Background: Haemophilus influenzae is the causative pathogen for various infectious diseases, such as respiratory infections, otitis media, sinusitis, and meningitis. This study aimed to investigate the prevalence and molecular characteristics of β-lactam resistance in non-typeable H. influenzae isolates in South Korea. Methods: In total, 115 non-duplicated H. influenzae isolates were included in this study.Bacterial identification and serotyping were performed using matrix assisted laser desorption ionization-time of flight mass spectrometry and polymerase chain reaction (PCR) of bexA, respectively. Antimicrobial susceptibility was tested using the broth microdilution method.The production of β-lactamase was determined using nitrocefin disks. The presence of blaTEM and blaROB was confirmed using PCR. ftsI was analyzed to identify amino acid mutations in penicillin-binding protein (PBP) 3. Results: Resistance rates to ampicillin, amoxicillin–clavulanate, and cefuroxime were 67.8%, 13.9%, and 32.2%, respectively. None of the isolates were resistant to cefotaxime or ceftriaxone. Among 78 ampicillin-resistant isolates, 71 were β-lactamase-producing ampicillinresistant (BLPAR), and 7 were β-lactamase-non-producing ampicillin-resistant. All BLPAR isolates carried blaTEM, and none carried blaROB. Among 16 amoxicillin–clavulanate-resistant isolates, 15 β-lactamase producers harbored blaTEM. Four to 7 PBP3 mutations per isolate were detected in all 16 non-β-lactamase-producing ampicillin-resistant or cephalosporinresistant isolates. Conclusion Beta-lactam resistance in non-typeable H. influenzae isolates is highly prevalent in South Korea, primarily because of blaTEM and various PBP3 mutations. Therefore, continuous monitoring of antimicrobial resistance rates and mechanisms in non-typeable H.influenzae is necessary.

Purpose: This study developed and implemented case-based flipped learning using illness script worksheets and investigated the responses of preclinical students and professors to the intervention in terms of its effectiveness, design, and implementation. Methods: The study was conducted at a medical school in Korea, where the “clinical reasoning method” course, originally a lecture-oriented course, was redesigned into a flipped learning. In total, 42 second-year medical students and 15 professors participated in this course. After the class, online surveys were conducted, and a focus group interview was held with seven students to explore the students’ experiences in more detail. Results: In total, 37 students and seven professors participated in the survey. The mean score for all items is 3.12/4 for the student survey and 3.43/4 for the professor survey. The focus group interview results were categorized as the beneficial aspects and challenges for the development of clinical reasoning. Conclusion The findings indicated that their responses to the intervention were generally positive, and it is thought to be an effective instructional method for fostering clinical reasoning skills in preclinical medical students.

Purpose: Developing clinical reasoning across the medical curriculum requires valid, reliable, and feasible assessment tools. However, few validated tools are available for the convenient and efficient quantification of clinical reasoning. Thus, this study aimed to create a shorter version of the Diagnostic Thinking Inventory (DTI) and validate it in the Korean medical education context (DTI-SK). Methods: The DTI-SK was constructed using content validity and a translation and back-translation process. It comprises two subcategories and 14 items. Its validity and reliability were explored using exploratory and confirmatory factor analyses, mean comparisons of four medical student groups (med 1 to med 4), and internal consistency using Cronbach’s α. Two hundred medical students were invited to participate through email, and the survey was administered for 2 weeks. Results: Data from 136 students were analyzed. Exploratory factor analysis revealed two factors with eigenvalues greater than 1.0 and they together explained 54.65% of the variance. Confirmatory factor analysis demonstrated that the model had acceptable level of fit and convergent validity. Discriminant validity was confirmed using heterotrait-monotrait criterion. Group comparisons demonstrated that the med 4 students showed significantly higher scores than the med 1 and 2 students. The inventory exhibited strong internal consistency for all items (Cronbach’s α=0.906). Conclusion The findings indicated that the DTI-SK is a reliable and valid tool for measuring medical students’ clinical reasoning in the context of Korean medical education.

Purpose: This study examined medical students’ self-directed learning skills in online learning contexts, and whether there were any differences among the student groups (from pre-medical program year 1 to medical program year 2) amid the coronavirus disease 2019 (COVID-19) pandemic. It also explored the components of self-directed learning skills influencing their perceived learnring performance and satisfaction in online learning contexts. Methods: This study used a cross-sectional survey design and convenience sampling. It was conducted in a Korean medical school, which delivered all courses online because of the COVID-19 pandemic. The self-directed learning skill survey, which included student satisfaction and perceived learning performance items, was disseminated over two weeks through email to the participants. The collected data were analyzed through descriptive statistics, analysis of variance, and multiple regressions. Results: The survey response rate was 70% (140/200). The overall mean of self-directed learning skills was 3.85. Students in medical year 2 showed the highest score (4.15), while students in medical year 1 showed the lowest score (3.69). The learning plan category score (3.74) was the lowest among the three categories. The pre-medical program year 1 students showed the lowest score in the perceived learning performance (3.16), and only the learning plan category impacted student satisfaction (t=2.605, p=0.041) and perceived learning performance (t=3.022, p=0.003). Conclusion When designing online learning environments, it is imperative to provide features to help students set learning goals and search diverse online learning resources. In addition, it is an effective strategy to provide the students in medical program year 1 with self-directed learning skills training or support for successful online learning.

Purpose: This research investigated the critical factors that affect the e-learning quality. The student satisfaction model with the five factors such as content, system, learner, instructor and interaction was proposed and empirically examined. It also investigated the relationship between the interaction and other constructs. Methods: This study used a cross sectional survey design, and convenience sampling. To examine the critical factors and their relationship, a survey of 28 items was developed based on previous studies and sent out through a learning management system to all the students (n=250) enrolled in the pre-med 1 to the medicine 3 in one medical school in Korea. The medical school delivered all the courses online due to the coronavirus disease 2019 pandemic. The collected data (n=209, 83.6%) were analyzed through structural equation modeling by using IBM AMOS ver. 26.0 and IBM SPSS ver. 26.0 (IBM Corp., Armonk, USA). Results: The determinants of e-learning student satisfaction were system, learner, instructor, and interaction qualities, which together explained 72.6% of the variance of student satisfaction and the determinants of e-learning interaction quality were content and system qualities, which together explained 62.9% of the variance of interaction quality. Conclusion The results of this study presented practical guidelines to improve e-learning quality in terms of student satisfaction in medical education contexts. The results indicated that more efforts should be directed toward improving interaction features such as interactive teaching styles, collaborative activities, providing instructors and learners with proper training for e-learning prior to e-learning and a quality of contents, and upgrading e-learning system for better performance and service.

Purpose: This study investigated medical educators’ readiness for online teaching by exploring their perceived ability and importance of online teaching competencies and identified the highest priority of their educational needs. Methods: In this study, 144 medical education faculty members from a university were invited to participate. The faculty online teaching readiness scale was virtually distributed at the end of the spring semester of 2020 and 38 faculty members responded for 2 weeks. The collected data were analyzed with descriptive statistics, paired t-tests, Borich Needs Assessment, and the Locus for Focus model. Results: The overall average perceived ability was 2.76, while the overall average perceived importance was 3.36. The course design and the technical competency categories showed the highest and lowest educational needs, respectively. Five competencies were given the highest priority of educational needs. Conclusion The results revealed that the medical educators are not ready for online teaching; thus, urgent educational needs for online teaching competencies exist.

Purpose: This study investigated the role of collective efficacy and co-regulation in terms of students’ performance during small group projects in a medical research program. The effect of collective efficacy in student performance was expected to be mediated by co-regulation. Methods: A total of 50 students who enrolled in a medical research program worked on their medical research project in small groups over a period of 9 weeks. After they had submitted their final research project reports as groups at the end of the course, the collective efficacy and co-regulation surveys were conducted online. Results: The mediation model was significant and explained 26.61% of the variance in student performance. The total effect of collective efficacy on student performance was significant and the indirect effect through co-regulation was also significant. Conclusion These results suggest that collective efficacy influenced student performance through co-regulation in group learning contexts. Considering the fact that more and more collaborative learning now occurs in medical education, the result of this study can provide significant insights for enhancing students’ performance in small group contexts.

Purpose: This study aimed to design and implement an introductory-level course-based research experience (CRE) through project-based learning (PBL) for undergraduate medical students and investigate their learning experience and research skill development, with the ultimate objective of exploring whether CRE can be effectively utilized for undergraduate research experience. Methods: This study included 40 second-year premedical students enrolled in “Scientific thinking and medical research,” which was developed as an introductory-level CRE through PBL. It was a three-credit course and the students met twice a week for one semester. The students’ learning experiences were examined with a 15-item survey including three open-ended questions, while their research skills were assessed through the research reports using a research skill rubric at the end of the course. Results: The findings showed that the students perceived the course structure as appropriate and helpful. They also considered the group work experience to be positive and productive. Learner satisfaction items also earned positive responses in general. Regarding the research skill assessment, the mean value of the research skill scores of each group was 19.11 out of 27 and the mean value of each research skill score was 2.12 out of 3. Conclusion Overall, the students were satisfied with their research experience, and their research skills were developed, suggesting that this introductory CRE through PBL can be effectively and efficiently utilized for undergraduate research experience.

There have been few studies investigating the association between atopic dermatitis (AD) and prenatal exposure to heavy metals. We aimed to evaluate whether prenatal exposure to heavy metals is associated with the development or severity of AD in a birth cohort study. A total of 331 subjects were followed from birth for a median duration of 60.0 months. The presence and severity of AD were evaluated at ages 6 and 12 months, and regularly once a year thereafter. The concentrations of lead, mercury, chromium, and cadmium in umbilical cord blood were measured by inductively coupled plasma mass spectrometry. Cord blood mononuclear cells (CBMCs) were isolated and stimulated for analysis of cytokine production using ELISA. Heavy metal levels in cord blood were not associated with the development of AD until 24 months of age. However, a positive correlation was observed between the duration of AD and lead levels in cord blood (p=0.002). AD severity was also positively associated with chromium concentrations in cord blood (p=0.037), while cord blood levels of lead, mercury, and cadmium were not significantly associated with AD severity (p=0.562, p=0.054, and p=0.055, respectively). Interleukin-13 production in CBMCs was positively related with lead and chromium levels in cord blood (p=0.021 and p=0.015, respectively). Prenatal exposure to lead and chromium is associated with the persistence and severity of AD, and the immune reaction toward a Th2 polarization.
Cacao ; Cadmium ; Chromium ; Cohort Studies ; Dermatitis, Atopic ; Enzyme-Linked Immunosorbent Assay ; Fetal Blood ; Interleukin-13 ; Mass Spectrometry ; Metals, Heavy ; Parturition ; Plasma ; Umbilical Cord

BACKGROUND: Several factors contribute to differences in Streptococcus pneumoniae serotype distribution. We investigated the serotype distribution and antimicrobial resistance of S. pneumoniae isolated between 2014 and 2016 in Korea. METHODS: We collected a total of 1,855 S. pneumoniae isolates from 44 hospitals between May 2014 and May 2016, and analyzed the serotypes by sequential multiplex PCR. We investigated the distribution of each serotype by patient age, source of the clinical specimen, and antimicrobial resistance pattern. RESULTS: The most common serotypes were 11A (10.1%), followed by 19A (8.8%), 3 (8.5%), 34 (8.1%), 23A (7.3%), and 35B (6.2%). The major invasive serotypes were 3 (12.6%), 19A (7.8%), 34 (7.8%), 10A (6.8%), and 11A (6.8%). Serotypes 10A, 15B, 19A, and 12F were more common in patients ≤5 years old, while serotype 3 was more common in patients ≥65 years old compared with the other age groups. The coverage rates of pneumococcal conjugate vaccine (PCV)7, PCV10, PCV13, and pneumococcal polysaccharide vaccine 23 were 11.8%, 12.12%, 33.3%, and 53.6%, respectively. Of the 1,855 isolates, 857 (46.2%) were multi-drug resistant (MDR), with serotypes 11A and 19A predominant among the MDR strains. The resistance rates against penicillin, cefotaxime, and levofloxacin were 22.8%, 12.5%, and 9.4%, respectively. CONCLUSIONS: There were significant changes in the major S. pneumoniae serotypes in the community. Non-PCV13 serotypes increased in patients ≤5 years old following the introduction of national immunization programs with the 10- and 13-polyvalent vaccines.
Cefotaxime ; Humans ; Immunization Programs ; Korea ; Levofloxacin ; Multiplex Polymerase Chain Reaction ; Penicillins ; Pneumococcal Vaccines ; Pneumonia ; Serogroup ; Streptococcus pneumoniae ; Streptococcus ; Vaccines