Kyoung-Ki Lee

Occurrence, physiological responses and toxicity of nickel in plants

The focus of the review is on the specific aspects of nickel’s effects on growth, morphology, photosynthesis, mineral nutrition and enzyme activity of plants. The mobility of nickel in the environment and the consequent contamination in soil and water is of great concern. Also, the detrimental effects of excessive nickel on plant growth have been well known for many years. Toxic effects of nickel on plants include alterations in the germination process as well as in the growth of roots, stems and leaves. Total dry matter production and yield was significantly affected by nickel and also causes deleterious effects on plant physiological processes, such as photosynthesis, water relations and mineral nutrition. Nickel strongly influences metabolic reactions in plants and has the ability to generate reactive oxygen species which may cause oxidative stress. More recent evidence indicates that nickel is required in small amounts for normal plant growth and development. Hence, with the increasing level of nickel pollution in the environment, it is essential to understand the functional roles and toxic effects of nickel in plants.

An outbreak of highly pathogenic H5N1 avian influenza in Korea, 2008

In spite of intensive surveillance programs for the control of HPAI, an outbreak of highly pathogenic avian influenza (HPAI) H5N1 in Korea in April 2008 caused serious damage to poultry farms, as did previous outbreaks in 2003/2004 and 2006/2007. Six viruses were selected from the Korean 2008 isolates for genetic analysis, and all eight gene segments from each of the influenza viruses were sequenced. A phylogenetic analysis showed that all of the viruses were of the same virus type and that the hemagglutinin (HA) gene was clustered with that of clade 2.3.2 viruses. However, the internal and neuraminidase (NA) genes were closely related to those of the clade 2.3.4 viruses (recent human and bird isolates from Southeast Asia).

Genetic relatedness of H6 subtype avian influenza viruses isolated from wild birds and domestic ducks in Korea and their pathogenicity in animals

We report the genetic characterization of H6 avian influenza (AI) viruses isolated from domestic ducks and wild birds in Korea between April 2008 and April 2009. A phylogenetic analysis showed that the H6N1 viruses of wild birds and domestic ducks were of the same genotype (K-1) and were similar to the H6N1 virus isolated from a live poultry market in 2003, as six of the eight gene segments of those viruses had a common source. However, the H6N2 viruses of domestic poultry were separated into four genotypes (K-2a, K-2b, K-2c and K-2d) by at least a triple reassortment between influenza viruses of low pathogenicity from Korean poultry (H9N2 and H3N2) and viruses from aquatic birds. In an experimental infection of animals, certain H6 AI viruses replicated well in chickens and mice without pre-adaptation, indicating that H6 virus pathogenicity has the potential to be altered due to multiple reassortments, and that these reassortments could result in interspecies transmission to mammals.

Phylogenetic analysis and characterization of Korean orf virus from dairy goats: case report

An outbreak of orf virus infection in dairy goats in Korea was investigated. Suspected samples of the skin and lip of affected goats were sent to the laboratory for more exact diagnosis. Orf virus was detected by electron microscopy and viral DNA was identified by PCR. To reveal the genetic characteristics of the Korean strain (ORF/09/Korea), the sequences of the major envelope protein (B2L) and orf virus interferon resistance (VIR) genes were determined and then compared with published reference sequences. Phylogenetic analysis revealed that the ORF/09/Korea strain was closest to the isolates (Taiping) from Taiwan. This is believed to be the first report on the molecular characterization of orf virus in Korea.

Molecular epidemiological and serological studies of bovine leukemia virus (BLV) infection in Thailand cattle

BLV is the etiological agent of enzootic bovine leucosis. BLV has negative effects on animal health and causes economic losses worldwide. However, epidemiological studies on BLV are relatively unknown in many parts of Asian countries. Thus, this study sought to explore BLV infections in cattle in Thailand to determine the extent of the geographic distribution of BLV and to measure its prevalence rates. For this study, 744 cattle from 11 farms in 9 provinces of Thailand were screened in 2013 and 2014 by ELISA and nested PCR. Of those cattle, 41 BLVs were genetically characterized using 188 BLV gp51 env gene sequences available in GenBank. The BLV prevalence in Thailand was high, ranging from 5.3% to 87.8%, as determined by PCR and 11.0% to 100% as determined by ELISA, according to geographical region. Phylogenetic analysis showed that Thailand BLVs belonged to genotypes 1 and 6 and a new genotype 10, which are sporadically observed across Thailand with a prevalence of 31.7%, 19.5%, and 48.8%, respectively. A significant number of amino acid substitutions were also found in the gp51 sequences, of which unique changes in genotype 10 have not been reported previously. Briefly, the majority of substitutions were confined to CD4+/CD8+ T-cell epitopes, neutralizing domains, and E-D-A epitopes. Those observations indicate that BLV infections in Thailand cattle are prevalent and that the geographic distribution of BLV is dynamic, with a high level of genetic diversity. This distribution implies a long-term BLV infection in cattle populations and the movement of infected cattle. In sum, this study suggests that intensive surveillance and effective prevention strategies are required to determine the prevalence of BLV in Thailand and control continuous infections with BLVs.

Molecular characterization of a Korean bovine parainfluenza virus type 3 isolate

Bovine parainfluenza virus type 3 (BPIV-3) was isolated from Korean native cattle that presented clinical signs of mild pneumonia. The complete genome of a representative isolate (12Q061) was sequenced. The newly identified strain, which was found to be distinct from the previously reported genotypes A (BPIV-3a) and B (BPIV-3b) and closely related to the Chinese strain SD0835, was tentatively classified as genotype C (BPIV-3c). Our results suggest a relationship between BPIV-3 genetic variation and the geographic location of its isolation. Identification of these new BPIV-3 genotypes may facilitate the development of improved diagnostic methods and vaccines. This is to our knowledge the first report of the identification and molecular characterization of BPIV-3 in Korea.

Sequencing and phylogenetic analysis of the gp51 gene from Korean bovine leukemia virus isolates

BackgroundBovine Leukemia virus (BLV) infection of cattle has been reported in Korea for more than three decades. However, to date, there have been few studies regarding Korean BLV since 1980s. Thus, the purpose of this study is to perform a diagnosis and molecular characterization of BLV strains circulating in Korea and to estimate genetic diversity of different genotypes of BLV.MethodTo investigate the distribution of BLV variants in the world and assess the evolutionary history of Korean BLV isolates, a comprehensive molecular analysis of the BLV env gp51 gene was conducted using recent worldwide BLV isolates. The isolates included 50 samples obtained from two cattle farms in southeastern Korea in 2014.ResultsSequence and phylogenetic analyses of partial 444-nt fragment sequences and complete gp51 sequences of BLV revealed eight distinct genotypes of BLV showing geographic distribution of the world. Most Korean BLV isolates were found to belong to genotype 1 which is a major genotype prevailed throughout the world, and only four isolates from one farm were classified as genotype 3 related to the US and Japan isolates. Analysis of amino acids of Korean BLV isolates showed several sequence substitutions in the leader peptide, conformational epitope, and neutralizing domain regions. The observations suggest the possibility of affecting on viral infectivity and formation.ConclusionKorean BLV isolates showed the close relationship to genotype 1 and 3. Further study to identify the diversity of BLV circulating in Korea is necessary with samples collected nationwide because this study is the first report of BLV genotype 3 being in circulation in Korea.

Isolation and characterization of orf viruses from Korean black goats.

Five cases of orf virus infection in Korean black goats were diagnosed in our laboratory between 2010 and 2011. One orf virus (ORF/2011) was isolated from an ovine testis cell line (OA3.Ts) for use as a vaccine candidate. Sequences of the major envelope protein and orf virus interferon resistance genes were determined and compared with published reference sequences. Phylogenetic analyses revealed that orf viruses from Korean black goats were most closely related to an isolate (ORF/09/Korea) from dairy goats in Korea. This result indicates that the orf viruses might have been introduced from dairy goats into the Korean black goat population.

A novel reassortant H1N2 virus related to the pandemic H1N1 2009 influenza virus isolated from Korean pigs

Abstract Since the discovery of the pandemic H1N1 (pH1N1) virus in 2009, a novel reassortant H1N2 virus (A/Swine/Korea/VDS1/2010) containing the pH1N1 segments has been detected in Korean pig populations. The hemagglutinin and neuraminidase genes of this virus are derived from reassortant H1N1- and H1N2-group viruses, respectively, identified in Korean pigs, while other genes originate from contemporary circulating pH1N1 viruses. The antigenic and biological properties of this novel virus, as determined by clinical, pathological, serological, and genetic analyses, are similar to those of pH1N1 viruses, which infect swine easily (Weingartl et al. J Virol 84:2245–2256, 2010; Brookes et al. PLoS one 5:e9068, 2010; Lange et al. J Gen Virol 90:2119–2123, 2009). Determining whether this virus will become established and pose a threat to mammalian populations requires further investigation.

Biogenic Synthesis of Gold Nanoparticles (Quasi-Spherical, Triangle, and Hexagonal) Using Lonicera Japonica Flower Extract and Its Antimicrobial Activity

The development of an eco-friendly and reliable process for the synthesis of metallic nanoparticles is an important step in the field of the nanotechnology. In the present study, gold nanoparticles (AuNPs) have been synthesized by bio-reduction of chloroauric acid using Lonicera japonica flower extract. AuNPs were characterized using UV-Visible absorption spectroscopy, FTIR, SEM, EDX, TEM, SAED, and XRD. The antimicrobial activity of these AuNPs was evaluated using Gram-positive (S. aureus and B. subtilis), Gram-negative (E. coli), and Fungi C. albicans and S. cerevisiae. The results showed that the combination of ampicillin with AuNPs results in better antimicrobial effects.