388 



ORDER IV. EUBACTERIALES 



cal with those of Salmonella poona and Sal- 

 monella worthington. 



There is no correhition between the sero- 

 tj^pes and the biochemical characters except 

 for Shigella flexneri 3, which acidifies rham- 

 nose, and Shigella flexneri 6, which has par- 

 ticular biochemical characters. 



Serotype Shigella flexneri 6 contains 

 strains each of which possesses biochemical 

 properties at variance with those of the 

 other strains as well as with those of the 

 other serotypes of this species : strain Boyd 

 88 produces acid from mannitol and glucose 

 and sometimes late acid from dulcitol; 

 strain Shigella (Type Manchester) produces 

 acid and gas from mannitol and glucose and 

 late acid and gas from dulcitol; Shigella 

 (Type Newcastle) does not ferment manni- 

 tol but produces acid and gas from glucose 

 and late acid and gas from dulcitol. 



Other varieties of Shigella flexneri have 

 been reported as not fermenting mannitol: 

 Nelson (1948) isolated non-mannitol-fer- 

 menting strains whose type antigens were 

 similar to those of Shigella flexneri 4 (Boyd 

 103) . Shigella rabaulensis Munford and Mohr 

 (1944) and Shigella rio de Assis and Stafkow- 

 sky (1948) also belong to this group: S. 

 rabaulensis has an R antigen which, al- 

 though belonging to the group antigen, is 

 specific for S. rabaulensis; S. rio is a degen- 

 erate variant of S. rabaulensis. Denier and 

 Huet (Bull. Soc. Path. Exot., 5, 1912, 263) 

 isolated a strain, which they called Saigon 

 Bacillus, in Indo China which does not 

 ferment mannitol; it produces acid without 

 gas from glucose, maltose and occasionally 

 from rhamnose and xylose in 12 to 24 days; 

 it does not ferment mannitol, lactose, su- 

 crose, dulcitol or sorbitol and it produces 

 indole; it has a type 4 major antigen and 

 minor antigens similar to those of several 

 other serotypes oi Shigella flexneri. Pacheco, 

 Rubinsten, Piechaud and Kirch suggest 

 that the name Shigella saigonensis be used 

 to include all strains of S. flexneri which do 

 not ferment mannitol. 



Source: Isolated from feces in cases of 

 dysentery. 



Habitat: The most common cause of dys- 

 entery epidemics and sometimes of infantile 

 gastroenteritis. Found in the feces of the 



sick and in the feces of convalescents or of 

 carriers of dysentery bacilli. 



6. Shigella alkalescens (Andrewes, 1918) 

 Weldin, 1927. (Bacillus alkalescens An- 

 drewes, Lancet, 194, 1918, 560; Weldin, Iowa 

 State Coll. Jour. Sci., 1, 1927, 179; Proshi- 

 gella alkalescens Borman, Stuart and 

 Wheeler, Jour. Bact., 48, 1944, 363.) 



al.ka.les'cens. Arabic al the; Arabic 

 noun gaily the ashes of saltwort, etc.; M.L. 

 part. adj. alkalescens alkaline-making. 



Rods, 0.5 by 1.0 to 1.5 microns, occurring 

 singly and in pairs. Non-motile. Gram-nega- 

 tive. 



Cultures in gelatin, on agar, in broth and 

 on potato are similar to those of Shigella 

 flexneri Castellani and Chalmers. 



Litmus milk: Turns blue in 4 to 10 days; 

 whey produced in 3 to 5 days. 



Indole is produced. 



Hydrogen sulfide not produced. 



Acid but no gas from glucose, mannitol, 

 xylose, rhamnose, maltose, dulcitol, sorbitol 

 and occasionally from sucrose. Lactose, 

 dextrin and salicin are not attacked. 



Nitrites produced from nitrates. 



Trimethylamine produced from tri- 

 methylamine oxide; trimethylamine also 

 produced from choline. 



Aerobic, facultatively anaerobic. 



Optimum temperature, 37° C. Growth at 

 45.5° C. 



Not generally accepted as pathogenic. 



Distinctive characters: Produces tri- 

 methylamine from choline. Certain strains 

 (serotypes 1 and 2) have the property of 

 agglutinating the erythrocytes of man, 

 monkeys, dogs or sheep (Griffith, 1948). 



Source: Isolated from the feces of con- 

 valescents from dysentery and from healthy 

 individuals; also isolated from a blood cul- 

 ture by Starkey (Jour. Canad. Med. Assn., 

 31, 1934, 41) and from cases of bacilluria by 

 Snyder and Hanner (Jour. Inf. Dis., 60, 

 1937, 51). 



Habitat: Found in the intestinal canal. 

 Suspected as a cause of diarrhoea. 



7. Shigella sonnei (Levine, 1920) Wel- 

 din, 1927. (Group III of Sonne, Sonne, Cent, 

 f. Bakt., I Abt., Orig., 75, 1915, 408; Bacillvs 



