Collaborative Study to Establish National Reference Standards for Anti-HIV-1 Antibody.

Background: National reference standards for anti-HIV-1 antibody are needed to evaluate the performance and maintain the quality control of anti-HIV-1 antibody assays. The aim of this study was to prepare a mixed-titer performance panel and assess its suitability as a national reference standard for anti-HIV-1 antibody according to stability, collaboration, and other studies. Methods: Nineteen serum samples from different HIV patients were obtained, along with 15 units of fresh frozen plasma samples with negative anti-HIV-1 antibody results. Ten anti-HIV-1 antibody-positive candidate standards and two negative candidate standards were prepared based on the reactivity in the Alinity i HIV Ag/Ab combo assay (Abbott Laboratories, Wiesbaden, Germany). A collaborative study was conducted across eight laboratories using five anti-HIV-1 antibody assays. Real-time and accelerated stability were evaluated to assess the long-term stability. Results: In the collaborative study, results of all five anti-HIV-1 antibody assays were positive for all 10 candidate standards prepared using HIV patient samples. The CV of each assay for every candidate standard was within 10%, except for one assay result. No real-time and accelerated stability change trend was observed at -70°C or -20°C, supporting that the reference standards were maintained in a stable state at -70°C for long-term storage. Conclusions: The overall results suggest that the 12 candidate standards could serve as national reference standards for anti-HIV-1 antibody.

Guidelines for the Laboratory Diagnosis of Monkeypox in Korea.

While the coronavirus disease 2019 pandemic is ongoing, monkeypox has been rapidly spreading in non-endemic countries since May 2022. Accurate and rapid laboratory tests are essential for identifying and controlling monkeypox. Korean Society for Laboratory Medicine and the Korea Disease Prevention and Control Agency have proposed guidelines for diagnosing monkeypox in clinical laboratories in Korea. These guidelines cover the type of tests, selection of specimens, collection of specimens, diagnostic methods, interpretation of test results, and biosafety. Molecular tests are recommended as confirmatory tests. Skin lesion specimens are recommended for testing in the symptomatic stage, and the collection of both blood and oropharyngeal swabs is recommended in the presymptomatic or prodromal stage.

Guidelines for Mobile Laboratories for Molecular Diagnostic Testing of COVID-19.

With the rapid spread of the coronavirus disease (COVID-19), the need for rapid testing and diagnosis and consequently, the demand for mobile laboratories have increased. Despite this need, there are no clear guidelines for the operation, maintenance, or quality control of mobile laboratories. We provide guidelines for the operation, management, and quality control of mobile laboratories, and specifically for the implementation and execution of COVID-19 molecular diagnostic testing. These practical guidelines are primarily based on expert opinions and a laboratory accreditation inspection checklist. The scope of these guidelines includes the facility, preoperative evaluation, PCR testing, internal and external quality control, sample handling, reporting, laboratory personnel, biosafety level, and laboratory safety management. These guidelines are useful for the maintenance and operation of mobile laboratories not only in normal circumstances but also during public health crises and emergencies.

Update of Guidelines for Laboratory Diagnosis of COVID-19 in Korea.

Korean Society for Laboratory Medicine and the Korea Disease Prevention and Control Agency have announced guidelines for diagnosing coronavirus disease (COVID-19) in clinical laboratories in Korea. With the ongoing pandemic, we propose an update of the previous guidelines based on new scientific data. This update includes recommendations for tests that were not included in the previous guidelines, including the rapid molecular test, antigen test, antibody test, and self-collected specimens, and a revision of the previous recommendations. This update will aid clinical laboratories in performing laboratory tests for diagnosing COVID-19.

Development of a multiplex real-time PCR assay for the simultaneous detection of four bacterial pathogens causing pneumonia.

Classification of clinical symptoms and diagnostic microbiology are essential to effectively employ antimicrobial therapy for lower respiratory tract infections (LRTIs) in a timely manner. Empirical antibiotic treatment without microbial identification hinders the selective use of narrow-spectrum antibiotics and effective patient treatment. Thus, the development of rapid and accurate diagnostic procedures that can be readily adopted by the clinic is necessary to minimize non-essential or excessive use of antibiotics and accelerate patient recovery from LRTI-induced damage. We developed and validated a multiplex real-time polymerase chain reaction (mRT-PCR) assay with good analytical performance and high specificity to simultaneously detect four bacterial pathogens causing pneumonia: Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Moraxella catarrhalis. The analytical performance of mRT-PCR against target pathogens was evaluated by the limit of detection (LOD), specificity, and repeatability. Two hundred and ten clinical specimens from pneumonia patients were processed using an automatic nucleic acid extraction system for the "respiratory bacteria four" (RB4) mRT-PCR assay, and the results were directly compared to references from bacterial culture and/or Sanger sequencing. The RB4 mRT-PCR assay detected all target pathogens from sputum specimens with a coefficient of variation ranging from 0.29 to 1.71 and conservative LOD of DNA corresponding to 5 × 102 copies/reaction. The concordance of the assay with reference-positive specimens was 100%, and additional bacterial infections were detected from reference-negative specimens. Overall, the RB4 mRT-PCR assay showed a more rapid turnaround time and higher performance that those of reference assays. The RB4 mRT-PCR assay is a high-throughput and reliable tool that assists decision-making assessment and outperforms other standard methods. This tool supports patient management by considerably reducing the inappropriate use of antibiotics.

Clinical Performance of the Standard Q COVID-19 Rapid Antigen Test and Simulation of its Real-World Application in Korea.

The rapid antigen test (RAT) for coronavirus disease (COVID-19) represents a potent diagnostic method in situations of limited molecular testing resources. However, considerable performance variance has been reported with the RAT. We evaluated the clinical performance of Standard Q COVID-19 RAT (SQ-RAT; SD Biosensor, Suwon, Korea), the first RAT approved by the Korean Ministry of Food and Drug Safety. In total, 680 nasopharyngeal swabs previously tested using real-time reverse-transcription PCR (rRT-PCR) were retested using SQ-RAT. The clinical sensitivity of SQ-RAT relative to that of rRT-PCR was 28.7% for all specimens and was 81.4% for specimens with RNA-dependent RNA polymerase gene (RdRp) threshold cycle (Ct) values ≤23.37, which is the limit of detection of SQ-RAT. The specificity was 100%. The clinical sensitivity of SQ-RAT for COVID-19 diagnosis was assessed based on the Ct distribution at diagnosis of 33,294 COVID-19 cases in Korea extracted from the laboratory surveillance system of Korean Society for Laboratory Medicine. The clinical sensitivity of SQ-RAT for COVID-19 diagnosis in the Korean population was 41.8%. Considering the molecular testing capacity in Korea, use of the RAT for COVID-19 diagnosis appears to be limited.

Coinfections with Respiratory Pathogens among COVID-19 Patients in Korea.

The detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in upper and lower respiratory specimens and coinfection with other respiratory pathogens in patients with coronavirus disease 2019 (COVID-19) was investigated. Study subjects (N = 342) were retrospectively enrolled after being confirmed as SARS-CoV-2 positive, and their nasopharyngeal swab (NPS), oropharyngeal swab (OPS), and sputum specimens were restored for SARS-CoV-2 retesting and respiratory pathogen detection. The majority of the subjects (96.5%, N = 330) were confirmed as SARS-CoV-2 positive using NPS/OPS specimens. Among the COVID-19 patients (N = 342), 7.9% (N = 27) and 0.9% (N = 3) were coinfected with respiratory viruses and Mycoplasma pneumoniae, respectively, yielding an 8.8% (N = 30) overall respiratory pathogen coinfection rate. Of the respiratory virus coinfection cases (N = 27), 92.6% (N = 25) were coinfected with a single respiratory virus and 7.4% (N = 2) with two viruses (metapneumovirus/adenovirus and rhinovirus/bocavirus). No triple coinfections of other respiratory viruses or bacteria with SARS-CoV-2 were detected. Respiratory viruses coinfected in the patients with COVID-19 were as follows: rhinovirus (N = 7, 2.1%), respiratory syncytial virus A and B (N = 6, 1.8%), non-SARS-CoV-2 coronaviruses (229E, NL63, and OC43, N = 5, 1.5%), metapneumovirus (N = 4, 1.2%), influenza A (N = 3, 0.9%), adenovirus (N = 3, 0.9%), and bocavirus (N = 1, 0.3%). In conclusion, the diagnostic value of utilizing NPS/OPS specimens is excellent, and, as the first report in Korea, coinfection with respiratory pathogens was detected at a rate of 8.8% in patients with COVID-19.

Erratum: COVID-19 Molecular Testing in Korea: Practical Essentials and Answers From Experts Based on Experiences of Emergency Use Authorization Assays.

[This corrects the article on p. 439 in vol. 40.].

Surveillance of Coronavirus Disease 2019 (COVID-19) Testing in Clinical Laboratories in Korea.

In response to the ongoing coronavirus disease 2019 (COVID-19) pandemic, an online laboratory surveillance system was established to monitor severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) real-time reverse transcription-PCR (rRT-PCR) testing capacities and results. SARS-CoV-2 rRT-PCR testing data were collected from 97 clinical laboratories, including 84 medical institutions and 13 independent clinical laboratories in Korea. We assessed the testing capacities to utilize SARS-CoV-2 rRT-PCR based on surveillance data obtained from February 7th to June 4th, 2020 and evaluated positive result characteristics according to the reagents used and sample types. A total of 1,890,319 SARS-CoV-2 rRT-PCR testing were performed, 2.3% of which were positive. Strong correlations were observed between the envelope (E) gene and RNA-dependent RNA polymerase (RdRp)/nucleocapsid (N) genes threshold cycle (Ct) values for each reagent. No statistically significant differences in gene Ct values were observed between the paired upper and lower respiratory tract samples, except in the N gene for nasopharyngeal swab and sputum samples. Our study showed that clinical laboratories in Korea have rapidly expanded their testing capacities in response to the COVID-19 outbreak, with a peak daily capacity of 34,193 tests. Rapid expansion in testing capacity is a critical component of the national response to the ongoing pandemic.

COVID-19 Molecular Testing in Korea: Practical Essentials and Answers From Experts Based on Experiences of Emergency Use Authorization Assays.

Coronavirus disease 2019 (COVID-19) is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Early detection of COVID-19 and immediate isolation of infected patients from the naive population are important to prevent further pandemic spread of the infection. Real-time reverse transcription (RT)-PCR to detect SARS-CoV-2 RNA is currently the most reliable diagnostic method for confirming COVID-19 worldwide. Guidelines for clinical laboratories on the COVID-19 diagnosis have been recently published by Korean Society for Laboratory Medicine and the Korea Centers for Disease Control and Prevention. However, these formal guidelines do not address common practical laboratory issues related to COVID-19 real-time RT-PCR testing and their solutions. Therefore, this guideline is intended as a practical and technical supplement to the "Guidelines for Laboratory Diagnosis of COVID-19 in Korea".

Guidelines for Laboratory Diagnosis of Coronavirus Disease 2019 (COVID-19) in Korea.

The outbreak of coronavirus disease 2019 (COVID-19), which began in December 2019, is still ongoing in Korea, with >9,000 confirmed cases as of March 25, 2020. COVID-19 is a severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection, and real-time reverse transcription-PCR is currently the most reliable diagnostic method for COVID-19 around the world. Korean Society for Laboratory Medicine and the Korea Centers for Disease Prevention and Control propose guidelines for diagnosing COVID-19 in clinical laboratories in Korea. These guidelines are based on other related domestic and international guidelines, as well as expert opinions and include the selection of test subjects, selection of specimens, diagnostic methods, interpretation of test results, and biosafety.

Molecular Characteristics of GES-Type Carbapenemase-Producing Pseudomonas aeruginosa Clinical Isolates from Long-Term Care Facilities and General Hospitals in South Korea.

Since carbapenems have been used for the treatment of infections in medical settings, multidrug-resistant Pseudomonas aeruginosa containing resistance for carbapenems has become a major cause of nosocomial infections worldwide. Information on carbapenemase-producing P. aeruginosa isolates at community hospitals, including long-term care facilities and general hospitals, has rarely been reported in South Korea. The aims of this study were to describe the characteristics of seven carbapenemase-producing P. aeruginosa isolates recovered from two long-term care facilities in South Korea. The carbapenemase genes were identified by PCR and sequencing. Strain typing was assessed by pulsed field gel electrophoresis and multilocus sequence typing (MLST) analysis. Isolates with a genomic island and class I integron surrounding blaGES-type were confirmed by the PCR mapping method. Of seven GES-type carbapenemase-producing P. aeruginosa isolates, the blaGES-24 gene was detected in six isolates, and the blaGES-5 gene was detected in one isolate. The epidemiological relatedness of the seven isolates carrying blaGES-24 and blaGES-5 showed >81% similarity. Five isolates carrying blaGES-24 were sequence type 155 (ST155) by MLST, followed by one ST244 isolate carrying blaGES-24 and one ST308 isolate carrying blaGES-5. blaGES-type genes were embedded in two different class I integrons in a genomic island-15-like region. Our results indicate the possible spread of carbapenemase-producing P. aeruginosa and present a current threat of antimicrobial resistance in community hospitals.

Multiple Human Papillomavirus Infection Is Associated with High-Risk Infection in Male Genital Warts in Ulsan, Korea.

Further understanding of male human papillomavirus (HPV) infection is necessary to prevent infection in men, as well as transmission to women. In our current study, we investigated patterns of HPV infection and genotype distributions in male genital warts using the Anyplex II HPV28 Detection kit. We reviewed the medical records of 80 male patients who presented to 5 neighborhood clinics in Ulsan, Korea, for the treatment of genital warts between April 2014 and January 2015. All patients underwent HPV genotyping. The prevalence and characteristics of HPV infection were analyzed, and the patterns of HPV infection according to age were assessed. Among the study patients, 13 (16.3%) were negative for HPV infection, 46 (57.3%) were infected with low-risk HPV, and 21 (26.3%) were infected with high-risk HPV. Patients with multiple HPV infection were more likely to have high-risk HPV infection (P = 0.001). The prevalence of HPV infection was much higher in samples obtained by tissue excision due to a definite lesion (P = 0.001). There were no differences in high-risk HPV infection (P = 0.459), multiple HPV infection (P = 0.185), and recurrence at diagnosis (P = 0.178) according to age. HPV-6 and HPV-11 were the most common type overall (39.7% and 13.8%, respectively). HPV-16 and HPV-18 were the most common high-risk infections (both 3.4%). HPV infection is not only commonly encountered in male genital warts, but is also accompanied by high-risk HPV and multiple infections.

Relationship between the severity of diversion colitis and the composition of colonic bacteria: a prospective study.

BACKGROUND/AIMS: Diversion colitis is the inflammation of the excluded segment of the colon in patients undergoing ostomy. It has been suggested that a change in colonic flora may lead to colitis; however, direct evidence for this disease progression is lacking. The aim of this study was to evaluate the relationship between the severity of diversion colitis and the composition of colonic bacteria. METHODS: We used culture methods and polymerase chain reaction to analyze the colonic microflora of patients who underwent rectal cancer resection with or without diversion ileostomy. In the diversion group, we also evaluated the severity of colonoscopic and pathologic colitis before reversal. RESULTS: This study enrolled 48 patients: 26 in the diversion group and 22 in the control group. Significant differences were observed between the two groups in the levels of Staphylococcus (p=0.038), Enterococcus (p<0.001), Klebsiella (p<0.001), Pseudomonas (p=0.015), Lactobacillus (p=0.038), presence of anaerobes (p=0.019), and Bifidobacterium (p<0.001). A significant correlation between the severity of colitis and bacterial composition was only observed for Bifidobacterium (p=0.005, correlation coefficient=-0.531). CONCLUSIONS: The colonic microflora differed significantly between the diversion and control groups. Bifidobacterium was negatively correlated with the severity of diversion colitis.

Comparison of the Anyplex II HPV28 assay with the Hybrid Capture 2 assay for the detection of HPV infection.

BACKGROUND: Human papillomavirus (HPV) testing is an important part of cervical cancer screening and management of women with abnormal cytology results. The Hybrid Capture 2 (HC2) has been recommended for use as a reference test. OBJECTIVE: To evaluate a new real-time PCR assay (Anyplex II HPV28) for detecting high risk (HR) HPV and to compare it to the HC2. In addition, we compared the genotyping results of the Anyplex II HPV28 to those of sequencing analysis. STUDY DESIGN: A total of 1114 cervical swab specimens were consecutively obtained from a single healthcare center. We submitted all specimens for HPV detection with Anyplex II HPV28 and HC2, then analyzed the discordant results using multiplex PCR followed by direct sequencing. RESULTS: HC2 detected 72 (6.5%) cases with HR HPV, while Anyplex II HPV28 identified 138 (12.4%) cases. The overall agreement rate was 91.4% (1018/1114) of cases. Discordant results between these two assays were observed in 96 cases; 15 were positive only by HC2, and 81 were positive only by Anyplex II HPV28. Sequencing analyses performed in 80 cases of discordant results revealed 11 false-positive, and 67 false-negative results using HC2 tests and two false-positive results using Anyplex II HPV28. CONCLUSIONS: The Anyplex II HPV28 assay is analytically more sensitive in the detection of the 13 HR types represented by the HC2 assay and exhibited a higher concordance with comprehensive genotyping based on the sequencing analysis, and it could be used as a laboratory testing method for identifying HPV genotypes.

First outbreak of KPC-2-producing Klebsiella pneumoniae sequence type 258 in a hospital in South Korea.

In this study, we report the first outbreak of KPC-2-producing Klebsiella pneumoniae isolates from three patients admitted to a neurosurgery department in a South Korean teaching hospital. Multilocus sequence typing showed that the isolates were identical to the previous KPC producers in South Korea and other countries, suggesting clonal spread.

Clonal change of blaSIM-1-carrying Acinetobacter spp. from 2003 to 2008 in the hospital where it was initially discovered.

SIM-1 metallo-ß-lactamase was first discovered from carbapenem-resistant Acinetobacter spp. isolated in a Korean University Hospital in 2003, and was recently reported to have been discovered in A. baylyi isolated in nearby China. The aims of this study were to reveal clonal changes in bla(SIM-1)-harboring Acinetobacter isolates collected from 2003 to 2008 in the same Korean hospital, where they were first discovered to gain further insight into the relation between bla(SIM-1)-harboring plasmids and Acinetobacter spp. Among 1,761 nonduplicated imipenem-resistant Acinetobacter spp. isolates, 29 isolates were identified as bla(SIM-1) carriers. They were categorized into nine types according to pulsed-field gel electrophoresis findings. While most bla(SIM-1)-carrying isolates from 2003 to 2005 belonged to A. pittii, those from 2006 to 2007 were mostly isolates of A. nosocomialis. Most of the bla(SIM-1) genes were carried on ca. 280-kb plasmids and were only discovered in non-baumannii Acinetobacter spp. Integrons carrying the bla(SIM-1) gene were identical in structure in all species. These findings suggest that the plasmids were transferable, but not promiscuous. Further surveillance should be continued to detect and control further spread of the bla(SIM-1) gene, as the appearance of the bla(SIM-1) gene in different Acinetobacter spp. in different countries has already begun.

Liver abscess caused by Brevundimonas vesicularis in an immunocompetent patient.

Invasive infections caused by Brevundimonas vesicularis are very rare in humans. We experienced an unusual case of liver abscess due to B. vesicularis in an immunocompetent young male. The patient was successfully treated by liver abscess drainage and with antimicrobial therapy of ceftriaxone followed by ampicillin/sulbactam. The organism found in the aspiration culture of the abscess material was initially reported, by using a VITEK 2 system, as Sphingomonas paucimobilis. However, later, B. vesicularis was confirmed as the true pathogen through 16S rRNA gene sequencing. To our knowledge, this is the first case of liver abscess caused by B. vesicularis.

Evaluation of BACTEC Plus aerobic and anaerobic blood culture bottles and BacT/Alert FAN aerobic and anaerobic blood culture bottles for the detection of bacteremia in ICU patients.

Blood culture is the most valuable laboratory test for the diagnosis of bacteremia and sepsis. The BACTEC FX and BacT/Alert 3D automated blood culture systems are commonly used in Korean health care facilities. A controlled clinical evaluation of the resin-containing BACTEC Plus aerobic (BA) and anaerobic (BN), and the charcoal-containing FAN aerobic (FA) and anaerobic (FN) bottles using blood from intensive care unit (ICU) patients was designed. The performances of these 2 systems with media containing particle absorbing antimicrobial agents were evaluated using the culture positivity rate and time to detection (TTD). TTD was collected using data management systems, either the Epicenter (BD Diagnostic Systems) or the hospital laboratory information system. A total of 1539 four-bottle sets were collected from 270 patients in medical and surgical ICUs. Blood culture samples included 1539 bottles each of BA, BN, FA, and FN, and yielded 113 (7.3%), 90 (5.8%), 104 (6.8%), and 80 (5.2%) positive bacterial or fungal isolates, respectively. There were significant differences between the resin-containing BA and BN samples in culture positivity and also between the charcoal-containing FA and FN samples, especially for Escherichia coli (25/27 versus 17/27, P < 0.05) and Acinetobacter baumannii (14/15 versus 7/15, P < 0.05). Significantly shorter recovery time was observed in BACTEC Plus aerobic bottles than in FAN aerobic bottles (17.2 and 24.7 h, respectively) (P < 0.001).