508 



ORDER IV. EUBACTERIALES 



At present thirty-one serotypes of Diplo- 

 coccus pneumoniae are recognized on the 

 basis of serological reactions, chiefly the 

 Neufeld "Quellung" phenomenon as induced 

 by type-specific immune rabbit serums. Fol- 

 lowing the description of Pneumococcus 1 by 

 Neufeld and Handel (Arb. a. d. k. Gesund- 

 heitsamte, 3^, 1910, 293), Dochez and 

 Gillespie (Jour. Amer. Med. Assoc, 61, 1913, 

 727) divided the species into Types 1, 2, 3 

 and a heterogeneous group 4; Cooper, Ed- 

 wards and Rosenstein (Jour. Exp. Med., Jf9, 

 1929, 461) separated Types 4 to 13 from the 

 strains previously designated as group 4, 

 and later Cooper, Rosenstein, Walter and 

 Peizer (Jour. Exp. Med., 55, 1932, 531) con- 

 tinued the classification to Type 32. Due to 

 marked cross-reactions, it was subsequently 

 decided that Type 6 was identical with Type 

 26, and that Types 15 and 30 were identical. 

 This resulted in the deletion of the Cooper 

 Types 26 and 30, thus leaving thirty of the 

 original thirty-two types. Type 33 (Wilder) 

 has been described by Walter, Blount, Beat- 

 tie and Cotler (Jour. Inf. Dis., 66, 1940, 181) 

 as a distinct tj^pe; sufficient recognition has 

 been accorded to justify the acceptance of 

 this type, thereby making a total of thirty- 

 one types of the species. In a still more 

 recent publication, Walter, Guevin, Beattie, 

 Cotler and Bucca (Jour. Immunol., Ji.1, 1941, 

 279) recommend the addition of nine new 

 types and eight subtypes. These, together 



with new strains reported by Kauffmann, 

 M0rch and Schmith (Jour. Immunol., 39, 

 1940, 397), if eventually recognized, would 

 make a total of fifty-five types. Eddy still 

 more recently, taking into account all 

 known types, raises the number of recog- 

 nized types to seventy five (U. S. Public 

 Health Repts., 59, 1944, 449-468). 



Note : Pneumococci, regardless of serolog- 

 ical type, manifest three chief culture 

 phases (or stages) : Mucoid, Smooth and 

 Rough. The Mucoid (M) form corresponds 

 to that previously designated as Smooth (S) 

 and represents the typical phase of the 

 species; Smooth (S) supersedes the earlier 

 term Rough (R); and the present Rough 

 (R) form is a relatively newly described 

 variant. The most frequently observed dis- 

 sociative trend is M -^ S — > R. Serological 

 types are recognizable only in the Mucoid 

 form due to the presence of type-specific 

 polysaccharides in the capsular material; 

 both Smooth and Rough forms are devoid of 

 capsular material but possess species-spe- 

 cific antigens common to all members of the 

 species. Smooth and Rough forms are non- 

 pathogenic, possess distinctive growth 

 characteristics and require special technic 

 for accurate observations. The cultural 

 characteristics given are those of the mucoid 

 and smooth phases only, e.g., see growth in 

 broth. 



Genus 11. Streptococcus Rosenbach, 1884.* 



(Mikroorganismen bei den Wundinfectionskrankheiten des Menschen. Wiesbaden, 1884, 22.) 



Strep. to. coc'cus. Or. adj. streptus pliant; Gr. noun coccus a grain, berry; M.L. mas.n. 

 Streptococcus pliant coccus. 



Cells spherical or ovoid, rarely elongated into rods, occurring in pairs or short or long 

 chains. Capsules are not regularly discernible but may become conspicuous with some 

 species under certain conditions. Non-motile except a few strains in the enterococcus 

 group. Gram-positive. No pigments are produced with the exception of an occasional strain 

 in Lancefield's groups B and D, which may produce brick-red pigment or yellow pigments 

 under appropriate environmental conditions. A fermentable carbohydrate or polyhydroxy 

 alcohol is necessary for satisfactory growth in artificial media. Growth in broth culture 

 is variable in character. Rough variants may show granular growth that tends to settle out 

 quickly, leaving a clear supernatant. Smooth variants may show uniform turbidity with 

 little tendency to settle out. Such variants may be noted within one species. A pellicle is 

 never formed. Growth on agar surface is usually scanty. Colonies are small, usually less 



* Revised by Dr. C. F. Niven, Jr., American Meat Institute Foundation, The University 

 of Chicago, Chicago, Illinois, in consultation with Professors J. M. Sherman and Harry W. 

 Seeley, Cornell University, Ithaca, New York, November, 1953. 



