CLINICAL STUDIES ON URINARY TRACT INFECTIONS CAUSED BY SERRATIA MARCESCENS
I. Clinical and Bacteriological Studies on Urinary Tract Infections Caused by Serratia marcescens
1983 Volume 74 Issue 4 Pages 467-484
Details
1983 Volume 74 Issue 4 Pages 467-484
We studied the distrbution and incidence of Serratia, the clinical background of urinary tract infections caused by Serratia marcescens, and the O-serotype, biotype and susceptibility to antimicrobial agents of strains isolated from urine specimens in the Departemmt of Urology, Sapporo Medical College Hospital from January 1975 to December 1981.
The results are as follows:
1) The annual incidence of Serratia isolated from UTI patients ranged from 2.4% to 18.4% in inpatients and from 0.4% to 5.2% in out-patients. The incidence showed an increasing pattern until 1980. Among the species, S. marcescens accounted for 88.0%. During the period, 154 strains of S. marcescens were isolated from 146 UTI patients.
2) In the clinical background, high age, use of indwelling catheter and instruments in the urinary tract, existence of basic diseases including malignant tumors of the urinary tract, and medication with antimicrobial agents can be considered to have causal relationships to the infections. Therefore, these Serratia infections bear an aspect of being opportunistic infections.
3) Using the O-serotype, 122 strains (79.2%) could be classified. The main serotypes were 0-16 (15.6%), 0-4 (14.3%), 0-5 (12.3%), 0-14 (8.4%) and 0-9 (4.5%). These serotype distributions changed every year, sometimes being common in only one year. The API20 system resulted in classification of the isolates into 21 biotypes, but 70.1% of the strains fell into only 4 biotypes. By using the serotype together with the biotype, more detailed classification can be achieved.
4) We measured the MICs of the isolated strains to determine their antimicrobial susceptibilities. They were mostly resistant to β-lactam antibotics. Aminoglycoside antobiotics and ST showed good antibacterial activity. However, after 1977, the isolates showed a pattern of increasing resistance to the aminoglycosides.
