Biology subjects

Suk, H.-J.

Publications and source records attributed to Suk, H.-J..

3 recordsLinked to original sources

bioRxiv2026

Rapid Cas13a-based penA genotyping for cefixime susceptibility in Neisseria gonorrhoeae

BackgroundAntimicrobial resistance in Neisseria gonorrhoeae is an urgent public health threat. Resistance-guided therapy can assure appropriate treatment and reintroduce alternative therapeutic options by identifying genetic predictors of resistance. Mosaicism at codons 375-377 of the penA gene are associated with cefixime resistance. Rapid, field-deployable assays for predicting cefixime susceptibility are lacking. MethodsWe used a machine-learning algorithm to develop a CRISPR Cas13a-based assay to detect the absence of mosaicism at codons 375-377 of the penA gene combined with isothermal amplification in a single reaction. We integrated the assay onto a portable fluorescence-based platform. We evaluated performance using cultured isolates and compared results with PCR genotyping and phenotypic antimicrobial susceptibility testing. We also assessed feasibility of reagent lyophilization for cold-chain-independent deployment. ResultsAmong 40 N. gonorrhoeae isolates, the Cas13a penA assay demonstrated 100% concordance with PCR genotyping and 92{middle dot}5% (95% CI 79.6-98.4%) concordance with phenotypic cefixime susceptibility. Median time to detection was 12 minutes (IQR 5 minutes). The lyophilized detection system detected all 12 isolates with a median time to detection of 45{middle dot}0 minutes (IQR 40-45) compared to 45{middle dot}0 minutes (IQR 35-50) for the positive aqueous control, although peak fluorescence was higher for the aqueous control (p<0.01). ConclusionThe Cas13a assay was rapid and demonstrated strong correlation with genotypic and phenotypic cefixime susceptibility in N. gonorrhoeae, while a lyophilized assay retained functionality.

bioengineering↗

bioRxiv2023

Gamma sensory stimulation and effects on the brain

Findings by the Tsai lab and others 1-8 demonstrate that 40 Hz frequency sensory stimulation induces electrophysiological responses and attenuates pathology in mouse models of Alzheimers disease (AD). A recent study in Nature Neurosciene 9 concluded that the stimulation does not affect endogenous gamma oscillations or amyloid burden. We welcome research investigating 40 Hz sensory stimulation, and the article by Soula et al enhances our understanding of the brains electrophysiological response to 40Hz. However, we respectfully suggest that the data in Soula et al are consistent with a neuronal response to 40 Hz, which we further support with new data in humans. Moreover we contend the non-significant effects on amyloid are due to technical limitations of the study.

neuroscience↗

bioRxiv2020

Expansion Sequencing: Spatially Precise In Situ Transcriptomics in Intact Biological Systems

AbstractMethods for highly multiplexed RNA imaging are limited in spatial resolution, and thus in their ability to localize transcripts to nanoscale and subcellular compartments. We adapt expansion microscopy, which physically expands biological specimens, for long-read untargeted and targeted in situ RNA sequencing. We applied untargeted expansion sequencing (ExSeq) to mouse brain, yielding readout of thousands of genes, including splice variants and novel transcripts. Targeted ExSeq yielded nanoscale-resolution maps of RNAs throughout dendrites and spines in neurons of the mouse hippocampus, revealing patterns across multiple cell types; layer-specific cell types across mouse visual cortex; and the organization and position-dependent states of tumor and immune cells in a human metastatic breast cancer biopsy. Thus ExSeq enables highly multiplexed mapping of RNAs, from nanoscale to system scale. One Sentence SummaryIn situ sequencing of physically expanded specimens enables multiplexed mapping of RNAs at nanoscale, subcellular resolution.

genomics↗