Chemical pathology : being a discussion of general pathology from the standpoint of the chemical processes involved / by H. Gideon Wells.

  • Wells, H. Gideon (Harry Gideon), 1875-1943.
Date:
1918
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Licence: In copyright

Credit: Chemical pathology : being a discussion of general pathology from the standpoint of the chemical processes involved / by H. Gideon Wells. Source: Wellcome Collection.

    124/734 (page 118)
    Kantorowicz 58 and de Waele 59 state that bacteria contain an in- tracellular anti-protease which, with most bacteria, holds in check the proteolytic action; only with the liquefying bacteria are the proteases in excess. Bacteria grow well in strong solutions of en- zymes, and without destroying the enzymes (Fermi).60 After Gram- negative bacteria have been heated to 80° they are readily digested by trypsin, pepsin or leucocytic proteases; but Gram-positive bacteria are resistant even after heating. This is ascribed by Jobling and Petersen60a to the unsaturated fatty acids, which are present in greater amounts in Gram-positive bacteria. Autolysis of Bacteria.—Autolysis occurs also in bacteria, their proteolytic enzymes digesting the cell substance whenever the organ- isms are killed by agents (chloroform, toluene, etc.) that do not de- stroy these enzymes, and which, being fat solvents, may facilitate di- gestion by removing the inhibitory lipoids. Even the absence of food leads to autolysis, presumably because the normally existing auto- lytic processes are not counteracted by synthesis of new protein ma- terial ; hence, autolysis occurs when bacteria are placed in salt solution or distilled water. Although it had been known for many years that yeast cells digest one another when there is nothing else for them to live upon, the first definite study of bacterial autolysis seems to have been made by Levy and Pfersdorff61 and Conradi.62 The former digested anthrax bacilli (in whose bodies are contained rennin, lipase and protease) under toluene for several weeks and obtained a slightly toxic product. Conradi permitted dysentery bacilli and typhoid bacilli to digest themselves in normal salt solution for twenty-four to forty-eight hours at 37° C., and obtained in this way the soluble, highly poisonous endotoxins of the bacteria, which are liberated by the destruction of the bacterial structure by the autolytic enzymes. Longer autolysis results in the destruction by the enzymes of the en- dotoxins themselves. Rettger 63 found among the autolytic products of bacteria, leucine, tyrosine, basic substances, and phosphoric acid. Under favorable conditions complete autolysis can occur in two to ten days. Brieger and Mayer64 found that at room temperature (15° C.) practically no autolysis occurs with typhoid bacilli in distilled water, and the soluble products thus obtained are quite non-toxic, although if injected into animals they give rise to the production of agglu- tinins and bacteriolysins. Bertarelli65 has used the products of 58 Munch, med. Woch., 1909 (56), 897. 59 Cent. f. Bakt., 1909 (50), 40. so Arch. Farmacol., 1909 (8), 481. eoa Jour. Exp. Med., 1914 (20), 321. 61 Deut. med. Woch., 1902 (28), 879. 62 Ibid., 1903 (29), 26. 63 Jour. Med. Research, 1904 (13), 79. 64 Deut. med. Woch., 1904 (30), 980 65 Cent. f. Bakt., 1905 (38), 584.