Multiplex PCR assay to identify Pseudomonas grimontii and P. marginalis simultaneously

A multiplex colony-direct PCR method was developed to identify Pseudomonas grimontii and P. marginalis simultaneously. Species-specific primer sets were designed based on the sequences of the rpoD or rpoB genes. The universal primer set for the 16S rRNA gene, chosen as an internal control, was also added to the PCR mixture to avoid incorrect judgement due to false negatives. By this method, two DNA fragments, one from the species-specific amplifications and the other from the 16S rRNA gene, were stably obtained from the strains belonging to the targeted species, showing that this method is useful for their identification.