gastric-mucosa-quantitative-polymerase-chain-reaction-analysis-for

Gastric Mucosa Quantitative Polymerase Chain Reaction Analysis for Detecting <em>Helicobacter pylori</em> and Antibiotic Resistance

Helicobacter pylori is a main pathogen that infects nearly half of the global population and is threatening public health due to its increasing antibiotic ...

Southern Medical University

Scrub typhus is a vector-borne infectious disease caused by . Accurate and timely diagnosis at the early infection stage could save the patients' lives. Traditional technologies were limited to rapidly and successfully detecting  due to poor specificity, especially in the condition of atypical symptoms. The technology of Metagenomic next-generation sequencing (mNGS) is amenable to finding the real pathogen because it holds potential as a diagnostic platform for unbiased pathogen identification and precision medicine. Herein, we reported two clinical case reports relative to the  infection diagnosed by mNGS. We hope these two cases will improve clinical diagnosis.

Metagenomics as New Tool for Diagnosis of Scrub Typhus: Two Case Reports.

Adjusting intracellular metabolic pathways and adopting suitable live state such as biofilms, are crucial for bacteria to survive environmental changes. Although substantial progress has been made in understanding how the histone-like nucleoid-structuring (H-NS) protein modulates the expression of the genes involved in biofilm formation, the precise modification that the H-NS protein undergoes to alter its DNA binding activity is still largely uncharacterized. This study revealed that acetylation of H-NS at Lys19 inhibits biofilm development in Shewanella oneidensis MR-1 by downregulating the expression of glutamine synthetase, a critical enzyme in glutamine synthesis. We further found that nitrogen starvation, a likely condition in biofilm development, induces deacetylation of H-NS and the trimerization of nitrogen assimilation regulator GlnB. The acetylated H-NS strain exhibits significantly lower cellular glutamine concentration, emphasizing the requirement of H-NS deacetylation in Shewanella biofilm development. Moreover, we discovered in vivo that the activation of glutamine biosynthesis pathway and the concurrent suppression of the arginine synthesis pathway during both pellicle and attached biofilms development, further suggesting the importance of fine tune nitrogen assimilation by H-NS acetylation in Shewanella. In summary, posttranslational modification of H-NS endows Shewanella with the ability to respond to environmental needs by adjusting the intracellular metabolism pathways.

Acetylation of xenogeneic silencer H-NS regulates biofilm development through the nitrogen homeostasis regulator in Shewanella.

Rapid and sensitive RNA detection is of great value in diverse areas, ranging from biomedical research to clinical diagnostics. Existing methods for RNA detection often rely on reverse transcription (RT) and DNA amplification or involve a time-consuming procedure and poor sensitivity. Herein, we proposed a CRISPR/Cas12a-enabled amplification-free assay for rapid, specific, and sensitive RNA diagnostics. This assay, which we termed T7/G4-CRISPR, involved the use of a T7-powered nucleic acid circuit to convert a single RNA target into numerous DNA activators via toehold-mediated strand displacement reaction and T7 exonuclease-mediated target recycling amplification, followed by activating Cas12a -cleavage of the linker strands inhibiting split G-Quadruplex (G4) assembly, thereby inducing fluorescence attenuation proportion to the input RNA target. We first performed step-by-step validation of the entire assay process and optimized the reaction parameters. Using the optimal conditions, T7/G4-CRISPR was capable of detecting as low as 3.6 pM target RNA, obtaining ∼100-fold improvement in sensitivity compared with the most direct Cas12a assays. Meanwhile, its excellent specificity could discriminate single nucleotide variants adjacent to the toehold region and allow species-specific pathogen identification. Furthermore, we applied it for analyzing bacterial 16S rRNA in 40 clinical urine samples, exhibiting a sensitivity of 90% and a specificity of 100% when validated by RT-quantitative PCR. Therefore, we envision that T7/G4-CRISPR will serve as a promising RNA sensing approach to expand the toolbox of CRISPR-based diagnostics.

CRISPR/Cas12a-Powered Amplification-Free RNA Diagnostics by Integrating T7 Exonuclease-Assisted Target Recycling and Split G-Quadruplex Catalytic Signal Output.

Fungal peritonitis, an uncommon complication in continuous ambulatory peritoneal dialysis (CAPD), has recently garnered increased attention due to its incidence and potential mortality. To the best of our knowledge, this is the first confirmed case of  () causing CAPD-related peritonitis in a patient with chronic nephrotic syndrome in Guangzhou, China. After prompt removal of the peritoneal catheter and active antifungal therapy, no clinical manifestations of peritonitis were observed. Our report underscores the importance of enhancing clinical awareness regarding  and ensuring timely diagnosis in cases of CAPD-related fungal peritonitis.

Article	Year
Metagenomics as New Tool for Diagnosis of Scrub Typhus: Two Case Reports. International medical case reports journal\| PubMed ID: 37789830	2023
Acetylation of xenogeneic silencer H-NS regulates biofilm development through the nitrogen homeostasis regulator in Shewanella. Nucleic acids research\| PubMed ID: 38142446	2024
CRISPR/Cas12a-Powered Amplification-Free RNA Diagnostics by Integrating T7 Exonuclease-Assisted Target Recycling and Split G-Quadruplex Catalytic Signal Output. Analytical chemistry\| PubMed ID: 38860917	2024
First case of fungal peritonitis caused by in China. Medical mycology case reports\| PubMed ID: 39502836	2024

Yong Ling

Biography

JoVE Journal Publications

Other Publications