The ICSP, formerly the International Committee on Systematic Bacteriology (ICSB), is a committee of appointed representatives from the national microbiological societies and co-opted members that oversees the nomenclature of prokaryotes, determines the rules by which prokaryotes are named, as documented in the International Code of Nomenclature of Prokaryotes (ICNP), and supervises the publishing of the International Journal of Systematic and Evolutionary Microbiology (IJSEM). More details of the functions of the ICSP are given in Article 3 of our Statutes. ICSP is a committee under the Bacteriology and Applied Microbiology Division of the International Union of Microbiological Societies (IUMS). The Judicial Commission of the ICSP issues Opinions concerning matters related to the interpretation of the ICNP.

In the 19th century and the first half of the 20th century, bacteriologists followed the provisions of the Botanical Code of Nomenclature, because bacteria had traditionally been considered to be fungi, i.e., the Schizomycetes. However, the methods of study were very different for plants and bacteria. In bacteriology, emphasis was put on cultural characteristics and viable cultures for nomenclatural type material. Type cultures are not permitted under the Botanical Code; therefore, at the First International Congress of Microbiology in Paris in 1930, proposals were made for bacteriology to establish its own Code of Nomenclature. A committee under the guidance of the American bacteriologist R. E. Buchanan began work on this and, at the Second Congress in London in 1936, a draft Code was presented and placed under the aegis of the International Committee for Bacteriological Nomenclature [later, the International Committee on Systematic Bacteriology (ICSB), and now, the ICSP]. Buchanan condensed the provisions for nomenclature into a few broad principles that are still valid today. Editions of the International Code of Nomenclature of Bacteria (ICNB), latterly, the International Code of Nomenclature of Prokaryotes (ICNP), were issued in 1958, 1975, 1990 and 2019. A new edition is due for publication in late 2022.


ICSP Chairman:  Iain Sutcliffe, PhD, Professor of Microbiology. Faculty of Health & Life Sciences, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK.

ICSP Executive Secretary:  Aharon Oren, PhD, Professor of Microbial Ecology.Institute of Life Sciences, The Hebrew University of Jerusalem, 9190401 Jerusalem, Israel. Phone: +972-2-65-84951.

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See a pre-publication (pre-print) of the 2022 revised version of the ICNP (download document)
Until published, this preprint version should be used when referencing the ICNP.

Note:  The pre-print revised version of the ICNP has been uploaded to Zenodo – see:


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