50 Infernational Code of Nomenclature 



Recommendation 8a. Sect. 1. Naming of Taxa 



RECOMMENDATION 8a (3). The term "group" in bacteriology should be 

 used with great care and be well defined if ambiguity is to be avoided. It has 

 been used in somewhat different senses by those working in various fields 

 of bacteriology. "Group" is used to designate congeries of organisms having 

 common characteristics. In many cases the groups are based upon antigenic 

 analyses, they are assemblages of related serotypes. 



ANNOTATIONS 



Recommendation Sa (3) . Among the several bacteriological uses of 

 "group" are the following: 



(1) "Group" is used by the Enterobacteriaceae Subcommittee of 

 the International Committee on Bacteriological Nomenclature 

 to emphasize the belief that recognition and diagnosis of the 

 many serotypes is of fundamental significance. Those having 

 some similarities in antigenic structure are placed together 

 in "subgroups," then by use of various physiological tests 

 larger groups are formed. The committee uses such designa- 

 tions as Salmonella group, Escherichia group, Shigella group 

 where other bacteriologists would use the designations genus 

 Salmonella, genus Escherichia, etc. An effort is made to avoid 

 in some cases the conventional terminology of biology for 

 what are regarded as good reasons. 



(2) Workers with certain bacterial genera and families have used 

 the term "group" in antigenic analysis to designate species or 

 subgenera (e.g., Streptococcus group A Lancefield) , or varie- 

 ties or subspecies (e.g., Neisseria meningitidis group I Scott) . 

 It has been suggested that the term gi^oup be reserved for 

 primary serological divisions and designated by capital let- 

 ters. Any serological subdivisions within the group should 

 be designated as serotypes and distinguished by Arabic num- 

 bers (e.g., Streptococcus pyogenes Rosenbach group A Lance- 

 field, serotype 1 Griffith) . 



The term "group" has not as yet achieved in bacteriology a gen- 

 erally accepted and consistent definition. 



