Abstract

The authors performed the antibiotic susceptibility test against randomly selected 13 gram negative bacilli isolated from various specimens at clinical pathology laboratory. Fifty strains of K. pneumoniae, thirty strains of P. aeruginosa and twenty-five strains of Salmonella group A and Shigella subgroup B in each, totally 130 strains were tested. Sixty percent of K. pneumoniae, were isolated from urine, forty-three point three percent of P. aeruginosa were from pus, fifty six percent of Salmonella group A were from blood and one hundred percent of Shigella subgroup B were from stool. By disc diffusion method, the K. pneumoniae and P. aeruginosa were sensitive to Amikacin(AMK), the Salmonella group A were sensitive to the Amikacin(AMK), Ampkicillin(AMP), Cephalothin(CEP), Chloramphenicol(CAM), Gentamicin(GAM) and Tobramycin(TOB), the Shigella subgroup B were sensitive to Amikacin(AMK), Cephalothin(CEP), Gentamicin(GAM) and Tobramycin(TOB). By agar dilution method, the K. pneumoniae and P. Salmonella group A were sensitive to Amikacin(AMK), Ampicillin(AMP), Cephalothin(CEP), Gentamicin(GAM) and Tobramycin(TOB) and the Shigella subgroup were sensitive to Amikacin(AMK), Gentamicin(GAM) and Tobramycin(TOB). By agar dilution method, the most of cases of antibiotic susceptibility to pathogens except some Salmonella group A and Shigella subgroup B show tendency of wide range of MIC from 1.0㎍/㎖ to over 256㎍/㎖. On comparison of numbers of sensitive species strains by disc diffusion and agar dilution methods, most of the antibiotics except Tetracycline(TET) show relative linearity in sensitivity but in general, the disc diffusion appeared to be showing more numbers of sensitive strains than the agar dilution methods. On correlation of sensitivity between isolated bacteria from various specimen and antibiotics, the strains of K. pneumoniae isolated from urine showed a tendency of resitancy to Ampickllin(AMP), Chloramphenicol(CAM) and Tetracycline(TET), the strains of P. aeruginosa isolated from pus and ear discharge showed a tendency of sensitivity to Ampikacin(AMK), the most strains of Salmonella group A and Shigella subgroup B isolated from various clinical materials were sensitive to all antibiotics except Tetracycline(TET) in Salmonella group A and Amplicillin(AMP), Chloramphenical(CAM) and Tetracycline(TET) in Shigella subgroup B.