[Metagenomic Sequencing for Pathogens Detection in a Critically Ill Patient].

OBJECTIVE: To detect pathogens in a critically ill patient using metagenomic sequencing. METHODS: A critically ill patient with severe acute pancreatitis suffered from abdominal pain and progressed into unconsciousness. Tissue smear, culture, automated biochemical identification and antibiotic susceptibility test, viral load determination by real-time fluorescence quantitative PCR, and immunohistochemical pathological tests were performed to detect pathogens, in addition to metagenomic sequencing based on the BGISEQ-100 high throughput sequencing platform. The sequences exclusive of host sequences were searched in the microbial genome database including viruses, bacteria, fungi and parasites. RESULTS: The patient was infected with methicillin-resistant Staphylococcus aureus, carbapenem-resistant Klebsiella pneumoniae and carbapenem-resistant Acinetobacter baumannii, verified by both the routine methods and the metagenomic sequencing. The metagenomic sequencing also detected cytomegalovirus (CMV) with a turn-around time of 5 days. Real-time fluorescent quantitative PCR confirmed 189 000 copies/mL CMV load. CONCLUSION: In this case, three species of bacteria and one virus were detected by metagenomic sequencing quickly and accurately. Metagenomic sequencing may be helpful for diagnosing infectious diseases in critically ill patients.