Evaluation of MALDI-TOF MS System for the Identification and Differentiation of Burkholderia cepacia Complex Species

Abstract

To evaluate the performance of MALDI-TOF MS system as a tool for identification and differentiation of Burkholderia cenocepacia from other species of Burkholderia cepacia complex (Bcc). Fiftythree suggestive colonies were submitted to the MALDI-TOF Microflex LT 4.0® (Bruker Daltonik, Bremen, Germany) system for identification. We compared two protocols of protein extraction: (A) Direct Method and (B) Tube Extraction. In parallel, all isolates were subjected to molecular diagnosis (primers for recA gene) to identify species belonging to Bcc and to differentiate B. cenocepacia in genomovar IIIA or IIIB. MALDI-TOF was able to identify all isolates to the genus level and 94.3% (50/53) to species using both methods. The MALDI-TOF system was able to identify 38 out of the 40 isolates identified as B. cenocepacia by molecular techniques. In conclusion, MALDI-TOF Microflex LT 4.0® is a feasible technique and presents a low cost of reagents; it can be used for the reliable differentiation of B. cenocepacia from other species of Bcc.