FAMILY IV. ENTEROBACTERIACEAE 



339 



(Parr) , from an infected eye (Kluy ver) and 

 from contaminated water supplies (Tittsler, 

 Jour. Bact., 33, 1937, 450). 

 Habitat: Found in fecal matter. 



3. Escherichia freundii (Braak, 1928) 

 Yale, 1939. {Bacterium freundii Braak, 

 Onderzoekingen over Vergisting van Glyc- 

 erine. Thesis, Delft, 1928, 140; Citrobacter 

 freundii Werkman and Gillen, Jour. Bact., 

 23, 1932, 176 (type species of genus Citro- 

 bacter Werkman and Gillen, ibid., 173); 

 Yale, in Manual, 5th ed., 1939, 394.) 



freun'di.i. M.L. gen. noun freundii of 

 Freund; named for A. Freund, who first 

 observed that trimethyleneglycol was a 

 product of fermentation (1881). 



Short rods, with rounded ends, occurring 

 singly, in pairs and in short chains. Motile 

 or non-motile. Gram-negative. 



Gelatin stab: Liquefaction by 4 out of 15 

 cultures (Werkman and Gillen, op. cit., 1932, 

 177) . No liquefaction by any strains (Titts- 

 ler and Sandholzer, Jour. Bact., 29, 1935, 

 353; Carpenter and Fulton, Amer. Jour. 

 Pub. Health, 27, 1937, 822). 



Agar slant: Smooth, gray, shining, fili- 

 form, butyrous growth. 



Litmus milk: Acid in 2 days; coagulation 

 may or maj' not take place; no peptoniza- 

 tion. 



Potato: Abundant, 3'ellowish white 

 growth. 



Indole may or may not be produced 

 (Werkman and Gillen, op. cit., 1932, 177; 

 Tittsler and Sandholzer, o-p. cit., 1935, 353). 



Hydrogen sulfide produced in proteose 

 peptone, ferric citrate agar (Levine, Epstein 

 and Vaughn, Amer. Jour. Pub. Health, 2^, 

 1934, 505; Tittsler and Sandholzer, Amer. 

 Jour. Pub. Health, 27, 1937, 1240). 



Methyl red test positive. Voges-Proskauer 

 test negative (Koser, Jour. Bact., 9, 1924, 

 59). Some strains give a positive methj'l red 

 and a positive Voges-Proskauer test 

 (Parr, Jour. Bact., 36, 1938, 1). 



Acid and gas from glucose, fructose, 

 galactose, arabinose, xylose, raffinose, 

 lactose, maltose, mannose, rhamnose, tre- 

 halose, glycerol, mannitol and sorbitol. 

 Sucrose, salicin, dulcitol, adonitol and 

 inositol may or may not be fermented. 

 Cellobiose usually fermented while a- 



methyl-glucoside may or may not be fer- 

 mented (Tittsler and Sandholzer, op. cit., 

 1935, 353; Carpenter and Fulton, op. cit., 

 1937, 822). No acid or gas from amygdalin, 

 dextrin, erythritol, glycogen, inulin or 

 melezitose. 



Trimethyleneglycol produced from glyc- 

 erol by anaerobic fermentation (Braak, 

 op. cit., 1928, 146; Werkman and Gillen, 

 op. cit., 1932, 167). 



Citric acid utilized as a sole source of 

 carbon. 



Nitrites produced from nitrates. 



Uric acid not utilized as a sole source of 

 nitrogen (Koser, op. cit., 1924, 59; Werkman 

 and Gillen, op. cit., 1932, 167). 



Catalase-positive. 



Aerobic, facultatively anaerobic. 



Growth requirements: Good growth on 

 ordinarj^ laboratory media. Optimum 

 growth temperature, between 30° and 37° C. 

 Gas not produced in Eijkman test when 

 carried out at 45° to 46° C. (Levine, Epstein 

 and Vaughn, op. cit., 1934, 505). No gas at 

 44° C. (Wilson, Med. Res. Council, London, 

 Special Rept., Ser. 206, 1935, 165). 



Serology: This species, like Escherichia 

 coli, is divisible into serological types. The 

 serology of E. freundii has not been studied 

 as extensively as that of E. coli. In fact 

 study of these organisms has been confined 

 almost exclusively to aberrant cultures of 

 the group which ferment lactose slowly. 

 The cultures which ferment lactose slowly 

 or not at all have long caused difficulty in 

 the diagnosis of enteric infections since they 

 often are mistaken for members of the genus 

 Salmonella. It is only within the past two 

 3'ears that reliable and rapid methods of 

 differentiation of this species from sal- 

 monellas through KCN and decarboxylase 

 tests have become available (M0ller, Acta. 

 Path, et Microbiol. Scand., 26, 1954, 115 

 and 158). 



The slow lactose-fermenting organisms 

 of the E. freundii group have been desig- 

 nated as the Bethesda-Ballerup group 

 (Edwards, West and Bruner, Jour. Bact., 

 55, 1948, 711). Since these are often confused 

 with salmonellas, H was natural that they 

 should have attracted greater attention 

 among medical bacteriologists than typical 

 E. freundii cultures. Through the work of 



