sp. nov., a novel pathogenic species isolated from tuberculous pleurisy patient.

INTRODUCTION

represents a group of bacteria that exhibit significant value in industrial and agricultural applications, while also posing pathogenic risks to humans. 704A1 was isolated from a patient with tuberculous pleurisy. Its 16S rRNA sequence showed the highest homology (99.72%) with a strain without defined species classification. It is necessary to clarify the species 704A1 belonging to and its potential pathogenicity to humans.

METHODS

Systematical evaluations including phenotypic and biochemical characteristics, antibiotic susceptibility, genomic sequencing were conducted. The pathogenicity and immunological characteristics were tested by intranasally inoculated C57BL/6J mice.

RESULTS

704A1 is Gram negative rod-shaped bacterium with flagella at single extreme. Showing highly similar with , 704A1 also displayed distinct characteristic peaks in fatty acid profiling and MALDI-TOF analysis. 704A1 was resistance to 21 antibiotics, including four anti-tuberculosis drugs: rifampicin, streptomycin, rifabutin, and cycloserine. The average nucleotide identity (ANI) values of 704A1 compared to defined species ranged from 80.03% to 89.6%, below than both the commonly accepted 95%-96% ANI threshold for prokaryote species and the 95% threshold suggested for . Though no mortality was observed, 704A1 could cause severe consolidation in murine lung tissue and has the ability of hematogenous dissemination.

CONCLUSION

Results supported the classification of 704A1 (=GDMCC 1.4133) as a novel species within the genus , for which the name sp. nov. is proposed. 704A1 is a multi-antibiotic resistance strain with potentially stronger pathogenicity than and requires more clinical attention. The isolation of 704A1 underscored the importance of sustained surveillance and taxonomic clarity of species emerging from clinical environments.