Matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of bacteria isolated from pharmaceutical clean rooms.

Introduction: During the manufacturing of sterile drugs, it is of the utmost importance to meet the minimum requirements for asepsis recommended by the legislations on good manufacturing practices-based efficient environmental monitoring.

Aims and methods: The availability of relatively simple to use matrix-assisted laser desorption ionization-time of flight mass spectromtomy (MALDI-TOF MS) devices in the last years has changed the laboratory workflows for the microbial identification, mainly in the clinical area. Thus, the objective of this work was to evaluate the suitability of the MALDI-TOF MS technique for the identification of bacteria isolated from the environment of clean rooms used in some stages of the production of a viral vaccine. Eighteen known bacterial species commonly isolated from clean rooms studied were identified by MALDI-TOF technique and by a biochemical technique (BBL Crystal^® System).

Results: Performance of MALDI-TOF MS was better than biochemical technique for correct species identifications (88.89% and 38.89%, respectively) and produced less unreliable identification (5.55% and 22.22%).

Conclusion: MALDI-TOF MS can be implemented for routine identification of bacteria in a pharmaceutical quality control laboratory, but as a database-dependent system, maybe some isolated not identified by this technique must be additionally studied and, if appropriate, added to an in-house database.