390 



ORDER IV. EUBACTERIALES 



Habitat: A cause of dysentery in man; 

 causes diarrhoea in infants and adults. 



8. Shigella dispar (Andrewes, 1918) 

 Bergey et al., 1930. {Bacilhis ceylanensis B 

 (sic), Castellani, Jour. Hyg., 7, 1907, 9; 

 Bacillus dispar (in part) Andrewes, Lancet, 

 194^, 1918, 560 (see Shigella sonnei; Andrewes 

 included in Bacillus dispar all lactose-fer- 

 menting members of the dysentery group) ; 

 Castellanus castellanii Cerruti, Jour. Trop. 

 Med. and Hyg., 33, 1930, 207; Bergey et al., 

 Manual, 3rd ed., 1930, 364; Proshigella 

 dispar Borman, Stuart and Wheeler, Jour. 

 Bact., 48, 1944, 363.) 



dis'par. L. adj. dispar unlike. 



Rods. Non-motile. Gram-negative. 



Culturally resembles Shigella sonnei 

 Weldin. 



Gelatin: No liquefaction. 



Milk is sometimes slowly coagulated. 



Indole is produced. 



Hydrogen sulfide not produced. 



Acid from xylose and occasionall}' from 

 lactose and dulcitol. 



Nitrites produced from nitrates. 



Trimethylamine produced from tri- 

 methylamine o.xide. 



Antigenic structure : The antigens of this 

 species mtiy be identical with those of 

 Shigella boydii 5, Shigella flexneri 6 and cer- 

 tain strains of Escherichia coli. 



Dissociation: The S colonies do not dis- 

 sociate into phase II but change rather 

 rapidly into S ^ R variants. 



Relationships to other species: Culturally 

 resembles Shigella sonnei Weldin but differs 

 from the latter biochemically and serologi- 

 cally. 



Kauffman and Frantzen combine Shigella 

 alkalescens and S. dispar, placing them in a 

 group they call the "Alkalescens-Dispar 

 Group." This was done to include these two 

 organisms in the Escherichia coli anaerogenes 

 group because they have O and K antigens 

 similar to those found in the genus Es- 

 cherichia. O agglutination may be masked by 

 the K antigen or by a capsular A antigen. 

 Frantzen described eight biochemical and 

 serological groups of Alkalescens-Dispar. 

 The diagnosis of the groups is determined 

 by the agglutination of a boiled emulsion 

 with one of the eight specific sera. The O 

 antigens of these eight groups have fractions 

 similar to the somatic antigens of certain 

 varieties of Escherichia coli. Oftentimes the 

 biochemical and serological characters show 

 no relationship, except in the case oi Shigella 

 alkalescens Type 1, which has stable bio- 

 chemical characters. 



Source : Isolated from the feces and intes- 

 tines of persons suffering from dysentery. 



Habitat: Most frequently found in the 

 urine of persons having cystitis, pyelitis or 

 pyelonephritis, in the blood of persons ill 

 with septicemia and in the feces of dysen- 

 tery patients or of healthy individuals. 

 Pathogenic for the urinary tract ; very rarely 

 causes dysentery. 



