COMPARISON OF 6 DIFFERENT METHODS FOR TYPING PSEUDOMONAS-AERUGINOSA STRAINS ISOLATED FROM BOTTLED AND WELL WATERS

Twenty-three strains of Pseudomonas aeruginosa isolated from bottled a nd well waters were biotyped, serotyped and examined by antimicrobial susceptibility, plasmid content, analysis of chromosomal DNA EcoRI rib opatterns (ribotyping) and by a PCR-based procedure. Phenotypic method s showed poor discrimination power between strains, and plasmids were detected in 29% of isolates. Southern blot hybridisation analysis show ed genetic diversity between isolates, and six different ribotypes wer e defined. Arbitrarily primed polymerase chain reaction (AP-PCR) analy sis also differentiated between the strains with higher discriminatory power than ribotyping, since 13 different profiles were obtained. Bot h DNA-based methods are valuable alternatives to traditional typing sy stems for P. aeruginosa, and AP-PCR could be particularly useful for e pidemiological studies. (C) 1997 Elsevier Science Ltd.