1.A survey on laboratory capacity, testing practices, and management during COVID-19 pandemic response in Korea:a cross-sectional survey study
Changseung LIU ; Daewon KIM ; Jung-Hyun BYUN ; Jeonghyun CHANG ; Sungjin JO ; Heungsup SUNG
Annals of Clinical Microbiology 2025;28(1):5-
Background:
The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted global infrastructure. We surveyed laboratories to analyze the changes in testing methods and procedures to improve future pandemic preparedness.
Methods:
This study surveyed laboratory physicians and technologists in South Korea and analyzed responses from 126 of 323 institutions. The survey was conducted in May 2023 using the proficiency test of the Korean Association of External Quality Assessment Service and examined the diagnostic procedures, personnel, equipment, and quality control. The survey comprised 15 questions covering respondent demographics, public-private proficiency projects, COVID-19 testing procedures, and laboratory status.
Results:
Of the 126 laboratories, 66.7% performed bacterial smear and culture, 65.9% had biosafety level 2 facilities, and 39.7% had separate nucleic acid extraction areas. Furthermore, 98.4% of the laboratories had biological safety cabinets, the median number of PCR machines was four units, and 77.8% had autoclaves. The median numbers of personnel managing and conducting tests were one and three, respectively. Additionally, 88.1% of the laboratories found the COVID-19 proficiency test helpful, with key benefits in terms of accuracy and skill improvement. COVID-19 tests were primarily used for symptomatic or contact person testing, pre-admission screening, and periodic proactive testing. Specialized testing laboratories conducted up to 50,000 tests daily, and tertiary hospitals conducted up to 1,500 tests.Emergency, pooled, and rapid antigen tests were widely used. Most respondents wanted future tests for respiratory viruses, bacteria, and viral diarrhea, indicating a willingness to participate.
Conclusion
Aggressive testing and collaboration between health agencies and laboratories are crucial for managing emerging diseases. Systematic preparations are essential to maintain and strengthen laboratory capabilities for future infectious disease outbreaks.
2.A survey on laboratory capacity, testing practices, and management during COVID-19 pandemic response in Korea:a cross-sectional survey study
Changseung LIU ; Daewon KIM ; Jung-Hyun BYUN ; Jeonghyun CHANG ; Sungjin JO ; Heungsup SUNG
Annals of Clinical Microbiology 2025;28(1):5-
Background:
The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted global infrastructure. We surveyed laboratories to analyze the changes in testing methods and procedures to improve future pandemic preparedness.
Methods:
This study surveyed laboratory physicians and technologists in South Korea and analyzed responses from 126 of 323 institutions. The survey was conducted in May 2023 using the proficiency test of the Korean Association of External Quality Assessment Service and examined the diagnostic procedures, personnel, equipment, and quality control. The survey comprised 15 questions covering respondent demographics, public-private proficiency projects, COVID-19 testing procedures, and laboratory status.
Results:
Of the 126 laboratories, 66.7% performed bacterial smear and culture, 65.9% had biosafety level 2 facilities, and 39.7% had separate nucleic acid extraction areas. Furthermore, 98.4% of the laboratories had biological safety cabinets, the median number of PCR machines was four units, and 77.8% had autoclaves. The median numbers of personnel managing and conducting tests were one and three, respectively. Additionally, 88.1% of the laboratories found the COVID-19 proficiency test helpful, with key benefits in terms of accuracy and skill improvement. COVID-19 tests were primarily used for symptomatic or contact person testing, pre-admission screening, and periodic proactive testing. Specialized testing laboratories conducted up to 50,000 tests daily, and tertiary hospitals conducted up to 1,500 tests.Emergency, pooled, and rapid antigen tests were widely used. Most respondents wanted future tests for respiratory viruses, bacteria, and viral diarrhea, indicating a willingness to participate.
Conclusion
Aggressive testing and collaboration between health agencies and laboratories are crucial for managing emerging diseases. Systematic preparations are essential to maintain and strengthen laboratory capabilities for future infectious disease outbreaks.
3.A survey on laboratory capacity, testing practices, and management during COVID-19 pandemic response in Korea:a cross-sectional survey study
Changseung LIU ; Daewon KIM ; Jung-Hyun BYUN ; Jeonghyun CHANG ; Sungjin JO ; Heungsup SUNG
Annals of Clinical Microbiology 2025;28(1):5-
Background:
The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted global infrastructure. We surveyed laboratories to analyze the changes in testing methods and procedures to improve future pandemic preparedness.
Methods:
This study surveyed laboratory physicians and technologists in South Korea and analyzed responses from 126 of 323 institutions. The survey was conducted in May 2023 using the proficiency test of the Korean Association of External Quality Assessment Service and examined the diagnostic procedures, personnel, equipment, and quality control. The survey comprised 15 questions covering respondent demographics, public-private proficiency projects, COVID-19 testing procedures, and laboratory status.
Results:
Of the 126 laboratories, 66.7% performed bacterial smear and culture, 65.9% had biosafety level 2 facilities, and 39.7% had separate nucleic acid extraction areas. Furthermore, 98.4% of the laboratories had biological safety cabinets, the median number of PCR machines was four units, and 77.8% had autoclaves. The median numbers of personnel managing and conducting tests were one and three, respectively. Additionally, 88.1% of the laboratories found the COVID-19 proficiency test helpful, with key benefits in terms of accuracy and skill improvement. COVID-19 tests were primarily used for symptomatic or contact person testing, pre-admission screening, and periodic proactive testing. Specialized testing laboratories conducted up to 50,000 tests daily, and tertiary hospitals conducted up to 1,500 tests.Emergency, pooled, and rapid antigen tests were widely used. Most respondents wanted future tests for respiratory viruses, bacteria, and viral diarrhea, indicating a willingness to participate.
Conclusion
Aggressive testing and collaboration between health agencies and laboratories are crucial for managing emerging diseases. Systematic preparations are essential to maintain and strengthen laboratory capabilities for future infectious disease outbreaks.
4.A survey on laboratory capacity, testing practices, and management during COVID-19 pandemic response in Korea:a cross-sectional survey study
Changseung LIU ; Daewon KIM ; Jung-Hyun BYUN ; Jeonghyun CHANG ; Sungjin JO ; Heungsup SUNG
Annals of Clinical Microbiology 2025;28(1):5-
Background:
The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted global infrastructure. We surveyed laboratories to analyze the changes in testing methods and procedures to improve future pandemic preparedness.
Methods:
This study surveyed laboratory physicians and technologists in South Korea and analyzed responses from 126 of 323 institutions. The survey was conducted in May 2023 using the proficiency test of the Korean Association of External Quality Assessment Service and examined the diagnostic procedures, personnel, equipment, and quality control. The survey comprised 15 questions covering respondent demographics, public-private proficiency projects, COVID-19 testing procedures, and laboratory status.
Results:
Of the 126 laboratories, 66.7% performed bacterial smear and culture, 65.9% had biosafety level 2 facilities, and 39.7% had separate nucleic acid extraction areas. Furthermore, 98.4% of the laboratories had biological safety cabinets, the median number of PCR machines was four units, and 77.8% had autoclaves. The median numbers of personnel managing and conducting tests were one and three, respectively. Additionally, 88.1% of the laboratories found the COVID-19 proficiency test helpful, with key benefits in terms of accuracy and skill improvement. COVID-19 tests were primarily used for symptomatic or contact person testing, pre-admission screening, and periodic proactive testing. Specialized testing laboratories conducted up to 50,000 tests daily, and tertiary hospitals conducted up to 1,500 tests.Emergency, pooled, and rapid antigen tests were widely used. Most respondents wanted future tests for respiratory viruses, bacteria, and viral diarrhea, indicating a willingness to participate.
Conclusion
Aggressive testing and collaboration between health agencies and laboratories are crucial for managing emerging diseases. Systematic preparations are essential to maintain and strengthen laboratory capabilities for future infectious disease outbreaks.
5.A survey on laboratory capacity, testing practices, and management during COVID-19 pandemic response in Korea:a cross-sectional survey study
Changseung LIU ; Daewon KIM ; Jung-Hyun BYUN ; Jeonghyun CHANG ; Sungjin JO ; Heungsup SUNG
Annals of Clinical Microbiology 2025;28(1):5-
Background:
The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted global infrastructure. We surveyed laboratories to analyze the changes in testing methods and procedures to improve future pandemic preparedness.
Methods:
This study surveyed laboratory physicians and technologists in South Korea and analyzed responses from 126 of 323 institutions. The survey was conducted in May 2023 using the proficiency test of the Korean Association of External Quality Assessment Service and examined the diagnostic procedures, personnel, equipment, and quality control. The survey comprised 15 questions covering respondent demographics, public-private proficiency projects, COVID-19 testing procedures, and laboratory status.
Results:
Of the 126 laboratories, 66.7% performed bacterial smear and culture, 65.9% had biosafety level 2 facilities, and 39.7% had separate nucleic acid extraction areas. Furthermore, 98.4% of the laboratories had biological safety cabinets, the median number of PCR machines was four units, and 77.8% had autoclaves. The median numbers of personnel managing and conducting tests were one and three, respectively. Additionally, 88.1% of the laboratories found the COVID-19 proficiency test helpful, with key benefits in terms of accuracy and skill improvement. COVID-19 tests were primarily used for symptomatic or contact person testing, pre-admission screening, and periodic proactive testing. Specialized testing laboratories conducted up to 50,000 tests daily, and tertiary hospitals conducted up to 1,500 tests.Emergency, pooled, and rapid antigen tests were widely used. Most respondents wanted future tests for respiratory viruses, bacteria, and viral diarrhea, indicating a willingness to participate.
Conclusion
Aggressive testing and collaboration between health agencies and laboratories are crucial for managing emerging diseases. Systematic preparations are essential to maintain and strengthen laboratory capabilities for future infectious disease outbreaks.
6.Standardized Medical Terminology: Awareness and Application Among Members of the Korean Society for Laboratory Medicine
Shinae YU ; Byung Ryul JEON ; Changseung LIU ; Dokyun KIM ; Hae-Il PARK ; Hyung Doo PARK ; Jeong Hwan SHIN ; Jun Hyung LEE ; Qute CHOI ; Sollip KIM ; Yeo Min YUN ; Eun-jung CHO ;
Annals of Laboratory Medicine 2025;45(6):635-637
7.In-vitro Activities of Zoliflodacin and Solithromycin Against Neisseria gonorrhoeae Isolates from Korea
Kyoung Ho ROH ; Nguyen Dinh LUONG ; Changseung LIU ; Young Hee SEO ; Hyukmin LEE ; Magnus UNEMO ; Kyungwon LEE
Annals of Laboratory Medicine 2025;45(6):626-629
Novel antimicrobial agents are continually developed to address the global threat of multidrug-resistant Neisseria gonorrhoeae. Promising candidates include zoliflodacin and, possibly, solithromycin. We evaluated their in-vitro activities against gonococcal isolates collected in Korea. In total, 250 N. gonorrhoeae isolates obtained across Korea between 2016 and 2018 were used to determine the minimum inhibitory concentrations (MICs) of 10 therapeutic agents using the CLSI agar dilution method. Most isolates (94.8%, 237/250) demonstrated non-susceptibility to penicillin G, tetracycline, and ciprofloxacin, and susceptibility to ceftriaxone and spectinomycin was substantially high. The half-maximal IC (MIC50) and 90% IC (MIC90) values for zoliflodacin were 0.03 and 0.06 µg/mL, respectively; 0.06 and 0.12 µg/mL, respectively, for solithromycin; and 0.03 and 0.12 µg/mL, respectively, for ceftriaxone. Notably, no cross-resistance was observed between zoliflodacin and ciprofloxacin, despite both targeting DNA topoisomerase II enzymes. Zoliflodacin and solithromycin demonstrated significant in-vitro activity against multidrug-resistant N.gonorrhoeae isolates, and zoliflodacin has shown non-inferiority to ceftriaxone/azithromycin dual therapy in a clinical phase 3 trial. Collectively, our findings highlight the potential of zoliflodacin as a novel therapeutic agent for gonococcal infections, particularly in the context of rising multidrug resistance, and highlight the need for continued surveillance and development of alternative antimicrobial strategies.
8.Epidemiology and Subtype Distribution of Blastocystis Among Asymptomatic Volunteers in South Korea: A Multicenter Study
Seong Hoon KIM ; Jung-Hyun BYUN ; YeJin OH ; Changseung LIU ; Mi Hyun BAE ; Eun Jeong WON
Annals of Clinical Microbiology 2023;26(1):11-17
Background:
Blastocystis is a genus of intestinal, anaerobic protozoan parasites that can be isolated from humans, animals, and the environment. We aimed to determine the distribution of Blastocystis and subtypes (STs) using stool samples obtained from healthy volunteers at collection centers in South Korea.
Methods:
A total of 478 stool samples from volunteers were collected at five collection centers throughout South Korea. The presence of Blastocystis was determined using PCR based on the small subunit (SSU) rRNA gene, and Blastocystis STs were confirmed through sequencing of the SSU rRNA gene.
Results:
Molecular analysis revealed the presence of Blastocystis in 27 (5.6%) of the enrolled participants. Two STs were identified: ST3 (66.7%) and ST1 (33.3%). The positive rates of Blastocystis varied by geographical region, ranging from 1.2%–12.0%. ST3 was the predominant subtype in all centers except one, where only ST1 was isolated. Phylogenic analysis showed clustering based on ST, but no significant differences were found among the regions. There was no association between Blastocystis colonization and either age or sex of the participants.
Conclusions
The results of this multicenter study demonstrated colonization by Blastocystis, mainly ST3, in the gastrointestinal tracts of asymptomatic individuals in South Korea.
9.Multicenter study on the molecular epidemiology of intestinal protozoan parasites in Korea
Changseung LIU ; YeJin OH ; Young Jin KO ; Mi Hyun BAE ; Jung-Hyun BYUN ; Eun Jeong WON
Annals of Clinical Microbiology 2023;26(3):69-76
Background:
Intestinal protozoa are potential diarrhea-causing pathogens and monitored worldwide. The Korea Centers for Disease Control and Prevention has also been monitoring intestinal protozoa causing diarrhea for many years. Recently, the overall protozoa detection rate has decreased to less than 1%, but whether protozoa infection causing diarrhea has declined or is being underestimated has not been studied. This study aimed to investigate the molecular epidemiology of intestinal protozoan pathogens in stool samples collected from multiple Korean centers.
Methods:
Stool samples were collected from five university hospitals and a commercial laboratory. Direct smear and trichrome staining were performed on all samples. The presence of Cryptosporidium parvum, Giardia lamblia, Entamoeba histolytica, Cyclospora cayetanensis, Dientamoeba fragilis, and Blastocystis hominis were detected using Allplex™ Gastrointestinal Parasite Assays (Seegene Inc., Korea). Microsporidia species and Kudoa septempunctata were detected using PowerChek™ Microsporidia Multiplex and Kudoa Real-time PCR kits (Kogene Biotech, Korea), respectively.
Results:
The collected samples included 279 diarrheal and 51 non-diarrheal samples. Among the 279 diarrheal samples, nine samples [B. hominis (n=7), C. parvum (n=1), and Microporidia species (n=1)] were positive, but there were no positive samples for K. septempunctata. We could not detect any protozoa by direct smear and trichrome staining. Among the 51 nondiarrheal samples, 10 (19.6%) samples were positive for B. hominis, but no other protozoa were observed
Conclusion
This multicenter study showed that the detection rate of intestinal protozoa is currently low in diarrheal samples from Korea. However, B. hominis was frequently detected in non-diarrheal samples, indicating their low pathogenicity.
10.Clinical and Microbiological Risk Factors for Community-Associated Clostridioides difficile Infections
Young Ah KIM ; Heejung KIM ; Dokyun KIM ; Changseung LIU ; Seok Hoon JEONG
Annals of Clinical Microbiology 2022;25(2):53-58
Background:
The incidence of community-associated (CA) Clostridioides difficile infection (CDI) has increased in Korea. In this study, we evaluated CA-CDI risk factors in terms of clinical features and ribotype considering its region-specific molecular epidemiology.
Methods:
A retrospective case-control study was performed on two groups of CDI patients:127 subjects with CA-CDI and 265 subjects with healthcare-associated (HA)-CDI. Risk factors for CA-CDI were evaluated in terms of clinical and microbiological features such as toxin type and ribotype.
Results:
A comparison of the two groups of CDI patients revealed that inflammatory bowel disease, diarrhea, abdominal pain, and fever were more closely associated with CA-CDI. The toxin types and ribotypes of C. difficile were similar between the two groups. After adjusting for variables, no risk factors were identified for CA-CDI compared with HA-CDI.
Conclusion
Specific risk factors for CA-CDI were not identified in this study.

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