Fig. 1

Study flowchart. Representation of each step of the study, recruited participants included healthy controls and patients with suspected bacterial infections. Patients with suspected bacterial infections were divided based on bacterial culture results, including culture-negative patients, respiratory tract infected patients, and bloodstream infected patients. The bloodstream infected patients were further divided into Simple Bloodstream Infection Subgroup and Mixed Bloodstream Infection Subgroup, based on sputum culture results. All infected patients and 10 patients with negative bacterial cultures were followed up after receiving antibiotic therapy