Fig. 3

The metagenomic next-generation sequencing of the bronchoalveolar lavage fluid showing positive results for L. pneumophila and A. baumannii. The sequence read refers to the number of specific sequences that can be uniquely matched to a certain bacterial genus or species. The relative abundance refers to the proportion of a certain microbial genus or species in the microorganisms detected in the entire specimen. A high abundance corresponds to a great proportion of certain bacteria. The Q index refers to the content of different microbial nucleic acids in the specimen, which is calculated through the measured value of the internal standard molecule. A high Q index corresponds to a high microbial content and a high accuracy in pathogen detection