Direct identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) from positive blood culture bottles: An opportunity to customize growth conditions for fastidious organisms causing bloodstream infections

• Published in: Indian journal of medical research (New Delhi, India : 1994) Vol. 146; no. 4; pp. 541 - 544
• Main Authors: Sharma, Megha, Gautam, Vikas, Mahajan, Monika, Rana, Sudesh, Majumdar, Manasi, Ray, Pallab
• Format: Journal Article
• Language: English
• Published: India Wolters Kluwer India Pvt. Ltd 01.10.2017; Medknow Publications and Media Pvt. Ltd; Medknow Publications & Media Pvt. Ltd; Medknow Publications & Media Pvt Ltd
• Subjects: Antibiotics; Bacteremia; Bacteria; Blood culture; Causes of; Health aspects; Identification; Identification and classification; Ions; Laboratories; Mass spectrometry; Methods; Microbiology; Mortality; Organisms; Original; Scientific imaging; Sepsis; Studies; United States > US; Germany; India; Culture-negative bacteraemia - fastidious organisms - MALDI-TOF MS
• ISSN: 0971-5916
• DOI: 10.4103/ijmr.IJMR_823_16

Culture-negative bacteraemia has been an enigmatic entity with respect to its aetiological agents. In an attempt to actively identify those positive blood cultures that escape isolation and detection on routine workflow, an additional step of MALDI-TOF MS (matrix-assisted laser desorption ionization-time of flight mass spectrometry) based detection was carried out directly from the flagged blood culture bottles. Blood samples from 200 blood culture bottles that beeped positive with automated (BACTEC) system and showed no growth of organism on routine culture media, were subjected to analysis by MALDI-TOF MS. Forty seven of the 200 (23.5%) bacterial aetiology could be established by bottle-based method. Based on these results, growth on culture medium could be achieved for the isolates by providing special growth conditions to the fastidious organisms. Direct identification by MALDI-TOF MS from BACTEC-positive bottles provided an opportunity to isolate those fastidious organisms that failed to grow on routine culture medium by providing them with necessary alterations in growth environment.