Compassionate Use of Omadacycline in a Down Syndrome Pre-Schooler With Critically Ill Atypical Pneumonia Caused by Macrolide-Resistant Mycoplasma Pneumoniae.

Background: Rapid and accurate identification of causative organisms and prompt initiation of pathogen-targeted antibiotics are crucial for managing atypical pneumonia. The widespread application of targeted next-generation sequencing (t-NGS) in clinical practice demonstrates significant targeted advantages in rapid and accurate aetiological identification and antimicrobial resistance genes detection, particularly for difficult-to-culture, rare, or unexpected pathogens. An alarming surge of acquired macrolide resistance (MR) in Case Presentation: In this case report, we present for the first time the compassionate use of omadacycline (OMC) in a Down syndrome pre-schooler with critically ill atypical pneumonia caused by macrolide-resistant MP. The treatment achieved a favourable therapeutic effect without any related adverse events (AEs) during hospitalization and follow-up. Conclusion: In clinical practice, rapid and accurate identification of causative organisms should be a priority for prompt initiation of pathogen-targeted antibiotics, in which tNGS possesses enormous potential, particularly for difficult-to-culture MP. At present, OMC is not recommended in the package insert for clinical application in pediatric patients under 8 years of age due to potential age-specific AEs on tooth colour and development as well as bone growth. The superior efficacy and safety of OMC in the management of critically ill atypical pneumonia caused by macrolide-resistant MP were comprehensively documented in this Down syndrome pre-schooler, which merits future well-designed studies to validate our findings, enhance understanding of the features of OMC, and further expand its clinical application in preschool-aged patients.