[Comparative studies of antimicrobial agents against causative organisms isolated from urinary tract infections (1983). I. Susceptibility distribution].

During 1979-1983 in vitro activities of antimicrobial agents against causative bacteria isolated from patients with urinary tract infections (UTI) were investigated by Microbiological Research Group of UTI including the 8 institutions in Japan. Of all strains (219) isolated from patients with simple UTI, 65.3% were E. coli, and 9.6% Klebsiella spp.; these species accounted for about 75% of all isolates in 1983. MPC and CCL among the oral antimicrobial agents have showed potent activities against E. coli, MPC at 1.56 micrograms/ml and CCL at 3.13 micrograms/ml inhibited 80% of E. coli from simple and complicated UTI. CTM, CTX, CZX, CMX and LMOX among the parenteral antimicrobial agents, at concentrations of 0.20 micrograms/ml or less inhibited 90% of E. coli isolated from simple and complicated UTI. The frequency of isolates from patients with complicated UTI, without catheter, was as follows; E. coli 27.6%, P. aeruginosa 20.1%, Streptococcus spp. 12.6%, Serratia spp. 8.8% and Klebsiella spp. 8.0%. The frequency of isolates from patients with complicated UTI, indwelling catheter, was as follows; P. aeruginosa 22.6%, Streptococcus spp. 18.0%, Serratia spp. 15.0%, Proteus spp. 12.4%, and Enterobacter spp. and Klebsiella spp. are 6.0%, respectively, in 1983. The antibacterial activity (MIC80) against E. coli, Klebsiella spp., P. mirabilis, Citrobacter spp. and Serratia marcescens from simple and complicated UTI was compared, for example, among third generation cephem antibiotics. Four drugs such as CMX, CZX, CTX and LMOX showed virtually comparable activities while CPZ was slightly less active against the strains tested. There have been many studies reported concerning the antibacterial activity of various drugs against clinical isolates from patients with infections, but it seems that, to our knowledge, no article has dealt with yearly surveys on antimicrobial susceptibility of bacterial isolates from defined clinical specimens with the same period of each year at the same series of institutions.