Amedeo Bondi

Penicillin. Resistant Staphylococci.

Summary (1) In a study of the susceptibility of 115 strains of staphylococci to penicillin 16 or 13.9% were found to be resistant. (2) All strains resistant to penicillin produced penicillinase; none of the susceptible strains had this property. (3) Many of the penicillinase-producing staphylococci produce coagulase indicating the importance of the former in infection. (4) Staphylococci naturally resistant to penicillin appear to be resistant as a result of their ability to produce penicillinase.

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.

Production of Penicillinase by Bacteria.

Conclusions A simple test for the qualitative and quantitative determination of penicillinase produced by bacteria is described. Bacteria capable of producing penicillinase are widely distributed in nature; such organisms vary considerably as to the amount of penicillinase they produce. The possible significance of penicillinase and penicillinase-producing bacteria in relation to penicillin therapy is discussed.

Relationship of Penicillinase to the Action of Penicillin

Conclusions Inability to produce penicillinase is not a determining factor in the sensitivity of an organism to penicillin. However, penicillinase-producing bacteria are not likely to be highly susceptible to penicillin. Development of resistance to penicillin by a bacterium is not associated with acquisition by the bacterium of the ability to produce penicillinase.

Influence of sodium benzoate by ingestion upon urinary excretion of streptomycin.

Summary The results indicate, therefore, that the oral administration of sodium benzoate in tablets in dose of 10 to 20 grains (0.65 to 1.3 g) every 4 hours for 6 doses totalling 60 to 120 grains (3.9 to 7.8 g) along with single intramuscular injections of 0.25 and 0.5 g (250,000 and 500,000 units) of streptomycin does not appear to reduce materially the urinary excretion of streptomycin, and does not enhance or prolong the maintenance of the serum levels of the compound. It is to be emphasized, however, that these preliminary results are inconclusive and, in view of the clinical importance of the subject in relation to the administration of streptomycin, additional investigations are being conducted.

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.