Abstract
An antibiogram is a method of presenting accumulated data on the sensitivity of isolated bacterial strains in various facilities and regions to different antimicrobial agents, and is an important source of information when beginning empirical therapy of an infection. Data on strains isolated in one hospital over a given period of time are generally aggregated together, but some strains may show big differences in sensitivity depending on the department and specimen type. The present study investigated P. aeruginosa, which is isolated in large numbers, so resistant strains can easily become a problem in treatment, and examined the differences in rates of susceptibility to 13 types of antimicrobial agents across departments, among different specimen types, and between outpatients and inpatients. In 2009, 369 P. aeruginosa isolates were obtained from 369 patients (83 from outpatients, 286 from inpatients), and five departments detected 30 or more isolates. Significant differences were seen between the five departments in antimicrobial susceptibility rates for three drugs, but significant differences were seen between the four specimen types (respiratory, urinary, gastrointestinal, purulent exudate), for 11 of the 13 drugs. High susceptibility rates were seen for respiratory specimens and purulent exudate specimens, and low susceptibility rates for urinary specimens and stool specimens. Susceptibility rates for all drugs were lower for isolates from inpatients than from outpatients. There were large differences in the sensitivity rates of P. aeruginosa from urinary tract specimens and from respiratory specimens, so an antibiogram stratified by specimen type seemed to be useful for planning treatment. Differences in the sensitivity rates between each department was mainly due to the differences in specimen types, so the need for an antibiogram for each department was thought to be low.
