A Case of Septic Shock Following Catheter-related Infection Caused by Lactococcus lactis subsp. lactis in an Adult

ABSTRACT

Lactococcus lactis is a gram-positive cocci used extensively in the dairy industry, but considered an unusual pathogen in humans. Among its five subspecies, L. lactis subsp. lactis in particular has rarely been reported as a pathogen. We report a case of septic shock caused by L. lactis subsp. lactis in an adult patient. A 64-yr-old male patient was admitted to outpatient clinics, with chief complaints of fever and chills for one week after convalescent hospital admission. He had severe ileus requiring surgery. He had a peripherally inserted central catheter from convalescent hospital, which was immediately removed. From two sets of blood and catheter tip cultures, we identified L. lactis subsp. lactis using the Vitek 2 system (bioMerieux Inc., USA), and confirmed this result by 16S rRNA sequencing. The patient was empirically treated with ciprofloxacin, and he recovered and was discharged.