Rapid and accurate detection of tuberculosis (TB) drug resistance is critical for the successful treatment and control of TB. Here, we investigated resistance to anti-TB drugs and genetic variations in 215 drug-resistant Mycobacterium tuberculosis isolates in Korea. Genetic variations were observed in rpoB Ser531Leu, katG Ser315Thr, and gyrA Asp94Gly; however, the minimum inhibitory concentrations varied, which can be attributed to other resistance mechanisms. Examination of genetic relatedness among drug-resistant isolates revealed that the cluster size of resistant bacteria was less than six strains, suggesting no evidence of a large-scale epidemic caused by a specific strain. However, rpoC mutants of the rifampicin-resistant isolates were composed of five types of clusters, suggesting that these compensatory mutations advance propagation. In the present study, more than 90% of the resistance mechanisms to major anti-TB drugs were identified, and the effect of each mutation on drug resistance was estimated. With the clinical application of recent next-generation sequencing-based susceptibility testing, the present study is expected to improve the clinical utilization of genotype-based drug susceptibility testing for the diagnosis and treatment of patients with drug-resistant TB.

Vibrio vunificus is known to cause septicemia and severe wound infections in patients with chronic liver diseases or an immuno-compromised condition. We carried out the molecular characterization of V. vulnificus isolates from human Vibrio septicemia cases based on pulsed-field gel electrophoresis (PFGE) using NotI and SfiI.

김현규, 정혜란, 김지은, 박영준. Public Health Weekly Report 2025;18:119-35. https://doi.org/10.56786/PHWR.2025.18.11suppl.9

Objectives: In this study, we performed comparative genomic and transcriptomic analysis of clinical isolates of Mycobacterium tuberculosis collected from patients with drug-susceptible tuberculosis (DS-TB). The clinical isolates were categorized based on treatment duration: standard 6 months or >6 months.Methods: Study participants were recruited from a 2016 to 2018 tuberculosis cohort, and clinical M. tuberculosis isolates were collected from the sputum of patients with tuberculosis. We analyzed the genome and transcriptome of the isolated M. tuberculosis.Results: Genomic analysis revealed a specific non-synonymous single-nucleotide polymorphism in pe_pgrs9 and ppe34, exclusive to the group treated for >6 months. Transcriptomic analysis revealed increased expression of various virulence-associated protein family genes and decreased expression of ribosomal protein genes and ppe38 genes in the group treated for >6 months.Conclusion: The identified genetic variation and gene expression patterns may influence treatment outcomes by modulating host immune responses, increasing virulence, and potentially contributing to persister cell formation in M. tuberculosis. This study provides insights into the genetic and transcriptomic factors associated with prolonged DS-TB treatment. However, our study identified molecular characteristics using a small sample size, and further detailed studies are warranted.

In this study, we present whole genome sequences of Staphylococcus aureus RN4220. Using PacBio DNA sequencing and de novo assembly, we obtained a single contig of 2,697,647 bp, which includes 2,652 predicted genes comprising protein-coding sequences, tRNAs, and rRNAs.

Clinical isolates of Mycobacterium tuberculosis M64 strain from South Korea lack the katG gene, which is associated with isoniazid resistance. Herein, we report the whole genome sequence of M. tuberculosis M64, with genomic coverage of 2,791× and a genome size of 4,353,699 bp.