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Background: Lymphocytic choriomeningitis virus (LCMV) infection in immunocompromised hosts can result in disseminated disease, meningoencephalitis, and death. Published cases in transplant recipients have been traced to transmission from infected donors. We report 2 cases of serious, non-donor-derived LCMV infection in solid organ transplant recipients., Methods: Initial identification of LCMV infection was done by using metagenomic next-generation sequencing (mNGS). Subsequent evaluations and confirmatory testing involved molecular diagnostics, serology, and phylogenetic analysis. A detailed epidemiologic investigation was conducted., Results: LCMV was detected by mNGS in 2 solid organ transplant recipients from distinct donors. A heart transplant recipient (from donor 1) died of progressive, disseminated LCMV infection, while a kidney transplant recipient (from donor 2) with LCMV meningoencephalitis survived. A multistate laboratory and epidemiologic investigation of both donors and all their organ recipients was initiated. Postmortem samples were obtained from both donors, and pretransplant and/or posttransplant samples were obtained from 5 of the 6 organ recipients. mNGS, serologic, and real-time reverse-transcription polymerase chain reaction testing confirmed LCMV infection in both solid organ transplant recipients. Epidemiologic investigation revealed significant pretransplant rodent exposures for both LCMV-infected recipients. Laboratory studies for the other organ recipients from both donors were negative for LCMV infection., Conclusions: Our investigations suggest that LCMV infection in 2 solid organ transplant recipients originated from rodent exposure preceding transplantation and were not donor derived. Although uncommon, healthcare providers should be aware of LCMV-associated serious and life-threatening illness in immunocompromised hosts. Diagnostic modalities are limited to reference laboratories., Competing Interests: Potential conflicts of interest. C. Y. C. receives research funding from Abbott Laboratories and Delve Bio for pathogen detection and discovery projects using mNGS and is a cofounder of and owns equity in Delve Bio. C. Y. C. is also a coinventor on US patent 11380421, Pathogen Detection Using Next Generation Sequencing, under which algorithms for taxonomic classification, filtering, and pathogen detection are used by SURPI+ software. All other authors report no potential conflicts., (Published by Oxford University Press on behalf of Infectious Diseases Society of America 2025.)

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 93.6% sensitivity, 93.8% specificity, and 93.7% accuracy compared to gold-standard clinical multiplex RT-PCR testing. Performance increased to 97.9% overall predictive agreement after discrepancy testing and clinical adjudication, which was superior to that of RT-PCR (95.0% agreement). To enable discovery of novel, sequence-divergent human viruses with pandemic potential, de novo assembly and translated nucleotide algorithms were incorporated into the automated SURPI+ computational pipeline used by the mNGS assay for pathogen detection. Using in silico analysis, we showed that after removal of all human viral sequences from the reference database, 70 (100%) of 70 representative human viral pathogens could still be identified based on homology to related animal or plant viruses. Our assay, which was granted breakthrough device designation from the US Food and Drug Administration (FDA) in August of 2023, demonstrates the feasibility of routine mNGS testing in clinical and public health laboratories, thus facilitating a robust and rapid response to the next viral pandemic., Competing Interests: Competing interests C.Y.C. is a founder of Delve Bio and on the scientific advisory board for Delve Bio, Flightpath Biosciences, Biomeme, Mammoth Biosciences, BiomeSense and Poppy Health. He is also an inventor on US patent 11380421, “Pathogen detection using next generation sequencing”, under which algorithms for taxonomic classification, filtering, and pathogen detection are used by SURPI+ software. C.Y.C. receives research support from Delve Bio and Abbott Laboratories, Inc. The other authors declare no competing interests., (© 2024. The Author(s).)

A pulsed laser light illumination system was attached to a high-voltage electron microscope (HVEM) for in situ observation of light-induced behaviors of nano objects. The wavelength λ of emitted laser pulses was 1064, 532 or 266 nm, and the pulse duration was 6-8 ns. Using this combined HVEM system, we observed the deformation behavior of gold nanorods irradiated by a pulsed laser (λ = 1064 nm) at an intensity of 310 J m(-2) pulse or higher. A single shot of pulsed laser reduced the aspect ratio of the gold nanorods from 5 to a much smaller value. The extent of the reduction increased at higher laser intensities. However, at 310 J m(-2) pulse(-1), additional pulsed shots induced limited further deformation. The mean aspect ratio approximated to 2.5 even after irradiation with 7 pulses (total fluence exceeding 2 MJ m(-2)). In situ high resolution transmission electron microscopy (HRTEM) observation revealed that deformation was accompanied by total atomic restructuring of the nanorod interiors., (© The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)