Clinical performance of the BioFire Blood Culture Identification 2 panel for microorganism species identification and resistance gene detection in blood culture-positive specimens

by Haruki Naruse, Noriyuki Watanabe, Sachie Koyama, Sachi Tanaka, Yoshitada Taji, Yasuhiro Ebihara

Introduction

Bloodstream infections are life-threatening, and the rapid identification of pathogens and resistance genes is essential for the administration of appropriate antimicrobial agents. The BioFire Blood Culture Identification 2 (BCID2) panel on the FilmArray multi-parameter genetic analyzer is a fully automated PCR test that rapidly identifies species and resistance genes. Here, we compared the performance of the Filmarray BCID2 panel (BCID2 method) with the conventional method.

Methods

Among the blood culture-positive specimens submitted between January 2023 and November 2024, this study analyzed 201 specimens that contained the target microorganisms of the BCID2 panel. In our laboratory, after subculturing the culture medium obtained from a positive blood-culture bottle, we perform species identification using mass spectrometry and drug susceptibility testing (the conventional method). We compared the results of the BCID2 method with those of the conventional method.

Results

Concordance between the BCID2 and conventional methods was found in 152 of the 161 monomicrobial specimens (94.4%) and in 31 of the 40 polymicrobial specimens (77.5%). The 18 specimens that were discordant were mostly matched at the genus level, but the BCID2 method also detected other microorganisms that were not identified by the conventional method. Resistance genes were identified in 57 of the 61 matched specimens (93.4%).

Conclusion

The BCID2 method exhibits excellent identification results and resistance gene detection rates, suggesting that it is a reliable and rapid diagnostic test system for bloodstream infections.

Anti-cancer effect of a novel photodynamic therapy using glucose-linked chlorin e6 conjugated trastuzumab for HER2-positive gastrointestinal cancers

by Makiko Sasaki, Mamoru Tanaka, Akihiro Nomoto, Ryusei Yamasaki, Tomokazu Yoshimura, Shigenobu Yano, Yasunari Sasaki, Yuki Kojima, Taketo Suzuki, Hirotada Nishie, Keiji Ozeki, Takaya Shimura, Eiji Kubota, Hiromi Kataoka

Photodynamic therapy (PDT) is an anti-cancer therapy that employs a photosensitizer (PS) and an optimal wavelength of light, causing a photochemical reaction that releases reactive oxygen species, thereby inducing cancer cell death via oxidative stress. Because light irradiation is limited to the tumor site, PDT has minimal adverse effects. The cancer cell selectivity of the PS is important for reducing damage to the normal mucosa caused by scattered light. Antibody-drug conjugates (ADC) are novel anti-cancer therapies that combine a monoclonal tumor-surface-receptor-targeting antibody with a drug bonded through chemical linkers. ADCs enable the targeted delivery of a variety of drugs to cancer cells while minimizing their delivery to healthy tissues. One such tumor surface receptor is the human epidermal growth factor receptor 2 (HER2), which is of interest in the treatment of many cancers, including gastrointestinal cancer. To improve tumor selectivity and minimize damage to the mucosa surrounding the tumor in PDT, we established a novel PS glucose-linked chlorin e6-conjugated trastuzumab (G-Ce6-trastuzumab) that is conjugated to existing PS glucose-linked chlorin e6 (G-Ce6) and evaluated its anti-cancer effect compared to G-Ce6. The effect of PDT was evaluated using HER2-high-expression cells NCI-N87 and HER2-low-expression cells MKN-45. G-Ce6-trastuzumab is internalized by the intracellular organelles in cancer cells. Evaluation of cell death using the WST-8 assay also demonstrated a significantly higher cytotoxic effect of G-Ce6-trastuzumab in HER2-high-expression cells compared with conventional PS G-Ce6. Thereby, G-Ce6-trastuzumab may be an excellent novel PS for PDT because of its strong selectivity for HER2-high-expression cells.

Bacterial community associated with the surface and inside of centipede forcipules: Identification and characterization

by Yasutaka Tanaka, Daiki Mizushima, Yoshimitsu Izawa, Tomohiro Matsumura, Chikara Yonekawa, Hirotomo Kato, Takashi Mato

Background

In tropical to subtropical regions, centipede bites may prompt medical attention, with manifestations largely reflecting venom-related discomfort, although infections, including rare fatal necrotizing soft tissue infection (NSTI), have been reported. However, no reports are available on the commensal bacteria on centipede forcipules.

Objectives

This study aimed to investigate bacterial species residing on and in centipede forcipules and their potential role in post-bite infections.

Methods

Nine Scolopendra mutilans, three Scolopendra japonica, and two Bothropolys rugosus were collected from three regions in Japan. The bacterial composition of their forcipules was analyzed using 16S ribosomal ribonucleic acid gene sequencing and microbiome analysis.

Findings

A diverse bacterial community was observed on the centipede forcipules. Among the NSTI-associated genera examined (Escherichia, Staphylococcus, and Streptococcus), only Staphylococcus was identified as a minor population.

Conclusion

This study provides the first evidence that some bacteria found on centipede forcipules have been previously isolated from centipede bite infections. The risk of infection from bacteria on centipede forcipules during a centipede bite appears low. However, the presence of diverse bacterial species emphasizes the importance of thoroughly cleaning centipede bite wounds to prevent secondary infection.

Effects of aquatic exercise on arterial stiffness and endothelial function in adults: A systematic review and meta-analyses

by Emily Dunlap, Yanbing Zhou, Manny M.Y. Kwok, Billy C.L. So, Hirofumi Tanaka

Objective

To evaluate the effects of aquatic exercise compared with non-exercise controls and land-based exercise on arterial stiffness and endothelial function.

Design

Systematic review and meta-analyses of randomized controlled trials assessed using the Cochrane risk-of-bias tool and Grading of Recommendations Assessment, Development and Evaluation.

Data sources

PubMed/MEDLINE, CINAHL Plus, SPORTDiscus, and reference lists, searched from database inception to April 16, 2025.

Eligibility criteria

Studies evaluating chronic aquatic exercise (multi-session interventions) compared with land-based exercise or non-exercise comparison groups in adults, measuring arterial stiffness via pulse wave velocity (PWV) or endothelial function via flow-mediated dilation (FMD).

Results

This review includes 18 randomized controlled trials with 845 participants (mean age 65 ± 7 years). Studies compared aquatic exercise with non-exercise controls (8 studies), land-based exercise (6 studies), or both (4 studies). Exercise sessions averaged 50 minutes, 3 times weekly for 11 weeks. Most studies (17 out of 18) implemented moderate-to-vigorous intensity protocols. Aquatic exercise resulted in improvements in arterial stiffness compared with non-exercise controls (7 studies; SMD = –2.37, 95% CI: –4.46 to –0.29; I² = 98%: low certainty), with most evidence reflecting systemic and peripheral PWV. Changes in arterial stiffness did not differ from those observed after land-based exercise (6 studies; SMD = –0.07, 95% CI: –0.34 to 0.20; I² = 0%, moderate certainty). For endothelial function, aquatic exercise may improve outcomes versus non-exercise controls (6 studies; SMD = 0.91, 95% CI: 0.39 to 1.43; I² = 68%; low certainty) and may lead to greater improvements than land-based exercise (7 studies; SMD = 0.55, 95% CI: 0.05 to 1.06; I² = 75%; low certainty).

Conclusion

Aquatic exercise improves systemic and peripheral arterial stiffness as well as endothelial function compared with non-exercising controls. Changes in arterial stiffness do not differ from those observed after land-based exercise. Aquatic exercise may provide greater improvement in endothelial function than land-based exercise, though this is supported by low-certainty evidence, and substantial heterogeneity limits confidence in the generalizability of this finding.

PROSPERO registration

CRD42025642087.