It is held that the organs of the body normally are sterile; in fact, this is the principle on which asepsis in surgery and medicine is supposed to be based. There has accumulated considerable evidence, however, that this apparently fundamental postulate must be essentially modified. It has been generally conceded that bacteria can pass through an ulcerated or abraded intestinal mucosa or other epithelial surface, but an intact surface is supposed to be an efficient barrier to the entrance of germs.
Adami1 injected the colon bacillus intravenously into animals, and in 15 minutes these organisms were found in the cells of the liver and kidney. In two or three hours later the organisms appeared as diplococcoid forms and often arranged in the cells in a characteristic manner. This diplococcus appearance is due probably to the disintegration of the bacteria by the tissues of the body. Organisms may be seen frequently
BACTERIA IN NORMAL TISSUE.. JAMA. 1904;XLII(25):1628-1629. doi:10.1001/jama.1904.02490700028007