Ability of the MeltPro MTB/PZA Assay to Detect Susceptibility to Pyrazinamide in Rifampin-Resistant Tuberculosis Patients.

Prediction of susceptibility to pyrazinamide (PZA) directly from sputum has been challenging. The MeltPro MTB/PZA assay, based on melting curve analysis, can simultaneously detect Mycobacterium tuberculosis and the resistance to PZA from sputum. We aimed to evaluate the MeltPro MTB/PZA assay to predict PZA resistance among rifampin-resistant tuberculosis (RR-TB) patients. We prospectively enrolled RR-TB patients in the registered trials, and their baseline sputum samples were obtained to perform the assay and culture. DNA sequencing of culture isolates was analyzed and used as the reference standard. Sanger sequencing was performed for samples with discrepant results between next-generation sequencing (NGS) and the investigational assay. The main analysis was conducted in the population of patients with interpretable results by both NGS and the assay. A total of 239 patients with RR-TB were screened, and 220 underwent the MeltPro MTB/PZA assay. The assay provided no information for 25 of 220 patients (11.4%). Among the remaining 195 patients, 13 had negative culture or insufficient raw NGS sequencing data, and 15 had indeterminate assay results. A total of 167 patients were included in the main analysis. Against DNA sequencing, the sensitivity, specificity, and negative predictive value of the assay for detecting resistance to PZA were 91.4% (95% confidence interval [CI], 87.1% to 95.6%), 89.9% (95% CI, 85.3% to 94.5%), and 95.2% (95% CI, 91.9% to 98.4%), respectively. In conclusion, the MeltPro MTB/PZA assay is a fast semiautomatic molecular platform to rapidly predict resistance to PZA from sputum and holds promise as a screening tool with satisfactory sensitivity. IMPORTANCE This study evaluated the accuracy of the MeltPro MTB/PZA assay at detecting the presence of PZA resistance through registered clinical trials. Compared to DNA sequencing, the assay had high sensitivity and negative predictive value, suggesting its potential utility as a screening tool in clinical practice. The assay could serve as an ideal primary screening tool in low PZA-resistant M. tuberculosis prevalence settings and could be used as an additional test to identify PZA resistance rapidly and initially in the RR-TB population.

Clinical remission of a critically ill COVID-19 patient treated by human umbilical cord mesenchymal stem cells: A case report.

RATIONALE: The COVID-19 cases increased very fast in January and February 2020. The mortality among critically ill patients, especially the elder ones, is relatively high. Considering many patients died of severe inflammation response, it is urgent to develop effective therapeutic strategies for these patients. The human umbilical cord mesenchymal stem cells (hUCMSCs) have shown good capabilities to modulate the immune response and repair the injured tissue. Therefore, investigating the potential of hUCMSCs to the treatment of COVID-19 critically ill patients is necessary. PATIENT CONCERNS: A 65-year-old woman felt fatigued and had a fever with body temperature of 38.2C, coughed up white foaming sputum. After 1 day, she had chest tightness with SPO2 of 81%, and blood pressure of 160/91 mm Hg. DIAGNOSE: According to the guideline for the diagnosis and treatment of 2019 novel coronavirus infected pneumonia (Trial 4th Edition), COVID-19 was diagnosed, based on the real-time RT-PCR test of SARS-CoV-2. INTERVENTIONS: After regular treatment for 12 days, the inflammation symptom of the patient was still very severe and the potential side effects of corticosteroid were observed. Then, allogenic hUCMSCs were given 3 times (5 × 10 cells each time) with a 3-day interval, together with thymosin α1 and antibiotics daily injection. OUTCOMES: After these treatments, most of the laboratory indexes and CT images showed remission of the inflammation symptom. The patient was subsequently transferred out of ICU, and the throat swabs test reported negative 4 days later. LESSONS: These results indicated the clinical outcome and good tolerance of allogenic hUCMSCs transfer.