Contents:

I. Epidemiology of R-Factors.- a) The Incidence and Ecology of R-Factors in Different Environments.- Evolutionary Aspects of Plasmid Mediated Resistance in a Hospital Environment.- The Geographical Predominance of Resistance Transfer Systems of Various Compatibility Groups in Salmonellae.- Effect of an Antibiotic-Supplemented Feed on the Ecology of E. coli on a Farm.- The Survival of R-Plasmids in the Absence of Antibiotic Selection Pressure.- b) Molecular Factors Responsible For the Spread of R-Factors (Transposons).- Limitations on the Transposition of TnA.- Transposable Neomycin Phosphotransferases.- The Transposition of Ampicillin Resistance: Nature of Ampicillin Resistant Haemophilus influenzae and Neisseria gonorrhoeae.- Properties of DNA Insertion Elements of E. coli.- Studies on IS DNA.- II. Molecular and Biochemical Aspects.- a) Phenotypic Effects of R-Factor Genes.- The Coding of Small RNA Molecules by the Resistance Factor R 1.- Evolutional Process of the Formation of Multiple Resistance Plasmids.- Plasmid-Mediated Tetracycline Resistance in E. coli.- What is the Mechanism of Plasmid-Determined Resistance to Aminoglycoside Antibiotics?.- Effect of Plasmids on Cell Division and on the Cell Envelope of Escherichia coli.- b) Metabolism of R-Factor DNA.- Molecular Cloning of DNA From the R-Plasmid R6K.- Dissociation and Recombination of Fragments with Defined Functions of the Antibiotic Resistance Factor R1.- The Molecular Nature of R-Factors in Different Bacterial Hosts.- Copy Mutants of the Plasmid R1 as a Tool in Studies of Control of Plasmid Replication.- III. Round Table Discussion.- a) Measures Against the Spread of R-Factors.- b) Possible Pharmaceutical Approaches to the Control of R-Factors.- List of Participants.- List of Authors.