Evaluation of the VITEK 2 AST-N439 card for susceptibility testing of novel β-lactam/β-lactamase inhibitor combinations and colistin in carbapenem-non-susceptible gram-negative bacilli.

Unlabelled: We assessed the performance of the VITEK 2 AST-N439 card for susceptibility testing of novel β-lactam/β-lactamase inhibitor (BL/BLI) combinations and colistin in carbapenem-non-susceptible gram-negative isolates. A total of 425 clinical isolates, including ( = 242), ( = 97), and ( = 86), were tested using VITEK 2, with broth microdilution as the reference standard. Minimum inhibitory concentrations were interpreted according to Clinical and Laboratory Standards Institute breakpoints.

Experimental study on factors influencing low identification rates and spectral quality of using the Sepsityper kit.

The MBT Sepsityper Kit (Sepsityper) has a low identification rate for , and the underlying causes remain unclear. To elucidate these factors, we investigated five factors under controlled conditions simulating bloodstream infections: blood culture bottle type, blood culture system, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) platform, lysis buffer volume used in Sepsityper, and sample preparation method used for MALDI-TOF MS analysis. The results showed that anaerobic bottles had a higher identification rate than aerobic bottles (5.

Differential severity of SARS-CoV-2 variant infections in children and adults with COVID-19.

We performed virus whole-genome sequencing of 6916 upper respiratory swabs from adults and children from March 2020 to May 2023 and collected clinical metadata to assess differences in SARS-CoV-2 variant severity and symptomatology. Multivariable logistic regression showed a severity peak with Delta, which had the highest likelihood of severe infection. In children, another peak was observed with BA.

Evaluation of the cobas SARS-CoV-2 & Influenza A/B v2 assay for detecting SARS-CoV-2 and influenza A and B viruses in nasopharyngeal swab specimens.

Accurate and rapid diagnostic assays that simultaneously detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A/B are crucial for effective clinical management and infection control. In the present study, we evaluated the cobas SARS-CoV-2 & Influenza A/B v2 assay (Roche Diagnostics, Basel, Switzerland) using the Roche cobas 5800 system, comparing it to the Allplex SARS-CoV-2/FluA/FluB/RSV assay (Seegene, Seoul, Republic of Korea). A total of 871 nasopharyngeal swab specimens, including 164 SARS-CoV-2-positive, 76 influenza A-positive, 77 influenza B-positive, and 554 negative specimens, were tested using the cobas and Allplex assays in parallel.

Detection of HIV RNA after CAR-T Cell Therapy in A Relapsed/refractory Diffuse Large B-cell Lymphoma Patient: Possibility of False Positivity and Clinical Implications.

CAR-T cell therapy using lentiviral vectors can lead to false-positive HIV RNA detection, making distinguishing true infection from vector-related signals challenging. A 64-year-old male with relapsed/refractory DLBCL (RR-DLBCL) underwent multiple lines of treatment, including R-CHOP, R-ICE, autologous stem cell transplantation (ASCT), and tisagenlecleucel (tisa-cel, Kymriah). Infectious disease screening before CAR-T therapy was negative for HIV.

Comparison of conventional culture and automated blood culture system for microbiologic diagnosis of pleural infection.

Microbiological diagnosis of pleural infection is often hindered by the low sensitivity of conventional culture. The automated blood culture system (ABCS) has been shown to improve diagnostic sensitivity for the culture of non-blood specimens. This study examined the additional diagnostic benefit of ABCS against conventional bacterial culture in patients who underwent thoracentesis or percutaneous drainage.

Microbiological and clinical epidemiology of cryptococcosis in non-HIV Korean patients: 4-year collection.

Background: Cryptococcosis causes a high burden of disease worldwide; however, it has been relatively rare in Korea, where data on its prevalence and clinical characteristics remain limited. This study aimed to characterize the microbiological features of clinical cryptococcal isolates and to investigate the clinical profiles of HIV-negative patients with cryptococcosis in South Korea.

Methods: Clinical isolates of Cryptococcus species were collected from two university hospitals in South Korea (about 5000 beds, in total) over a 4-year period.

Group B Detection Rate and Clindamycin Resistance Among Reproductive-Age Women in Korea During 2003-2022.

Background: Group B (GBS) is one of the leading causes of neonatal early-onset sepsis, resulting in high mortality and significant comorbidity. Intrapartum penicillin prophylaxis is recommended for pregnant women with GBS colonization to prevent vertical transmission. For pregnant women at high risk of anaphylaxis to penicillin, clindamycin is recommended only if the susceptibility of GBS isolates has been identified.

Clinical and microbiological analyses of colistin-resistant strains among carbapenem-resistant complex clinical isolates.

Carbapenem-resistant complex (CR-ECC), which is rapidly increasing as the cause of nosocomial infections, has limited treatment options. The aim of this study is to investigate the microbiological and clinical traits and molecular epidemiology of isolates of CR-ECC and provide guidance for antibiotic selection in clinical practice. Clinical CR-ECC isolates (ertapenem MIC ≥ 2 mg/L) were collected from 2021 to 2022.

Evaluation of the Allplex stx1/2/2a/2d Typing (ASTXT) assay for the diagnosis and typing of Shiga toxin-producing Escherichia coli.

This study assessed the performance of the Allplex stx1/2/2a/2d Typing (ASTXT) assay (Seegene) for diagnosis and typing Shiga toxin-producing Escherichia coli. Analytical sensitivity and specificity were evaluated using 18 spiked strains, and cross-reactivity was tested on 114 strains including E. coli without Shiga toxin.

Characterization of an Enterococcus sp. SMC-9 strain isolated from bile of a patient with cholangitis.

The genus Enterococcus is increasingly recognized for its involvement in various human infections, with several species known to be pathogenic. This study characterized Enterococcus sp. SMC-9, isolated from bile of a patient with cholangitis, and compared its characteristics with those of Enterococcus montenegrensis CoE-012-22T, recently isolated from dried beef sausage.

Comparison of the STANDARD M10 . , Xpert . , and BD MAX Cdiff assays as confirmatory tests in a two-step algorithm for diagnosing infection.

Current guidelines recommend a two-step algorithm rather than relying solely on a single test for diagnosing infection. This algorithm starts with enzyme immunoassay (EIA) for detecting glutamate dehydrogenase (GDH) and toxins A/B, followed by nucleic acid amplification test (NAAT) for GDH-positive but toxin-negative cases. This study compared the performance of three commercial NAATs: the STANDARD M10 , Xpert , and BD MAX Cdiff assays, utilized as confirmatory testing of the two-step algorithm.

Laboratory validation of a clinical metagenomic next-generation sequencing assay for respiratory virus detection and discovery.

Tools for rapid identification of novel and/or emerging viruses are urgently needed for clinical diagnosis of unexplained infections and pandemic preparedness. Here we developed and clinically validated a largely automated metagenomic next-generation sequencing (mNGS) assay for agnostic detection of respiratory viral pathogens from upper respiratory swab and bronchoalveolar lavage samples in <24 h. The mNGS assay achieved mean limits of detection of 543 copies/mL, viral load quantification with 100% linearity, and 93.

Comparative evaluation of the STANDARD M10 and Xpert . assays for detection of toxigenic in stool specimens.

This study compared the performance of two commercial molecular assays, the STANDARD M10 assay (M10) and the Xpert assay (Xpert), for detecting toxigenic in stool specimens. A total of 487 consecutive stool specimens submitted for routine testing between June and November 2023 were included. Following routine testing using C.

Evaluation of the QMAC-dRAST System Version 2.5 for Rapid Antimicrobial Susceptibility Testing of Gram-Negative Bacteria From Positive Blood Culture Broth and Subcultured Colony Isolates.

Background: Rapid antimicrobial susceptibility testing (AST) for bloodstream infections (BSIs) facilitates the optimization of antimicrobial therapy, preventing antimicrobial resistance and improving patient outcomes. QMAC-dRAST (QuantaMatrix Inc., Korea) is a rapid AST platform based on microfluidic chip technology that performs AST directly using positive blood culture broth (PBCB).

Antimicrobial activity of ceftazidime-avibactam against KPC-2-producing Enterobacterales: a cross-combination and dose-escalation titration study with relebactam and vaborbactam.

Unlabelled: With the introduction of ceftazidime-avibactam worldwide, the antimicrobial activity of new β-lactam/β-lactamase inhibitors (BL/BLIs) needs to be investigated. From January 2020 to June 2023, carbapenemase (KPC)-producing Enterobacterales were collected. With a broth microdilution test of new BL/BLIs, cross-activity test with nine combinations of BLs and new BLIs and dose-escalation titration test for non-susceptible isolates were conducted to investigate inhibitory activities of new BLIs.

Evaluation of the Humasis COVID-19 Antigen Rapid Diagnostic Test for the Diagnosis of SARS-CoV-2 Infection.

Objective: We assessed the performance of the Humasis COVID-19 AgHS Test (Humasis, Korea), a novel antigen rapid diagnostic test (Ag-RDT) based on lateral flow immunoassay.

Methods: 85 SARS-CoV-2-positive and 155 SARS-CoV-2-negative nasopharyngeal swab specimens confirmed by rRT-PCR were tested using the Humasis and PBCheck Ag-RDTs. The analytical specificity of the Humasis Ag-RDT was evaluated using 27 strains of human respiratory pathogens.

Features which discriminate between tuberculosis and haematologic malignancy as the cause of pleural effusions with high adenosine deaminase.

Background: Adenosine deaminase (ADA) is a useful biomarker for the diagnosis of tuberculous pleurisy (TBP). However, pleural effusions with high ADA can also be caused by other diseases, particularly hematologic malignant pleural effusion (hMPE). This study aimed to investigate the features that could differentiate TBP and hMPE in patients with pleural effusion ADA ≥ 40 IU/L.

Clinical Course of Patients With Mediastinal Lymph Node Tuberculosis and Risk Factors for Paradoxical Responses.

Background: Paradoxical responses (PR) occur more frequently in lymph node tuberculosis (LNTB) than in pulmonary tuberculosis and present difficulties in differential diagnosis of drug resistance, new infection, poor patient compliance, and adverse drug reactions. Although diagnosis of mediastinal LNTB has become much easier with the development of endosonography, limited information is available. The aim of this study was to investigate the clinical course of mediastinal LNTB and the risk factors associated with PR.

Complications of the Central Nervous System in Pediatric Patients With Common Cold Coronavirus Infection During 2014-2019.

Background: In pediatric patients, the common cold coronavirus (ccCoV) usually causes mild respiratory illness. There are reports of coronavirus causing central nervous system (CNS) infection in experimental animal models. Some immunocompromised patients have also been reported to have fatal CNS infections with ccCoV.

False-positive galactomannan immunoassay in the glucose component of total parenteral nutrition products.

This manuscript describes an occurrence of false-positive GM tests in patients receiving TPN products from a manufacturer who had recently changed the supplier of the glucose component. We describe the clinical presentation of nine false-positive cases and the results of serologic and microbiological investigations of the TPN products suspected of contamination with GM. Attempts to detect GM in parenteral nutrition products were made since the detection of GM in sodium gluconate-containing solutions in 2007, but none of them identified the source of elevated GM indexes in TPN products.