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Updated: Jan 24, 2026

Development and Assessment of Intracellular Infection Models for Staphylococcus aureus
Published on: January 17, 2025
Evaluation of the compact dry X-SA method for enumerating Staphylococcus aureus in artificially contaminated food
Hajime Teramura1, Shingo Mizuochi, Hidemasa Kodaka
1Nissui Pharmaceutical Co., Ltd, Ibaraki, Japan. h-teramura@yki.nissui-pharm.jp
Abstract:
Compact Dry X-SA (CD-XSA), a ready-to-use and self-diffusible dry medium sheet culture system for the detection and enumeration of Staphylococcus aureus, was evaluated. A total of 50 S. aureus strains, which were studied for the inclusivity study, grew as blue-colored colonies on the CD-XSA. When 114 bacteria other than S. aureus and 3 yeasts were inoculated for the exclusivity study, 37 strains produced white colonies, and 4 strains produced blue colonies, and 3 strains produced magenta colonies, while 73 other strains failed to grow. The CD-XSA method was compared with the mannitol salt agar with egg yolk (MSEY) method, the Baird-Parker agar (BP) method and the 3M Petrifilm(TM) STX (3M-STX) method in 105 artificially contaminated food samples. The correlation coefficients between CD-XSA and MSEY, CD-XSA and BP, and CD-XSA and 3M-STX were 0.945, 0.960 and 0.977, respectively.
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