This letter documents the origins of Legionella taurinensis, a newly described bacterial species. The type strain and related isolates were collected in March 1988 from an oxygen bubble humidifier in a large university hospital in Turin, Italy, where nosocomial Legionella infection had occurred. The strains were initially isolated by Dr. L. Franzin at the Infectious Diseases Institute of Turin and were first identified as Legionella spiritensis. Franzin subsequently brought the strains to the National Reference Center for Legionella in Lyon, France. Later molecular and phenotypic analysis by Lo Presti and colleagues revealed that these strains, which showed red autofluorescence under UV light and differed from L. spiritensis, represented a distinct new species. This letter clarifies the provenance and history of the type strain (Turin I no. 1T, ATCC 700508T) and associated strains that were eventually formally named Legionella taurinensis, emphasizing the clinical importance of their isolation from hospital water systems.

Key findings

• Legionella taurinensis was isolated from an oxygen bubble humidifier in a Turin university hospital during a nosocomial Legionella infection outbreak in March 1988
• The type strain was initially misidentified as Legionella spiritensis before molecular and phenotypic characterization revealed it as a new species
• The strain exhibits red autofluorescence under longwave UV light, distinguishing it from L. spiritensis
• This letter documents the complete provenance and history of the type strain designation (Turin I no. 1T, ATCC 700508T)