Publications by authors named "Koji Iio"

Background: Blood culture remains the gold standard for diagnosing bacteremia; however, contamination inevitably occurs in 2-3% of cases, requiring differentiation between true bacteremia and contamination. Although time to positivity (TTP) aids in this clinical decision, with detection after 24 hours generally indicating contamination, technological advances in blood culture systems may have shortened this threshold interval.

Methods: This study retrospectively analyzed blood culture data in our hospital from April 2023 to January 2025 to determine the optimal TTP cutoff.

View Article and Find Full Text PDF

Phaeohyphomycosis is a rare fungal infection that presents significant challenges in diagnosis and treatment. Herein, we document a case of a cerebellar abscess caused by Cladophialophora bantiana. A 77-year-old woman with type 2 diabetes mellitus and a previous history of diffuse large B-cell lymphoma gradually developed ataxia and was transferred to an emergency department.

View Article and Find Full Text PDF

Objectives: is a significant pathogen causing invasive meningococcal disease, posing clinical and public health concerns worldwide. This study aimed to investigate the genetic characteristics of clinical isolates at Okayama University Hospital in Japan.

Methods: Between 2018 and 2023, five clinical strains were isolated, of which three were subjected to the antimicrobial susceptibility testing and whole genetic analysis using MiSeq platform (Illumina, San Diego, CA, USA).

View Article and Find Full Text PDF

Introduction: Corynebacterium species potentially develop high-level daptomycin resistance (HLDR) shortly after daptomycin (DAP) administration. We aimed to investigate the clinical and microbiological characteristics of HLDR Corynebacterium infections.

Methods: We first presented a clinical case accompanied by the results of a comprehensive genetic analysis of the isolate, and then performed a systematic scoping review.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates carbapenemase-producing Enterobacterales (CPE) at Okayama University Hospital over 5 years (2013-2018), revealing a variety of CPE isolates with different phenotypic and genetic characteristics.
  • Eight CPE isolates were identified, mainly carrying blaIMP-1 and blaIMP-6 genes, with significant diversity in bacterial species and carbapenem susceptibility patterns.
  • The findings highlight the importance of continuous genetic surveillance and customized infection control measures to combat the spread of CPE.
View Article and Find Full Text PDF

Cryptococcus prostatitis is an uncommon manifestation of cryptococcal infection that occurs mostly in immunocompromised patients. Tocilizumab, an anti-interleukin-6 receptor monoclonal antibody, has been associated with an increased risk of cryptococcal infections. However, there have been no documented cases of cryptococcal prostatitis in patients receiving tocilizumab therapy.

View Article and Find Full Text PDF

We investigated the prevalence and characteristics of Cefazolin inoculum effect (CInE) among clinical MSSA isolates in Japan. Although 35.5 % (39 isolates) were positive for the blaZ gene, none met the phenotypic criteria for CInE.

View Article and Find Full Text PDF
Article Synopsis
  • Ureaplasma urealyticum is a rare pathogen linked to septic arthritis, especially in patients with low immunoglobulin levels, and this is the first reported case of such an infection in Japan.
  • A 23-year-old woman with secondary hypogammaglobulinemia experienced severe joint inflammation that did not respond to standard treatments; advanced imaging and fluid analysis revealed U. urealyticum as the cause.
  • The case underscores the importance of using 16S rRNA gene sequencing for identifying difficult-to-culture bacteria in septic arthritis, confirming U. urealyticum as a potential threat in immunocompromised individuals.
View Article and Find Full Text PDF

In this age of antimicrobial resistance (AMR), improving treatment using existing antibiotics is desirable. Extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (ESBL-E) are high priority AMR pathogens according to the World Health Organization. Cephamycin-class beta- lactams are tolerant to hydrolysis by ESBL activity and have bactericidal effects on ESBL-E.

View Article and Find Full Text PDF

Ceftolozane (CTLZ) is a novel cephalosporin antibiotic that exhibits broad-spectrum activity against gram-negative pathogens, including Pseudomonas aeruginosa, especially when combined with tazobactam (TAZ). We examined the minimum inhibitory concentration (MIC) of CTLZ/TAZ for 21 multidrug-resistant P. aeruginosa (MDRP) and eight carbapenem-resistant P.

View Article and Find Full Text PDF

Intravesical Bacillus Calmette-Guérin (BCG) instillation is an established immunotherapy for superficial bladder cancer. Herein, we describe a case of disseminated BCG infection that developed immediately after the first BCG injection. A 76-year-old man diagnosed with non-invasive bladder cancer underwent intravesical BCG instillation; he developed high fever and systemic arthralgia later that night.

View Article and Find Full Text PDF

Granulicatella species are rare, nutritionally variant streptococci that cause infective endocarditis. Their clinical and microbiological characteristics remain unknown. We reviewed five years of Granulicatella cases in our hospital database (Jan 2017-Jun 2022), finding 6 Granulicatella adiacens cases and 1 Granulicatella elegans case.

View Article and Find Full Text PDF

Inducible resistance to the macrolide, lincosamide, and streptogramin B (iMLSB) antibiotic family is a latent mechanism for antimicrobial resistance in Staphylococcus aureus. We here investigated the frequency and genotypic profiles of iMLSB resistance in clindamycin (CLDM)-susceptible S. aureus isolated in Okayama University Hospital from June 2020 to June 2021.

View Article and Find Full Text PDF

Buruli ulcer is the third most common mycobacterial infection worldwide and is mainly diagnosed in tropical regions. Globally, this progressive disease is caused by Mycobacterium ulcerans; however, Mycobacterium ulcerans subsp. shinshuense, an Asian variant, has been exclusively identified in Japan.

View Article and Find Full Text PDF

Amidst the global spread of antimicrobial resistance, New Delhi metallo-β-lactamase (NDM)-type carbapenemase-producing Enterobacterales (CPE) remain uncommon in Japan, and the detection of such highly drug-resistant organisms is limited to inbound cases. There is little evidence regarding the prevalence of NDM β-lactamase gene (bla)-harboring CPE in the domestic community, especially in the provincial cities of Japan. Herein, we report the isolation of a bla-harboring plasmid in Enterobacter cloacae complex strain isolated from an elderly woman without a history of traveling abroad who had resided in a long-term care facility in Okayama, Japan.

View Article and Find Full Text PDF

Introduction: Long-term care hospitals (LTCHs) are at a high risk for the inflow and spread of antimicrobial resistance (AMR) pathogens. However, owing to limited laboratory resources, little is known about the extent to which AMR organisms are endemic.

Methods: We performed active surveillance for carbapenem-resistant Enterobacteriaceae (CRE) and extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) in newly admitted patients at Marugame Medical Center, a nearly 200-bedded LTCH located in Kagawa, Japan.

View Article and Find Full Text PDF

Candida dubliniensis phenotypically mimics Candida albicans in its microbiological features; thus, its clinical characteristics have yet to be fully elucidated. Here we report the case of a 68-year-old Japanese man who developed C. dubliniensis fungemia during treatment for severe coronavirus disease 2019 (COVID-19).

View Article and Find Full Text PDF

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of nosocomial and community infections, and vancomycin (VCM) is widely recommended as a first-line therapeutic drug. Minimum inhibitory concentrations (MICs) of VCM ≤2 μg/mL are defined as susceptible, but increases in these levels, known as "VCM MIC creep" have been reported. The aim of this study was to investigate VCM MIC creep during the promotion of a national antimicrobial stewardship campaign.

View Article and Find Full Text PDF

The emergence of high-level daptomycin (DAP)-resistant (HLDR) Corynebacterium striatum has been reported as a result of loss-of-function point mutations or premature stop codon mutations in a responsible gene, pgsA2. We herein describe the novel detection of an HLDR C. striatum clinical isolate, in which IS30-insertion was corroborated to cause destruction of pgsA2 gene.

View Article and Find Full Text PDF