Earle H. Spaulding

Interference With the Antibacterial Action of Streptomycin by Reducing Agents

The antibacterial activity of streptomycin in infusion agar plate cultures of E. coli and other bacteria is diminished by anaerobic incubation. The bacteriostatic activity of this antibiotic for E. coli is reduced in the presence of cysteine, sodium thioglycollate, stannous chloride, sodium bisulfite, sodium hydrosulfite, sodium formate, and sodium thiosulfate. Cysteine was the most active of the agents tested. Further investigation is necessary to determine the nature of this interference. It is possible that this phenomenon is related to the mode of action of streptomycin.

Demonstration of Globi and Leprosy Bacilli by Fluorescence Microscopy.

Hagemann 1 reported the superiority of a fluorescence method using berberine sulfate stain for demonstrating leprosy bacilli in nasal mucus and thick blood smears. The same year he 2 proposed an auramin-fluorescence technic for the routine identification of acid-fast fast bacteria, especially tubercle bacilli. The suitability of this method for cultures of Myco. leprae has been confirmed by Küster 3 and for leproma smears by Kline and Leach. 4 Recently one of us (H.J.H.) has investigated the separation and concentration of acid-fast organisms from the tissues of leprosy patients. To cryochemed spleen† distilled water was added and direct impression smears were made from a piece of the tissue. One set of smears was stained with auramin O and examined according to the fluorescence procedure described by Richards and Miller. 5 A representative field is shown in the accompanying photomicrographs. The faint material in the background is non-acid-fast splenic cellular substance. The acid-fast bacilli have a characteristic granular appearance. Although no accurate comparison was made with Ziehl-Neelsen stained smears, the fluorescence technic was clearly superior for demonstrating globi and leprosy bacilli. It is of interest to note that Richards, Kline and Leach 6 believed more tubercle bacilli could be demonstrated in the same microscopic fields by fluorescence than by the conventional method.

Effectiveness of Sulfanilamide upon Anaerobic Hemolytic Streptococci

Summary 1. Two weakly virulent strains of “anaerobic,” Group A, hemolytic streptococci were subjected to in vivo and in vitro tests with sulfanilamide. 2. One strain was resistant, the other moderately susceptible, to the drug in mice. 3. No essential difference between the strains could be demonstrated, however, by in vitro bacteriostatic, phagocytic and biochemical tests. 4. Following adaptation to aerobic incubation (14 and 18 months) both strains were refractory in mice. 5. The results indicate that anaerobiosis, per se, was not the fundamental factor in determining drug response of these “anaerobic” hemolytic streptococci.