Growth inhibitory effect of combined treatment of tetracycline (TC) and oleandomycin (OM), at a ratio of 2:1, on certain species of pathogenic bacteria including drug-resistant ones was examined. By the crossed paper strip method, synergistic effects were demonstrated against 9 of the 16 strains of Staphylococcus aureus, and all of the 5 strains of Escherichia coli studied. Antagonism was observed with none of the strains and with 2 strains of Streptococcus pyogenes and 2 strains of Streptococcus pneumoniae tested in the present experiments. The MICs determined by the agar dilution method, also gave similar results, although synergism was not conclusively demonstrated by this method. With representative strains of S. aureus, synergism was evidenced by quantitative measurement of growth inhibition. In some strains, 1.0 mug of one drug per ml of medium inhibited the induction of resistance to the second drug. Such a small dose of one drug also inhibited the development of a mutant resistant to the second drug. These inhibitory actions were thought to be one of the important factors causing the synergistic effect of TC and OM on drug resistant bacteria.

Drug Combinations↗

PubMed1975

The effect of prostagrandin F2alpha E1 and some spasmolytic agents on the exposed cat basilar artery.

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Animals↗

PubMed1975

[Comparative studies of the therapeutic effect of colistin methanesulfonate administered intramuscularly and intravenously on the acute bacterial infection in mice (author's transl)].

The therapeutic potencies of colistin methanesulfonate (CLM) was assessed quantitatively in acute infection of mice with clinically isolated strains of Escherichia coli and Pseudomonas aeruginosa, and effect of different routes of administration was compared. There was no detectable difference in the therapeutic effect of CLM when intramuscular (im) or intravenous (iv) administration was initiated one hour after the infection. On the other hand, a significant difference in ED50 given by im and iv administrations was observed, indicating the superiority of iv administration, when the treatment started 4 to approximately hours after the infection. No difference in the therapeutic effect of polymyxin B (PMB) and tetracycline (TC) administered via either im or iv route was found even in the delayed administration. In contrast to PMB and TC, lower toxicity of CLM was determined when it was administered iv rather than im.

Acute Disease↗