Assessment of validity of counterimmunoelectrophoresis and ELISA in the routine diagnosis of amoebiasis.

Counterimmunoelectrophoresis (CIE) was used to detect antibodies against Entamoeba histolytica in 99 sera from amoebiasis suspected patients using antigens from the HK-9 and HT-12 strains of axenically cultivated E. histolytica. There was no significant difference of seropositive rates using antigens from these two strains suggesting the both strains were equally suitable for use in the routine CIE test for the diagnosis of amoebiasis. In comparison with ELISA, the CIE test was a little less sensitive than ELISA with per cent sensitivity of 93.5 and 100 respectively. Two amoebic liver abscess patients who were CIE negative were ELISA positive. The CIE seropositive rate was related to the period after onset of clinical symptoms with per cent positivity of 66.7, 93.3 and 100 when the sera were tested on less than or equal to 5, 6-10 and greater than or equal to 11 days of illnesses respectively.

Cellulose acetate membrane precipitin (CAP)test in amoebiasis using antigens from four different strains of Entamoeba histolytica.

A simple cellulose acetate membrane precipitin (CAP) test was evaluated against immunoelectrophoresis (IEP) test using saline extract from 4 different strains (HK-9, HT-10, HT-12 and HT-31) of axenically grown Entamoeba histolytica as the antigens. All 81 sera from patients with amoebic liver abscess were positive in the IEP against the antigens from all 4 strains. With the CAP test the number positive against antigens from HK-9, HT-10, HT-12 and HT-31 were 79,77,79 and 71 respectively Sera from 100 blood donors were negative by both IEP and CAP tests against antigens from all 4 strains. Comparison between the number of precipitating bands demonstrated by either IEP or CAP test showed that strain HT-12 was the best source of antigen in exhibiting significantly more number of precipitating bands, strain HT-31 was the poorest. The strain HT-10 was comparatively superior to strain HT-31 in the CAP test whereas in the IEP test strain HK-9 and HT-31 were both inferior to strain HT-10.

Protection afforded by anti-hemolysin against V. cholerae El Tor infection in experimental cholera.

Specific antisera to V. cholerae El Tor hemolysin were prepared. The sera exhibited the following characteristics: formed a single precipitin band in immunoelectrophoresis against the crude preparation of hemolysin, had no passive hemagglutinating antibodies against V. cholerae LPS sensitized cells, possessed neutralizing property to the homologous hemolysin, and afforded some small degree of protection to oral challenge of V. cholerae El Tor in experimental animals.

Effects of antibody to Vibrio cholerae El Tor hemolysin on pathological changes of the intestines in cholera.

Pathological abnormalities of the infant mouse small intestines were evident after V.cholerae El Tor, Ogawa, infection. These were revealed by an enteritis manifested by mononuclear cells containing inflammatory exudate, intervillous blood capillary congestion, marked increase in goblet cells, desquamation of epithelium and diapedesis of cells. Mice received V.cholerae pretreated with high concentration of antihemolysin, though developed diarrhea, had marked decrease in pathological severity. The less amount of the antibodies the more pathological changes were found.