FAMILY X. LACTOBACILLACEAE 



523 



Action on blood: Greening (alpha hemo- 

 lytic) to indifferent (gamma hemolytic). 



Abundant growth in broth media con- 

 taining fermentable carbohydrate with 

 the production of uniform turbidity and 

 heavy sediment. 



Some strains are actively motile (Leven- 

 sen, Ann. Inst. Past., 60, 1938, 99; Bruner, 

 Edwards, Doll and Moran, Cornell Veteri- 

 narian, 38, 1948, 313; Auerbach and Felsen- 

 feld, Jour. Bact., 56, 1948, 587). 



A few strains are reported that are 

 yellow pigmented (Hannay, Jour. Gen. 

 Microbiol., 4, 1950, 294). 



Not fibrinolytic. 



Temperature relations: Growth at 10° and 

 45° C. Survives 60° C. for 30 minutes. 



Tolerance tests: Growth in broth contain- 

 ing 6.5 per cent NaCl. Growth at pH 9.6 

 (Sherman and Stark, Jour. Dairy Sci., 17, 

 1934, 525; Shattock and Hirsch, Jour. Path. 

 Bact., 69, 1947, 495). Growth in milk con- 

 taining 0.1 per cent methylene l)lue. Growth 

 on 40 per cent and higher concentrations of 

 bile in blood agar. 



Litmus milk: Acidified, usually curdled 

 with complete reduction of litmus before 

 curdling. Some cultures do not reduce lit- 

 mus before curdling. 



Final pH in glucose broth, between 4.0 

 and 4.4. 



Acid from glucose, maltose, lactose, 

 trehalose and salicin. All cultures ferment 

 glycerol, although this substance may be 

 fermented only under aerobic conditions by 

 some strains (Gunsalus and Sherman, Jour. 

 Bact., 45, 1943, 155). Mannitol and sorbitol 

 are fermented with only occasional ex- 

 ceptions. Arabinose and sucrose may or 

 may not be fermented. Inulin and raffinose 

 are seldom fermented. 



Some strains are able to ferment citric 

 acid in the absence of any fermentable car- 

 bohydrate with the production of acetic 

 acid, carbon dioxide, formic acid and lactic 

 acid (Campbell and Gunsalus, Jour. Bact., 

 48, 1944, 71). 



No polysaccharide is synthesized from 

 sucrose. 



Starch and gelatin not hydrolyzed. 

 Sodium hippurate may or may not be hy- 

 drolyzed. Esculin split. 



Ammonia produced from arginine. 



Tyrosine is decarboxylated with the pro- 

 duction of tyramine and carbon dioxide. 



Distinctive characters: This species and 

 the other members of the enterococcus 

 group are easily distinguished from the 

 other Streptococcus species by their wide 

 temperature limits of growth, their salt 

 tolerance and their ability to initiate 

 growth at pH 9.6. They are also considerably 

 more tolerant to penicillin than the other 

 streptococci, most strains being able to 

 grow in the presence of 0.5 to 1.0 unit of this 

 antibiotic per ml. All enterococci are dis- 

 tinctive in their ability to decarboxylate 

 tyrosine. 



Source : Human feces and the intestine of 

 many warm-blooded animals. Occasionally 

 encountered in urinary infections and in the 

 blood stream and heart lesions in subacute 

 endocarditis cases. Associated with Euro- 

 pean foul-brood of bees; found in milk and 

 dairy products. Has been associated with 

 mild outbreaks of food poisoning. 



Habitat: Intestines of humans and many 

 other warm-blooded animals. 



16a. Streptococcus faecalis var. lique- 

 faciens (Sternberg, 1893, emend. Orla- 

 Jensen, 1919) Mattick, 1947. {Streptococcus 

 liquefaciens Sternberg*, Manual of Bac- 

 teriology, 1893, 613; Orla-Jensen, The Lac- 

 tic Acid Bacteria, 1919, 142; Mattick, Proc. 

 Fourth Internat. Cong, for Microbiology, 

 Copenhagen, 1947, 519.) 



li.que.fa'ci.ens. L. part. adj. liquefaciens 

 liquefying. 



This variety was regarded as a separate 

 species. Streptococcus liquefaciens, in the 

 Manual, 6th ed., 1948, 326, but it is believed 

 that the differences are not sufficient to 

 warrant species distinction. This variety 

 possesses the same characteristics as Strep- 

 tococcus faecalis except as given below. It 

 is a member of the enterococcus group and 

 Lancefield's group D. It can not be dis- 



* Streptococcus liquefaciens Frankland and Frankland, 1888 (Phil. Trans. Roy. Soc. 

 London, 178, B, 1888, 264), may have been an organism identical with Sternberg's; it was 

 described as producing a yellow pigment, as do certain strains of Streptococcus faecalis. 



