Improving the Diagnosis of Bloodstream Infections: PCR Coupled with Mass Spectrometry

Jordana-Lluch, Elena; Giménez, Montserrat; Quesada, M. Dolores; Ausina, Vicente; Martró, Elisa

Since its original description by the team of Ibis Biosciences, the PCR/ESI-MS technology has been continuously evolving. The first instrument, named TIGER (for Triangulation Identification for the Genetic Evaluation of Risk) [31] , was initially designed for biodefense and surveillance applications, due to its capability to identify previously unknown and unculturable microorganisms. Shortly after, a commercial version of this technology appeared, the Ibis T5000 [17, 30] . In this format, the sample processing was automated and a software system permitted management of the instrumentation, signal analysis, and report generation. This version of the instrument was intended to be used in health and industry settings; it provided highly sensitive detection without the need for a highly trained operator. With the incorporation of Ibis Biosciences into the Abbott group, the system was upgraded [29] . This system, the PLEX-ID, was used in the aforementioned studies [21, 22, 32, 33, 35] . Recently, a newer version has been developed with improvements focused on the analysis of direct patient specimens. One of the principal changes is the use of a larger volume of blood (5 mL) in order to increase sensitivity. Changes in the extraction process allow BioMed Research International 5 A PCR/ESI-MS assay is able to differentiate species in the Mycobacterium tuberculosis complex and classify these species based on drug resistance [38, 39] . This technology has also proved its usefulness for epidemiological proposes, given that it enables molecular genotyping [40] . For instance, genotyping of Staphylococcus aureus [41, 42] , Acinetobacter baumannii [43] [44] [45] , and respiratory pathogens [46, 47] [50] [51] [52] . Moreover, this technology shows a great promise for the global surveillance of influenza virus [53] [54] [55] . Remarkably, it was able to detect the novel H1N1 strain during the 2009 influenza virus outbreak without any modification in the Influenza Surveillance Assay (Ibis Biosciences, Carlsbad, CA, USA) [56] .