Failure of Aureomycin in Treatment of Experimental Leishmaniasis

Abstract

Aureomycin has recently been demonstrated both experimentally and clinically to be effective against amebiasis( 1 , 2 , 3 , 4 ), trichomonas vaginalis vaginitis( 5 ) and malarial infestations( 6 , 7 ). It is, therefore of interest to know whether this antibiotic will also act on another parasitic infection, namely, Leishmaniasis (Leishmania donovani).

Materials and methods. Chinese hamsters, weighing 20 to 30 g each, were infected by intraperitoneal injection of 0.2 ml of a saline suspension of leishmania, prepared by mixing 30 ml of sterile saline solution with a finely ground spleen, freshly removed from a heavily infected hamster. The animals were divided into 2 groups and each group was further divided into 3 subgroups of 20 animals each. Aureomycin∗ was given intraperitoneally twice a day, i.e. 9 a.m. and 5 p.m., for 5 days for group A, for 10 days for group B. For the former, treatment was started immediately after the injection of leishmania, and for the latter, the antibiotic was not given until 2 months after infection. The dosage schedule of aureomycin was carried out according to the following plan:

Subgroup 1. 3 mg per animal per day.

Subgroup 2. 1.5 mg per animal per day.

Subgroup 3. 0.5 ml normal saline per animal per day and served as infected, untreated controls.

Results. During the period of treatment, 8 hamsters in group A-1 and 10 in group B-1 died, apparently due to drug intoxication: Post-mortem examination of those animals revealed the presence of hemorrhages in the lungs with extensive peritoneal adhesions. All the rest survived and were killed 2 months after the completion of the treatment. The degree of parasitization was determined by the microscopic examination of the smears made from spleens at autopsy.