Nationwide surveillance of antibacterial susceptibility in bacterial respiratory pathogens in Japan, 2022-2023.

The emergence and spread of antimicrobial resistant (AMR) have become a major global concern. This nationwide surveillance study, conducted by the Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases, and Japanese Society for Clinical Microbiology from 2022 to 2023, examined the antimicrobial susceptibility of respiratory pathogens. A total of 1057 bacterial isolates from 28 medical institutions, predominantly tertiary medical centers, were analyzed.

Breakthrough Infection After a Primary Series of COVID-19 Vaccination Induces Stronger Humoral Immunity and Equivalent Cellular Immunity to the Spike Protein Compared with Booster Shots.

The long-term immune implications of administering more than four doses of COVID-19 vaccine and the impact of breakthrough infections are not fully understood. We conducted a follow-up cohort study on Japanese healthcare workers who received more than three doses of the BNT162b2 vaccine. We assessed both the anti-SARS-CoV-2 antibody titer and cellular immunity in 429 participants and investigated the numbers, types, and brands of COVID-19 vaccines administered, as well as the episodes of COVID-19 infections after the third dose.

Cefiderocol susceptibility of Stenotrophomonas maltophilia species complex and carbapenem-resistant Pseudomonas aeruginosa isolates from blood cultures at a university hospital in Tokyo, Japan.

Objective: Cefiderocol, a siderophore cephalosporin, has shown promise against carbapenem-resistant strains such as Pseudomonas aeruginosa and Stenotrophomonas maltophilia species complex. Despite its recent approval in Japan, susceptibility data remain limited. Therefore, this study evaluated the cefiderocol susceptibility of carbapenem-resistant P.

Efficacy of De-Escalation to Cefmetazole in Patients with Bacteremic Urinary Tract Infections Caused by Extended-Spectrum β-Lactamase-Producing Escherichia coli.

This study aimed to clarify the optimal value for the unbound cefmetazole concentration to remain above the minimum inhibitory concentration (MIC) (fT ≥ MIC) for efficacy of de-escalation to cefmetazole in patients with bacteremic urinary tract infection by extended-spectrum β-lactamase-producing Escherichia coli. This double-center retrospective observational study was conducted at Tokyo Bay Urayasu Ichikawa Medical Center and Keio University Hospital from January 2012 to October 2022. Efficacy was determined via clinical evaluation (mortality rate, recurrence rate, vital changes) and bacteriological evaluation, and the optimal fT ≥ MIC was calculated via receiver operating characteristic curve analysis.

Germline variants and mosaic chromosomal alterations affect COVID-19 vaccine immunogenicity.

Vaccine immunogenicity is influenced by the vaccinee's genetic background. Here, we perform a genome-wide association study of vaccine-induced SARS-CoV-2-specific immunoglobulin G (IgG) antibody titers and T cell immune responses in 1,559 mRNA-1273 and 537 BNT162b2 vaccinees of Japanese ancestry. SARS-CoV-2-specific antibody titers are associated with the immunoglobulin heavy chain (IGH) and major histocompatibility complex (MHC) locus, and T cell responses are associated with MHC.

Critical illness caused by a difficult-to-diagnose Schaalia cardiffensis infection with septicemia, pulmonary involvement, and disseminated intravascular coagulation syndrome: A case report and literature review.

Infection caused by Schaalia cardiffensis, formerly Actinomyces cardiffensis, is uncommon, and its clinical characteristics remain largely unknown. This report presents a case of S. cardiffensis infection causing critical illness in an elderly patient, along with a literature review.

Fully automated identification of Neisseria meningitidis using the BD MAX system in a clinical laboratory setting: A preliminary study.

The rapid and accurate identification of Neisseria meningitidis, a pathogen that causes invasive infections and meningitis, is crucial for its effective clinical management and infection control. However, identification using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry may misidentify other Neisseria species as N. meningitidis, thus necessitating confirmatory tests based on biochemical properties.

Optimal incubation duration of liquid cultures for assessing culture negative conversion in patients with Mycobacterium avium complex and Mycobacterium abscessus pulmonary diseases.

Purpose: Mycobacterial liquid culturing typically requires six weeks or longer, primarily because of the slow growth rate of Mycobacterium tuberculosis. This study aimed to evaluate the potential of shortening the duration of mycobacterial liquid culturing in healthcare settings with high prevalence rates of non-tuberculous mycobacteria.

Methods: We retrospectively analyzed the relationship between mycobacterial species and time to positive testing of liquid cultures from sputum samples using the Mycobacteria Growth Indicator Tube system over a 3.

Using a Systems Engineering Approach to Build a PCR Testing System at a Medical School During the COVID-19 Pandemic.

Background: During the COVID-19 pandemic, there was an increasing need to expand diagnostic testing in hospitals. At Keio University Hospital (KUH), clinical staff were concerned that the demand for PCR testing might exceed the capacity of the Clinical Laboratory. In response, basic researchers at Keio University School of Medicine (KUSM) set out to build a new, collaborative, PCR testing system.

Cellular and humoral immune responses to COVID-19 booster vaccination in Japanese dialysis patients.

Background: Dialysis patients are susceptible to developing severe coronavirus disease 2019 (COVID-19) due to hypoimmunity. Antibody titers against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) after the primary vaccinations are lower in hemodialysis (HD) patients than in healthy individuals. This study aimed to evaluate the effect of a SARS-CoV-2 booster vaccination in HD and peritoneal dialysis (PD) patients based on antibody titers and cellular and humoral immunity.

Seroprevalence of severe acute respiratory syndrome coronavirus 2 N antibodies between December 2021 and march 2023 in Japan.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in 2019 in China and rapidly spread worldwide, leading to a pandemic. The threat of SARS-CoV-2 is subsiding as most people have acquired sufficient antibodies through vaccination and/or infection to prevent severe COVID-19. After the emergence of the omicron variants, the seroprevalence of antibodies against the N protein elicited by SARS-CoV-2 infection ranged from 44.

The utility of smartphone-based quantitative analysis of SARS-CoV-2-specific antibody lateral flow assays.

Objectives: Although antibody measurements using lateral flow assay (LFA) kits are convenient, they usually require a specialized reader for quantification. However, a smartphone-based quantification application can be used as a reader for LFA kits. We investigated the quantification ability of the application for SARS-CoV-2-specific antibodies.

Analysis of Risk Factors for Developing Tuberculosis in Patients Who Received Prophylactic Latent Tuberculosis Infection Treatment with Experience of Biologic Medications.

Biologic medications have dramatically improved the treatment outcomes of immunological inflammatory diseases, but their immunosuppressive effects put patients at risk for tuberculosis (TB). We investigated the risk factors for developing TB in patients treated for latent tuberculosis infection (LTBI) who also had experience of using biologic medications. At Keio University Hospital, we retrospectively investigated patients treated with anti-mycobacterial drugs before or concurrently with biologic medications from January 2012 to August 2020.

Comparing minimum inhibitory concentrations of amikacin for pulmonary Mycobacterium avium complex disease: An analysis of culture media differences.

Mycobacterium avium complex (MAC) is considered a paramount microbe, especially in East Asia, including Japan. The commonly used commercial Minimum Inhibitory Concentrations (MIC) assay using Middlebrook 7H9 (7H9) medium deviates from the latest Clinical and Laboratory Standards Institute (CLSI) guidelines. Alternatively, measurement with cation-adjusted Mueller-Hinton broth (CAMHB) that conforms to CLSI standards is not yet widely available.

Cost-Effectiveness of Universal Asymptomatic Preoperative SARS-CoV-2 Polymerase Chain Reaction Screening: A Cost-Utility Analysis.

Background: An early report has shown the clinical benefit of the asymptomatic preoperative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) screening test, and some clinical guidelines recommended this test. However, the cost-effectiveness of asymptomatic screening was not evaluated. We aimed to investigate the cost-effectiveness of universal preoperative screening of asymptomatic patients for SARS-CoV-2 using polymerase chain reaction (PCR) testing.

Clinical characteristics of patients with COVID-19 harboring detectable intracellular SARS-CoV-2 RNA in peripheral blood cells.

Objectives: Although SARS-CoV-2 RNAemia has been reported to strongly impact patients with severe COVID-19, the clinical characteristics of patients with COVID-19 harboring detectable intracellular SARS-CoV-2 RNA remain unknown.

Methods: We included adult patients who had developed COVID-19 between February and September 2020. Total white blood cells derived from the buffy coat of peripheral whole blood were used to detect SARS-CoV-2 RNA using the Illumina COVIDSeq test.