Genetic Analysis of Hepatitis A Virus Isolated from Korea

Lee, Kyung-Ok,Jeong, Su-Jin,Seong, Hye-Soon,Kim, Kyung-Tae,Hwang, Yoo-Sung,Kim, Gee-Young,Lee, Sun-Hwa The Korean Society for Microbiology 2009 Journal of Bacteriology and Virology Vol.39 No.3

Hepatitis A virus (HAV) is one of the most important causes of acute infectious hepatitis. The aim of this study was to determine the genotypes of HAV that have been circulating in Koreans. A total of 76 sera referred to our institute for HAV genotyping from 11 Korean provinces were used for this study. Those samples were diagnosed by positive of IgM anti-HAV. HAV RNA was extracted from $150{\mu}l$ of serum, and reverse transcription PCR-sequencing was used to detect and characterize HAV RNA. Primer pairs from the VP1/2A region of the HAV were used for amplification and sequencing. HAV RNA was found in 64.5% (n = 49) of the 76 patient sera with acute hepatitis A. Forty-seven strains were genotype IIIA in a total of 49 isolated strains (95.9%, 47/49); only two strains belonged to genotype IA (4.1%, 2/49). Thirty eight genotype IIIA isolates were 100% identical to consensus amino acid sequences of the reference strain AJ299467. The amino acid change of L772F was found in two IIIA strains; other IIIA isolates showed one amino acid change. Amino acid of genotype IA was compared to reference strain L20541. K801R was found in 1 strain and Q810S in both strains. The amino acid change of K801R was the first report in Koreans. Until recently HAV genotype IA has been reported as a major circulating HAV genotype in Koreans. In the present study, the predominant HAV strain in Koreans seemed to be HAV genotype IIIA.

Antibody Response in Korean Raccoon Dogs Inoculated with Inactivated Rabies Vaccines

Yang, Dong-Kun,Go, Tae-Oh,Nam, Young-Hee,Kim, Ha-Hyun,Cho, Soo-Dong,Lee, Kyung-Woo,Choi, Sung-Suk,Song, Jae-Young The Korean Society for Microbiology 2012 Journal of Bacteriology and Virology Vol.42 No.3

Since sylvatic rabies was first identified in South Korea in 1993, over three million bait vaccine doses have been distributed to rabies risk regions in order to block transmission of rabies among wild animals. New progressive strategy is needed to eliminate sylvatic rabies completely in rabies risk regions. Before applying the preventive program related to eradication, immunogenicity of inactivated rabies vaccines available in Korea has to be evaluated in Korean raccoon dogs (Nyctereutes procyonoides koreensis). Six groups of raccoon dogs in wild rescue center of Gyeonggi-do were vaccinated intramuscularly with single dose of six inactivated commercial rabies vaccines (designated A to F). Serum samples at the time of vaccination, and two and four weeks post vaccination were obtained and analyzed by virus neutralizing assay (VNA). All raccoon dogs inoculated with vaccines C, D, E or F, showed VN antibody titers ranging from 0.5 to 13.77 IU/ml. Half of four raccoon dogs immunized with vaccine B revealed VN titer over 0.5 IU/ml, and one of four raccoon dogs inoculated with vaccine A showed protective antibody titer. This finding suggests that most of the commercially available inactivated rabies vaccines could induce protective immunity in Korean raccoon dogs and be applicable to new rabies control program.

Analysis of the Cell Lysate Proteome of a Korean Mycobacterium tuberculosis Isolate K01 with H37Rv and H37Ra Strains

Ryu, Sung-Weon,Park, Sang-Chan,Bang, Mun-Nam,Han, Sung-Sik,Park, Young-Kil,Park, Sue-Nie,Shim, Young-Soo,Kan, Seong-Man,Bail, Gill-Han The Korean Society for Microbiology 2004 Journal of Bacteriology and Virology Vol.34 No.2

Despite recent economic prosperity, Korea still has high prevalence of tuberculosis. Molecular biologic characterization of Korean Mycobacterium tuberculosis strains might provide a deeper understanding of the forces contributing to the spread of tuberculosis in Korea. Therefore, we analyzed the cell lysate proteome of a representative Korean Mycobacterium tuberculosis isolate (K01) in comparison with laboratory reference strains H37Rv and H37Ra. Seven spots were strongly expressed only in K01 strain compared with M. tuberculosis H37Rv and H37Ra. Through continuous MALDI-MS analysis, these spots were identified as hypothetical protein Rv3849, secreted immunogenic protein Mpt64, Acetyl/propionyl-CoA Carbpxylase (AceD1), alkyl hydroperoxide reductase C (AhpC), N-acetylmuramyl-L-alanine amidase, a putative UDP glucose epimerase, and a transposase. A deeper study of these proteins may provide a clue in the development of effective new anti-tuberculosis vaccines against Korean M. tuberculosis isolates.

Prevalence of Human Papillomavirus Genotypes in Routine Pap Smear of 2,562 Korean Women Determined by PCR-DNA Sequencing

Lee, Kyung-Ok,Jeong, Su-Jin,Park, Min-Young,Seong, Hye-Soon,Shin, Eun-Sim,Choi, Kyeong-Hwan,Kim, Gee-Young,Lee, Sun-Hwa The Korean Society for Microbiology 2009 Journal of Bacteriology and Virology Vol.39 No.4

The infections by human papillomaviruses (HPVs) are clearly associated with the subsequent development of cervical cancer. In this study, HPV genotype distribution and prevalence were detected in Korean women from January to December 2008 using PCR-DNA sequencing. A total of 2,562 cervical samples from Korean women having routine Pap smear cytology screening were used. HPV DNA was extracted from cervical swab samples and amplified by PCR in L1 region of HPV. HPV DNA was detected in 23.2% and 65.5% from the groups of normal and abnormal Pap cytology, respectively. The prevalence of high-risk types of HPV had the highest frequency in the <30 year-olds' group (50.6%). The prevalence of HPV in normal, ASCUS, LSIL and HSIL groups was 23.2%, 58.1%, 96.3% and 97.0%, respectively. Moreover, the frequencies of the high-risk types of HPV were 16.2% in the normal Pap cytology, 44.7% in the ASCUS, 76.1% in the LSIL and 94.1% in the HSIL groups. The prevalence of the high-risk types of HPV increased in proportion to the severity of the cytological classification. In the HSIL group, HPV type 16 was the most frequently found at 32.4%, followed by types 58, 53 and 33 at 17.6%, 14.7% and 11.8%, respectively. HPV type 82 was found in 5.6% of the HSIL group and was not detected in the normal Pap cytology group. The frequency of high-risk type of HPV 82 is firstly reported in Korean women. This finding could be an informative basis for the development of future HPV vaccination strategies in Korean women.

Distinct Genetic Variation of Helicobacter pylori cagA, vacA, oipA, and sabA Genes in Thai and Korean Dyspeptic Patients

Boonyanugomol, Wongwarut,Kongkasame, Worrarat,Palittapongarnpim, Prasit,Jung, Myunghwan,Shin, Min-Kyoung,Kang, Hyung-Lyun,Baik, Seung-Chul,Lee, Woo-Kon,Cho, Myung-Je The Korean Society for Microbiology and Biotechnol 2018 한국미생물·생명공학회지 Vol.46 No.3

Differences in host ethnicities and geographical distributions may influence the genetic variation and pathogenesis of Helicobacter pylori strains, particularly with respect to those with a high risk of gastric cancer and in Asian Enigma regions. We simultaneously identified H. pylori virulence-associated genes involved in inflammation and cell damage in Thai and Korean dyspeptic patients. The virulence-associated gene cagA, cagA genotypes (East Asian and Western type cagA), vacA genotypes (s- and m-), oipA, and sabA were detected in Thai and Korean dyspeptic patients by polymerase chain reaction (PCR), real-time PCR, and DNA sequence analysis. Comparisons between the two regions showed that cagA, East Asian type cagA, and vacA s1/m1 in Korean dyspeptic patients occurred at rates of 100%, 86.67%, and 88.89%, respectively (p < 0.05). The oipA- and sabA-positive samples were significantly more predominant in the Korean population (95.56%, 91.11%) than in the Thai population (32%, 34%). DNA sequence analysis revealed differences in the patterns of cytosine-thymine dinucleotide repeats of oipA and sabA among the two populations of dyspeptic patients. Our results indicate that the H. pylori strains detected in the two regions were divergent, and strains colonizing the Korean dyspeptic patients may be more virulent than those in the Thai population. Our data may help explain H. pylori pathogenesis in Asian Enigma areas with a low gastric cancer incidence. However, other factors involving H. pylori infection in these two regions should be further analyzed.

Genetic Characterization of Porcine Circovirus Type 2 Detected from the Pigs in Commercial Swine Farms in Korea

Oh, Sey-Seok,Chu, Jia-Qi,Park, Sang-Hun,Park, Chang-Sik,Kim, Myung-Cheol,Jun, Moo-Hyung The Korean Society for Microbiology 2006 Journal of Bacteriology and Virology Vol.36 No.3

Porcine circovirus type 2 (PCV-2) has been nowadays recognized as a major agent causing postweaning multisystemic wasting syndrome (PMWS) in pigs worldwide. PMWS most commonly affects the weaned piglets, being of increasing importance to the pig industry in Korea. Seven commercial farms affected with PMWS and 2 farms free from PMWS, located in the southern part of Gyeonggi province, were selected for this study. The peripheral mononuclear cells were tested for the presence of ORF2 gene by PCR, and 54 (68.4%) of 79 samples were positive. All of 9 herds tested included the positive cases. The positive rates by herds were 50 to 100% in the PMWS-affected herds and 40 to 62.5% in the PMWS-free herd. The nucleotide and amino acid sequences of ORF2 gene of 6 strains were characterized. Homologies among 6 strains revealed 92.1 to 100% in the nucleotide and 92.3 to 100% in the amino acid. The overall ranges of homologies for 25 strains comprised 2 Korean and 23 foreign strains were 91.1 to 100% in the nucleotide and 89.7 to 100% in the amino acid. Three regions of greater heterogeneity were found in immunorelevant epitopes of the capsid protein, and the sequences between 57 to 80 aa revealed higher mutation than other areas. In the phylogenetic tree analysis, KOR 71 strain was clustered together with Korean strains previously isolated in Korea. The remaining 5 strains were closely clustered with other European and Asian strains. The results will be valuable for improving our understanding of the molecular epidemiology of PCV-2 in Korea and development of preventive measures for PMWS.

Naturally Occurring Mutations of Hepatitis B virus and Hepatitis C Virus in Korean Chronic Patients by Distinct CD4 T Cell Responses

Kim, Hong,Kim, Bum-Joon The Korean Society for Microbiology 2014 Journal of Bacteriology and Virology Vol.44 No.1

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are among the most common causes of chronic liver disease worldwide. The host immune pressure against hepatitis viruses during the chronic infection has led to mutations in their coding genes, which could play a pivotal role in the clinical outcomes of chronic patients. Our recent molecular epidemiologic studies regarding the HBV precore/core (preC/C) regions and HCV nonstructural 5B (NS5B) protein suggest the presence of distinct CD4 T cell immune pressure against HBV and HCV in Korean chronic patients. However, induced HBV and HCV mutations seem to exert an opposite effect on Korean chronic hepatitis B (CHB) and chronic hepatitis C (CHC) patients, respectively. On the basis of two of our recent papers, we focused in this review on the relationships between the mutation patterns of HBV preC/C and HCV NS5B, which were presumed to be caused by distinct CD4 T cell pressure in the Korean population and their effect on the clinical outcomes and liver disease progression of CHB and CHC patients.

Cross-reactivity of Vaccine and Fields Strains of Bovine Coronaviruses in Korea

Lee, Ga-Ram,Song, Jae-Young,Cho, In-Soo,Yoon, So-Rah The Korean Society for Microbiology 2010 Journal of Bacteriology and Virology Vol.40 No.1

Bovine coronavirus (BCoV) causes severe diarrhea in newborn calves, and is associated with winter dysentery in adult cattle and respiratory infections in calves and feedlot cattle. Although the Korean BCoV vaccine strain, BC94, was isolated in 1995, there has still been no report of a molecular characterization of the vaccine strain. To characterize the vaccine strain, relationships between BC94 and field strains were investigated, based on sequence analysis and cross-immunity. We determined the complete sequences of the HE, N, and S genes from BC94 and four NVRQS isolates (SUN5, A3, 0501, 0502). Due to its major role in antigenicity, the spike proteins of the BCoVs were analyzed. BC94 showed distinctive genetic divergence from field isolates collected from 2002 to 2005. BC94, SUN5, and A3 had no virulence-specific sequence and there was a single amino acid change, from asparagine to lysine at residue 175, in the polymorphic region. Strains 0501 and 0502 had virulence-specific sequences at all seven sites. Although the recently isolated Korean BCoVs and BC94 were genetically different, the cleavage site of spike genes at 763~768 (KRRSRR) and the antigenic domain II of the spike protein, amino acid position 528, were conserved in all NVRQS isolates. The antigenic relatedness of KCD9, representative of recent Korean BCoVs, was compared with the Korean vaccine strain BC94. KCD9 showed cross-reactivity against BC94 by virus neutralization (VN) test. These results suggest that BC94 is antigenically closely related to field isolates and is still effective as a vaccine strain.

Genetic Characterization of Haemagglutinin 1 Domain of Influenza B Viruses Isolated in Korea during $1988{\sim}1999$

Shin, Gu-Choul,Na, Byoung-Kuk,Lee, Joo-Yeon,Ahn, Jung-Bae,Park, Jong-Won,Lee, Jin-Soo,Kim, Jee-Hee,Kim, Woo-Joo,Kang, Chun The Korean Society for Microbiology 2003 Journal of Bacteriology and Virology Vol.33 No.4

Although Korean influenza virus isolates have been genetically associated with the vaccine strains of the corresponding year, influenza B viruses have prevailed almost every year in Korea during the past decades. We have 'analyzed the genetic characteristics and evolutionary patterns of the haemagglutinin (HA) 1 domains of influenza B viruses isolated during 1988-1999 using direct RT-PCR and sequencing. Phylogenetic analysis of influenza B viruses isolated in Korea indicated that antigenically and genetically distinguishable strains of the lineage II and lineage III variants had been cocirculated. Variants prevailed in early 1990s are represented in 1996/97 and 1998/99 and some different variants have been co circulated geographically and prevailed concurrently in Korea. All HA1s of Korean isolates have amino acid substitutions mainly in the region between position 124 and 310, which was previously proposed an immunodominant region. Insertion-deletion patterns of the HA gene revealed that Korean influenza B viruses were evolved from Lee40 with different manner between lineage II and III viruses. Lineage III viruses were also divided into two groups as conserved group and inserted group, in relation to Lee40. But lineage II viruses had evolved with directional pattern. Antigenic index proposed that influenza B isolates prevailed since 1996/97 seasons might had emerged from the antigenic variants of a Seo1697-like virus and that new variants might appear from the lineage II viruses resulting in persistent prevalence in Korea.

Epidemiology of Shigellosis in Korea

Lee, Je-Chul,Jeong, Young-Sook,Oh, Jae-Young,Kang, Hee-Young,Kim, Kwang-Hoon,Kim, Jung-Min,Lee, Yoo-Chul,Cho, Dong-Taek,Seol, Sung-Yong The Korean Society for Microbiology 2006 Journal of Bacteriology and Virology Vol.36 No.2

Shigellosis is an acute diarrheal disease caused by bacteria of the genus Shigella. Following the occurrence of a large outbreak of shigellosis as well as sporadic cases since 1998, shigellosis has been a major health problem in Korea. There have been major changes in epidemiology during the last five decades concerning shigellosis in terms of total incidence of shigellosis, prevalence of certain serogroups, selection of specific clones, and introduction of new Shigella clones. S. dysenteriae was the most prevalent species until the early twentieth century, S. flexneri was the most prevalent until the late 1980s, and S. sonnei has been the most prevalent since 1990. Diverse serotypes of S. dysenteriae (4 serotypes), S. flexneri (8 serotypes), and S. boydii (4 serotypes) were found during the Korean War and many of these Korean endemic Shigella strains circulated in the community until the late 1970s. However, the endemic strains of S. dysenteriae, S. boydii, and S. sonnei disappeared in the late 1980s. A new clone of S. sonnei that was introduced between the late 1980s and the early 1990s was responsible for a large proportion of shigellosis in recent years. S. flexneri serotype 4a was the most frequently found during the Korean War and then the incidence of S. flexneri 2a gradually increased with time. S. flexneri isolates detected from 1991 to 1997 were all serotype 2a. However, the diverse clones of S. flexneri reemerged in Korea since 1999. It has not been determined whether the S. flexneri strains from the 2000s were the descendants of the Korean endemic strains or imported new strains, but the PFGE patterns were different between S. flexneri strains from the 1980s and 2000s. The widespread of new S. sonnei strains and the persistence of S. flexneri strains are responsible for the endemicity of shigellosis in Korea.