Resistance Factors and Their Ecological Importance to Bacteria and to Man

Abstract

This chapter explores how man has made the production of antibacterial substances into a multimillion dollar concern; and the selection pressure that this effort exerts on the bacterial population is immense—particularly in certain niches important to man. Transferable antibiotic resistance is merely one example of a general phenomenon, but its study may show the nature of the steps involved in this process and thereby how to mitigate it. Spread certainly occurs: and it frequently goes a great way to undermine the value of new therapeutic agents. The chapter examines the aspects of bacterial genetics and biochemistry that are relevant to the survival and transmission of antibiotic resistance genes between bacterial cells. The chapter discusses the nature and processes associated with the survival and transfer of R-factors and other plasmids in bacteria. The chapter also examines certain examples claiming to show the importance of R-factor-mediated transfer of antibiotic resistance genes during the course of a clinical infection, and try to assess how widespread this process is and how serious in a clinical context. The chapter emphasizes on the aspects of R-factor behavior that have most importance from the ecological point of view and also focuses on the molecular basis of the process.