Trimethoprim resistance; epidemiology and molecular aspects: --a review based upon a Symposium held on 19 April 1989 at the 4th European Congress of Clinical Microbiology, Nice, France

Abstract

Introduction Trimethoprim resistance was first recognised in gram-negative bacteria 20 years ago. Workers in several research centres have studied the epidemiology and molecular aspects of trimethoprim resistance over the intervening years, initially in gram-negative bacteria and more recently in gram-positive bacteria. The introduction of this completely novel synthetic antimicrobial provided a unique opportunity to study the full evolution of bacterial resistance to an antimicrobial drug, without the pre-existing influence of resistance genes selected by other related compounds. Consequently, the model provided by trimethoprim resistance has considerable relevance to our understanding of the evolution of bacterial resistance to antimicrobial agents in general. Recent years have seen exciting and major advances in the use of modern DNA technology to study the epidemiology of trimethoprim resistance. Considerable progress has been made in evaluating the importance of the different resistance mechanisms, especially those carried by resistance plasmids. Nevertheless, in most countries resistance to trimethoprim has only recently reached clinically significant proportions and it remains a widely used and valuable component of the antimicrobial armamentarium. The papers presented in this review are based on a Symposium held at the 4th European Congress of Clinical Microbiology in April 1989. The Symposium provided a forum for the various aspects of trimethoprim resistance to be brought together and resulted in the collation of research material which forms this review.