Application of Different Sampling Methods Combined with Metagenomic Next-Generation Sequencing to Detect Pathogens in Children with Severe Pneumonia on Mechanical Ventilation.

Objective: The aim of this study was to explore the value of applying different sampling methods combined with metagenomic next-generation sequencing (mNGS) to detect pathogens in children with severe pneumonia on mechanical ventilation. Methods: Forty children with severe pneumonia on mechanical ventilation were selected, and routine endotracheal suctioning and bronchoalveolar lavage fluid (BALF) sampling methods were performed. The diagnostic efficacy of different sampling methods combined with mNGS versus traditional etiological pathogen detection strategies was compared. Results: The positive rate of mNGS pathogen detection after routine endotracheal suctioning and BALF sampling was higher than that of traditional etiological detection strategies (P < 0.05). There was no significant difference in the positive rates of pathogen detection by routine endotracheal suctioning + mNGS and BALF + mNGS (P > 0.05). Conclusion: Compared with traditional etiological detection strategies, mNGS is more efficient for diagnosing pathogens. In clinical practice, an appropriate sampling method should be selected for mNGS-based detection according to the condition of the patient. These findings could be of great importance in the diagnosis and treatment of severe pneumonia.

Application Value of Metagenomic Next-Generation Sequencing for Bloodstream Infections in Pediatric Patients Under Intensive Care.

Purpose: This study aimed to analyze the application value of metagenomic next-generation sequencing (mNGS) as a basis for the proper adjustment of the clinical treatment of bloodstream infections (BSIs) in pediatric patients under intensive care. Methods: We retrospectively enrolled 46 pediatric patients with clinically diagnosed BSIs who were hospitalized in the pediatric intensive care unit of the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University from June 2018 to July 2021. Blood samples were collected for cultivation and for mNGS detection of pathogens. Results: Among the 46 children, the average turnaround time for blood culture tests was 3.2 days, and the results revealed pathogens in three children (6.5%). The average turnaround time for mNGS was 2.2 days, and pathogens were found in 30 children (65.2%). The difference in positivity rates between blood culture and mNGS was significant (p<0.05). Blood culture tests found three pathogens, while mNGS identified 28 pathogens, indicating that mNGS detected significantly more types of pathogens than the traditional diagnostic method for pathogenic microorganisms. In some children, more than one pathogen was detected. Conclusion: mNGS can help identify pathogenic microorganisms associated with BSI in some pediatric patients under intensive care.