Detection of Novel Thermotolerant Tepidimonas sp. Bacteria in Human Respiratory Specimens, Hong Kong, China, 2024.

In patients with acute respiratory infections (ARIs), routine diagnostic tests often fail to identify the microbial cause; thus, many ARIs have undetermined etiology. We investigated potential involvement of thermotolerant bacteria in ARIs among patients in Hong Kong, China, by incubating blood agar inoculated with respiratory specimens at 50°C for 5 days. Among 7,257 specimens analyzed, 58 specimens from 57 patients grew thermotolerant bacteria not identified by other methods. We identified Tepidimonas spp. in 42 isolates, 3 of which appear to be a novel Tepidimonas species (tentatively Tepidimonas hongkongensis sp. nov). Genomic analysis revealed various virulence, resistance, and stress-related genomes in the 3 isolates. Tepidimonas spp. bacteria were predominantly isolated from patients with chronic lung disease and malignancies. We also detected T. hongkongensis in hospital water samples but at a lower percentage than in respiratory specimens, suggesting colonization potential. Clinical implications of T. hongkongensis remain unknown; continued surveillance could determine its role in ARIs.