A Study on Microorganisms Isolated from Clinical Specimens and Their Antimicrobial Susceptibility

It is very important to evaluate the pattern of predominant microorganisms and their antimicrobial susceptibility in new established hospitals. The recognition of changes in antimicrobial susceptibility pattern is reliable guide for selection proper antibiotics.

I evaluated the distribution of micreerganisms and the pattern of antemicrebial susceptibility on 3,583 clinical isolates at Ewha Womans University Mokdong Hospital from September 1993 to August 1994. The pattern of antibiotic susceptibility was also compared between two periods(Sep., 1993-Feb., 1994 and March 1994-Aug., 1994).

The results were as follows:

1) The total isolation rate was 20.3%(3,247 specimens were cultured from 15,979 specimens requested).

2) The most commonly isolated microorganisms were E. coli, Staphylococcus aureus, Pseudomonas aeruginoas, Staphyliciccus epidermidis, and Entercoccus faecalis in decreasion rate.

3) E.coli was highly resistant to ampicillin, piperacillin and revealed over 70% sensitivity to cephalothin. gentamicin and tobramycin.

4) Pseucimonas aeruginosa was highly resistant to ampicillin, cephalithin and revealed over 70% esnsivity to ceftazidime, amikacin, gentamicin, tobramycin, ciprofloxacin and piperacillin.

5) Staphylococcus aureus was highly resistant to ampicillin, penicillin and revealed about 50% sensitivity to oxacillin, cephalothin and clindamycin. The susceptibility pattern of Staphlococcus epidermis was slightly different.

6) The sensitivityto penicillin of Enteococcus faecalis is 60% and that of Streptococcus pneumoniae was 71%.

7) The antimicrobial susceptibility of Pseudomonas aeruginosa, Staphlococcus aureus and Streptococcus pneumoniae were slightly decreased during last 6 months.

There were some differences of the distribution distribution of microorganisms and their antimicrobial susceptovolity pattern on isolates of ther study with comparison of other reports in Korea. Antimicrobial susceptibility pattern showed slightly increase of resistant strains. This study suggested that the periodic evaulation of antimicrobial suceptibility pattern was desirable.