640 BACTERIA OF THE INTESTINAL TRACT 



this agent materially reduced the number of intestinal organisms. Naphthalene, iodo- 

 form, chloroform, chlorine water, turpentine, menthol, camphor, magnesium sul- 

 phate, and bismuth salicylate have been employed, with apparently some reduction 

 in bacterial numbers and activities. 



On the other hand, no diminution in bacterial numbers or in putrefaction products 

 could be demonstrated by Morax,' Biernacki,^ Schutz,^ Strasburger,^ and others. 

 Harris^ failed to obtain any reduction in the bacterial count by the employment of 

 beta-naphthol, salol, and guayacol carbonate. 



Quite recently Rettger, Valley, and Plastridge^ have found that certain resorcinol 

 derivatives, when fed to adult white rats daily in amounts up to 0.3 gm.. caused a 

 reduction in bacterial numbers, and the almost complete disappearance of all intesti- 

 nal organisms except Bacterium aerogenes, and that after continued oral administration 

 of these agents, the aerogenes type increased in numbers and constituted almost the 

 entire flora. Further attempts to eliminate this organism were unsuccessful. 



The stomach possesses a slightly antiseptic property, owing to the acidity of the 

 gastric juice, but its function as a germ-destroying organ is said to be almost negli- 

 gible. The usually small bacterial content of the chyle is due very largely to a dis- 

 tinct bactericidal action of the wall of the duodenum and ileum, according to the 

 claims of different investigators (Klein, Landsberger, Kohlbrligge, Moro, and others), 

 Escherich believed that the sparsity of bacteria may be explained by dilution with 

 large amounts of germ-free intestinal juice, which in itself has been shown not to be 

 bactericidal. 7 



The first notable contributions to intestinal bacteriology were those of Escherich, s 

 in which he described for the first time the organism Bad. coli, which is so character- 

 istically an intestinal bacterium and which has been the object of so much interest 

 as an index to the serious pollution of water supplies, etc.; also its close ally, Ba€t. 

 aerogenes. Although Escherich noted the predominance of gram positive organisms 

 in nurslings' stools, he was unable to isolate the aciduric types later described. 



The digestive tract of normal infants is sterile at birth, as has been shown by 

 Breslauer, Senator, Escherich, Popoff, Tissier, Moro, and others. Adventitious or- 

 ganisms make their entrance through the mouth and anus soon after birth, and con- 

 stitute a heterogeneous flora which gives way to certain definite types as soon as the 

 infant is placed on an all-milk diet. Tissier^ made the observation that the predom- 

 inating organism of the nursling's flora is a gram positive bacillus, Lactobacillus 

 bifidus (Tissier), which persists as the outstanding organism as long as mother's milk 

 constitutes the entire diet. 



' Morax, V.: Zlschr.f. physiol. Chemie, 10, 318. 1886. 



2 Biernacki, E.: Deiitsches Arch.f. klin. Med., 49, 87. 1892. 



3 Schiitz, R.: Arch.f. Verdauungskr., 7, 43. 1901. 



4 Strasburger, J.: Ztschr.f. klin. Med., 48, 491. 1903. 



5 Harris, N. M.: J.A.M.A., 59, 1344. 1912. 

 ^ Unpublished work. 



^ Cf. chap, vi for a further discussion of bacteria in feces. 

 * Escherich, T.: /oc. «■;. 

 'Tissier, H.: These. Paris, 1900. 



