Genetic Characterization and Pathogenesis of H5N1 High Pathogenicity Avian Influenza Virus Isolated in South Korea during 2021-2022.

High pathogenicity avian influenza (HPAI) viruses of clade 2.3.4.4 H5Nx have been circulating in poultry and wild birds worldwide since 2014. In South Korea, after the first clade 2.3.4.4b H5N1 HPAI viruses were isolated from wild birds in October 2021, additional HPAIV outbreaks occurred in poultry farms until April 2022. In this study, we genetically characterized clade 2.3.4.4b H5N1 HPAIV isolates in 2021-2022 and examined the pathogenicity and transmissibility of A/mandarin duck/Korea/WA585/2021 (H5N1) (WA585/21) in chickens and ducks. Clade 2.3.4.4b H5N1 HPAI viruses caused 47 outbreaks in poultry farms and were also detected in multiple wild birds. Phylogenetic analysis of HA and NA genes indicated that Korean H5N1 HPAI isolates were closely related to Eurasian viruses isolated in 2021-2022. Four distinct genotypes of H5N1 HPAI viruses were identified in poultry, and the majority were also found in wild birds. WA585/21 inoculated chickens showed virulent pathogenicity with high mortality and transmission. Meanwhile, ducks infected with the virus showed no mortality but exhibited high rates of transmission and longer viral shedding than chickens, suggesting that they may play an important role as silent carriers. In conclusion, consideration of both genetic and pathogenic traits of H5N1 HPAI viruses is required for effective viral control.

Genetic Characterization of Novel H7Nx Low Pathogenic Avian Influenza Viruses from Wild Birds in South Korea during the Winter of 2020-2021.

Zoonotic infection with avian influenza viruses (AIVs) of subtype H7, such as H7N9 and H7N4, has raised concerns worldwide. During the winter of 2020-2021, five novel H7 low pathogenic AIVs (LPAIVs) containing different neuraminidase (NA) subtypes, including two H7N3, an H7N8, and two H7N9, were detected in wild bird feces in South Korea. Complete genome sequencing and phylogenetic analysis showed that the novel H7Nx AIVs were reassortants containing two gene segments (hemagglutinin (HA) and matrix) that were related to the zoonotic Jiangsu-Cambodian H7 viruses causing zoonotic infection and six gene segments originating from LPAIVs circulating in migratory birds in Eurasia. A genomic constellation analysis demonstrated that all H7 isolates contained a mix of gene segments from different viruses, indicating that multiple reassortment occurred. The well-known mammalian adaptive substitution (E627K and D701N) in PB2 was not detected in any of these isolates. The detection of multiple reassortant H7Nx AIVs in wild birds highlights the need for intensive surveillance in both wild birds and poultry in Eurasia.

Pathogenesis and genetic characteristics of a novel reassortant low pathogenic avian influenza A(H7N6) virus isolated in Cambodia in 2019.

The first human case of zoonotic A(H7N4) avian influenza virus (AIV) infection was reported in early 2018 in China. Two months after this case, novel A(H7N4) viruses phylogenetically related to the Jiangsu isolate emerged in ducks from live bird markets in Cambodia. During active surveillance in Cambodia, a novel A(H7N6) reassortant of the zoonotic low pathogenic AIV (LPAIV) A(H7N4) was detected in domestic ducks at a slaughterhouse. Complete genome sequencing and phylogenetic analysis showed that the novel A(H7N6) AIV is a reassortant, in which four gene segments originated from Cambodia A(H7N4) viruses and four gene segments originated from LPAIVs in Eurasia. Animal infection experiments revealed that chickens transmitted the A(H7N6) virus via low-level direct contacts, but ducks did not. Although avian-origin A(H7Nx) LPAIVs do not contain the critical mammalian-adaptive substitution (E627K) in PB2, the lethality and morbidity of the A(H7N6) virus in BALB/c mice were similar to those of A(H7N9) viruses, suggesting potential for interspecies transmission. Our study reports the emergence of a new reassortant of zoonotic A(H7N4) AIVs with novel viral characteristics and emphasizes the need for ongoing surveillance of avian-origin A(H7Nx) viruses.

Pathogenicity of H9N2 low pathogenic avian influenza viruses of different lineages isolated from live bird markets tested in three animal models: SPF chickens, Korean native chickens, and ducks.

Since its first appearance in 1996, H9N2 avian influenza virus (AIV) of the Y439 lineage persisted in Korean live bird markets (LBMs) until the last documented occurrence in 2018. However, in June 2020, the avian influenza surveillance program detected a novel H9N2 AIV belonging to the Y280 lineage, which has zoonotic potential, in a Korean native chicken (KNC) from a LBM. In this study, we infected KNCs and ducks (the 2 major species held at LBMs), as well as SPF chickens, with Y280-lineage H9N2 AIV LBM261/20 and Y439-equivalent LBM294/18 to compare pathogenicity and transmissibility. In SPF chickens, LBM261/20 replicated mostly in the respiratory tract and spread rapidly among birds. By contrast, LBM294/18 replicated preferentially in the gastrointestinal tract and transmitted more slowly than LBM261/20. LBM261/20 replicated for a longer time in KNCs than in SPF chickens, and only in the respiratory tract; by contrast, LBM294/18 was detected in the oropharynx and cloaca. Ducks did not shed either virus or seroconvert. Taken together, the data suggest that the scheme used to monitor the newly introduced H9N2 AIV of the Y280 lineage needs to be modified to place emphasis on oropharyngeal sampling. Such changes will facilitate better disease control and protect public health.

Multiple Reassortants of H5N8 Clade 2.3.4.4b Highly Pathogenic Avian Influenza Viruses Detected in South Korea during the Winter of 2020-2021.

During October 2020-January 2021, we isolated a total of 67 highly pathogenic avian influenza (HPAI) H5N8 viruses from wild birds and outbreaks in poultry in South Korea. We sequenced the isolates and performed phylogenetic analysis of complete genome sequences to determine the origin, evolution, and spread patterns of these viruses. Phylogenetic analysis of the hemagglutinin (HA) gene showed that all the isolates belong to H5 clade 2.3.4.4 subgroup B (2.3.4.4b) and form two distinct genetic clusters, G1 and G2. The cluster G1 was closely related to the 2.3.4.4b H5N8 HPAI viruses detected in Europe in early 2020, while the cluster G2 had a close genetic relationship with the 2.3.4.4b H5N8 viruses that circulated in Europe in late 2020. A total of seven distinct genotypes were identified, including five novel reassortants carrying internal genes of low pathogenic avian influenza viruses. Our Bayesian discrete trait phylodynamic analysis between host types suggests that the viruses initially disseminated from migratory waterfowl to domestic duck farms in South Korea. Subsequently, domestic duck farms most likely contributed to the transmission of HPAI viruses to chicken and minor poultry farms, highlighting the need for enhanced, high levels of biosecurity measures at domestic duck farms to effectively prevent the introduction and spread of HPAI.

Data resource profile: the allergic disease database of the Korean National Health Insurance Service.

Researchers have been interested in probing how the environmental factors associated with allergic diseases affect the use of medical services. Considering this demand, we have constructed a database, named the Allergic Disease Database, based on the National Health Insurance Database (NHID). The NHID contains information on demographic and medical service utilization for approximately 99% of the Korean population. This study targeted 3 major allergic diseases, including allergic rhinitis, atopic dermatitis, and asthma. For the target diseases, our database provides daily medical service information, including the number of daily visits from 2013 and 2017, categorized by patients' characteristics such as address, sex, age, and duration of residence. We provide additional information, including yearly population, a number of patients, and averaged geocoding coordinates by eup, myeon, and dong district code (the smallest-scale administrative units in Korea). This information enables researchers to analyze how daily changes in the environmental factors of allergic diseases (e.g., particulate matter, sulfur dioxide, and ozone) in certain regions would influence patients' behavioral patterns of medical service utilization. Moreover, researchers can analyze long-term trends in allergic diseases and the health effects caused by environmental factors such as daily climate and pollution data. The advantages of this database are easy access to data, additional levels of geographic detail, time-efficient data-refining and processing, and a de-identification process that minimizes the exposure of identifiable personal information. All datasets included in the Allergic Disease Database can be downloaded by accessing the National Health Insurance Service data sharing webpage (https://nhiss.nhis.or.kr).

Influence of temperature on the antigenic changes of virus-like particles.

PURPOSE: In this study, we investigated whether the antigenic changes of the virus-like particles (VLPs) are affected by the temperature during storage. MATERIALS AND METHODS: After exposing the recombinant influenza VLPs to various temperatures for a period, antigenic changes were examined through in vitro hemagglutination receptor binding assay and in vivo mouse experiments. RESULTS: Influenza VLPs were exposed at three different temperatures of low, middle, and high on a thermo-hygrostat. High temperature exposed influenza VLPs were showed significantly reduced HA activity and immunogenicity after mouse single immunization over time compared low and middle. When the VLPs exposed to the high temperature were inoculated once in the mice, it was found that the immunogenicity was significantly reduced compared to the VLPs exposed to the low temperature. However, these differences were almost neglected when mice were inoculated twice even with VLPs exposed to high temperatures. CONCLUSION: This study suggests that similar protective effects can be expected by controlling the number of vaccination and storage conditions, although the antigenic change in the VLP vaccines occurred when exposed to high temperature.

Three-dimensional micropatterning of semiconducting polymers via capillary force-assisted evaporative self-assembly.

Controlled evaporative self-assembly of semiconducting polymers has mostly been studied on 2-dimensional flat substrates. In this study, we reported capillary-assisted evaporative self-assembly of poly(3-hexylthiophene 2,5-diyl) (P3HT) into 3-D micro-ring patterns through the stick-slip phenomenon within a 3-dimensional cylinder. We deconvoluted the well-known two-step stick-slip phenomenon into three regimes through in situ monitoring of the P3HT self-assembly process using a high-speed camera: pinning and deposition; depinning and slip; and retraction regimes. Furthermore, we investigated the effects of various parameters associated with the self-assembly, including polymer concentration, tilt angle, magnetic field, and evaporation temperature, thus achieving self-assembled microarchitectures with diverse dimensions ranging from dots to lines and networks. The self-assembled microstructures were analyzed qualitatively and quantitatively by evaluating the fast Fourier transform image, surface coverage, fractal dimension and lacunarity of the micropatterns.

Nanoarchitecturing of Natural Melanin Nanospheres by Layer-by-Layer Assembly: Macroscale Anti-inflammatory Conductive Coatings with Optoelectronic Tunability.

Natural melanins are biocompatible conductors with versatile functionalities. Here, we report fabrication of multifunctional poly(vinyl alcohol)/melanin nanocomposites by layer-by-layer (LBL) assembly using melanin nanoparticles (MNPs) directly extracted from sepia officinalis inks. The LBL assembly offers facile manipulation of nanotextures as well as nm-thickness control of the macroscale film by varying solvent qualities. The time-resolved absorption was monitored during the process and quantitatively studied by fractal dimension and lacunarity analysis. The capability of nanoarchitecturing provides confirmation of complete monolayer formation and leads to tunable iridescent reflective colors of the MNP films. In addition, the MNP films have durable electrochemical conductivities as evidenced by enhanced charge storage capacities for 1000 cycles. Moreover, the MNP covered ITO (indium tin oxide) substrates significantly reduced secretion of inflammatory cytokines, TNF-α, by raw 264.7 macrophage cells compared to bare ITO, by a factor of 5 and 1.8 with and without lipopolysaccharide endotoxins, respectively. These results highlight the optoelectronic device-level tunability along with the anti-inflammatory biocompatibility of the MNP LBL film. This combination of performance should make these films particularly interesting for bioelectronic device applications such as electroceuticals, artificial bionic organs, biosensors, and implantable devices.