ARBITRARY PRIMED PCR FINGERPRINTING AND SEROTYPING OF CLINICAL PSEUDOMONAS-AERUGINOSA STRAINS

Arbitrary primed PCR (AP-PCR) analysis was compared with serotyping as a means of high-resolution typing of Pseudomonas aeruginosa. Seventy- four isolates from 3 different hospitals and 18 reference strains were studied. Serotyping provided good index of discrimination, although e leven isolates could not be serotyped. Genomic DNA was amplified with a single 10 nucleotide primer (sequence 5'-AGG GGT CTT G-3'). The stra ins were genetically diverse and 61 different AP-PCR profiles of 2-7 b ands between 0.3 and 2.4 kb were obtained. AP-PCR profiles were not co nsistently associated with serotypes, but they clearly subtyped strain s of the same serotype. Numerical analysis of AP-PCR patterns defined 7 groups at the 55% similarity level, and identified predominant strai ns in each hospital. The results show that AP-PCR analysis provides a simple and practical approach to typing P. aeruginosa that is more dis criminatory than traditional serotyping scheme. We suggest that maximu m discrimination can be achieved by a combination of both methods.