On the Pathogenicity of Pathogenic Coll

Abstract

To understand the role of pathogenic coll in coll enteritis, the author and his co-workers have been engaged for several years in a comparative study of pathogenic and normal or non-pathogenic coll strains. The results are summarized as follows:
1) A strict and fundamental discrimination of the two coll groups was neither in their contagiosity nor in their persistence practicable, as indicated by the results of bacillus isolation from the feces of healthy and morbid examinees, consisting of infants, children and adults. The difference was merely a relative one.
2) Excepting 0-113, 126 standard strains out of E. coll 0-1 to 0-127, as well as isolated strains were seeded in a modified Andersen's synthetic medium, in which NH4Cl was substituted by various amino acids as the nitrogen source. The bacterial growth was determined photometrically.
i) Utilization of amino acids as the nitrogen source varied according to the kind of amino acids employed and to different o-antigen groups. Pathogenic strains tended to be associated with an intense utilization of amino acids. The results were regarded to be of importance, because some amino acids, such as glutamic acid, aspartic acids, etc., could be liberated in the small intestine as decomposition products of milk.
ii) Utilization of sugars as the carbon source exhibited likewise a remarkable variati on, according to the kind of sugars and strains. It was noteworthy, that only a small number of strains, including almost all pathogenic strains, could utilize sucrose (0-25, 0-26, 0-55, 0-111, 0-126, 0-127, etc.).
iii) These results indicated that the majority of pathogenic coll strains was endowedwith a greater advantage in the multiplication in the small intestine.
3) No definite relation was confirmed between the o-antigen groups and the hemolytic action of the bacilli on goat's erythrocytes, skin reaction in rabbits or the quantity of histamine or tyrarine as revealed by paper chromatography and indi cative of the activity of hitamine or tyrosine decarboxylase.
4) In view of fatty degeneration of the liver, reported in many autopsy cases of coll enteritis, experimental investigations were performed to induce degenerative liver changes in mice. Aqueous extracts of the standard strains of E. coll 0-1 to 0-127 as well as the isolated strains were injected intraperitoneally in an uniform quantity equivalent to 2mg. of the bacilli. The animals were sacrificed in 2 to 5 days, and the liver was examined histologically. The most remarkable fatty degeneration was induced by strains 0-11, 23, 35, 65, 66, 68, 81, 85, 99, 111, 112 and 120. Almost all liver cells were filled up with small fat droplets. The next most remarkable changes were those due to strains 0-3, 6, 8, 10, 16, 18, 20, 21, 26, 54, 55, 57, 58, 60, 62, 67, 71, 72, 80, 82, 83, 84, 86, 90, 93, 103, 105, 106, 107, 108, 117, 123 and 125. Strains 0-4, 13, 15, 17, 19, 22, 24, 27, 30, 32, 36, 41, 43, 61, 64, 60, 73, 74, 75, 78, 87, 97, 98, 100, 102, 104, 118, 119, 121, 122, 124, 126 and 127 caused remarkable, though somewhat slighter, fatty degeneration. The other remaining strains caused only slight, if any, or no fatty degeneration. It was noticed that the capacity of inducing fatty degeneration of the liver was by no means confined to pathogenic strains, though the majority of the latter caused the intensive changes.
5) Endotoxin was regarded to be the main factor responsible f or the pathogenicity of coll strains in coll enteritis.
6) o-agglutinin against normal and pathogenic coll was demonstrated in varying quantities in the sera of infants, adults and pregnant women.
7) Further investions from other points of view were required for the problems concerning the pathogenicity of coll strains.