Detection of Acidovorax avenae subsp. citrulli using PCR and MALDI-TOF MS

Virulent strains of Acidovorax avenae subsp. citrulli (Aac) and avenae cause bacterial fruit blotch in cucurbits and bacterial stripe in rice, respectively. Here, we describe a rapid (1 h) method to identify virulent strains of Aac using a combination of short PCR and matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Single-stranded DNA of the PCR products was analyzed by MALDI-TOF MS after digestion by an enzyme and alkali denaturation. The mass spectra differed among the strains as a result of the differences in their nucleotide sequences. This new method allows rapid identification of virulent strains of Aac.