Development of a highly sensitive and rapid detection method for Pea enation mosaic virus using loop-mediated isothermal amplification assay.

The Pea enation mosaic virus (PEMV) has infected plants in the family Leguminosae such as pea, chickpea, faba bean, and lentil plants worldwide that the virus can be transmitted by sap, aphids, and seeds. Among the damages that PEMV disease cause in plants are reduced crop productivity, severely misshapen pods, wart-like outgrowths or proliferation on the surface. Previously, enzyme-linked immunosorbent assay (ELISA), reverse transcription (RT)-nested polymerase chain reaction (PCR), and real-time PCR had been used to detect PEMV. However, these methods are time-consuming and require specific equipments. For this reason, the development of a highly specific and sensitive detection method has become necessary. In this study, a new method for PEMV-1 using the loop-mediated isothermal amplification (LAMP) assay has been developed with specific primer sets as inner- and outer primers. Results showed PEMV-1 has been successfully detected that LAMP could confirm a diluted PEMV-1 up to 10-6 cDNA. LAMP is about 10,000 times more sensitive than the RT-nested PCR and/or real-time PCR. Moreover, the processing time of the LAMP was decreased 3 h than RT-nested PCR. Although future validation will be required to confirm enablement in the field area, this study provides a valuable method to identify PEMV-1 that could offer some advantages including rapid detection, high specificity and high sensitivity than others.

Metagenomic Analysis of Airborne Bacterial Community and Diversity in Seoul, Korea, during December 2014, Asian Dust Event.

Asian dust or yellow sand events in East Asia are a major issue of environmental contamination and human health, causing increasing concern. A high amount of dust particles, especially called as particulate matter 10 (PM10), is transported by the wind from the arid and semi-arid tracks to the Korean peninsula, bringing a bacterial population that alters the terrestrial and atmospheric microbial communities. In this study, we aimed to explore the bacterial populations of Asian dust samples collected during November-December 2014. The dust samples were collected using the impinger method, and the hypervariable regions of the 16S rRNA gene were amplified using PCR followed by pyrosequencing. Analysis of the sequencing data were performed using Mothur software. The data showed that the number of operational taxonomic units and diversity index during Asian dust events were higher than those during non-Asian dust events. At the phylum level, the proportions of Proteobacteria, Actinobacteria, and Firmicutes were different between Asian dust and non-Asian dust samples. At the genus level, the proportions of the genus Bacillus (6.9%), Arthrobacter (3.6%), Blastocatella (2%), Planomicrobium (1.4%) were increased during Asian dust compared to those in non-Asian dust samples. This study showed that the significant relationship between bacterial populations of Asian dust samples and non-Asian dust samples in Korea, which could significantly affect the microbial population in the environment.

Molecular characterization of highly pathogenic avian influenza H5N8 viruses isolated from Baikal teals found dead during a 2014 outbreak in Korea.

Nineteen highly pathogenic avian influenza (HPAI) H5N8 viruses were isolated from wild birds in the Donglim reservoir in Gochang, Jeonbuk province, Korea, which was first reported to be an outbreak site on January 17, 2014. Most genes from the nineteen viruses shared high nucleotide sequence identities (i.e., 99.7% to 100%). Phylogenetic analysis showed that these viruses were reassortants of the HPAI H5 subtype and the H4N2 strain and that their hemagglutinin clade was 2.3.4.4, which originated from Eastern China. The hemagglutinin protein contained Q222 and G224 at the receptor-binding site. Although the neuraminidase protein contained I314V and the matrix 2 protein contained an S31N substitution, other mutations resulting in oseltamivir and amantadine resistance were not detected. No substitutions associated with increased virulence and enhanced transmission in mammals were detected in the polymerase basic protein 2 (627E and 701D). Non-structural-1 was 237 amino acids long and had an ESEV motif with additional RGNKMAD amino acids in the C terminal region. These viruses caused deaths in the Baikal teal, which was unusual, and outbreaks occurred at the same time in both poultry and wild birds. These data are helpful for epidemiological understanding of HPAI and the design of prevention strategies.