Evaluation of superinfection, antimicrobial usage, and airway microbiome with metagenomic sequencing in COVID-19 patients: A cohort study in ShanghaiOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This retrospective cohort study evaluated superinfection, antimicrobial usage, and the airway microbiome in COVID-19 patients. It tested the value of metagenomic sequencing for detecting co-infecting pathogens. Metagenomic sequencing of plasma and airway samples was performed alongside conventional culture. Airway microbiome diversity was analyzed by Shannon index and compared across patient groups using metagenomic reads.
Who was studied?
The cohort was 323 laboratory-confirmed COVID-19 patients at the Shanghai Public Health Clinical Center, from January to March 2020. They were stratified as mild (229), severe (78), and critically severe (16). Metagenomic sequencing was applied to 10 critically severe cases at roughly 5-day intervals. Airway microbiome comparisons also drew on intubated and non-intubated non-COVID-19 patients as reference groups.
What were the most important findings?
Overall co-infection was 17 of 323 patients (5.3%). Rates rose across severity: 0 of 229 mild, 4 of 78 severe (5.1%), and 13 of 16 critically severe (81.3%). Klebsiella pneumoniae was the most frequently detected bacterium. Proven fungal co-infection was significantly associated with higher mortality (p=0.029). All antimicrobials and carbapenems were used in 100% and 81.3% of critically severe cases, but targeted therapy accounted for only 18.3% of antimicrobial days. The critically severe airway microbiome had low diversity and was enriched in Acinetobacter, Klebsiella, Ralstonia, and Sphingomonas.
What are the greatest implications of this study?
The findings show superinfection is common in critically ill COVID-19 patients and that fungal co-infection flags a high mortality risk needing intensive attention. Metagenomic sequencing may support more precise antimicrobial decisions than culture alone. The airway microbiome shift resembled that of intubated non-COVID-19 patients, suggesting intubation and ventilation, not the virus itself, drive it. This argues for shortening mechanical ventilation. The study is retrospective and observational, so causation is not established.