[Detection of carbapenem-producing Enterobacteriaceae by MALDI-TOF MS].

ABSTRACT

OBJECTIVE: To evaluate a rapid matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) assay in detecting carbapenemase-producing Enterobacteriaceae. METHODS: Thirty-four carbapenemase-producing Enterobacteriaceae and 50 carbapenem susceptible Enterobacteriaceae clinical isolates were tested. After a 2-hour incubation of bacteria with meropenem, the mixtures were centrifuged and the supernatants analyzed by MALDI-TOF MS. RESULTS: All spectra of carbapenem susceptible Enterobacteriaceae showed peaks of m/z 384, 406, 428 while those of carbapenemase-producing Enterobacteriaceae m/z 358, 380, 402, 424, 446, 468. And the assay of MALDI-TOF MS was highly consistent with sequencing (P = 1.000). CONCLUSION: MALDI-TOF MS can detect carbapenemase-producing Enterobacteriaceae rapidly and accurately.