QMAC-DST for Rapid Detection of Drug Resistance in Pulmonary Tuberculosis Patients: A Multicenter Pre-Post Comparative Study.

Background/Objectives: This study explores the impact of QMAC-DST, a rapid, fully automated phenotypic drug susceptibility test (pDST), on the treatment of tuberculosis (TB) patients. Methods: This pre-post comparative study, respectively, included pulmonary TB patients who began TB treatment between 1 December 2020 and 31 October 2021 (pre-period; pDST using the Löwenstein-Jensen (LJ) DST (M-kit DST)) and between 1 November 2021 and 30 September 2022 (post-period; pDST using the QMAC-DST) in five university-affiliated tertiary care hospitals in South Korea. We compared the turnaround times (TATs) of pDSTs and the time to appropriate treatment for patients whose anti-TB drugs were changed based on these tests between the groups. All patients were permitted to use molecular DSTs (mDSTs). Results: A total of 182 patients (135 in the M-kit DST group and 47 in the QMAC-DST group) were included. The median TAT was 36 days for M-kit DST (interquartile range (IQR), 30-39) and 12 days for QMAC-DST (IQR, 9-15), with the latter being significantly shorter (p < 0.001). Of the total patients, 10 (5.5%) changed their anti-TB drugs based on the mDST or pDST results after initiating TB treatment (8 in the M-kit DST group and 2 in the QMAC-DST group). In the M-kit DST group, three (37.5%) patients changed anti-TB drugs based on the pDST results. In the QMAC-DST group, all changes were due to mDST results; therefore, calculating the time to appropriate treatment for patients whose anti-TB drugs were changed based on pDST results was not feasible. In the QMAC-DST group, 46.8% of patients underwent the first-line line probe assay compared to 100.0% in the M-kit DST group (p < 0.001), indicating that rapid QMAC-DST results provide quicker assurance of the ongoing treatment by confirming susceptibility to the current anti-TB drugs. Conclusions: QMAC-DST delivers pDST results more rapidly than LJ-DST, ensuring faster confirmation for the current treatment regimen.

9 months of delamanid, linezolid, levofloxacin, and pyrazinamide versus conventional therapy for treatment of fluoroquinolone-sensitive multidrug-resistant tuberculosis (MDR-END): a multicentre, randomised, open-label phase 2/3 non-inferiority trial in South Korea.

BACKGROUND: With the introduction of new anti-tuberculosis drugs, all-oral regimens with shorter treatment durations for multidrug-resistant tuberculosis have been anticipated. We aimed to investigate whether a new all-oral regimen was non-inferior to the conventional regimen including second-line anti-tuberculosis drugs for 20-24 months in the treatment of fluoroquinolone-sensitive multidrug-resistant tuberculosis. METHODS: In this multicentre, randomised, open-label phase 2/3 non-inferiority trial, we enrolled men and women aged 19-85 years with multidrug-resistant tuberculosis confirmed by phenotypic or genotypic drug susceptibility tests or rifampicin-resistant tuberculosis by genotypic tests at 12 participating hospitals throughout South Korea. Participants with fluoroquinolone-resistant multidrug-resistant tuberculosis were excluded. Participants were randomly assigned (1:1) to two groups using a block randomisation, stratified by the presence of diabetes and cavitation on baseline chest radiographs. The investigational group received delamanid, linezolid, levofloxacin, and pyrazinamide for 9 months, and the control group received a conventional 20-24-month regimen, according to the 2014 WHO guidelines. The primary outcome was the treatment success rate at 24 months after treatment initiation in the modified intention-to-treat population and the per-protocol population. Participants who were "cured" and "treatment completed" were defined as treatment success following the 2014 WHO guidelines. Non-inferiority was confirmed if the lower limit of a 97·5% one-sided CI of the difference between the groups was greater than -10%. Safety data were collected for 24 months in participants who received a predefined regimen at least once. This study is registered with ClinicalTrials.gov, NCT02619994. FINDINGS: Between March 4, 2016, and Sept 14, 2019, 214 participants were enrolled, 168 (78·5%) of whom were included in the modified intention-to-treat population. At 24 months after treatment initiation, 60 (70·6%) of 85 participants in the control group had treatment success, as did 54 (75·0%) of 72 participants in the shorter-regimen group (between-group difference 4·4% [97·5% one-sided CI -9·5% to ∞]), satisfying the predefined non-inferiority margin. No difference in safety outcomes was identified between the control group and the shorter-regimen group. INTERPRETATION: 9-month treatment with oral delamanid, linezolid, levofloxacin, and pyrazinamide could represent a new treatment option for participants with fluoroquinolone-sensitive multidrug-resistant tuberculosis. FUNDING: Korea Disease Control and Prevention Agency, South Korea.

Evaluation of Five User-Friendly Whole Genome Sequencing Software for Mycobacterium tuberculosis in Clinical Application.

BACKGROUND: Whole genome sequencing (WGS) is an increasingly useful tool for tuberculosis (TB) diagnosis and disease management. In this study, we evaluated the utility of user-friendly WGS tools in reporting resistance profiles and identifying lineages of clinical TB isolates from South Korea. METHODS: Forty clinical samples from TB patients showing discrepancies between their rapid molecular and conventional drug susceptibility tests were used in this study. Among these clinical isolates, 37 strains were successfully evaluated via WGS software, using the GenTB, TB Profiler, PhyResSE, CASTB, and Mykrobe. RESULTS: More accurate and faster susceptibility results could be obtained with isoniazid than with rifampin. Using the phenotypic test as the gold standard, the isoniazid concordance rate between phenotypic drug susceptibility test (DST) and WGS (GenTB: 45.9%, TB profiler: 40.5%, PhyResSE: 40.5%, CASTB: 48.6%, and Mykrobe: 43.2%) was much higher than between phenotypic DST and rapid molecular genotypic DST (18.9%) among the 37 strains. In contrast, the rifampin concordance rate between phenotypic DST and WGS and that between phenotypic DST and rapid molecular genotypic DST was similar (81.1-89.2%). We also found novel mutations associated with INH in katG and ahpC gene region, not covered by the line probe assay. In addition, lineage analysis identified 81.1% of these samples as L2 East Asian lineage strains, and 18.9% as L4 Euro-American lineage strains. CONCLUSION: WGS may play a pivotal role in TB diagnosis and the detection of drug resistance, genetic diversity, and transmission dynamics in the near future because of its accuracy, speed, and extensibility.

Cross-Contamination versus Outbreak: Pre-XDR Mycobacterial Strains Confirmed by Whole-Genome Sequencing.

Whole-genome sequencing (WGS) is promising for the quality control of laboratory facilities for Mycobacterium tuberculosis (MTB) strains. We describe the clinical and laboratory characteristics of false positive versus true positive MTB cultures based on WGS, which were experienced in a real clinical setting. Strain harvest and DNA extraction from seven isolates from pre-extensive drug-resistant (pre-XDR) TB patients transferred to the Korea University Ansan Hospital were performed, and epidemiologic links and clinical information, including the phenotypic drug susceptibility test (pDST), were investigated. WGS was performed using Ion GeneStudio with an ION530tm chip (average sequencing depth, ~100-fold). In the phylogenetic tree, identical and different strains were distributed separately. Five of the seven isolates were identical; the remaining two isolates differed from the others. The images of the referred pre-XDR-TB patients with false positive MTB that were analyzed were of regions close to old TB scars. Further, the results of WGS gene mutation analysis for ethambutol, streptomycin, and fluoroquinolone resistance in all six patients were not concordant with the pDST results. WGS and clinical information were useful in differentiating laboratory cross-contamination from true positive TB, thereby avoiding the unnecessary treatment of false positive patients and delay in treating true positive TB patients, with reliable genotypic drug resistance results.

Hypericin-assisted photodynamic therapy against anaplastic thyroid cancer.

BACKGROUND: Hypericin (HYP) extracted from St. John's wort (Hypericum perforatum L.) is a natural photosensitizer in clinical photodynamic therapy (PDT). PDT is one of the powerful methods for cancer treatments because of its excellent tumoritropic characteristics and photosensitizing properties. However, limited reports on the efficacy of PDT on anaplastic thyroid cancer (ATC) have been published. Especially HYP-associated PDT has not been investigated in vitro and in vivo. In this study, we evaluated the effect of HYP for PDT against FRO ATC cells. METHODS: The activities of HYP-assisted PDT were investigated in ATC cells. The ATC FRO cells were treated with a combination of HYP dose and laser power. The viability of FRO cells was measured by MTT assay, and Trypan blue staining was performed to monitor cell death. Detection reactive oxygen species (ROS) and mitochondrial membrane potential after HYP-assisted PDT were analyzed by confocal microscopy. For in vivo study, FRO cells were injected into nude mice. After intravenous injection of HYP, Laser was irradiated and nude mice were monitored in Day 4, 7, 14. RESULTS AND CONCLUSIONS: The rate of FRO cell death was increased by applying HYP dose and laser power dependent. Moreover, HYP and laser irradiation induced FRO cell death was mediated by the intracellular ROS generation and mitochondrial damage. Finally, the HYP-assisted PDT eliminated FRO cell tumor from the mouse in vivo. These data demonstrate that HYP could be an effective photosensitizer for human ATC therapy.

Excessive Iodine Status among School-Age Children in Korea: A First Report.

BACKGROUND: Korea is considered an iodine sufficient country, and several studies have been conducted regarding iodine status in healthy Korean adults, pregnant women, and preschool children. However, data on iodine status in Korean school-age children are lacking. Therefore, the iodine nutrition status of Korean school-age children was investigated by measuring urine iodine concentration (UIC). METHODS: This cross-sectional study conducted between April and September 2016 comprised 373 school-age children. UIC was determined using a modified microplate method employing ammonium persulfate digestion followed by Sandell-Kolthoff reaction. RESULTS: The median UIC was 458.2 µg/L. Excessive iodine intake (>300 µg/L) was found in 286 children (76.7%), with extremely high values exceeding 1,000 µg/L in 19.6% of subjects. Insufficient iodine intake (<100 µg/L) was observed in eight children (2.1%). UIC values were not significantly different between sexes. CONCLUSION: Korean school-age children showed excessive iodine intake. Therefore, education regarding adequate iodine intake in school-age children is needed.

Biocompatible astaxanthin as a novel marine-oriented agent for dual chemo-photothermal therapy.

The photothermal effect of a marine-oriented xanthophyll carotenoid, astaxanthin (AXT), was characterized based on its potential absorption of visible laser light and conversion of optical light energy into heat for thermal treatment. As an antioxidant and anticancer agent, AXT extracted from marine material can be utilized for photothermal therapy due to its strong light absorption. The current study investigated the feasibility of the marine-based material AXT to increase the therapeutic efficacy of chemo-photothermal therapy (PTT) by assessing photothermal sessions in both cells and tumor tissues. A quasi-cw Q-switched 80 W 532 nm laser system was utilized to induce thermal necrosis in in vitro and in vivo models. An in vitro cytotoxicity study of AXT was implemented using squamous cell carcinoma (VX2) and macrophage (246.7) cell lines. In vivo PTT experiments were performed on 17 rabbits bearing VX2 tumors on their eyes that were treated with or without intratumoral injection of AXT at a dose of 100 µl (300 µg/ml) followed by laser irradiation at a low irradiance of 0.11 W/cm2. Fluorescence microscopy images revealed cellular death via apoptosis and necrosis owing to the dual chemo-photothermal effects induced by AXT. In vivo experimental results demonstrated that the AXT-assisted irradiation entailed a temperature increase by 30.4°C after tumor treatment for 4 min. The relative variations in tumor volume confirmed that the tumors treated with both AXT and laser irradiation completely disappeared 14 days after treatment, but the tumors treated under other conditions gradually grew. Due to selective light absorption, AXT-assisted laser treatment could be an effective thermal therapy for various drug-resistant cancers.

Current iodine nutrition status and awareness of iodine deficiency in tuguegarao, Philippines.

The Philippines is one of the countries where adequate iodine status has been achieved. However, iodine deficiency still remains an important public health problem in this country. In this study, we evaluated iodine nutrition status and investigated an awareness status of iodine deficiency targeting high school students of Tuguegarao, Philippines. A total of 260 students provided samples for urinary iodine analysis, among which 146 students completed thyroid volume measurement by ultrasonography and answering the questionnaires. The median urinary iodine level was 355.3 µg/L and only 3.8% of the students were in the range of iodine deficiency status according to the ICCIDD criteria. Although 62.3% of students answered that they can list problems resulting from iodine deficiency, a majority of students (70.5%) were unable to identify problems other than goiter. They did not appreciate that adequate iodine levels are important during pregnancy and for development of children. 33.6% of students answered that they did not use iodized salt and the biggest reason was that they did not find it necessary. Based on these results, we suggest that a future strategy should be focused on vulnerable groups to completely eliminate iodine deficiency, including women at their reproductive ages and during pregnancy.