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62 result(s) for "Gu, Se Hun"
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Discovery and genomic characterization of Ulleung virus harbored by Crocidura utsuryoensis on Ulleung Island in Republic of Korea
Hantaviruses are zoonotic RNA viruses that cause hemorrhagic fever with renal syndrome and hantavirus cardiopulmonary syndrome, posing significant public health risks. This study reports the identification and genomic characterization of Ulleung virus (ULLEV), a newly discovered genetic lineage of Orthohantavirus jejuense harbored by Crocidura utsuryoensis , a shrew species endemic to Ulleung Island, Republic of Korea. In 2009, a surveillance effort involving 62 shrews revealed a molecular prevalence of 64.5%. Metagenomic next-generation sequencing identified four viral variants, with ULLEV Cu09-33 fully characterized. Comparative genomic and phylogenetic analyses confirmed ULLEV as a distinct subtype within O. jejuense and suggested that ULLEV and Jeju virus (JJUV) share a common ancestor, with divergence shaped by long-term co-evolution with their hosts and geographic isolation. Haplotype network analysis of mitochondrial DNA detected eight unique haplotypes in C. utsuryoensis , distinct from C. shantungensis populations, indicating genetic isolation. While incongruences among the tripartite genomes of ULLEV and JJUV suggested independent evolutionary trajectories, evidence for reassortment remains insufficient. These findings highlight the ecological significance of geographically isolated environments as reservoirs for unique hantavirus lineages and underscore the need for expanded genomic surveillance and phylogenetic studies to assess the zoonotic potential and public health implications of ULLEV.
Longitudinal study of Orthohantavirus hantanense in Apodemus agrarius and disease risk assessment in the Republic of Korea during 2000–2019
Orthohantavirus hantanense (HTNV) is a zoonotic pathogen transmitted by rodents and the causative agent of hemorrhagic fever with renal syndrome (HFRS) in East Asia. Long-term reservoir population ecology studies have enhanced our understanding of hantavirus infection patterns and support disease risk assessments critical for military and civilian populations in HTNV high-risk areas. Here, we evaluated fluctuations in the population dynamics of Apodemus agrarius , the primary reservoir of HTNV, assessed hantavirus seroprevalence, and conducted a descriptive analysis of HFRS disease risks in the Republic of Korea (ROK). From 2000 to 2019, a total of 12,476 small mammals representing 15 species were captured across locations spanning northern to southern regions. A. agrarius was the most frequently collected species in the ROK, with juvenile populations peaking during the late fall/winter seasons. A high proportion of A. agrarius captured at military installations/training sites near the Demilitarized Zone tested seropositive for immunoglobulin G antibodies against HTNV, whereas none of those trapped in Jeollanam Province were seropositive. Risk assessment identified high-risk HFRS zones in northern Gyeonggi and Gangwon Provinces. This study provides important insights for forecasting heightened viral transmission risks to humans and implementing targeted mitigation strategies in HFRS high-risk regions of the ROK.
Comparison of targeted next-generation sequencing for whole-genome sequencing of Hantaan orthohantavirus in Apodemus agrarius lung tissues
Orthohantaviruses, negative-sense single-strand tripartite RNA viruses, are a global public health threat. In humans, orthohantavirus infection causes hemorrhagic fever with renal syndrome or hantavirus cardiopulmonary syndrome. Whole-genome sequencing of the virus helps in identification and characterization of emerging or re-emerging viruses. Next-generation sequencing (NGS) is a potent method to sequence the viral genome, using molecular enrichment methods, from clinical specimens containing low virus titers. Hence, a comparative study on the target enrichment NGS methods is required for whole-genome sequencing of orthohantavirus in clinical samples. In this study, we used the sequence-independent, single-primer amplification, target capture, and amplicon NGS for whole-genome sequencing of Hantaan orthohantavirus (HTNV) from rodent specimens. We analyzed the coverage of the HTNV genome based on the viral RNA copy number, which is quantified by real-time quantitative PCR. Target capture and amplicon NGS demonstrated a high coverage rate of HTNV in Apodemus agrarius lung tissues containing up to 10 3 –10 4 copies/μL of HTNV RNA. Furthermore, the amplicon NGS showed a 10-fold (10 2 copies/μL) higher sensitivity than the target capture NGS. This report provides useful insights into target enrichment NGS for whole-genome sequencing of orthohantaviruses without cultivating the viruses.
Whole-genome sequencing and genetic diversity of severe fever with thrombocytopenia syndrome virus using multiplex PCR-based nanopore sequencing, Republic of Korea
Background Whole-genome sequencing plays a critical role in the genomic epidemiology intended to improve understanding the spread of emerging viruses. Dabie bandavirus, causing severe fever with thrombocytopenia syndrome (SFTS), is a zoonotic tick-borne virus that poses a significant public health threat. We aimed to evaluate a novel amplicon-based nanopore sequencing tool to obtain whole-genome sequences of Dabie bandavirus, also known as SFTS virus (SFTSV), and investigate the molecular prevalence in wild ticks, Republic of Korea (ROK). Principal findings A total of 6,593 ticks were collected from Gyeonggi and Gangwon Provinces, ROK in 2019 and 2020. Quantitative polymerase chain reaction revealed the presence of SFSTV RNA in three Haemaphysalis longicornis ticks. Two SFTSV strains were isolated from H. longicornis captured from Pocheon and Cheorwon. Multiplex polymerase chain reaction-based nanopore sequencing provided nearly full-length tripartite genome sequences of SFTSV within one hour running. Phylogenetic and reassortment analyses were performed to infer evolutionary relationships among SFTSVs. Phylogenetic analysis grouped SFTSV Hl19-31-4 and Hl19-31-13 from Pocheon with sub-genotype B-1 in all segments. SFTSV Hl20-8 was found to be a genomic organization compatible with B-1 (for L segment) and B-2 (for M and S segments) sub-genotypes, indicating a natural reassortment between sub-genotypes. Conclusion/Significance Amplicon-based next-generation sequencing is a robust tool for whole-genome sequencing of SFTSV using the nanopore platform. The molecular prevalence and geographical distribution of SFTSV enhanced the phylogeographic map at high resolution for sophisticated prevention of emerging SFTS in endemic areas. Our findings provide important insights into the rapid whole-genome sequencing and genetic diversity for the genome-based diagnosis of SFTSV in the endemic outbreak.
Multiple Lineages of Hantaviruses Harbored by the Iberian Mole (Talpa occidentalis) in Spain
The recent detection of both Nova virus (NVAV) and Bruges virus (BRGV) in European moles (Talpa europaea) in Belgium and Germany prompted a search for related hantaviruses in the Iberian mole (Talpa occidentalis). RNAlater®-preserved lung tissue from 106 Iberian moles, collected during January 2011 to June 2014 in Asturias, Spain, were analyzed for hantavirus RNA by nested/hemi-nested RT-PCR. Pairwise alignment and comparison of partial L-segment sequences, detected in 11 Iberian moles from four parishes, indicated the circulation of genetically distinct hantaviruses. Phylogenetic analyses, using maximum-likelihood and Bayesian methods, demonstrated three distinct hantaviruses in Iberian moles: NVAV, BRGV, and a new hantavirus, designated Asturias virus (ASTV). Of the cDNA from seven infected moles processed for next generation sequencing using Illumina HiSeq1500, one produced viable contigs, spanning the S, M and L segments of ASTV. The original view that each hantavirus species is harbored by a single small-mammal host species is now known to be invalid. Host-switching or cross-species transmission events, as well as reassortment, have shaped the complex evolutionary history and phylogeography of hantaviruses such that some hantavirus species are hosted by multiple reservoir species, and conversely, some host species harbor more than one hantavirus species.
Phylogeographic diversity and hybrid zone of Hantaan orthohantavirus collected in Gangwon Province, Republic of Korea
Hantaan orthohantavirus (Hantaan virus, HTNV), harbored by Apodemus agrarius (the striped field mouse), causes hemorrhagic fever with renal syndrome (HFRS) in humans. Viral genome-based surveillance at new expansion sites to identify HFRS risks plays a critical role in tracking the infection source of orthohantavirus outbreak. In the Republic of Korea (ROK), most studies demonstrated the serological prevalence and genetic diversity of orthohantaviruses collected from HFRS patients or rodents in Gyeonggi Province. Gangwon Province is a HFRS-endemic area with a high incidence of patients and prevalence of infected rodents, ROK. However, the continued epidemiology and surveillance of orthohantavirus remain to be investigated. Whole-genome sequencing of HTNV was accomplished in small mammals collected in Gangwon Province during 2015-2018 by multiplex PCR-based next-generation sequencing. To elucidate the geographic distribution and molecular diversity of viruses, we conducted phylogenetic analyses of HTNV tripartite genomes. We inferred the hybrid zone using cline analysis to estimate the geographic contact between two different HTNV lineages in the ROK. The graph incompatibility based reassortment finder performed reassortment analysis. A total of 12 HTNV genome sequences were completely obtained from A. agrarius newly collected in Gangwon Province. The phylogenetic and cline analyses demonstrated the genetic diversity and hybrid zone of HTNV in the ROK. Genetic exchange analysis suggested the possibility of reassortments in Cheorwon-gun, a highly HFRS-endemic area. The prevalence and distribution of HTNV in HFRS-endemic areas of Gangwon Province enhanced the phylogeographic map for orthohantavirus outbreak monitoring in ROK. This study revealed the hybrid zone reflecting the genetic diversity and evolutionary dynamics of HTNV circulating in Gangwon Province. The results arise awareness of rodent-borne orthohantavirus diseases for physicians in the endemic area of ROK.
Urinary genome detection and tracking of Hantaan virus from hemorrhagic fever with renal syndrome patients using multiplex PCR-based next-generation sequencing
Hantavirus infection occurs through the inhalation of aerosolized excreta, including urine, feces, and saliva of infected rodents. The presence of Hantaan virus (HTNV) RNA or infectious particles in urine specimens of patient with hemorrhagic fever with renal syndrome (HFRS) remains to be investigated. We collected four urine and serum specimens of Republic of Korea Army (ROKA) patients with HFRS. We performed multiplex PCR-based next-generation sequencing (NGS) to obtain the genome sequences of clinical HTNV in urine specimens containing ultra-low amounts of viral genomes. The epidemiological and phylogenetic analyses of HTNV demonstrated geographically homogenous clustering with those in Apodemus agrarius captured in highly endemic areas, indicating that phylogeographic tracing of HTNV genomes reveals the potential infection sites of patients with HFRS. Genetic exchange analyses showed a genetic configuration compatible with HTNV L segment exchange in nature. Our results suggest that whole or partial genome sequences of HTNV from the urine enabled to track the putative infection sites of patients with HFRS by phylogeographically linking to the zoonotic HTNV from the reservoir host captured at endemic regions. This report raises awareness among physicians for the presence of HTNV in the urine of patients with HFRS.
Typing of Yersinia pestis in Challenging Forensic Samples Through Targeted Next-Generation Sequencing of Multilocus Variable Number Tandem Repeat Regions
Microbial forensics involves analyzing biological evidence to evaluate weaponized microorganisms or their toxins. This study aimed to detect and type Yersinia pestis from four simulated forensic samples—human plasma diluted in phosphate-buffered saline (#24-2), tomato juice (#24-5), grape juice (#24-8), and a surgical mask (#24-10). Notably, samples #24-10 may have contained live bacteria other than Y. pestis. A real-time polymerase chain reaction confirmed the presence of Y. pestis in all samples; however, whole-genome sequencing (WGS) coverage of the Y. pestis chromosome ranged from 0.46% to 97.1%, largely due to host DNA interference and low abundance. To address these limitations and enable strain-level identification, we designed a hybridization-based target enrichment approach focused on multilocus variable number tandem repeat analysis (MLVA). Next-generation sequencing (NGS) using whole-genome amplification revealed that the accuracy of the 25 MLVA profiles of Y. pestis for samples #24-2, #24-5, #24-8, and #24-10 was 4%, 100%, 52%, and 0%, respectively. However, all samples showed 100% accuracy with target-enriched NGS, confirming they all belong to the same strain. These findings demonstrate that a targeted enrichment strategy for MLVA loci can overcome common obstacles in microbial forensics, particularly when working with trace or degraded samples where conventional WGS proves challenging.
Dynamic Circulation and Genetic Exchange of a Shrew-borne Hantavirus, Imjin virus, in the Republic of Korea
Hantaviruses (family Bunyaviridae ) are enveloped negative-sense tripartite RNA viruses. The natural hosts of hantaviruses include rodents, shrews, moles, and bats. Imjin virus (MJNV) is a shrew-borne hantavirus identified from the Ussuri white-toothed shrews ( Crocidura lasiura ) in the Republic of Korea (ROK) and China. We have isolated MJNV and determined its prevalence and molecular diversity in Gyeonggi province, ROK. However, the distribution and phylogeography of MJNV in other regions of ROK remain unknown. A total of 96  C. lasiura were captured from Gangwon and Gyeonggi provinces, ROK, during 2011–2014. Among them, four (4.2%) shrews were positive for anti-MJNV IgG and MJNV RNA was detected from nine (9.4%), respectively. Based on the prevalence of MJNV RNA, the preponderance of infected shrews was male and adult, consistent with the gender- and weight-specific prevalence of hantaviruses in other species. We monitored the viral load of MJNV RNA in various tissues of shrews, which would reflect the dynamic infectious status and circulation of MJNV in nature. Our phylogeographic and genomic characterization of MJNV suggested natural occurrences of recombination and reassortment in the virus population. Thus, these findings provide significant insights into the epidemiology, phylogeographic diversity, and dynamic circulation and evolution of shrew-borne hantaviruses.
Đakrông virus, a novel mobatvirus (Hantaviridae) harbored by the Stoliczka’s Asian trident bat (Aselliscus stoliczkanus) in Vietnam
The recent discovery of genetically distinct shrew- and mole-borne viruses belonging to the newly defined family Hantaviridae (order Bunyavirales) has spurred an extended search for hantaviruses in RNAlater®-preserved lung tissues from 215 bats (order Chiroptera) representing five families (Hipposideridae, Megadermatidae, Pteropodidae, Rhinolophidae and Vespertilionidae), collected in Vietnam during 2012 to 2014. A newly identified hantavirus, designated Đakrông virus (DKGV), was detected in one of two Stoliczka’s Asian trident bats ( Aselliscus stoliczkanus ), from Đakrông Nature Reserve in Quảng Trị Province. Using maximum-likelihood and Bayesian methods, phylogenetic trees based on the full-length S, M and L segments showed that DKGV occupied a basal position with other mobatviruses, suggesting that primordial hantaviruses may have been hosted by ancestral bats.