Book excerpt: This book resulted from presentations at an international conference on bacterial p1asmids held January 5-9, 1981 in Santo Domingo, Dominican Republic. This was the first meeting of its kind in the Southern Hemisphere. The meeting place was selected for its relaxed and comfortable climate, conducive to interactions among participants. More importantly the locale facilitated the participation of nearby Latin American clinical and research scientists who deal directly with the health manifestations of pathogenic p1asmids. Diseases and socio-economic practices of developing countries exist in the Dominican Republic whose scientific community could directly benefit from having the meeting there. The book includes the talks as well as extended abstracts of poster presentations from the meeting. This combination, which provides readers with reviews as well as recent findings, captures the full scientific exchange which took place during the 5-day meeting. As one indication of pathogenicity related to p1asmids, the conferees were surveyed for gastro-intestina1 problems during and after their stay in the Dominican Republic. The results are summarized at the end of this book.