• Microbiology and Biotechnology Letters
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• v.46 no.2
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• pp.162-170
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• 2018

Non-typhoidal Salmonella is one of the main pathogens causing food-borne illness in humans, with up to 20% of cases resulting from consumption of pork products. Over the gastroenteritis signs, multidrug resistant Salmonella has arisen. In this study, pan-susceptible phenotypic strains of Salmonella enterica serotype Weltevreden recovered from pig production chain in Chiang Mai, Thailand during 2012-2014 were chosen for analysis. The aim of this study was to use whole genome sequencing (WGS) data with an emphasis on antimicrobial resistance gene investigation to assess their pathogenic potential and genetic diversity determination based on whole genome Multilocus Sequence Typing (wgMLST) to expand epidemiological knowledge and to provide additional guidance for disease control. Analyis using ResFinder 3.0 for WGS database tracing found that one of pan-susceptible phenotypic strain carried five classes of resistance genes: aminoglycoside, beta-lactam, phenicol, sulfonamide, and tetracycline associated genes. Twenty four and 36 loci differences were detected by core genome Multilocus Sequence Typing (cgMLST) and pan genome Multilocus Sequence Typing (pgMLST), respectively, in two matching strains (44/13 vs A543057 and A543056 vs 204/13) initially assigned by conventional MLST and Pulsed-field Gel Electrophoresis (PFGE). One hundread percent discriminant ability can be achieved using the wgMLST technique. WGS is currently the ultimate molecular technique for various in-depth studies. As the findings stated above, a new of "gold standard typing method era" for routine works in genome study is being set.

• Journal of Oriental Neuropsychiatry
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• v.24 no.2
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• pp.163-178
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• 2013

Objectives : The purpose of this study is to investigate the characteristics of Sasang constitutional types in the university students. Methods : One hundred fifty students of Woosuk University participated in this study and their majors were Korean medicine, nursing science and pharmacy. The Sasang constitutional types were determined by the results of Two Step Questionnaire for Sasang Constitution Diagnosis (TS-QSCD). The subjects were also tested by Academic Motivation Tests (AMT), Multi-dimensional Learning Strategy Tests (MLST) and Learning Style Questionnaire of Sasang Constitution (LSQ-SC). The subscale scores of AMT, MSLT and each questions of AMT, MLST, LSQ-SC were compared among the different Sasang constitutions using analysis of variances (ANOVA). Results : There were no significant differences in AMT results between Sasang constitutions. In subscales of AMT, Feeling scales (FTF) scores of Soyangin was significantly higher than Taeeumin. Other subscales of AMT were not different between Sasang constitutions. There were no significant differences in MLST results between Sasang constitutions. Subscales of MLST were not different between Sasang constitutions. There were many questions between Soyangin and other constitutions in the analysis of questions of AMT, MLST, and LSQ-SC, and less between Taeeumin and Soeumin. Conclusions : These results suggest that the characteristics of Soyangin is more prominent compared with other constitutions in the learning style, and there were a little differences between Soeumin and Taeeumin.

• Korean Journal of Poultry Science
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• v.47 no.2
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• pp.115-119
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• 2020

Fowl cholera is an infectious disease caused by Pasteurella multocida that contributes to high economic loss in the commercial chicken industry. Three Pasteurella multocida strains were isolated from outbreaks of acute fowl cholera in the Korean layer farms from 2018 to 2019. One strain was identified and serotyped using capsular PCR typing. This strain was also genotyped by lipopolysaccharide (LPS) PCR typing as A: L3, whereas other strains were non-typable. The multilocus sequence typing (MLST) result showed that the A: L3 strain is sequence type (ST) 134; the non-typable strains were recorded as the following new STs: ST 366 and ST 374. Using phylogenetic tree analysis based on MLST sequences, we determined that ST 366 and ST 374 are closely related to the reference strains that were previously isolated from duck and chicken in Korea, and they were highly prevalent within the Korean cluster. In conclusion, Pasteurella multocida strains were identified and isolated in this study. Furthermore, this is the first report of using MLST to determine the prevalence of fowl cholera in Korea.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1467-1470
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• 2012

We compared rapid fingerprinting using repetitive sequencebased PCR (rep-PCR) for subtyping Campylobacter jejuni isolates to the widely used multilocus sequence typing (MLST). Representative C. jejuni isolates (n = 16) from broilers were analyzed using MLST and rep-PCR. Both techniques demonstrated an equal discriminatory power of 0.8917, and 9 subgroups were identified. Clonal identification of all 16 isolates was identical for both techniques. The rep-PCR as described in this study may be used as a rapid and cost-effective alternative for subtyping of C. jejuni isolates, or as an effective screening tool in large epidemiological studies.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1410-1416
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• 2015

Wolbachia is an obligate symbiotic bacteria that is ubiquitous in arthropods, with 25-70% of insect species estimated to be infected. Wolbachia species can interact with their insect hosts in a mutualistic or parasitic manner. Sequence types (ST) of Wolbachia are determined by multilocus sequence typing (MLST) of housekeeping genes. However, there are some limitations to MLST with respect to the generation of clone libraries and the Sanger sequencing method when a host is infected with multiple STs of Wolbachia. To assess the feasibility of massive parallel sequencing, also known as next-generation sequencing, we used pyrosequencing for sequence typing of Wolbachia in butterflies. We collected three species of butterflies (Eurema hecabe, Eurema laeta, and Tongeia fischeri) common to Korea and screened them for Wolbachia STs. We found that T. fischeri was infected with a single ST of Wolbachia, ST41. In contrast, E. hecabe and E. laeta were each infected with two STs of Wolbachia, ST41 and ST40. Our results clearly demonstrate that pyrosequencing-based MLST has a higher sensitivity than cloning and Sanger sequencing methods for the detection of minor alleles. Considering the high prevalence of infection with multiple Wolbachia STs, next-generation sequencing with improved analysis would assist with scaling up approaches to Wolbachia MLST.

• Journal of Microbiology and Biotechnology
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• v.28 no.5
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• pp.796-808
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• 2018

The intracellular bacterium Wolbachia pipientis is widespread in arthropods. Recently, possibilities of novel Wolbachia-mediated hosts, their distribution, and natural rate have been anticipated, and the coconut leaf beetle Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae), which has garnered attention as a serious pest of palms, was subjected to this interrogation. By adopting Wolbachia surface protein (wsp) and multilocus sequence type (MLST) genotypic systems, we determined the Wolbachia infection density within host developmental stages, body parts, and tissues, and the results revealed that all the tested samples of B. longissima were infected with the same Wolbachia strain (wLog), suggesting complete vertical transmission. The MLST profile elucidated two new alleles (ftsZ-234 and coxA-266) that define a new sequence type (ST-483), which indicates the particular genotypic association of B. longissima and Wolbachia. The quantitative real-time PCR analysis revealed a higher infection density in the eggs and adult stage, followed by the abdomen and reproductive tissues, respectively. However, no significant differences were observed in the infection density between sexes. Moreover, the wsp and concatenated MLST alignment analysis of this study with other known Wolbachia-mediated arthropods revealed similar clustering with distinct monophyletic supergroup B. This is the first comprehensive report on the prevalence, infection dynamics, and phylogeny of the Wolbachia endosymbiont in B. longissima, which demonstrated that Wolbachia is ubiquitous across all developmental stages and distributed in the entire body of B. longissima. Understanding the Wolbachia infection dynamics would provide useful insight to build a framework for future investigations, understand its impacts on host physiology, and exploit it as a potential biocontrol agent.

• Food Science of Animal Resources
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• v.40 no.5
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• pp.758-771
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• 2020

This study was to investigate the prevalence and characteristics of antimicrobial-resistant Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) from 4,264 retail meat samples including beef, pork, and chicken in Korea between 2013 and 2018. A broth microdilution antimicrobial susceptibility testing was performed for S. aureus. Molecular typing by multilocus sequence typing (MLST), spa typing, and pulsed-field gel electrophoresis (PFGE), was performed on mecA-positive S. aureus strain. S. aureus was isolated at a rate of 18.2% (777/4,264), of which MRSA comprised 0.7% (29 strains). MLST analysis showed that 11 out of the 29 MRSA isolates were predominantly sequence type (ST) 398 (37.9%). In addition, ST72, ST692, ST188, ST9, and ST630 were identified in the MRSA isolates. The spa typing results were classified into 11 types and showed a high correlation with MLST. The antimicrobial resistance assays revealed that MRSA showed 100% resistance to cefoxitin and penicillin. In addition, resistance to tetracycline (62.1%), clindamycin (55.2%), and erythromycin (55.2%) was relatively high; 27 of the 29 MRSA isolates exhibited multidrug resistance. PFGE analysis of the 18 strains excluding the 11 ST398 strains exhibited a maximum of 100% homology and a minimum of 64.0% homology. Among these, three pairs of isolates showed 100% homology in PFGE; these results were consistent with the MLST and spa typing results. Identification of MRSA at the final consumption stage has potential risks, suggesting that continuous monitoring of retail meat products is required.

• Journal of Microbiology and Biotechnology
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• v.32 no.12
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• pp.1605-1614
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• 2022

The strains associated with foodborne Salmonella enterica Thompson outbreaks in Korea have not been identified. Therefore, we characterized S. Thompson strains isolated from chocolate cakes linked to foodborne outbreaks in Korea. A total of 56 strains were isolated from preserved cake products, products in the supply chain distribution, the manufacturer's apparatus, and egg white liquid products used for cream preparation. Subsequently, serological typing, pathogenic gene-targeted polymerase chain reaction (PCR), pulsed-field gel electrophoresis (PFGE), and whole-genome multi-locus sequence typing (wgMLST) were performed to characterize these isolates. The antigen formula of all isolates was 7:k:1,5, namely Salmonella enterica subsp. enterica Serovar Thompson. All 56 isolates harbored invA, his, hin, and stn, and were negative for sefA and spvC based on gene-targeted PCR analyses. Based on PFGE results, these isolates were classified into one group based on the same SP6X01.011 pattern with 100% similarity. We selected 19 strains based on the region and sample type, which were subjected to wgMLST. Although the examined strains showed 100% similarity, they were classified into seven clusters based on allelic differences. According to our findings, the cause of these outbreaks was chocolate cake manufactured with egg white liquid contaminated with the same Salmonella Thompson. Additionally, comparative analysis of wgMLST on domestic isolates of S. Thompson from the three outbreaks showed genetic similarities of over 99.6%. Based on the results, the PFGE and wgMLST combination can provide highly resolved phylogeny and reliable evidence during Salmonella outbreak investigations.

• Food Science and Biotechnology
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• v.27 no.6
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• pp.1755-1760
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• 2018

The objective of this study was to perform genetic diversity analysis of 13 strains isolated from South Korean foods by multilocus sequence typing (MLST). For typing, seven housekeeping loci (atpA, dnaA, dnaK, gyrB, pheS, pyrG, and rpoA) were selected, amplified and analyzed. Fifty-one polymorphic sites varying from 1 to 22 in each species were identified. Thirteen sequence types were generated with allele numbers ranged from 2 to 10. The overall relationship between strains was assessed by unweighted pair group method with arithmetic mean dendrogram and minimum spanning tree. In addition, combined spits tree analysis revealed intragenic recombination. No clear relationship was observed between the isolation sources and strains. The developed MLST scheme enhanced our knowledge of the population diversity of Leu. citreum strains and will be used further for the selection of industrially important strain.

• Journal of Hospice and Palliative Care
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• v.19 no.2
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• pp.136-144
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• 2016

Purpose: To provide practical data for bioethics education, we identified correlations between recognition of good death, attitude towards withdrawal of meaningless life-sustaining treatment, and attitude towards euthanasia in nurses. Methods: Using convenience sampling, we recruited 218 nurses who had at least six-month work experience in one of the six general hospitals with 500 or more beds in Seoul, Busan, and Gyeongsang province. All participants understood the purpose of the study and agreed to take part in the study. The research tools used included the Concept of Good Death Measure (CoGD), the measurement tool for attitudes towards withdrawal of meaningless life-sustaining treatment (WoMLST), and the measurement tool for attitudes towards euthanasia. Data were analyzed using an Independent t-test, one-way ANOVA, and Pearson's correlation coefficient using SPSS 21 for Windows. Results: Nurses had normal levels on CoGD, WoMLST, and attitudes towards euthanasia. Nurses' CoGD, WoMLST, and euthanasia scores significantly differed depending on their education level, working period, and the importance of religion to them. A negative correlation was found between the CoGD and WoMLST scores, and WoMLST and euthanasia scores were positively correlated. Conclusion: Nurses should be trained to deal with ethical issues that may arise while caring for terminal patients. It is necessary for nurses to understand the concepts related to CoGD, WoMLST, and euthanasia, and to promote bioethics education with focus on decision-making and problem-solving ability in ethically conflicting situations.