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Original Article
- Molecular Epidemiological Study of Measles Cases in Gyeonggi Province
- Baek-Sang Han, Su-Kyong Moon, Sin-Hee Park, Kyong-Shin Ryu, Eun-Bee Kim
- Measles is one of the highly contagious infectious diseases in which about 90% of the groups that have no immunity against measles …
- Measles is one of the highly contagious infectious diseases in which about 90% of the groups that have no immunity against measles are infected when exposed to the measles virus. Even after the Republic of Korea was certified as a ‘national measles eradication’ by the WHO in March 2014, two import-related outbreaks of measles occurred in 2014 and 2019. In this study, we analyzed epidemiological characteristics and genetic distribution of measles cases. Ninety-eight nasopharyngeal or oropharyngeal swab samples that confirmed cases of measles in Gyeonggi province in 2019 were conducted genotyping assay and sequence analysis. Fifty cases were classified as group outbreak-related cases and Forty-eight cases were classified as sporadic cases. As a result of genetic analysis, these cases were classified into D8, B3, and A genotypes, and except for the A type which was known as the vaccine type, D8 and B3 types were identified as import-related measles viruses. As with these results, for the complete eradication of measles, not only a high-quality surveillance system but also molecular epidemiological analysis data must be supported. The results of this study are expected to be used as important data for establishing a quarantine system through the accumulation of measles virus genotyping data and case reports data in the future when measles occurs in South Korea. - COLLAPSE
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Original Article
- Status of the SARS-CoV-2 Mutant Virus (Delta, Omicron) outbreak in Chungcheongnamdo, Korea in Early 2022
- KyungA Yun, Ji Hee Kim, Na Hee Kwon, Woo-Sik Kim, Junhyuk Park
- As the coronavirus disease 2019 (COVID-19) spread worldwide, variants viruses are constantly emerging. And there has been a growing interest in the …
- As the coronavirus disease 2019 (COVID-19) spread worldwide, variants viruses are constantly emerging. And there has been a growing interest in the study of variant viruses, for the necessity of response to emergence and diffusion of new coronavirus variants. So, we conducted a survey of variant proportions of SARS-CoV-2 on positive samples of confirmed cases by Real-time Polymerase Chain Reaction (Real-time PCR). From December 26, 2021 to April 2, 2022, a total of 819 SARS-CoV-2 variants of concern (VOCs) were identified in COVID-19 positive samples. In the 2nd week of January 2022, detection rate of the Omicron subvariant BA.1 was 58.1%, overtaking Delta variant to become dominant type. However, in the 5th week of March, detection rate of another Omicron subvariant BA.2 was 75.9%, became dominant variant. These results imply that BA.1 was a dominant variant for two months and after that, omicron BA.1 was rapidly replaced by omicron BA.2. This research is valuable because it provided information which is helpful to response diffusion of new variants. Compared to Delta variant, a large number of mutations in the spike gene(S) of Omicron variant were detected. It raises concerns about changes in pathogenicity and transmissibility in new COVID variants. Therefore, we should develop new strategies against emergence and diffusion of SARS-CoV-2 variants throughout monitoring appearance of the new variants, analyzing the characteristics of new things. In this respect, the results of this research are useful because they offered good basic data for appreciating characteristics of new COVID variants by monitoring the emergence of Delta and Omicron variant. - COLLAPSE
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Original Article
- In vitro Antiviral Activity of Remdesivir Against SARS-CoV-2 and its Variants
- Aleksandra Nowakowska, Hanul Choi, Kihoon Park, Jinha Kim, Yuyeon Jang, Jungmin Chun, Young Bong Kim, Hee-Jung Lee
- The outbreak of COVID-19 has become a public health emergency of international concern; thus, it is important to not only develop drugs …
- The outbreak of COVID-19 has become a public health emergency of international concern; thus, it is important to not only develop drugs for treating COVID-19 but also develop a method for evaluating the therapeutic effect based on the characteristics of SARS-CoV-2 and its variants. To test the antiviral activity of a drug against COVID-19, in this study, we established and compared experimental conditions, such as the treatment time and mode of action (dose) of the therapeutic substance, and a test method to evaluate its effectiveness. We optimized an assay for testing antiviral activity by plaque reduction, tissue culture infectious dose 50, and quantitative RT-PCR. These methods were applied to test the antiviral efficacy of the therapeutic against SARS-CoV-2. Antiviral activity testing using in vitro assays against SARS-CoV-2 and its variants was assessed by measuring plaque-reducing or cytopathic effects in Vero-E6 cells. The in vitro assay was validated by evaluating the antiviral activity of remdesivir. Remdesivir reduced SARS-CoV-2 titer without detectable cytotoxicity and successfully inhibited viral replication in a dose-dependent manner. Therefore, we suggest this in vitro assay as an effective method for testing the antiviral activity for a potential repurposed drug against COVID-19 or rapid screening of therapeutic candidates. - COLLAPSE
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Original Article
- Regulation in the Expression of Virulence Factors of Helicobacter pylori by the Interaction between AGS Cells and H. pylori
- Yu-Ri Kim, Wongwarut Boonyanugomol, Won-jun An, Trinh Minh Phuong, Jin-Sik Park, Min-Kyoung Shin, Seung-Chul Baik, Woo-Kon Lee, Myung-Je Cho, Hyung-Lyun Kang, Myunghwan Jung
- Helicobacter pylori (H. pylori) was defined as a Class 1 pathogenic carcinogen by WHO causing chronic inflammation in the stomach, …
- Helicobacter pylori (H. pylori) was defined as a Class 1 pathogenic carcinogen by WHO causing chronic inflammation in the stomach, thereby increasing the risk of gastric cancer. Various virulence factors are involved in the mechanism of gastric cancer caused by H. pylori infection. These virulence factors usually show different expression levels depending on the environment of H. pylori, which can affect the risk of gastric cancer. In this study, the differences in the expression levels of major virulence factors of H. pylori depending on the environment were investigated by comparing expression levels of H. pylori cultured with AGS or alone. As a result, there was no difference in the expression of adhesins of alpA, sabA, and babA even after co-culture with AGS cells. In addition, the co-culture environment did not induce a difference in the expression levels of flaA and ureB. On the other hand, H. pylori co-cultured with AGS cells showed low expression levels of cagA, groEL, and oipA and high expression of vacA compared to H. pylori cultured alone. Our results suggest that not only the presence or absence of virulence factor genes but also differences in expression levels should be considered when evaluating the risk of gastric cancer after H. pylori infection based on the virulence factors. - COLLAPSE
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Original Article
- In silico Design of Multi-epitope Vaccines Targeting Iron-regulated lipoproteins of Staphylococcus aureus Using Immunoinformactics
- Eun Hwan Bae, Minhye Shin
- Staphylococcus aureus (S. aureus) is one of the dangerous pathogens involved in serious infections with high risk for morbidity and …
- Staphylococcus aureus (S. aureus) is one of the dangerous pathogens involved in serious infections with high risk for morbidity and mortality. Development of effective vaccines against S. aureus strains is urgently needed, but successful vaccines are not available yet. In this study, we designed five types of multi-epitope vaccine constructs, targeting lipoproteins associated bacterial iron metabolism, which are IsdE, SstD, SirA, HtsA, and SitC. Using immunoinformatic approaches, we selected various sequences as potent B cell and T cell epitopes and constructed virtual vaccines with linkers and N-terminal adjuvants. The vaccine constructs were evaluated and compared with respect to their physicochemical and structural properties as well as immunologic and allergenic profiles. Immune simulation studies showed the vaccines would increase immune cell populations and antibody and cytokine responses. The vaccine constructs had similar physicochemical and immunological characteristics, while specific constructs showed distinct immune- stimulatory properties. With a further investigation of the vaccine constructs on in vivo host testings, the newly designed S. aureus iron-regulated lipoprotein vaccines would help us to prevent S. aureus infection with greater efficacy and better safety. - COLLAPSE
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Original Article
- Endogenously Synthesized n-3 fatty Acids in fat-1 Transgenic Mice Suppresses B Cell Activation
- Da-Hee Kim, So-Hyun Park, Sang-Myeong Lee
- n-3 Polyunsaturated fatty acids (PUFAs) have been suggested as a preventive or therapeutic strategy for autoimmune or inflammatory diseases via the modulation …
- n-3 Polyunsaturated fatty acids (PUFAs) have been suggested as a preventive or therapeutic strategy for autoimmune or inflammatory diseases via the modulation of the activation, differentiation, and effector functions of various immune cells, especially T cells and macrophages. Despite the importance of B cells in the pathogenesis of autoimmune diseases, few studies have demonstrated their effect on B cells. In this study, we investigated the possible effects of n-3 PUFAs on B cell activation, differentiation, and isotype switching in fat-1 transgenic mice, which can convert n-6 PUFAs to n-3 PUFAs via n-3 desaturase derived from Caenorhabditis elegans. Fat-1 mice were fed a corn oil-rich diet for at least 4 weeks to increase the probability of converting n-6 PUFAs to n-3 PUFAs. Splenic B cells were then isolated, followed by stimulation with Toll-like receptor 4 or B cell receptor (BCR). Our results showed that increased n-3 PUFA levels in B cells by fat-1 overexpression inhibited B cell proliferation, cytokine secretion, such as interleukin (IL)-6, IL-10, tumor necrosis factor-α, plasma cell differentiation, and Ig isotype switching/secretion. These effects are possibly due to the suppression of Syk, Src, and AKT activation in B cells from fat-1 mice, as well as NF-κB. Collectively, our results suggest that fat-1 expression attenuates B cell responses, and n-3 PUFA supplementation can be a possible strategy to treat pathological conditions in which B cells play a key role. - COLLAPSE
Journal Informaiton
JOURNAL OF BACTERIOLOGY AND VIROLOGY
JOURNAL OF BACTERIOLOGY AND VIROLOGY
The Korean Society for Microbiology
대한미생물학회
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Tel: +82-02-887-3062 / Fax: +82-02-887-3063 / E-mail: ksm@ksmkorea.org Copyright© The Korean Society for Microbiology. Powered by APUB
Tel: +82-02-887-3062 / Fax: +82-02-887-3063 / E-mail: ksm@ksmkorea.org Copyright© The Korean Society for Microbiology. Powered by APUB