV), and SARS-CoV-2, which are all Alpha- and Beta-coronavirus. In a virus inhibiti

<i>Porcine epidemic diarrhea virus</i> (<i>PEDV</i>) causes continuous, significant damage to the swine industry worldwide. By RT-PCR-based methods, this study demonstrated the ongoing presence of <i>PEDV</i> in pigs of all ages in Korea at the average detection rate of 9.92%. By the application of Bayesian phylogenetic analysis, it was found that the nucleocapsid (N) gene of <i>PEDV</i> could evolve at similar rates to the spike (S) gene at the order of 10^-4 substitutions/site/year.

Swine abortion caused by viruses as well as bacteria has caused many economic losses in domestic farms over the years; however, bacterial abortion has not yet been studied in Korea. Several bacterial species were isolated from aborted fetuses (n = 103) for which the cause of death was not viral abortion. Among them, we focused on Aerococcus viridans, which had the highest positive rate within three provinces (Gangwon, Jeonnam and Gyeongnam). A total of 16 isolates were identified as A. viridans

Porcine circovirus type 3 (PCV3) has been reported in many countries such as USA, China, Korea and many European countries during 2015-2018. The six PCV3 strains named IH, SJ, N5, N10, N13 and N62 were detected out of 220 samples by PCR methods while the prevalence our study was conducted in 2017 to 2018. The six detected strains were hard to genotype with reference viruses due to their diverse phylogenetic relationship. PCV3 capsid, ORF3 and replicase protein coding genes were reassembled at th

Coronavirus, an important zoonotic disease, raises concerns of future pandemics. The bat is considered a source of noticeable viruses resulting in human and livestock infections, especially the coronavirus. Therefore, surveillance and genetic analysis of coronaviruses in bats are essential in order to prevent the risk of future diseases. In this study, the genome of HCQD-2020, a novel alphacoronavirus detected in a bat (<i>Eptesicus serotinus</i>), was assembled and described using next-generati

To effectively suppress porcine endogenous retroviruses (PERV)s, RNAi technique was utilized. RNAi is the up-to-date skill for gene knockdown which simultaneously multitargets both gag and pol genes critical for replication of PERVs. Previously, two of the most effective siRNAs (gag2, pol2) were found to reduce the expression of PERVs. Concurrent treatment of these two siRNAs (gag2+pol2) showed knockdown efficiency of up to 88% compared to negative control. However, despite the high initial knoc