Development of a PCR assay for the detection of Clavibacter michiganensis subsp. michiganensis

Clavibacter michiganensis subsp. michiganensis is a seed-borne bacterium listed as an A 3 pest in China. A pair of primers ClaF1-ClaR2 was deduced and a PCR protocol was developed for Clavibacter michiganensis subsp. michiganensis-specific amplification of a 250 bp ITS(intergenic spacer region)fragment when Cmm genomic DNA was used as template. No DNA was amplified from phenotypically related bacteria, including species of Curtobacterium, Arthrobacter, Rathayibacter, Rhodococcus and pathovars of Clavibacter and other pathogenic bacteria by the same primers. The PCR assay was proved to be sensitive for detection of Cmm sufficiently in 50 pg template DNA or 1×10~5 cfu strains. It was demonstrated to be a highly sensitive, specific and rapid PCR assay for the detection of Cmm.