Comparative DNA analysis of Bordetella pertussis clinical isolates by pulsed-field gel electrophoresis, randomly amplified polymorphism DNA, and ERIC polymerase chain reaction.

We used DNA fingerprinting by pulsed-field gel electrophoresis (PFGE), randomly amplified polymorphic DNA (RAPD) and PCR amplification of enterobacterial repetitive intergenic consensus sequences (ERIC-PCR) to compare 15 clinical isolates of Bordetella pertussis recovered between August 1993 and September 1995 from 13 infants and two adults, living in the same geographic area. PFGE produced 10 patterns and made it possible to differentiate all the isolates and to indicate an intrafamilial transmission. RAPD and ERIC-PCR generated banding patterns with small differences and had a poor discriminatory power. During the last 2 years, at Armand-Troussau pediatric hospital, 10 distinct clones of clinical B. pertussis isolates, with a predominant clone including seven strains, could be determined by the PFGE method.