Daesub Song

Transmission of avian influenza virus (H3N2) to dogs.

Infection with and transmission of the virus was identified in pet dogs with severe respiratory disease.

Experimental Infection of Dogs with Avian-Origin Canine Influenza A Virus (H3N2)

Susceptible dogs were brought into contact with dogs experimentally infected with an avian-origin influenza A virus (H3N2) that had been isolated from a pet dog with severe respiratory syndrome. All the experimentally infected and contact-exposed dogs showed elevated rectal temperatures, virus shedding, seroconversion, and severe necrotizing tracheobronchitis and bronchioalveolitis.

Porcine epidemic diarrhea: a review of current epidemiology and available vaccines

Porcine epidemic diarrhea virus (PEDV), an Alphacoronavirus in the family Coronaviridae, causes acute diarrhea, vomiting, dehydration, and high mortality rates in neonatal piglets. PEDV can also cause diarrhea, agalactia, and abnormal reproductive cycles in pregnant sows. Although PEDV was first identified in Europe, it has resulted in significant economic losses in many Asian swine-raising countries, including Korea, China, Japan, Vietnam, and the Philippines. However, from April 2013 to the present, major outbreaks of PEDV have been reported in the United States, Canada, and Mexico. Moreover, intercontinental transmission of PEDV has increased mortality rates in seronegative neonatal piglets, resulting in 10% loss of the US pig population. The emergence and re-emergence of PEDV indicates that the virus is able to evade current vaccine strategies. Continuous emergence of multiple mutant strains from several regions has aggravated porcine epidemic diarrhea endemic conditions and highlighted the need for new vaccines based on the current circulating PEDV. Epidemic PEDV strains tend to be more pathogenic and cause increased death in pigs, thereby causing substantial financial losses for swine producers. In this review, we described the epidemiology of PEDV in several countries and present molecular characterization of current strains. We also discuss PEDV vaccines and related issues.

Novel porcine epidemic diarrhea virus variant with large genomic deletion, South Korea.

Since 1992, porcine epidemic diarrhea virus (PEDV) has been one of the most common porcine diarrhea–associated viruses in South Korea. We conducted a large-scale investigation of the incidence of PEDV in pigs with diarrhea in South Korea and consequently identified and characterized a novel PEDV variant with a large genomic deletion.

Detection of Severe Acute Respiratory Syndrome-Like, Middle East Respiratory Syndrome-Like Bat Coronaviruses and Group H Rotavirus in Faeces of Korean Bats

Summary Bat species around the world have recently been recognized as major reservoirs of several zoonotic viruses, such as severe acute respiratory syndrome coronavirus (SARS‐CoV), Middle East respiratory syndrome coronavirus (MERS‐CoV), Nipah virus and Hendra virus. In this study, consensus primer‐based reverse transcriptase polymerase chain reactions (RT‐PCRs) and high‐throughput sequencing were performed to investigate viruses in bat faecal samples collected at 11 natural bat habitat sites from July to December 2015 in Korea. Diverse coronaviruses were first detected in Korean bat faeces, including alphacoronaviruses, SARS‐CoV‐like and MERS‐CoV‐like betacoronaviruses. In addition, we identified a novel bat rotavirus belonging to group H rotavirus which has only been described in human and pigs until now. Therefore, our results suggest the need for continuing surveillance and additional virological studies in domestic bat.

The recent ancestry of Middle East respiratory syndrome coronavirus in Korea has been shaped by recombination

Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe cases of human respiratory disease. Since 2012, the victims have mainly come from the Middle East countries or sporadically from some other geographical regions seeded by the travelers who visited the Middle East. Such an introduction through travelling led to the emergence of a MERS-CoV outbreak in Korea in May 2015, which caused more than 140 confirmed human cases in less than a month. Using 70 complete genome sequences of MERS-CoV isolates, including the most recent sequences for the Korean and Chinese isolates, we reconstructed the phylogenetic relationships of the complete genome and the individual protein coding regions. The Korean MERS-CoV strain clustered in the previously established Hafr-Al-Batin-1_2013 clade together with two Saudi Arabian and one Chinese strain sampled in 2015. Although these four strains remained monophyletic in the entire protein-coding region, this clade showed different phylogenetic relationships across the genome, indicating a shared unique recombination pattern that is different from previously reported putative recombination strains. Our findings suggest that the recent ancestor of the Korean and its related MERS-CoV strains is characterized by unique mosaic genome pattern that is different from other putative recombinants.

Evolutionary phylodynamics of foot-and-mouth disease virus serotypes O and A circulating in Vietnam

BackgroundFoot-and-mouth disease virus (FMDV) is one of the highest risk factors that affects the animal industry of the country. The virus causes production loss and high ratio mortality in young cloven-hoofed animals in Vietnam. The VP1 coding gene of 80 FMDV samples (66 samples of the serotype O and 14 samples of the serotype A) collected from endemic outbreaks during 2006–2014 were analyzed to investigate their phylogeny and genetic relationship with other available FMDVs globally.ResultsPhylogenetic analysis indicated that the serotype O strains were clustered into two distinct viral topotypes (the SEA and ME-SA), while the serotype A strains were all clustered into the genotype IX. Among the study strains, the amino acid sequence identities were shared at a level of 90.1–100, 92.9–100, and 92.8–100% for the topotypes SEA, ME-SA, and genotype IX, respectively. Substitutions leading to changes in the amino acid sequence, which are critical for the VP1 antigenic sites were also identified. Our results showed that the studied strains are most closely related to the recent FMDV isolates from Southeast Asian countries (Myanmar, Thailand, Cambodia, Malaysia, and Laos), but are distinct from the earlier FMDV isolates within the genotypes.ConclusionsThis study provides important evidence of recent movement of FMDVs serotype O and A into Vietnam within the last decade and their genetic accumulation to be closely related to strains causing FMD in surrounding countries.

Viral dominance of reassortants between canine influenza H3N2 and pandemic (2009) H1N1 viruses from a naturally co-infected dog

BackgroundSince avian-origin H3N2 canine influenza virus (CIV) was first identified in South Korea in 2008, the novel influenza virus has been reported in several countries in Asia. Reverse zoonotic transmission of pandemic H1N1 (2009) influenza virus (pH1N1) has been observed in a broad range of animal species. Viral dominance and characterization of the reassortants of both viruses was undertaken in the present study.FindingsHere we describe the viral dominance of 23 CIV reassortants between pH1N1 and canine H3N2 influenza viruses from a naturally co-infected dog. These results indicate that the M gene of pandemic H1N1 and the HA gene of canine H3N2 are predominant in the reassortants. Furthermore, unlike the original canine H3N2 virus, some reassortants showed high pathogenicity in mice.ConclusionsThis study suggests that continuous monitoring of influenza infection in companion animals may be necessary to investigate the potential of the emergence of novel influenza viruses.

Strategies for using nanoprobes to perceive and treat cancer activity: a review

Nanomedicine has seen a significant increase in research on stimuli-responsive activatable nanoprobes for tumor-specific delivery and diagnosis. The tumor microenvironment has particular characteristics that can be exploited to implement therapeutic strategies based on disparities between normal tissues and tumor tissues, including differences in pH, oxygenation, enzymatic expression, gene activation/inactivation, and vasculature. The nanocarriers of activatable nanoparticles maintain their structure while circulating in the body and, upon reaching the tumor site, are altered by unique tumoral stimuli, leading to the release of a drug or other agent. This review demonstrates the latest achievements in the use of internal stimuli-responsive, activatable nanoparticles with respect to unique design strategies and applications.

Influenza virus vaccine for neglected hosts: horses and dogs

This study provides information regarding vaccine research and the epidemiology of influenza virus in neglected hosts (horses and dogs). Equine influenza virus (EIV) causes a highly contagious disease in horses and other equids, and outbreaks have occurred worldwide. EIV has resulted in costly damage to the horse industry and has the ability of cross the host species barrier from horses to dogs. Canine influenza is a virus of equine or avian origin and infects companion animals that live in close contact with humans; this results in possible exposure to the seasonal epizootic influenza virus. There have been case reports of genetic reassortment between human and canine influenza viruses, which results in high virulence and the ability of transmission to ferrets. This emphasizes the need for vaccine research on neglected hosts to update knowledge on current strains and to advance technology for controlling influenza outbreaks for public health.