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

## TL;DR

A new thermotolerant Tepidimonas species was found in respiratory samples from Hong Kong, potentially linked to undiagnosed respiratory infections.

## Contribution

Discovery of a novel Tepidimonas species, Tepidimonas hongkongensis, in human respiratory specimens.

## Key findings

- 58 specimens from 57 patients grew thermotolerant bacteria not identified by other methods.
- 42 isolates were identified as Tepidimonas spp., including a novel species tentatively named Tepidimonas hongkongensis.
- T. hongkongensis was detected in hospital water samples, suggesting possible colonization.

## Abstract

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.