Retrospective Analysis of Staphylococcus argenteus Isolated from Food-Related Specimens in Nagoya

Area of Science:

• Microbiology
• Bacteriology
• Food Safety

Background:

• Staphylococcus argenteus, identified as a novel species in 2015, is distinct from Staphylococcus aureus.
• The historical prevalence and distribution of S. argenteus, particularly in food environments, remain largely uncharacterized.

Purpose of the Study:

• To investigate the historical presence and genetic diversity of Staphylococcus argenteus in food-related environments.
• To determine the timeline of S. argenteus dissemination in Nagoya City from 1986 to 2022.

Main Methods:

• Re-examination of 1,021 staphylococcal isolates from food specimens collected between 1986 and 2022.
• Identification using MALDI-TOF MS and confirmation through multilocus sequence typing (MLST).

Main Results:

• Sixty-five isolates (6.4%) were identified as S. argenteus, with the earliest detection in 1986.
• ST2854 was the most prevalent sequence type; clinically relevant ST1223 and ST2250 were detected since the 1990s.
• Genetically diverse S. argenteus strains, including novel sequence types, have been present in food environments since the 1980s.

Conclusions:

• Staphylococcus argenteus was disseminated in food-related environments in Nagoya City by the 1980s.
• Improvements in MALDI-TOF MS have enhanced S. argenteus identification in recent years.
• The long-term presence of diverse S. argenteus strains necessitates continued monitoring in food settings.