Whole-Genome Sequence Analysis of Isolates from a Patient with Persistent Fungemia and Determination of the Molecular Mechanisms of Multidrug Resistance.

Whole-genome sequencing (WGS) was used to determine the molecular mechanisms of multidrug resistance for 10 serial bloodstream isolates obtained from a neutropenic patient during 82 days of amphotericin B (AMB) or echinocandin therapy. For WGS, a library was prepared and sequenced using a Nextera DNA Flex Kit (Illumina) and the MiseqDx (Illumina) instrument. All isolates harbored the same Msh2p substitution, V239L, associated with multilocus sequence type 7 and a Pdr1p substitution, L825P, that caused azole resistance.

Accuracy Validation of the Elecsys HBsAg II Quant Assay and Its Utility in Resolving Equivocal Qualitative HBsAg Results.

: There are reports of false qualitative HBsAg results, because of various causes, such as samples with low HBsAg concentrations that may produce false positives. The main aims of this study were to validate the analytical accuracy and to assess the utility of the Elecsys assay compared to that of the qualitative HbsAg assay as a screening test in resolving equivocal qualitative HbsAg results. The limit of blank (LoB), the limit of detection (LoD), the limit of quantification (LoQ), and linearity were estimated to validate the analytical accuracy of the Elecsys HBsAg II Quant assay.

Evaluation of the Accuracy of Cr and BUN Using the ABL90 FLEX PLUS Blood Gas Analyzer and the Equivalence of Candidate Specimens for Assessment of Renal Function.

Background: The ABL90 FLEX PLUS (Radiometer) is a blood gas analyzer that also provides creatinine (Cr) and blood urea nitrogen (BUN) results. We assessed the accuracy of the ABL90 FLEX PLUS to measure Cr and BUN and find suitable candidate specimens against primary specimens (heparinized whole-blood (H-WB)).

Methods: Paired H-WB, serum, and sodium-citrated whole-blood (C-WB) samples (105) were collected.

Validation and application of new NGS-based HLA genotyping to clinical diagnostic practice.

Next-generation sequencing (NGS) has revolutionized clinical genotyping, providing high-resolution HLA genotyping with a low ambiguity rate. This study aimed to develop new NGS-based HLA genotyping (HLAaccuTest, NGeneBio, Seoul, KOREA) on the Illumina MiSeq platform and validate the clinical performance. The analytical performance of HLAaccuTest was validated for 11 loci comprising HLA-A, -B, -C, -DRB1/3/4/5, -DQA1, -DQB1, -DPA1, and -DPB1 using 157 reference samples.

Case report: Compound heterozygosity in gene with a large exon deletion and a novel rare p.Gly536Asp variant as a cause of severe pyruvate kinase deficiency.

Red cell pyruvate kinase (PK) deficiency is the most common cause of hereditary nonspherocytic hemolytic anemia and the most frequent enzyme abnormality of the glycolytic pathway. To the best of our knowledge, this is the first Korean PK deficiency study that analyzes copy number variation (CNV) using next-generation sequencing (NGS). A 7-year-old girl with jaundice was admitted for evaluation of a persistent hemolytic anemia.

Ionic Liquids for Intrinsically Stretchable Conductive Polymers.

Inspired by the classic hard-soft acid-base theory and intrigued by a theoretical prediction of spontaneous ion exchange between poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and hard-cation-soft-anion ionic liquid (IL), we treat PEDOT:PSS with a new IL composed of a (., extremely hard) cation (3-methylimidazolium, -MIM) and an extremely soft anion (tetracyanoborate, TCB). In fact, this IL (-MIM:TCB) accomplishes the same levels of ion-exchange-mediated PEDOT-PSS separation, PEDOT-rich nanofibril formation, and electrical conductivity enhancement (∼2500 S/cm) as its counterpart (EMIM:TCB with 1-ethyl-3-methylimidazolium), the best IL used for this purpose so far.

Pyogenic spondylitis caused by Klebsiella pneumoniae: should the possibility of hypervirulent Klebsiella pneumoniae be considered?

Background: Klebsiella pneumoniae is rare but the second most common causative agent among gram-negative bacteria that cause pyogenic spondylitis. However, there are no available studies on the serotype, virulence factors, and clinical characteristics associated with K. pneumoniae-caused pyogenic spondylitis.

Comparative Evaluation of Three Immunoassays for the Simultaneous Detection of Glutamate Dehydrogenase and Toxin A/B.

Background: In the medical laboratory, a step-by-step workflow for infection (CDI) detection using glutamate dehydrogenase (GDH) and toxin A/B assays for initial screening, along with a nucleic acid amplification test (NAAT), has been recommended recently. In this study, we evaluated these three immunoassays for the simultaneous detection of GDH and (CD) toxin A/B.

Methods: A total of 304 stool samples were tested for the presence of GDH antigen and CD toxin A/B using VIDAS GDH and toxin A/B (CDAB), RIDASCREEN GDH and toxin A/B (RIDA), and C.

Prostatic Abscess Caused by : A 6-Year Single-Center Study.

Hypervirulent (hvKp) is an important strain that can cause multiple organ infections. Although hvKp infection cases are increasing, there is limited information on the prostatic abscesses caused by . Furthermore, the clinical significance of hvKp associated with K1 or K2 capsular types or virulence genes in prostatic abscesses remains unclear.

Performance of Severe Acute Respiratory Syndrome Coronavirus 2 Serological Diagnostic Tests and Antibody Kinetics in Coronavirus Disease 2019 Patients.

Serological testing is recommended to support the detection of undiagnosed coronavirus disease 2019 (COVID-19) cases. However, the performance of serological assays has not been sufficiently evaluated. Hence, the performance of six severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binding antibody assays [three chemiluminescence (CLIAs) and three lateral flow immunoassays (LFIAs)] and a surrogate virus neutralization test (sVNT) was analyzed in a total of 988 serum samples comprising 389 COVID-19-positives and 599 COVID-19-negatives.

Identification of the novel HLA-C*04:440 allele using next-generation sequencing.

The HLA-C*04:440 allele differs from HLA-C*04:82:01 by a single non-synonymous change, c.14C > A.

The novel HLA-DRB1*04:05:19 allele identified by sequencing-based typing.

The HLA-DRB1*04:05:19 allele differs from DRB1*04:05:01:01 by a synonymous nucleotide polymorphism at cDNA position 102.

Effects of osmolality and solutes on the morphology of red blood cells according to three-dimensional refractive index tomography.

Phosphate-buffered saline (PBS) and Alsever's solution (AS) are frequently used as media in blood-related studies, while 0.9% normal saline (NS) is frequently used in transfusion medicine. Despite the frequent use, the effects of these solutions on the shape and volume of red blood cells (RBCs) have not been reported.

Sensitive electrochemical immunosensor to detect prohibitin 2, a potential blood cancer biomarker.

Blood cancers are difficult to cure completely and frequently show a poor prognosis. Recently, prohibitin 2 (PHB2) has been shown to be a potential biomarker for blood cancers. Sandwich ELISA can be used as a reference method for quantitative analysis of PHB2; however, ELISA can be challenging for early diagnosis and continuous monitoring method due to the need for large sample volumes (25 μL <), technical expertise, complex procedure, relative high cost, and non-portability.

Source Analysis and Effective Control of a COVID-19 Outbreak in a University Teaching Hospital during a Period of Increasing Community Prevalence of COVID-19.

Background: South Korea has been experiencing a third wave of coronavirus disease 2019 (COVID-19) since mid-November 2020. Our hospital in Gwangju metropolitan city experienced a healthcare-associated COVID-19 outbreak early in the third wave. The first confirmed COVID-19 patient was a symptomatic neurosurgery resident with high mobility throughout the hospital.

Disk Diffusion Susceptibility Testing for the Rapid Detection of Fluconazole Resistance in Isolates.

Background: Given the increased fluconazole resistance (FR) among isolates, we assessed the suitability of disk diffusion susceptibility testing (DDT) for the early detection of FR using well-characterized isolates.

Methods: In total, 188 isolates, including 66 (seven Erg11 mutants), 69 (33 Pdr1 mutants), 29 (15 Erg11 mutants), and 24 (eight Erg11 mutants) isolates, were tested in this study. FR was assessed using DDT according to the standard CLSI M44-ED3 method, except that two cell suspensions, McFarland 0.

Diagnostic Validation of a Clinical Laboratory-Oriented Targeted RNA Sequencing System for Detecting Gene Fusions in Hematologic Malignancies.

Targeted RNA sequencing (RNA-seq) is a highly accurate method for sequencing transcripts of interest with a high resolution and throughput. However, RNA-seq has not been widely performed in clinical molecular laboratories because of the complexity of data processing and interpretation. We developed and validated a customized RNA-seq panel and data processing protocol for fusion detection using 4 analytical validation samples and 51 clinical samples, covering seven types of hematologic malignancies.

Fluconazole-Resistant Candida glabrata Bloodstream Isolates, South Korea, 2008-2018.

We investigated the clinical outcomes and molecular mechanisms of fluconazole-resistant (FR) bloodstream infections. Among 1,158 isolates collected during multicenter studies in South Korea during 2008–2018, 5.7% were FR.

Evaluation of a Fully Automated Antinuclear Antibody Indirect Immunofluorescence Assay in Routine Use.

Indirect immunofluorescence assay (IFA) using HEp-2 cells as a substrate is the gold standard for detecting antinuclear antibodies (ANA) in patient serum. However, the ANA IFA has labor-intensive nature of the procedure and lacks adequate standardization. To overcome these drawbacks, the automation has been developed and implemented to the clinical laboratory.

Performance Evaluation of VITEK MS for the Identification of a Wide Spectrum of Clinically Relevant Filamentous Fungi Using a Korean Collection.

The correct identification of filamentous fungi is challenging. We evaluated the performance of the VITEK MS v3.0 system (bioMérieux, Marcy-l'Étoile, France) for the identification of a wide spectrum of clinically relevant filamentous fungi using a Korean collection.