ARBITRARILY PRIMED POLYMERASE CHAIN-REACTION AS A RAPID METHOD TO DIFFERENTIATE CROSSED FROM INDEPENDENT PSEUDOMONAS-CEPACIA INFECTIONS IN CYSTIC-FIBROSIS PATIENTS

We used DNA fingerprinting by the arbitrarily primed polymerase chain reaction (AP-PCR) technique for an epidemiological investigation of 23 Pseudomonas cepacia isolates obtained from 11 cystic fibrosis (CF) pa tients attending our CF center. This approach was compared with riboty ping, pulsed-field gel electrophoresis (PFGE), and conventional phenot ypic typing. AP-PCR and ribotyping were identical in resolving power, since the two methods generated four different profiles and identified the same group of strains. Six patients on the one hand and four on t he other harbored strains of the same genotype, thus raising the possi bility of either patient-to-patient transmission or acquisition from a common hospital environmental source. PFGE results were in good agree ment with those of the other two methods, but PFGE seems more discrimi native since it generated a fifth profile for a single strain in a gro up of four. Our results show in vivo stability for the three methods d uring a period extending from 3 to 41 months. These genotypic techniqu es are particularly promising for clinical laboratories to help to cla rify the epidemiology of P. cepacia in CF patients. The AP-PCR method constitutes an easier alternative to the well-established ribotyping m ethod. AP-PCR provides the quickest results with minimal technical com plexity. However, our results suggest that it is less discriminative t han the labor-intensive PFGE method.