From the laboratory and clinical studies on propionylmaridomycin (PMDM), a new macrolide antibiotic, the following results were obtained.
1) Antibacterial spectrum
The antibacterial activity of PMDM was similar to that of each known macrolide antibiotic such as leucomycin and josamycin, and this antibiotic did not induce a resistance.
The minimum inhibitory concentrations (MIC) of PMDM were 0.39-3.13 mcg/ml against
Staph. aureus. The MIC of PMDM for Streptococci group was found to be similar to that of this antibiotic against
Staph. aureus. But PMDM was ineffective against gram-negative enteric bacteria.
2) The sensitivity distribution for 54 clinical isolates of
Staph. aureusThe sensitivity distribution was studied on PMDM, 4 ″-deacyl-PMDM and other macrolide antibiotics. The sensitivity distribution of PMDM was found to be similar to that of josamycin and mydecamycin.
The standard curve at pH 7.0 was similar to that at pH 8. 0, but the standard curve was different between that in human serum and in monitrol serum to one tube on antibacterial activity.
3) Serum level and urinary excretion
Serum level and urinary excretion of PMDM were studied by the cup method with
S. lutea ATCC 9341 as a standard organism. Serum level of PMDM in healthy adults given a single oral dose of 400 mg demonstrated peak level of 0.46 mcg/ml respectively two hours after administration, and serum level at six hours after administration was 0.27 mcg/ml.
Concentration of PMDM in urine demonstrated peak level of 24.5 mcg/ml two hours after administration. The cumulative urinary recovery of PMDM was 0.55% for 8 hours after administration.
4) Tissue concentration
After oral administration of 200 mg/kg PMDM to SD strain rats, the highest tissue concentration of PMDM was found in lungs, followed by liver, muscle, serum, kidneys, heart and brain.
5) Metabolism
The metabolism was studied by thin layer chromatography and bioautography. The administered PMDM was metabolized to 4″ -deacyl-PMDM, maridomycin, 4Prime;-deacyl-maridomycin and unknown metabolites.
6) Clinical results Twenty-nine patients with infections in the field of surgery were treated with PMDM, which was effective in 19 patients (65.5%).
No noticeable side effects were found.
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