Strain, clone and species: comments on three basic concepts of bacteriology DIJKSHOORN, L. and URSING, B.M. and URSING, J.B.,, 49, 397-401 (2000), doi = https://doi.org/10.1099/0022-1317-49-5-397, publicationName = Microbiology Society, issn = 0022-2615, abstract= Different aspects of the terms strain, clone and species are discussed. The term strain is commonly used to denote a pure culture – here called ‘the strain in the taxonomic sense’ – but does also refer to a natural concept closely related to the clone. The term clone on the other hand is used both in a general and in a more restricted sense, the latter indicating a low degree of genetic exchange. The important distinction between the definition of a species and the criteria for a species is emphasised and the main kinds of criteria are considered. , language=, type=