Rapid detection of Mycobacterium tuberculosis cultures by direct ambient corona discharge ionization mass spectrometry of volatile metabolites

Abstract

The effective control of tuberculosis (TB) heavily relies on global population screening, but the current diagnostic routines cannot fully meet the demanded specificity and speed of TB recognition. Here we report on the detection Mycobacterium tuberculosis (MTB), which is the primary cause of TB infection, using ambient corona discharge ionization mass spectrometry analysis of volatile organic compounds (VOCs) emitted by bacterial cultures. For the initial MTB inoculum of 10⁴ colony-forming units (CFU) per mL, highly specific differential volatile metabolites of MTB, such as methyl nicotinate and benzoic acid, 4-methoxy-, methyl ester, could be detected after 15–20 days of incubation (Löwenstein–Jensen medium). The throughput of analysis was ca. 3 samples per minute, which is much faster than in traditional techniques. Overall, our results indicate the high suitability of ambient corona discharge ionization mass spectrometry for the rapid and cost-efficient TB screening using commonly available MS instrumentation.