1.Bacitracin given by mouth is an effective agent in terminating acute attacks of amebic colitis. Complete clinical recovery, healing of ulceration, and disappearance of amebae occurred in 8 severe cases. In one, clinical and parasite relapse occurred 8 months after therapy, and in 3 additional patients, parasite relapse occurred without clinical activity or evidence of disease 5, 18, and 350 days after therapy. In one severe case, bacitracin was effective after other amebicidal drugs and antibiotics, including aureomycin, failed to terminate the infection. Of 43 mildly symptomatic or asymptomatic patients who received one or more courses of bacitracin, apparent cures resulted in 80 per cent. The probability of cure from a single course of treatment is 66 per cent. The recommended dose is 80,000 units daily for 10 days. Toxicity from oral medication is negligible.
2.Auroemycin has been found effective in eliminating amebic infections in 31 of 32 mildly symptomatic or asymptomatic cases of amebiasis. In one of the latter, parasite relapse occurred 15 days after completion of therapy. In one severe case of amebic dysentery, 23.25 grams of aureomycin given during 9 days failed to terminate the clinical attack or eliminate E. histolytica. At the present stage of our follow-up observation, the cure rate is 93 per cent. Approximately 20 per cent of patients who received 2.0 grams or more of the drug daily had nausea and vomiting. At present, we advocate 2.0 grams daily for 10 days.
3.The uniform disappearance of enterococci and/or clostridia during therapy with bacitracin or aureomycin may indicate an important relationship between these organisms and the pathogenesis of clinical amebic colitis.
4.Chloromycetin was found ineffective in 6 cases of amebiasis, including one severe case of dysentery. Polymyxin B apparently eliminated E. histolytica from one of 7 patients treated.
5.Bacitracin and aureomycin represent important and potent additions to the agents available in the chemotherapy of intestinal amebiasis. The use of these antibiotics alone or in combination with other amebicidal drugs should materially influence the probability of cure in any given case of intestinal amebiasis.