Methylobacterium Radiotolerans Bacteremia in Hemodialysis Patients: The New Technique of Identification MALDI-TOF Mass Spectrometry

Abstract

Central venous catheter (CVC) infections represent one of the most common complications in hemodialysis patients. Understanding the risk factors that induce CVC infection and identifying the microorganisms that cause them, is essential for developing preventive strategies. Therefore, it is important to develop prophylaxis and surveillance protocols, but also to determine adequate diagnostic criteria that include the use of new laboratory tools, useful in identifying a wider range of pathogenic microorganisms. We reported a clinical case of CVC related infection caused by the gram negative Methylobacterium radiotolerans in a hemodialysis patient. Matrix-assisted laser desorption/ionizationtime of flight is a type of mass spectrometry (MALDI-TOF MS) which utilizes microbial protein mass distribution analysis, generating a signal that is decoded and represented as a peak on a Cartesian reference system. MALDI-TOF MS was fundamental in the identification of the pathogen, which remained previously unidentified using routine laboratory techniques. The use of MALDI-TOF MS has therefore allowed the pathogen's tempestive identification, accurate diagnosis and targeted antibiotic treatment, positively impacting on infection resolution, prognosis and patient survival.