Two hundred and forty-seven strains of Pseudomonas aeruginosa were isolated from various clinical specimens between 1987 and 1990 and in 1992 and their antimicrobial susceptibility to 22 drugs was tested by microdilution broth method and agar
dilution
method.
The most effective drugs against Pseudomonas were norfloxacin(Nf), ciprofloxacin(Cp), and moxalaetam (Mx). Only 18.6%, 28.1%, and 23.3% of strains were resistant to Nf, Cp and Mx respectively, and 50% MICs of durgs were low. However ,90% MICs of
Nf
and
Mx and resistance frequency of Pseudononas to them were increased year by year. Cefoperazone showed lowest resistance frequency rate, 18.4%, but its rate was increased to 67% in 1900 and 50% and 90% MICs were also increased sharply.
Aminoglycosides
and
others were not effective to inhibit the growth of Pseudomonas.
Frequencis of multiple drug resistant strains which were resisitant to 705 or more of number of drug tested were 16.7% in 1987 and 8.5% in 1988, however, they were increased to 20%, 33% and 36% and 36% in 1989 and 1992.
In conclusion, antimicrobial resistances of Pseudomonas to durgs including quinolones have been increased yearly, and we consider that countplans for preventing appearance of new multiple drug resistant Pseudomonas must be needea.
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