Detection of Fluoroquinolone Resistance Single-Nucleotide Polymorphisms in Neisseria gonorrhoeae gyrA and parC Using MALDI-TOF Mass Spectrometry

Many known mechanisms of drug resistance in microorganisms have genetic markers, which are specific genomic changes, mostly single-nucleotide polymorphisms (SNPs). A search for new methods of detecting SNPs is necessary for more efficient identification of resistant strains. A new method was proposed for SNP detection on the basis of minisequencing and/or sequencing with subsequent matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. The method was tested with a set of Neisseria gonorrhoeae clinical isolates in experiments on detecting the gyrA and parC SNPs that are markers of fluoroquinolone resistance. The results fully coincided with data previously obtained by gold-standard methods (sequencing and gel electrophoresis of sequencing products). Sequencing of short DNA fragments with MALDI-TOF mass spectrometry is of special interest. The new method considerably improves the efficiency of identification and genotyping of microorganisms and determination of their drug resistance markers.