Bacteraemia due to Comamonas kerstersii of unknown origin in a patient with decompensated liver cirrhosis and type 2 diabetes mellitus

<i>Comamonas kerstersii</i> is an emerging opportunistic pathogen in immunocompromised patients, particularly those with liver cirrhosis or diabetes, who present with bacteraemia of unknown origin after the exclusion of common pathogens.Matrix-assisted laser desorption/ionisation-time of flight mass spectrometry enables precise identification of <i>C. kerstersii.</i> Conventional automated systems may misidentify it as <i>C. testosteroni</i>, potentially leading to inappropriate therapy and missed diagnoses.In decompensated liver cirrhosis, <i>C. kerstersii</i> bacteraemia may result from bacterial translocation across the impaired intestinal barrier, rather than typical intra-abdominal sources, highlighting a novel pathogenic mechanism.