Studies on the Antibiotic Sensitivity of Escherichia coli Isolated from a Doctorless Area and Seoul National University Hospital

일부(一部) 무의촌지역(無醫村地域)과 병원(病院)에서 분리(分離)한 E.coli의 항생제(抗生劑) 감수성(感受性)에 대(對)하여

40 strains of E. coli isolated from residents of a doctorless area in Korea in 1976 and 40 strains of E. coli isolated from patients of Seoul National University Hospital from 1975 to 1976 were examined for susceptibilities to 14 antimicrobial agents by the agar dilution method. The susceptibilities of the two groups to each antimicrobial agent were compared and correlations in the antimicrobial susceptibility of the 80 strains of E. coli among the 14 antimicrobial agents were also analyzed. The results were obtained as follow: 1. With Tetracycline, Oxytetracycline, Doxycycline and Ampicillin, the mean MIC's of E. coli isolated from patients of Seoul National University Hospital were 8.6 to 14 times higher than. those of E. coli isolated from residents of a doctorless area. 2. With Streptomycin, Minocycline and Carbenicillin, the mean MIC's o{ E. coli isolated from patients of Seoul National University Hospital were 4.1 to 5.6 times higher than those of E. coil isolated from residents of a doctorless area. 3. With Kanamycin, Penicillin and Cotrimoxazole, the mean MIC's of E. coli isolated from patients of Seoul National University Hospital were 2.6 to 3.7 times higher than those of E. coli isolated from residents of a doctorless area. 4. There were no significant differences in susceptibility to Erythromycin respectively between E. coli isolated from patients of Seoul National University coli isolated from residents of a doctorless area. 5. E. coli isolated from patients of Seoul National University Hospital were resistant to Erythromycin(100%), Streptomycin(75%), Tetracycline(72.5%), Oxytetracycline(72.5%), Doxycycline(72.5%), Minocycline(67.5%), Penicillin(82.5%), Ampicillin(60%) and Carbenicillin(65%) respectively and were sensitive to Gentamicin(97.5%), Cephalexin(92.5%) and Kanamycin(72.5%) respectively. 6. E. coli isolated from residents of a doctorless, area were resistant to Erythromycin(100%), Streptomycin(40%) and Penicillin(50%) respectively and were sensitive to Gentamicin(100%), Kanamycin(92.5%), Tetracycline(87.5%), Oxytetracycline(87.5%), Doxycycline(87.5%), Minocycline(87.5%), Ampicillin(95%), Carbenicillin(92.5%) and Cephalexin(97.5%) respectively. 7. There were high correlations among the suscebtibilities of the 80 strains of E. coli to Tetracycline analogues(Tetracycline, Oxytetracycline, Doxycycline and Minocycline) and among susceptibilities of the 80 strains of E. coli to Penicillin analogues(Penicillin, Ampicillin and Carbenicillin). 8. There were relatively high correlations between the susceptibilities of the 80 strains of E. coli to Penicillin analogues and those to Tetracycline analogues, between the susceptibilities to Penicillin analogues and those to Streptomycin and between the susceptibilities to Tetracycline analogues and those to Streptomycin.