A Line Full of Lessons: A “Sake Lees”-Like Mass Revealing Bacillus cereus Contamination in an Amino Acid Infusion

<i>Bacillus cereus</i> (<i>B. cereus</i>) is a known cause of catheter-related bloodstream infections (CRBSIs) in healthcare settings, with increased risk observed in immunocompromised patients and those receiving amino acid-based parenteral nutrition. This condition is typically identified by local signs at the catheter insertion site and positive blood cultures. We report a case of an elderly hospitalized patient in whom an unusual visual finding, whitish, turbid, "sake-lees"-like crystalline aggregates within the infusion line, contributed to the diagnosis of <i>B. cereus</i>-associated CRBSIs. This case underscores the potential routes of <i>B. cereus</i> contamination in the medical environment and highlights the importance of rigorous infection control practices during infusion preparation and catheter-related procedures for hospitalized patients.