二次性尿路感染症由来菌に対するサルファ剤の試験管内抗菌力にかんする検討

Abstract

This report deals with in vitro assessment of sulfa drugs on their antibacterial activity against 191 strains of bacteria which were isolated from secondary urinary tract infection during the recent six months period in our clinic. The results obtained were summarized as follows. 1) A relation of inoculum size with MIC of sulfamethoxypyrimidine (SMP) was surveyed at the outset. As a result of this survey, it was found that even 3, 200 mcg/ml of SMP could not inhibit a strain of E. coli from growing if 10[5] c.c./ml solution of it was used for inoculation, while the E. coli was fully inhibited to grow by 25 mcg/ml if 10 c.c./ml. A strain of Klebswlla proved to be much the same as the E. coli. 2) MICs of SMP and sulfadiazine (SD) against the bacteria were determined by plate dilution method using a solution of 10[6] c.c./ml for Gram-positives and a solution of 10[5] c.c./ml for Gram-negatives as inoculum size. Majorities of E. coli, Klebsiella, Morganella, Serratia, Providencia, Staphylococcus aureus and Staphylococcus epidermidis, and all of Citrobacter and Enterococcus had MIC more than 1, 600 mcg/ml against SMP and SD. Sensitive bacteria having MIC less than 50 mcg/ml were found out in only a few percent of E. coli, Pseudomonas, Morganella and Staphylococcus aureus, and in about 40 percent of Proteus mirabilis which was proved to be most sensitive of all species in our series. 3) On a base of correlation of the sensitivity distribution of SMP and SD, a cross-resistance was estimated to exist closely between SMP and SD against Proteus mirabilis, Pseudomonas, Cloaca and Staphylococcus epidermidis. 4) As compared with sensitivity distribution of GM, CB-PC and CEZ against E. coli, Klebsiella, Pseudomonas, Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus, the sulfa drugs had the least sensitivity.