DETECTION OF THE THERMOLABILE TOXIN PRODUCED BY ENTEROTOXIGENIC E. COLI WITH A GENETIC PROBE AND THE SOLID PHASE RADIO-IMMUNOLOGICAL ASSAY / 解放军医学杂志

ABSTRACT

The paper reported two methods. a genetic probe and the solid phase radio-immunological assay, for the detection of the thermolabile toxin produced by Escherichia coli. The former is the application of a 32P-IabelIed probe of B subunit DNA prepared from Hind Ⅲ restriction fragment of LT-encoding DNA. and the latter is by using CNBr-activated paper as carrier and 125I-SPA to substitute the secondary antibody. Applying the methods to 160 strains of E. coli isolated from patients suffering from infantile diarrhea, the results showed that 42 out of 160 strains belong to the strain which produces the thormolabile toxin. These two methods not only have the advantages of being sensitive and specific, but also are beneficial favourable to the epidemiological survey and clinical diagnosis, because the testing bacteria are decomposed on the nitrocellulose membrane, so that hundreds of samples can be examined in one test.