The International Committee on Systematics of Prokaryotes (ICSP), formerly the International Committee on Systematic Bacteriology (ICSB), is a committee of appointed representatives from national microbiological societies and co-opted Life members that assesses the nomenclature of prokaryotes, determines the rules by which prokaryotes are named, as documented in the International Code of Nomenclature of Prokaryotes (ICNP), and oversees the publishing of the International Journal of Systematic and Evolutionary Microbiology (IJSEM). The functions of the ICSP are described in the Statutes of the International Committee on Systematics of Prokaryotes. 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, 2008 (2019), 2022 (2023) and 2025 (2026).

References

Oren, A., D.R. Arahal, H. Christensen, M. Göker, C. Manaia, E.R.B. Moore. 2026. International Code of Nomenclature of Prokaryotes. Prokaryotic Code (2025 Revision). IJSEM. 76: 006979. DOI 10.1099/ijsem.0.006979

Arahal D.R., M. Göker, R.L. Hahnke, C.M. Manaia, E.R.B. Moore, A. Oren, I.C. Sutcliffe and S. Ventura. 2025. Statutes of the International Committee on Systematics of Prokaryotes – July 2025 revision). Int. J. Syst. Evol. Microbiol. 75: 006918. DOI 10.1099/ijsem.0.006918

Contacts

ICSP Chair:  Edward Moore, PhD, Professor of Bacteriology, Sahlgrenska Academy, University of Gothenburg and CCUG, Gothenburg, Sweden, Phone: +46-70-259-8355; link: www.ccug.se/about/contact

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.

ICSP on LinkedIn:  https://www.linkedin.com/company/international-committee-on-systematics-of-prokaryotes

ICSP Slack channel: https://icnp-revision.slack.com 

Requests to change or update information should be sent to the ICSP Website Manager, Edward Moore: www.ccug.se/about/contact