Studies on the Pathogenicity of Pathogenic E. Coli
1959 Volume 33 Issue 7 Pages 661-682
Details
1959 Volume 33 Issue 7 Pages 661-682
The pathogenicity of E. coli was analyzed from 2 factors; multiplication in vivo and disease-producing activity, as the pathogenicity is thought to consist of these two factors according to the author.
A) Multiplication activity was investigated by culturing the human stools after the oral administration of pathogenic E. coli as well as nonpathogenic E. coli as contrast.
1) From stools of 15 adults who had swallowed nonpathogenic E. coli, O-16, this strain was recovered only in 12 cases in small amounts and for a short period of time. And the remaining 3 cases, O-16 was not recovered at all.
rom stools of 5 newborns given O-16 orally, this strain was recovered in all the cases.
A marked multiplication was recognized as well in 19 out of 20 adults given orally SM and SM-resistant O-16 simultaneously.
2) Out of 20 cases of human adults having swallowed pathogenic E. coli O-111: B4, 17 cases (85%) presented a marked multiplication.
3) Swallowed strains of E. coli were not recovered in 5 (71%) out of 7 cases with gastric hyperacidity, suggesting multiplication-inhibiting activity of gastric acid against exogenic E. coli. On the contrary, exogenic E. coli was isolated from stools of 17 (89.5%) out of 19 cases with gastric hypoacidity or anacidity.
B) Secondly, the disease-producing activity was studied through the De's experiment using rabbit's intestine coupled with the human experiments swallowing pathogenic E. coli.
1) Ten (50%) out of 20 adults who had swallowed 1 billion of O-1114-B4, suffered from diarrhea accompanied with slight abdominal pain and peristaltic sounds. One of them showed even an elevated temperature.
2) Out of 36 known strains of pathogenic E. coli, 26 strains (ca. 72%) caused macroscopic changes in the ligated loop of rabbit's bowel and 31 strains (ca. 86%) microscopic changes. Out of 40 strains of nonpathogenic E. coli as contrast, only 7 strains (17.5%) evoked macroscopic changes in the ligated loop of rabbit's bowel and 6 strains microscopic changes.
In addition, 4 pathogenic strains (3 strains of salmonella and 1 of Shigella) induced conspicuous macroscopic and microscopic changes.
