Usefulness of MALDI-TOF mass spectrometry in epidemiological control of etiologic agents of infection

Introduction: The use of the MALDI-TOF mass spectrometry in the routine of microbiological diagnostics has revolutionized procedures and response times of bacteriology.The use of this technique aims to epidemiological investigations in a hospital environment and represents a further significant opportunity, quickly feasible and extremely economical. Methods: By means of the MALDI-TOF-MS Vitek2 (MS Vitek2) mass spectrometer, accompanied by the AgnosTec-SARAMIS (bioMérieux, France) software, were analyzed the spectra of 149 bacterial isolates (139 Staphylococcus aureus and 10 Staphylococcus epidermidis) obtained from cultures of 148 patients (141 inpatients and 7 outpatients). Clinical isolates were stored at a temperature of -20°C.The isolates were then thawed and immediately cultured on agar blood medium. The colonies were subjected to analysis by MS Vitek on the day after sowing. The spectra obtained were analyzed and compared using the software AgnosTec-SARAMIS, which allowed the construction of a dendrogram. Results and conclusions: The evaluation of the data collected suggests that mass spectrometry could be an useful tool in epidemiological surveys. Speed of analysis and low costs make the MS Vitek2 an usable tool by many microbiology laboratories.