To avoid misinterpretations one should substitute the ambiguous notion of 'new disease' with 'emerging disease'. A disease can be classified emergent in at least five dif férent historical situations; 1) it existed before it could be first identified but was overlooked from a médical point of view because it could not be conceptualized as a nosological entity; 2) it existed but was not noticed until a quantitative and/or qualitative change in its mani festations; 3) it did not exist in a (...) particular région of the world before its introduction from other régions; 4) it never existed in a human population but only in an animal population; 5) it is completely new - the triggering germ and/or necessary environmental conditions did not exist prior to the first clinical manifestations. A sériés of historical examples illustrate this classification. (shrink)

Antibiotic development and usage, and antibiotic resistance in particular, are today considered global concerns, simultaneously mandating local and global perspectives and actions. Yet such global considerations have not always been part of antibiotic policy formation, and those who attempt to formulate a globally coordinated response to antibiotic resistance will need to confront a history of heterogeneous, often uncoordinated, and at times conflicting reform efforts, whose legacies remain apparent today. Historical analysis permits us to highlight such entrenched trends and processes, helping (...) to frame contemporary efforts to improve access, conservation and innovation. (shrink)

To avoid misinterpretations one should substitute the ambiguous notion of 'new disease' with 'emerging disease'. A disease can be classified emergent in at least five different historical situations; 1) it existed before it could be first identified but was overlooked from a medical point of view because it could not be conceptualized as a nosological entity; 2) it existed but was not noticed until a quantitative and/or qualitative change in its manifestations; 3) it did not exist in a particular region (...) of the world before its introduction from other regions; 4) it never existed in a human population but only in an animal population; 5) it is completely new — the triggering germ and/or necessary environmental conditions did not exist prior to the first clinical manifestations. A series of historical examples illustrate this classification. (shrink)

Plasmids are non-chromosomal hereditary determinants, mostly found in prokaryotes. Whereas Joshua Lederberg coined the term "plasmid" as early as 1952, today's concept was not established until the early 1970s. In this eclipse period, the plasmid's place was taken by the episome, following the 1958 publication of Elie Wollman and François Jacob. This paper analyzes the transition from the episome to a renewed plasmid concept both on the experimental and the conceptual level. It will become clear that intergeneric transfer experiments were (...) central to this development. These studies rely on conjugational transfer of extrachromosomal hereditary determinants between different bacterial genera. First, experimental systems employing intergeneric transfer shaped the new plasmid by enabling its representation as a species of circular DNA. Moreover, they had a destabilizing effect on the episome, leading to a crisis in the concepts of microbial genetics towards the end of the 1960s. The new plasmid then became one of the cornerstones of recombinant DNA technologies. In an historic perspective, intergeneric transfer experiments indicate a gradual transition of molecular biology from its early "analytic" to the "synthetic" phase of genetic engineering. Hence, the construction of genetic hybrids in vivo as epitomized in the studies shown here marks an intermediate state that one could designate as "recombinant DNA avant la lettre.". (shrink)