Abstract
In a recent article by Moench, Kahn and Torrey 1 a report was given of an analysis of the fecal flora in 33 cases of pernicious anæmia. The most striking feature revealed by these examinations was the constant presence of unusually large numbers of B. welchii in the stool specimens and presumably throughout the large intestine. These findings were a confirmation and extension of the earlier observations of Herter 2 and also of Simond. 3 It was suggested that the absorption of B. welchii toxin from the intestinal tract might conceivably be the essential etiological factor in the production of the clinical syndrome which characterizes pernicious anæmia, and that our findings justified further inquiry by experimental methods. In the present communication we wish to report in a preliminary way our observations on the effect of a potent B. welchii toxin on the blood of monkeys when injected intravenously.
Several strains of B. welchii, isolated from different cases of pernicious anæmia, were compared as regards toxin production, employing the Bull and Pritchett 4 method of production, and injecting graded amounts of the filtered toxin into the wing vein of pigeons. Our strain “Navital” proved the best suited for our purposes but it was deemed advisable to enhance its virulence by animal passages. Accordingly it was passed through six successive rabbits by intravenous inoculation, and then through four pigeons by injections into the breast muscles and recovery from the lesions on the death of the bird. The virulence of the whole culture was finally such that 0.02 cc. caused death within 18 hours. Sterile filtrates of the culture were found to be, however, only slightly more toxic than the unpassed strain.
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