Epidemiological typing of Stenotrophomonas (Xanthomonas) maltophilia by PCR.

We used two PCR methods for epidemiological typing of Stenotrophomonas (Xanthomonas) maltophilia with either arbitrary primers (random amplified polymorphic DNA) or enterobacterial repetitive intergenic consensus sequences as primers (ERIC-PCR). The analysis was performed with 38 isolates of S. maltophilia, comprising 9 nosocomial isolates from a burn unit, 20 other clinical isolates epidemiologically unrelated, and 9 isolates from one cystic fibrosis patient. Both methods indicated that all of the nosocomial episodes were independent. In contrast, the nine isolates from the cystic fibrosis patient were assigned to very closely related profiles, especially by ERIC-PCR. We conclude that random amplified polymorphic DNA and ERIC-PCR have comparable reproducible and discriminatory powers for epidemiological typing of S. maltophilia, but ERIC-PCR profiles can be more easily evaluated.