Page 16 INTERNATIONAL BUUETIN

STATUS OF THE GENERIC NAME BACTERIUM, THE SPECIFIC

NAME BACTERIUM COLI .9M) THE FAMILY NAhE B.4CTERIACEAE Preliminary Statement, File No. 5

The Editorial Roard has prepared the followinq preliminary state- ment for consideration by the Judicial Commission and for the in- formation of the members of the Intervational Committee on Bact- eriological Nomenclatiire. It is a revision of a statement earlier circulated,and disciissed at the meetings of the Commission and of the Committee held at the time of the International Microbiolog- ical Conyress at Rio de Janeiro (1950). The Judicial Commission, through its Editorial Board, will he pleased to receive comments, criticisms and siiqqestions from any person interested.

The Judicial Comnission has reveals much confusion with been asked to prepare and issiie reference to the use of the an opinion fixinp, the statiis of generic name Bacterium and of the qeneric name Bscteriurn Ehr- the family name Bacteriaceae. enbere;, of the specific name Proposal No.1 as submitted to Bacterium coli,and of the fam- the Commission seeks to elimin- ily name Bacterinceae. ate the conftlsion by the re- jection of these names,the F'ROPOSALS.Two proposals have second proposal would eliminate been received. the confusion by the careful definition of these names. 1.It is proposed that the ?en- eric nape Bacterium and the The following topics require family name Bacteriaceqe be de- examination : signated as nomin.7 rejicienda. A.Rejection or conservation of the generic name Bacterium Ehr- 2.It is proposed that the gen- enberg; 1828. eric name Bacterium and the R.Rejection or conservation of family name Bacteriaceae be de- the generic name Bacterium as signated as nomina conservanda, proposed or emended by later that the genus Bacterium be authors. desiqnated as the type genus of C.If Bacterium is conserved, the family Bacteriaceae, that designation of its type spe- the species Bacterium cof i be cies. designated as the type of the C.Rejection or conservation of genus Bacterium,and that a type the familv name Bacteriaceae or standard culture be selected with the designation of the for Bacterium coli. type genus if the name is con- served , The literature of bacteriology E.Conservation of the name of Page 17 BACTERIOLOGICAL NOMENCLATURE AND TAXONOMY

the type species of Bacterium came here Bacteriiirn terrno.Later if the aeneric name is con- Ehrenberg (1832)(3) included served. two species defini,tely, and F. Selection and approval of four tentatively. In 1838 he the type culture for the type (4 f i gu red Bac ter i urn tri 1 oc - species of Bacterium if this dare as a motile rod with one generic name is conserved. polar flagellum and with the cell divided into two or three A.Reject ion or conservation of compartments. Although in- the generic name Bacterium Ehr- cluded in descriptions by other enbere 1828. authors later, there does not seem to have been any subse- The generic name Bacterium was quent definite identification first proposed by Ehrenberg (1) of Bacterium triloculare. in 1828. A single species Bacterium trilocufare was in- The type species of Bacterium cluded in the protozoan family Ehrenberg 1828 is Bacterium Vibrioni, This organism was de- triloculare Fhrenberg 1828 by scribed as distinctly triloc- monotypy. If the genus Bacter- ular or triarticulate, sub- ium Fhrenberg 1828 is placed by fusiform, hyaline, body terete, international agreement in a 1/300 lines long (approximately list of nomina generica con- 7k), apparently multiplying by servanda this action would seem transverse division, and mo- to fix the qenus and its type tile. Found in the Oasis of species in a non-usable form, Jupiter Ammon, Siwa. Ehrenberg since the only species cannot again described the genus in be identified. Further it seems 1830 (2), then including eleven quite improbable that other species, several of them trans- species placed by later authors ferred to this genus from var- in the geniis Bacterium could be ious protozoan genera previpus- retained in a genus of which ly described by Mueller. The Bacterium triloculare is the Monas of the latter be- termo type ' - (l).Ehrenberg, C. F. Symbolae Physicae seu Icones et Descrip- tiones animalitim evertebratorum sepositis insectis quae ex itinere per Africam Borealem et Asiam Occidentalem. Berlin. 1928. (2).Ehrenberg, C. C. Reitrgge zur Kenntnis der Organisation der Infusorien und ihrer geographischen Verbrei tune. Abhandl. d. Berl.Akad. pp. 1-80. 1830. (3).Ehrenberg, C. G. Die geographische Verbreitung der Infusions- thierchen in Nord Afrika und West Asien,etc. Abhand1.d.k. Akad. d. Wiss. z. Berlin. Physik-Klasse. 1832. (4).Ehrenberg, C. G. Die Infusionsthierchen als vollkommene Org- anismen. Leipzig. 1838. Page 18 1N”ATIONAL BULLETIN

This difficulty of assigning In the sixth edition of Ber- species of bacteria to the gey’s Manual of Determinative genus Bacterium as described by Bacteriology Bacterium is de- Ehrenberg has led to the aban- fined as follows: “The term donment of the generic name by Bacterium is used to cover many authors. For example, species of nonsporeforming rod- Sternberg (1892) (1) stated shaped bacteria whose position =This genus established by Du- in the system is not definitely jardin is now generally aban- established.” doned, the species formerly in- cluded in it being transferred Obviously an organism placed in to the genus Bacillus.” the genus Bacterium but so in- adequately described as not to Breed, Conn and Baker (1918) be placeable in the appropriate (2) likewise suggested that the genus must remain as a species name be dropped, or at most dubia with its original name regarded as a general desig- retained until proper identif- nation for insufficiently de- ication is possible. scribed organisms. B. Rejection or conservation of This point of view was later the generic name Bacterium as advocated by Breed and Conn amended or proposed by later (1936) (3) with an important authors . proviso. While recommending that Bacterium as a formal gen- Bacterium Cohn 1872 (4). Cohn’s eric name be rejected, they be- descriptions were based largely lieved it advisable to retain on his concept of Bacterium it as a tentative but accepted termo as the organism respons- name for those species which ible for decay. Transfers of previously have been placed in liquid from decaying beans to a this genus and should remain medium containing ammonium tar- there until such time as they trate yielded a green fluor- may be satisfactorily allocated escence. Later Cohn (1875) (5) to other genera. included several other species in the genus. Trevisan (1879)

(l).Sternberg, G. M. Manual of Bacteriology. New York. 1892. (2).Breed,R.S. , H. J.Conn and J.C.Baker. Comments on the Evolution and Classification of the Bacteria. Jour. Bact. 2:445-459. 19 18. (3).Breed, R. S. and H. J. Conn. The Status of the Generic Name Bacterium Ehrenberg 1828. Jour. Bact. 3J:517-518. 1936. (4).Cohn, Ferdinand. Untersuchungen ueber Bakterien. 1. in Cohn’s Beitr.z.Biol.d.Pflanzen. &:127-224. 1872. (5).Cohn, Ferdinand. Untersuchungen ueber Bakterien. 11. in Cohn’s Beitr.z.Biol.d.Pf1anzen. (Heft 3). L:141-208. 1875. Page 19 BACl‘ERIOLOGICAL NOhENCLATURE AND TAXONOMY

(1) used the designation “Bact- Vi gnal , Cohn ) . erim Ehrenberg (1830 non 1828) emend. Cohn and included the Two other workers independently species B-termo. Apparently suggested defining the genus Trcvisan regarded the first de- Bacterium to include the polar scribed species B.triIocufare flagellate rods. Vuillemin as non-identifiable, and chose (1913) (4) published a proposal to date the generic name by an that Bacterium be designated as Ehrenberg publication contain- a nonen genericum conservandum ing the description of a spec- with Bacterium termo Ehrenberg ies which could be recognized. as a prototype and Bacterium Fyocyaneum, a fluorescent polar Erwin F. Smith (1905) (2) con- flagellate, as the type. Ender- cluded that none of the species lein (5) also defined Bacterium placed in the genus before the to include bacteria with polar work of Cohn could be identi- flagella, and designated B. fied. He repeated some of aeruginosum as the type. Cohn’s experiments and conclud- ed that the Bacterium termo of The approval of Bacterium Cohn Cohn is a polar flagellate rod 1872 as a genus conservandum capable of producing a fluor- with its later designation of escent pigment in a tartrate type species would make Pseudo- medium. Smith’s characteriza- monas Migula 1894 a later syn- tion of Bacterium was rather onym, and would require the use widely used by those working of the name in a way which has with bacterial diseases of not been accepted commonly by plants. bacteriologists. If the pro- posal (6) to make Pseudomonas Enlows (1920)( 3) designated the Migula 1894 a genus conservand- type species of Bacterium urn is approved, obviously it (Ehrenberg) emend. Cohn 1872 as would need to be conserved Bacterium termo (MGller 1773, against Bacterium Cohn 1872. Ehrenberg 1830, Dujardin 1841, (l).Trevisan, V. Primie Linee d’Introduzione allo Studio dei Bat- terj Italiani. Rend. Real. 1nst.Lombardo di Scienze e Lettere IV. Ser 11. lJ:13-21, 133-151. 1879. (2).Smith, Erwin F. Bacteria in Relation to Plant Diseases. Car- negie Inst. Washington. 1905. (S).Enlows, Ella M. A. The Generic Names of Bacteria. Hyg. Lab. Bull. 121, U. S.Pub1ic Health Service,Treasury Dept.p. 21.1920. (4).Vuillemin, Paul. Genera Schizomycetum. Ann. Mycologie ;:596. 1913. (5).Enderlein, Bakte r ien-Cyclogenie. 1925. (6).(Editorial Board). Status of Pseudomonas Migula 1894 as a Generic Name. 1ntern.Bull.Bact.Nom. and Taxonomy. L:41. 1951. Page 20 1N"ATICNAL BULLETIN

The type species of Bacterium has rarely been accepted by Cohn 1872 is Bacterium termo bacteriologists. No designation by monotypy. The species is of a type species of Bacterium one which has apparently not Migula 1894 has been found in been recognized by bacteriol- the literature. The author ogists in recent years. There gives Bacterium anthracis as is some question whether Bac- an example. If this organism terium termo could be identi- be regarded as the type species fied with sufficient exactness either on the basis of the 1914 to serve as a type species in notation or the definite cita- practice. tion in 1895 (2) the name be- comes a later synonym of Bac- Bacterium Migula 1894.The genus illus Cohn, a generic name con- was redefined to include only served by action of the second nonmotile rod-shaped organisms International Congress of either with or without endo- Microbiology in 1936. spores. Migula (1) ascribes the generic name to Cohn. This Bacterium Lehmann and Neumann definition was widely used, 1896. Zopf (1883) (3) modified particularly in botanical as the definition of Bacterium by contrasted with bacteriological emphasis upon his concept of circles. The wide acceptance pleomorphism. He included in was due in part to the inclu- the genus organisms having four sion of Migula's (1895) class- growth forms, cocci, short ification of the Schizomycetes rods, long rods and filaments. in Engler and Prantl's Pflanz- Later (1885)(4) he modified his enfamilien used so extensively generic diagnosis to include by botanists, to the publica- organisms existing as cocci and tion by Migula in 1897 and 1900 rods or filaments, with endo- of his two-volume System der spore formation absent or un- Bakterien, and to the accept- known. Apparently this is the ance of this diagnosis by first suggestion that absence Chester (1901) in his Manual of af spores is of nomenclatural Determinative Bacteriology . significance. Hueppe (1886)(5) also emphasized absence of In recent years this definition endospores as a generic char-

(I).Migula, W. Ueber ein neues System der Bakterien. Arb. Bact. Inst. Karlsruhe 2.235-238.1894. (2).Migula,W. Schizomycetes, in Engler and Prantl, Pflanzenfamil- ien. A (la), 1895. (3).Zopf, W. Die Spaltpilze. Encyklop.d.Naturwiss. Abt. 1.Lief. 32. 1883. (4).Zopf, W. Die Spaltpilze. Ed. 3. 1885. (S).Hueppe, F. Die Formen der Bakterien und ihre Beziehungen zu den Gat tungen und Arten. 1886. Page 21 BACTERIOLOGICAL “dATURE AND TAXONW

acter. However, the more com- It would seem that of the pro- plete characterization of the posals for fixing the author of genus is due to Lehmann and Bacterium after Ehrenberg, Neumann (1896)( 1) who recog- there are at least three that nized the genus as Bacterium are worthy of careful scrutiny, Cohn em. Hueppe. Numerous spe- namely,the proposal of Cohn cies are described and figured. that the genus Bacterium and among these are Bacterium in- its species Bacterium termo be fluenzae and Bacterium col i , defined to include the typical Apparently the latter is the decay-inducing organisms pro- first use of the name of the ducing a greenish fluorescent organism named Bacterium coli pigment; the proposal of Migula commune by Escherich (2) in its that the name be used to in- corrected form as a binomial in clude the non-motile rod-shaped the genus Bacterium. The treat- bacteria; and the proposal or ise on systematic bacteriology emendation developed by Lehmann by these authors went through and Neumann in which there is many editions and resulted in emphasis upon differentiation widespread acceptance. No type of Bacterium from Bacillus on species was designated. the basis of lack of endospore formation in the former. Orla-Jensen (1909) (3) further proposed to emend the genus to One of these proposals may be include only the coliform bac- accepted by international teria. He stated “Wir wollen agreement as the legitimate die artenreiche Gattung der publication of Bacterium as a Cali-Bakterien einfach Bacteri- generic name and the genus um nennen”. Winslow et al (4) placed in the list of genera proposed the designation of conservanda. The names as pro- Bacterium coli as the type spe- posed by other authors would be cies. The same recommendation placed in the list of genera was made by Buchanan ( 1918)( 5). r ej i c i enda *.

(l).Lehmann, K.B. and R. Neumann. Atlas und Grundriss der Bakter- iologie. Teil 11. Text. p. 224.1896. (2).Escherich, Th. Die Darmbacterien des Neugeborenen und Saeug- ling. Fortschr.d.Med. 2:520. 1885. (3).0rla-Jensen,S. Die Hauptlinien des natuerlichen Bakteriensys- tems. 2entr.f.Bakt. Abt.2. 3305-346. 1909. (4). Winslow, C-E.A.,Jean Broadhurst, mas. Krumwiede, L.A.Rogers, and G. H. Smith. (Committee of the Society of American Bac- teriologists on Characterization and Classification of Bac- terial Types). Preliminary Report. The Families and Genera of Bacteria. Jour. Bact. 2:552. 1917. (S)*Buchanan, R.E. Studies in the Nomenclature and Classification of the Bacteriaceae. Jour. Bact. 2 27-61. 1918. Page 22 INTERNATIONAL BULLETIN

C.Designation of the type species of the genus Bacterium

1.Bacterium Ehrenberg 1828. The type species by monotypy is Bacterium trifocufare Ehrenberg 1828. Conservation of the gen- eric name Bacterium Ehrenberg 1828 would probably make the name useless from the standpoint of assignment to it of other spe- cies of bacteria placed in the genus Bacterium as recognized by later authors. To fix upon Bacterium trifocufare as the type would be the equivalent of rejecting the generic name, at least of placing it in a list of nomina dubia or nomina inquirenda. Rule 24 (6 and 7) of the International Bacteriological Code reads: “A nameof a taxonomic group is illegitimate in the following cases: - (6).If its application is uncertain (nomen dubim), a list of names to be abandoned for this reason will be in- cluded under nomina rejicienda. (7).If the characterization of the group was based upon an impure or mixed culture, A list of names to be aban- doned for this reason (nomina confusa) will be includ- ed under nomina rejicienda. ”

Rejection of the generic name Bacterium Ehrenberg 1828 would make possible the recognition of the generic name Bacterium as proposed by some later author,if such action should be approved by international agreement.

2.Bacterium Cohn 1872. The type species by monotypy is Bacterium termo. Interpretations and emendations by later authors would include in the genus polar flagellate rods that produce fluor- escent pigment when grown in Cohn’s nutrient solution. The species Bacterium terrno is not recognized by most bacteriolog- ists at the present time because it probably was not based up- on a pure culture and is at presentunidentifiable. Designa- tion of a type species as recommended by several later writers would require international approval. The acceptance of Bact- erium Cohn 1872 would probably make Pseudomonas Migula 1894 a later synonym.

3.Bacteriurn Migula 1894. No record of the definite designation of a type species has been found. If the type were fixed upon as Bacillus anthracis the generic name would be a later synonym of Baci 11 us Cohn.

4.Bacterium Lehmann and Neumann 1896. These authors did not de- signate a type species. Bacterium influenzae was the first Page 23 BACIXRIOLOGICAL NOhENCLATURE AND TAXONOMY

species described. Escherich (1885 1.c.) gave the name Bacte- rium coli commune to one of the first organisms to be placed in this genus, adequately characterized and still recognized. Un- fortunately he used a trinomial to designate the organism,tech- nically rendering the name illegitimate. Apparently the first binomial designation of the organism was Bacterium escherichii Trevisan 1889 (1). This name has never come into use. The org- anism was named Bacillus cofi by Migula (1895) and Bacterium cofi by Lehmann and Neumann (1896). The correct designation would seem to be Bacterium coli (Migula) Lehmann and Neumann. Bacterium coli was designated as the type species of Bacterium by Winslow et af (1917 1.c.) and by Buchanan (1918 1.c.). The description and figures given by Lehmann and Neumann are ade- quate for the identification of the species. This designation of the type has been recognized and approved by many workers. It would seem that Bacterium coli (Migula) Lehmann and Neumann is the type species of Bacterium Lehmann and Neumann 1896 by subsequent designation from included species. If Bacterium Lehmann and Neumann 1896 is conserved,it is advis- able to note other generic names against which it should be conserved. These would include all names of genera and subgen- era that are based on the same type species. Among these are the following: Escherichia Castellani and Chalmers 1918, Coli- bacterium Orla-Jensen 1921, Enterobacter Rahn 1937 and Entero- bacterium Gieszczykiewicz 1939. If Bacterium Lehmann and Neu- mann is made a genus conservandum, these four generic names be- come later synonyms. If Bacterium is not conserved,these names should be examined as to their legitimacy and availability.

4a. Escherichia Castellani and Chalmers 1918. The type species was definitely designated by the authors as Escherichia cofi (Escherich) Castellani and Chalmers 1919. If Bacterium is conserved with Bacterium cofi as the type species,Escherich- ia becomes a later synonym.

4b.Colibacterium Orla-Jensen 1921. The author states: "The gen- us Bacterium will undoubtedly dissolve into several genera of which I may especially mention the Colibacterium and Aerogenesbacterium."The legitimacy of Colibacterium requires study. OrPa-Jensen suegested dividing the genus Bacterium into two genera. Rule 17 of the International Bacteriolog- ical Code of Nomenclature reads:- (l).Trevisan,V. I Genera e le Specie delle Bacteriaceae. Milan. 1889. Page 24 INTERNATIONAL BULLEI‘IN

“When a genus is divided into two or more genera the gen- eric name must be retained for one of them,or (if it has not been retained) must be reestablished. When a par- ticular species was originally designated as the type the generic name must be retained for the genus includ- ing that species. ”

It would seem that Cofibacterium is illegitimate on the ba- sis that it has the same type species BS Bacterium as recog- nized by Orla-Jensen. Further, the name Colibacterium seems to have been proposed quite provisionally and not definite- ly. Rule 12 of the code states in part:- “A name of a taxonomic group is validly published only if it has been definitely accepted by the author who pub- lished it. A name proposed provisionally (nomen provis- oriurn) in anticipation of the eventual acceptation of the group, or of the circumscription,,position or rank given to a group, or mentioned only incidentally is not validly published. ” Further, Rule 13 states:- “A name of a genus is not validly published unless it is accompanied (1) by a description of the genus; or (2) by the citation of a previously and effectively published description of the genus under another name; or (3) by a reference to a previously and effectively published de- scription of the genus as a subgenuss or other subdivi- sion of a genus. ”

Cofibacterium should probably be excluded from consideration as a generic name inasmuch as it has not been validly pub- li shed.

4c.Enterobactet Rahn 1937 (1). Rahn’s characterization of the genus is included in the following statements:- “The need for a name for the entire colon-typhoid group has been felt by those bacteriologists who do not agree with Castellani and Chalmers’ many genera (except as trivial names ). The name Enterobacteriaceae as a family name with the single genus Enterobacter is here proposed. The term is not entirely inclusive since such species (sic) as Serratia, Aerobacter and Erwinia are in this group which are not intestinal. However, it is not nec- essary that a family or genus name describe all species.” (l).Rahn, Otto. New Principle for the Classification of Bacteria. Zent. f.Bakt. Abt. 11. 3:273-286. 1937. BACTERIO~WGICALNOMENCLATURE AM, TAXONOMY

An interesting footnote is appended. “Two other names have been proposed. One is the neutral expression Virgula, the Latin name for the Greek Bacterium ....”

In a tabular OtJtline of the Eubacteriales the author gives a description of a new family Enterobacteriaceae and follows with the statement:- “Enterobacter (including Es cherichia, Salmonella, Aero- bacter, Klebsiella, Proteus, Erwinia, Shigella, and the gas-formers of Serratia, Pseudomonas, Flavobacterium and Achromobac ter .” The legitimacy of the name Enterobacter must be scrutinized. Rule 19 of the Bacteriological Code states:- @When two or more groups of the same rank are united, the oldest legitimate name or (in species and their subdivi- sions) the oldest legitimate epithet is retained. If the names or epithets are of the same date, the author who unites the group has the right of choosing one of them.” It would seem that Rahn disregarded this rule, common in es- sence to botany, bacteriology and zoology. No type species is designated. The validity of publication may also be questioned under Rule 13 above cited. Enterobacter is prob- ably to be regarded as not validly published, perhaps it may be regarded as a nomen nudum.

4d. Ent erobacteriim Gieszczykiewicz 1939. ( 1). This author accepts the generic name Bacterium which he subdivides into 12 sub- genera, of which the first is Enterobacterium. The subgenus is described and the statement made: “Typus: Bacterium (Ent erobacterium) coli Escherich.”

The subgeneric name apparently was validly published. Its standing should be examined under Rule 5, last sentence of paragraph 1: “Generic names and subgeneric names are subject to the Same rules and recommendations and, from a nomenclatural standpoint, they are coordinate.” However, There is a question as to conformity with the next sentence of Rule 5: “If a genus is divided into subgenera, one of the sub- genera (that which includes the type of the genus) should

(1 ).Gieszczykiewicz, IM. Zur Frage der Bakterien-Systematik. Bull. d. 1’Acad. Polonaise. Sc.Lettres. Classe Sc.Math. et Nat. Sere SC* Nat- (1) 9-27. 19s. Page 26 INTERNATIONAL BULLETIN

bear the same name as the genus.”

This would seem to indicate that the name Bacterium rather than Enterobacterium shottld have been chosen as the name of the subgenus. The author definitely includes in his sub- genus Enterobacterium the genera Escherichia, Aerobacter, Eberthella, Salmonella, Shigella, Kiebsiella.

The point may be made that this author definitely recommend- ed the use of the generic name Bacterium, and would seem by inference to have fixed upon Bacterium coli as the type species. Enterobacterium is a later synonym of Escherichia because it is based on the same type species.

Every effort in the preced- be mergedinthe genus Bacterium ing statement has been made to to any degree desired. There confine the discussion to might well be some nomenclatur- problems of nomenclature. All al problems involved. For ex- that is here involved is the ample, the oldest generic name fixing of the type species for of a genus that probably would Bacterium if the name is con- be included in the family to served, or the rejection of the which Bacterium is assigned generic name completely if it is Serratia. If Bacterium and is not conserved. The number Serratia were united, under the of species that should be in- rules the older name would be cluged in a conserved genus applied to the genus. Effect- Bacterium or the numberof oth- ive conservation of the generic er genera to be included in name Bac t eri um would r equi re the family to which it is as- that it be conserved against signed are important, but are all older genera having differ- not primarily problems of nom- ent type species as well as enclature. those having the same.

If Bacterium Lehmann and Neu- D. Rejection or conservation of mann is conserved with the type the familv name Bacteriaceae species Bacterium coli (Migula) and designation of the type Lehmann and Neumann, then all genus. genera having the same type species are synonyms and can The family designation Bacter- not be used legitimately as iaceae was apparently first generic names. For example, used by Cohn (1872 lc.) In his Escherichia would become a description of Microsphaera he synonym, but Aerobacter, Sal- employed the expression “Gruppe monella, Shigella, etc. could be de r Bac t eri aceae .” Apparent ly used as at present to designate the name was used to include different genera or they could all Schizomycetes in this family Page 27 BACTERIOLOCICAL NOMENCLATURE AND TAXOM

was described in some detail by there are other family names Trevisan (1879) and has been that might have priority, and used by many other authors against which it would be nec- since. Some of the earlier essary to conserve the family students employed the family name Bacteriaceae. One family name as all-inclusive, but in name that has come into some recent years it has in general use requires further consider- been more restricted in its ation, Enterobacteriaceae Rahn application. f9372 One proposal before the Com- Enterobacteriaceae Rahn 1937. mission is that the family name This author characterized the Bacteriaceae be rejected, the family and assigned to it a other that it be made a nomen single genus, Enterobacter, famiiiae conservandum. The name which in turn was defined to is derived from the name of one include the older genera Esch- of the contained genera, Bac- erichia, Salmonel la, Aerobact - t er i um . er, Kiebsiella, Proteus, Erwin- ia, Eberthella, Slidella, and Obviously conservation of the the gas-formers of Serratia, family name Bacteriaceae may be Pseudomonas, Ffavobacterium dependent upon the conservation md Achromobacfer. The name of a generic name Bacterium Enterobacferiaceae presumably from which the name could be is derived from Enterobacter. derived. The family Bacter- The validity of the name Enter- iaceae would include such gen- obacteriaceae may be tested era as are regarded as suffi- through application of the ciently closely related to Bac- Rules and Principles of the In- terium. What names should be ternational Bacteriological given to those genera would be Code of Nomenclature. Among, determined by whether Bacterium these are the following: Ehrenberg 1828, with its type species Bacterium triloculare, Rule 24. A name of a taxonomic or Bacterium Cohn 1872 with its group is illegitimate in the type species Bacterium termo, following cases: (1) If it was or BacteriumMiguia with some nomenclaturally superfluous type species to be selected, or when published, i.e., if the Bacterium Lehmann and Neumann group to which it was applied, with its type species Bacterium as circumscribed by its author, coli is chosec as the generic included the type of a name name to be conserved. which the author ought to have adopted under one or more of Inasmuch as one proposal is the rules. that Bacterium be so fixed that Bacterium coii is its type, it Principle 9. Each group with a is well to examine whether given circumscription, posi- Page 28 INTERNATIOh” BULLETIN

tion and rank can bear only one the name of an order is not valid name, the earliest that validated by mention of the in- is in accordance with the Rules cluded families; that of a fam- of Nomenclature. Provisions ily is not validated by mention may be made for certain excep- of the included genera; that of tions. Note: In subgenera, a genus is not validated by genera, and groups of higher mention of the included spec- rank, the valid name is the ies. earliest name published, pro- vided that this is in conform- It would seem that Rahn char- ity with the Rules of Nomen- acterized the family name En- clatu re. terobacteriaceae both by giving a description and giving the Principle 11. The application name of the single included of names of taxonomic groups is genus, Enterobacter, However, determined by means of nomen- the genus Enterobacter was not clatural types. A nomenclatur- characterized and no species al type is that constituent was named. Under Rule 12 En- element of a group to which the tetobacter was not validly pub- name of the group is permanent- lished and is a nomen nudum. ly attached, whether as an ac- Even if validly published, it cepted name or as a synonym. would be a later synonym of one The name of a group must be of the genera included within changed if the type bearing it. that name is excluded. The family name Enterobacter- Rule 9. For each valid name of iaceae Rahn was accepted, ade- each taxonomic group there quately characterized and used should be designated a type; by Bergey, Breed, Murray and that is for each species or Hitchens (1939)(1) in the fifth subspecies a type culture, edition of Bergey’s Manual and specimen, or description, for also by Breed, Murray and Hit- each genus a type species chens. in the sixth edition (genotype) (1948). However, the generic name Enterobacter was not ac- cepted, nor was it listed as a Rule 12. (in part). A group 1s not characterized and the pub- synonym of any of the several lication of its name is not contained genera. validated merely by mention of the subordinate groups included Family names should be derived in it; thus, the publication of from names of contained genera.

(l).Bergey, David H., Robert E, Breed, E.C.D.hlurray and A. Parker Hitchens. Enterobacteriaceae, in Bergey Manual of Determina- tive Bacteriology, Ed.5. p. 388. 1939. Page 29 BACTERIOLOGICAL NOMENCLATURE AND TAXONOMY

However, approval was given at their scien t i f i.c writings and the fifth Congress of Microbi- in their texts. ology at Rio de Janeiro to the validation of family names not Same international agreement SO derived, providing that which would do away with wide- there is international agree- spread confusion and misunder- ment. There has been no pro- standing is desirable. posal submitted to the Judicial Commission that En terobac t er -. Further examination of the iaceae Rahn be designated as a origin and status of the name farnilia conservanda. If Bacter- Lhterobacteriaceae may be use- iaceae is designated as a con- ful. served family name based upon the genus Bacterium with Bac- Rahn’s concept of a good family terium coli as a type species, name is that of one which is the family name Enterobacter- descriptive of all the organ- iaceae becomes a synonym. The isms contained within it and use of the family name Entero- one that includes a clear in- bacteriaceae has become rather dication of some characteristic common among those who base common to all. He is somewhat their bacterial nomenclature apologetic for the family upon Bergey’s Manual. For ex- name Enterobacteriaceae as ample, questions of nomenclat- not fully meeting this re- ure which arise in the indexing quirement. He apparently re- and abstracting in Biological gards Enterobacteriaceae as the Abstracts are generally settled equivalent of enterobacteria, by reference to this Manual. that is, the intestinal bacter- The name has been frequently ia. He notes that the name used in texts and in scien- does not properly characterize tific articles. all the organisms contained. He On the other hand, it should be says (p.381); “The term is not recognized that many bacteri- entirely inclusive since such ologists, as evidenced by the species (sic) as Serratia, request of the British Commit- Aerobacter and Erwinia are in tee for conservation of Bacter- this groiip which are not in- iaceae, have vigorously opposed testinal. However, it is not the introduction and advocacy necessary that a family or ge- of the family name Enterobac- nus name describes all spec- teriaceae. The name has been cies.”It may be noted that Rahn regarded as a wholly unjusti- also included in his family the fied replacement of an old, gas- formers “of Pseudomonas, valid and widely accepted name Flavobacterium and Achromobac- by one not formed in conformity ter.“ In other words, Of the with the rules of nomenclature. twelve genera brought together Many bacteriologists have re- six did not fall logically into fused to accept the new name in the group of the enterobacteria Page 30 INIXRNATIONAL BULLETIN of intestinal bacteria on the vious that the several genera basis of habitat. are grouped together in a fam- ily because they resemble the Although there is no warrant in genus whose name has been modi- any of the three biological fied to become the family name. codes of nomenclature for the point of view that the name of If the family name Bacteriaceae a genus or of a family should is rejected,it would seem de- in its etymological makeup in- sirable that the status of the dicate a characteristic common family name. En terobac teri aceae to all the contained organisms, be fixed by international a- nevertheless this point of view greement, and the type genus has not infrequently been held definitely designated. by bacteriologists. The Editorial Board, after a The ending -aceae as used as a survey of the facts presented suffix in the formation of fam- above,has developed the follow- ily names,originally a plural ing statement as logically re- ad j ect ive suffix, has become in presenting the various alter - practice a plural noun ending natives to be considered by the meaning “Those organisms which Judicial Commission in its resemble.. .”. If the suffix is formulation of an official added, as is customary, to the opinion as to the conservation stem of the name of a contained or rejection of the generis genus, the family name becomes name Bacterium and the family highly descriptive. It is ob- name Bacteriaceae. Alternatives suggested for consideration by the Judicial Commission.

The Judicial Conmission should determine whether stability and uniformity in bacteriological nomenclature would be advanced by an OPINION embodying one or more of the following alternatives. a.Reiectian or conservation of the generic name Bacterium. b.The generic name Bacterium Ehrenberg 1828 should be conserved (The type species would be Bacterium triloculare Ehrenberg 1828. ) 2b.The generic name Bacterium Ehrenberg 1828 should be rejected. c.Rejection of Bacterium Ehrenberg should make the name Bact- erium permanently unavailable for the name of a bacterial genus. 2c. Rejection of the generic name Bacterium Ehrenberg 1828 should not prevent the use of Bacterium as the name of a genus based upon a diagnosis and proposal of some later author and conserved in such use by international agree- Page 31 BACTERIOLOGICAL NOMENCLATURE AND TAXONOMY ment . d. Bacterium Cohn 1872 (with type species Bacterium termo Cohn) should be e. Conserved 2e. Rejected 2d. Bacterium Migula 1894(with type species to be designated) should be e. Conserved 2e. Re j ect ed 3d.Bacterium Lehmann and Newnann 1896 (with the type species Bacterium coli (Migula) Lehmann and Neumang should be e. Conserved 2e. Re jec t ed 4d. Bac t eri um shall be ascribed to- (authority) with .as the type species and should be conserved. 2a.Rejection or conservation of the family name Bacteriaceae.. b.The family name Bacteriaceae should be rejected ard made un- available for future use as a family name. (The Judicial Commission may b% requested to prepare an Opinion relative to the desirability of conservation of the family name En- terobacteriaceae). 2b.The family name should be conserved with the type species c. Bacterium triloculare Ehrenberg 1828. 2c. Bacterium termo Cohn 1872. 3c. Bac t eri urn hligula 1894. 4c.Bacterium coli (Migula) Lehmann and Neumann 1896. 5c .Bac t er i urn 3a.Should a decision be reached to conserve the generic name Bacteriua the Judicial Commission should develop a method to fix the type culture of the type species.