抄録
Complement fixation and sedimentation tests were carried out with sera and extracts of several organs of guinea pigs infected with entamoeba histolytica. Inoculation was performed by the injection of organisms directly into caecum. Out of 50 animals inoculated, 16 were found infected and 14 of them had amebic ulcers in intestines and the remaining 2 had no ulcer but had abundant amoebae in their caecal contents. All of the sera obtained from these 16 animals showed positive complement fixation. Out of 34 guinea pigs which were not successfully infected, 2 showed positive complement fixation. One of these 2 cases had a small ulcer in caecum, but it was not clear whether it was amebic or not.
Extracts of liver, lung, spleen and caecal wall of the test animals were also examined. Those extracts of infected animals showed also positive reaction. The extracts of caecal wall and spleen were likely to show more intense positive reaction than those of liver and lung. Organ-extracts of the guinea pigs, in which the infection was unsuccessful, showed positive reaction mostly at the highest concentration of the extracts, and in exceptional cases, positive reaction was seen at lower concentration.
Sedimentation tests was less reliable than the complement fixation tests. Sera or organextracts of infected animals showed positive reaction, and those of uninfected animals also showed positive reaction very often.
Serum obtained from the C. F. T. positive animals was added to the culture media of entamoeba histolytica with no effect upon the growth of the organisms.
Guinea pigs were repeatedly injected intraperitoneally with entamoeba histolytica and their sera became positive to the C. F. T. These animals were inoculated intracaecally with entamoeba histolytica. Incidences of infection and intestinal ulcer in these cases had no remarkable difference as compared with those in the control animals without previous injection of the organisms.
