Editing Clostridium botulinum (section)

==Taxonomic history==
{{Infobox genome
|image =
|caption =
|taxId=726
|ploidy=haploid
|chromosomes=2 (1 plasmid)
|size=3.91 Mb
|year=2007
}}
''C. botulinum'' was first recognized and isolated in 1895 by [[Emile van Ermengem]] from home-cured [[ham]] implicated in a botulism outbreak.<ref>{{cite journal | vauthors = van Ergmengem E | year = 1897 | title = Über einen neuen anaeroben Bacillus und seine Beziehungen Zum Botulismus | journal = Zeitschrift für Hygiene und Infektionskrankheiten | volume = 26 | pages = 1–8}}</ref> The isolate was originally named ''Bacillus botulinus'', after the Latin word for sausage, ''botulus''. ("Sausage poisoning" was a common problem in 18th- and 19th-century Germany, and was most likely caused by botulism.)<ref>{{cite journal | vauthors = Erbguth FJ | title = Historical notes on botulism, Clostridium botulinum, botulinum toxin, and the idea of the therapeutic use of the toxin | journal = Movement Disorders | volume = 19 | issue = Suppl 8 | pages = S2–S6 | date = March 2004 | pmid = 15027048 | doi = 10.1002/mds.20003 | s2cid = 8190807 }}</ref> However, isolates from subsequent outbreaks were always found to be [[Anaerobic organism|anaerobic]] spore formers, so [[Ida A. Bengtson]] proposed that both be placed into the genus ''Clostridium'', as the genus ''[[Bacillus]]'' was restricted to [[Aerobic organism|aerobic]] spore-forming rods.<ref>{{cite journal | vauthors = Bengston IA | year = 1924 | title = Studies on organisms concerned as causative factors in botulism | journal = Bulletin (Hygienic Laboratory (U.S.)) | volume = 136 | page = 101 fv|url=https://babel.hathitrust.org/cgi/pt?id=mdp.39015007772703}}</ref>

Since 1959, all species producing the botulinum neurotoxins (types A–G) have been designated ''C. botulinum''. Substantial phenotypic and [[genotypic]] evidence exists to demonstrate [[heterogeneity]] within the [[species]], with at least four clearly-defined "groups" (see {{section link||Groups}}) straddling other species, implying that they each deserve to be a genospecies.<ref name=Uzal>{{cite book|chapter=Taxonomic Relationships among the Clostridia | vauthors = Uzal FA, Songer JG, Prescott JF, Popoff MR |title=Clostridial Diseases of Animals |date=21 June 2016 | pages = 1–5 |doi=10.1002/9781118728291.ch1|isbn=978-1-118-72829-1}}</ref><ref name=Smith18>{{cite journal | vauthors = Smith T, Williamson CH, Hill K, Sahl J, Keim P | title = Botulinum Neurotoxin-Producing Bacteria. Isn't It Time that We Called a Species a Species? | journal = mBio | volume = 9 | issue = 5 | date = September 2018 | pmid = 30254123 | pmc = 6156192 | doi = 10.1128/mbio.01469-18 }}</ref>

The situation as of 2018 is as follows:<ref name=Smith18/>

* ''C. botulinum'' type G (= group IV) strains are since 1988 their own species, ''[[Clostridium argentinense|C. argentinense]]''.<ref name=argentinense>{{cite journal | vauthors = Suen JC, Hatheway CL, Steigerwalt AG, Brenner DJ | year = 1988 | title = ''Clostridium argentinense sp.nov.'': a genetically homogeneous group composed of all strains of ''Clostridium botulinum'' type G and some nonttoxigenic strains previously identified as ''Clostridium subterminale'' or ''Clostridium hastiforme'' | journal = International Journal of Systematic Bacteriology | volume = 38 | pages = 375–381 | doi = 10.1099/00207713-38-4-375 | doi-access = free}}</ref>
* Group I ''C. botulinum'' strains that do not produce a botulin toxin are referred to as ''[[Clostridium sporogenes|C. sporogenes]]''. Both names are [[conserved name]]s since 1999.<ref>{{cite journal | vauthors =  | title = Rejection of Clostridium putrificum and conservation of Clostridium botulinum and Clostridium sporogenes-Opinion 69. Judicial Commission of the International Committee on Systematic Bacteriology | journal = International Journal of Systematic Bacteriology | volume = 49 Pt 1 | issue = 1 | pages = 339 | date = January 1999 | pmid = 10028279 | doi = 10.1099/00207713-49-1-339 | doi-access = free }}</ref> Group I also contains ''[[Clostridium combesii|C. combesii]]''.<ref name="LPSN.combesii">{{cite web |title=Species: Clostridium combesii |url=https://lpsn.dsmz.de/species/clostridium-combesii |website=lpsn.dsmz.de |language=en}}</ref>
* All other botulinum toxin-producing bacteria, not otherwise classified as ''C. baratii'' or ''C. butyricum'',<ref>{{cite journal | vauthors = Arahal DR, Busse HJ, Bull CT, Christensen H, Chuvochina M, Dedysh SN, Fournier PE, Konstantinidis KT, Parker CT, Rossello-Mora R, Ventosa A, Göker M | title = Judicial Opinions 112-122 | journal = International Journal of Systematic and Evolutionary Microbiology | volume = 72 | issue = 8 | date = August 2022 | pmid = 35947640 | doi = 10.1099/ijsem.0.005481 | s2cid = 251470203 |quote=Opinion 121 denies the request to revise Opinion 69 and notes that Opinion 69 does not have the undesirable consequences emphasized in the request [Dobritsa ''et al.'' 2018].}}</ref> is called ''C. botulinum''. This group still contains three genogroups.<ref name=Smith18/>

Smith ''et al.'' (2018) argues that group I should be called ''C. parabotulinum'' and group III be called ''[[Clostridium novyi|C. novyi]]'' ''sensu lato'', leaving only group II in ''C. botulinum''. This argument is not accepted by the [[LPSN]] and would cause an unjustified change of the [[type strain]] under the [[Prokaryotic Code]]. (The current type strain ATCC 25763 falls into group I.)<ref name=Smith18/> Dobritsa ''et al.'' (2018) argues, without  formal descriptions, that group II can potentially be made into two new species.<ref name=Dobritsa18>{{cite journal | vauthors = Dobritsa AP, Kutumbaka KK, Samadpour M | title = Reclassification of Eubacterium combesii and discrepancies in the nomenclature of botulinum neurotoxin-producing clostridia: Challenging Opinion 69. Request for an Opinion | journal = International Journal of Systematic and Evolutionary Microbiology | volume = 68 | issue = 9 | pages = 3068–3075 | date = September 2018 | pmid = 30058996 | doi = 10.1099/ijsem.0.002942 | doi-access = free }}</ref>

The complete genome of ''C. botulinum'' ATCC 3502 has been sequenced at [[Wellcome Trust Sanger Institute]] in 2007. This strain encodes a type "A" toxin.<ref>{{cite web |title=Clostridium botulinum A str. ATCC 3502 genome assembly ASM6358v1 |url=https://www.ncbi.nlm.nih.gov/datasets/genome/GCF_000063585.1/ |website=NCBI |language=en}}</ref>